Objective Machado-Joseph disease （MJD）/Spinocerebellar ataxia type 3 （SCA3） is an autosomal dominant neurodegenerative disorder caused by an expansion of polyglutamine tract near the C-terminus of the MJD1 gene pr...Objective Machado-Joseph disease （MJD）/Spinocerebellar ataxia type 3 （SCA3） is an autosomal dominant neurodegenerative disorder caused by an expansion of polyglutamine tract near the C-terminus of the MJD1 gene product, ataxin-3. The precise mechanism of the MJD/SCA3 pathogenesis remains unclear. A growing body of evidence demonstrates that phosphorylation plays an important role in the pathogenesis of many neurodegenerative diseases. However, few kinases are known to phosphorylate ataxin-3. The present study is to explore whether ataxin-3 is a substrate of casein kinase 2 （CK2）. Methods The interaction between ataxin-3 and CK2 was identified by glutathione S-transferase （GST） pull-down assay and co-immunoprecipition assay. The phosphorylation of ataxin-3 by CK2 was measured by in vitro phosphorylation assays. Results （1） Both wild type and expanded ataxin-3 interacted with CK2α and CK2β in vitro. （2） In 293 cells, both wild type and expanded ataxin-3 interacted with CK2β, but not CK2α. （3） CK2 phosphorylated wild type and expanded ataxin-3. Conclusion Ataxin-3 is a substrate of protein kinase CK2.展开更多
NPR1 （Nonexpressor of Pathogenesis-Related gene 1） is a major co-activator of plant defense. Phosphorylations of NPR1 play important roles in fine-tuning its activity, however a kinase corresponding to such modifica...NPR1 （Nonexpressor of Pathogenesis-Related gene 1） is a major co-activator of plant defense. Phosphorylations of NPR1 play important roles in fine-tuning its activity, however a kinase corresponding to such modification remains uncharacterized. Here, we report that NPR1 interacts with PKS5 （SOS2-1ike Protein Kinase 5）. The AKR （AnKyrin Repeats） motif of NPR1 is required for this interaction. PKS5 phosphorylates NPR1 at the C-terminal region. Expression of PKS5 is induced quickly by Pseudomonas syringae pv. tomato DC3000. Expression level of two NPR1 target genes, WRKY38 and WRKY62, is reduced and/or delayed in pks5 mutants. Moreover, the expression of WRKY38 and WRKY62 displays a similar pattern in nprl-lpks5-1 double mutant comparing to that in nprl-1. Our results suggest that PKS5 functions at the upstream of NPR1 and might mediate expression of WRKY38 and WRKY62 possibly by interacting with and phosphorylating NPR 1.展开更多
Increasing evidence suggests that Cyclin A-Cdk2 activity is required in the apoptosis process induced by various stimuli.To determine a specific substrate of Cyclin A-Cdk2 for apoptosis,in this study,we carried out an...Increasing evidence suggests that Cyclin A-Cdk2 activity is required in the apoptosis process induced by various stimuli.To determine a specific substrate of Cyclin A-Cdk2 for apoptosis,in this study,we carried out an in vitro kinase assay using immunoprecipitated complex Cyclin A-Cdk2 as an enzyme source,and recombinant protein GST-Bad as a substrate.Our study showed that Bad was clearly phosphorylated by Cyclin A-Cdk2 in vitro.To examine whether protein Bad can also be phosphorylated by Cyclin A-Cdk2 kinase in vivo,we transiently overexpressed protein Bad with Cyclin A or Cdk2-dn,a dominant negative version of Cdk2,in Hela cells and determined the phosphorylation status of protein Bad.The test showed that protein Bad was clearly phosphorylated in Cyclin A overexpressed cells,but not in Cdk2-dn or mock transfectent.Moreover,etoposide also caused the phosphorylation of endogenetic Bad.In conclusion,here we provide first time evidence that protein Bad can be a substrate of Cyclin A-Cdk2 apoptosis for in vitro and in vivo.展开更多
Mitogen-activated protein kinase(MAPK)cascades play important roles in disease resistance in model plant species.However,the functions of MAPK signaling pathways in crop disease resistance are largely unknown.Here we ...Mitogen-activated protein kinase(MAPK)cascades play important roles in disease resistance in model plant species.However,the functions of MAPK signaling pathways in crop disease resistance are largely unknown.Here we report the function of HvMKK1-HvMPK4-HvWRKY1 module in barley immune system.HvMPK4 is identified to play a negative role in barley immune response against Bgh,as virus-induced gene silencing of HvMPK4 results in enhanced disease resistance whilst stably overexpressing HvMPK4 leads to super-susceptibility to Bgh infection.Furthermore,the barley MAPK kinase HvMKK1 is found to specifically interact with HvMPK4,and the activated HvMKK1^(DD) variant specifically phosphorylates HvMPK4 in vitro.Moreover,the transcription factor HvWRKY1 is identified to be a downstream target of HvMPK4 and phosphorylated by HvMPK4 in vitro in the presence of HvMKK1^(DD).Phosphorylation assay coupled with mutagenesis analyses identifies S122,T284,and S347 in HvWRKY1 as the major residues phosphorylated by HvMPK4.HvWRKY1 is phosphorylated in barley at the early stages of Bgh infection,which enhances its suppression on barley immunity likely due to enhanced DNA-binding and transcriptional repression activity.Our data suggest that the HvMKK1-HvMPK4 kinase pair acts upstream of HvWRKY1 to negatively regulate barley immunity against powdery mildew.展开更多
Fruit taste quality is greatly influenced by the content of soluble sugars,which are predominantly stored in the vacuolar lumen.However,the accumulation and regulation mechanisms of sugars in most fruits remain unclea...Fruit taste quality is greatly influenced by the content of soluble sugars,which are predominantly stored in the vacuolar lumen.However,the accumulation and regulation mechanisms of sugars in most fruits remain unclear.Recently,we established the citrus fruit vacuole proteome and discovered the major transporters localized in the vacuole membrane.Here,we demonstrated that the expression of tonoplast sugar transporter 2(CsTST2)is closely associated with sugar accumulation during sweet orange(Citrus sinensis)ripening.It was further demonstrated that CsTST2 had the function of transporting hexose and sucrose into the vacuole.Overexpression of CsTST2 resulted in an elevation of sugar content in citrus juice sac,calli,and tomato fruit,whereas the downregulation of its expression led to the reduction in sugar levels.CsTST2 was identified as interacting with CsCIPK23,which binds to the upstream calcium signal sensor protein CsCBL1.The phosphorylation of the three serine residues(Ser277,Ser337,and Ser354)in the loop region of CsTST2 by CsCIPK23 is crucial for maintaining the sugar transport activity of CsTST2.Additionally,the expression of CsCIPK23 is positively correlated with sugar content.Genetic evidence further confirmed that calcium and CsCIPK23-mediated increase in sugar accumulation depends on CsTST2 and its phosphorylation level.These findings not only unveil the functional mechanism of CsTST2 in sugar accumulation,but also explore a vital calcium signal regulation module of CsCBL1/CIPK23 for citrus sweetness quality.展开更多
Subject Code:C06With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Deng Xingwang(邓兴旺)from the State Key Laboratory of Protein and Plant Gene Research,Peki...Subject Code:C06With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Deng Xingwang(邓兴旺)from the State Key Laboratory of Protein and Plant Gene Research,Peking-Tsinghua Center for Life Sciences,School of Advanced Agriculture Sciences and School of展开更多
Long noncoding RNA and microRNA are regulatory noncoding RNAs that are implicated in Alzheimer's disease, but the role of long noncoding RNA-associated competitive endogenous RNA has not been fully elucidated. The...Long noncoding RNA and microRNA are regulatory noncoding RNAs that are implicated in Alzheimer's disease, but the role of long noncoding RNA-associated competitive endogenous RNA has not been fully elucidated. The long noncoding RNA growth arrest-specific 5(GAS5) is a member of the 5′-terminal oligopyrimidine gene family that may be involved in neurological disorders, but its role in Alzheimer's disease remains unclear. This study aimed to investigate the function of GAS5 and construct a GAS5-associated competitive endogenous RNA network comprising potential targets. RNA sequencing results showed that GAS5 was upregulated in five familial Alzheimer's disease(5×FAD) mice, APPswe/PSEN1dE9(APP/PS1) mice, Alzheimer's disease-related APPswe cells, and serum from patients with Alzheimer's disease. Functional experiments with targeted overexpression and silencing demonstrated that GAS5 played a role in cognitive dysfunction and multiple Alzheimer's disease-associated pathologies, including tau hyperphosphorylation, amyloid-beta accumulation, and neuronal apoptosis. Mechanistic studies indicated that GAS5 acted as an endogenous sponge by competing for microRNA-23b-3p(miR-23b-3p) binding to regulate its targets glycogen synthase kinase 3beta(GSK-3β) and phosphatase and tensin homologue deleted on chromosome 10(PTEN) expression in an Argonaute 2-induced RNA silencing complex(RISC)-dependent manner. GAS5 inhibited miR-23b-3p-mediated GSK-3β and PTEN cascades with a feedforward PTEN/protein kinase B(Akt)/GSK-3β linkage. Furthermore, recovery of GAS5/miR-23b-3p/GSK-3β/PTEN pathways relieved Alzheimer's disease-like symptoms in vivo, indicated by the amelioration of spatial cognition, neuronal degeneration, amyloid-beta load, and tau phosphorylation. Together, these findings suggest that GAS5 promotes Alzheimer's disease pathogenesis. This study establishes the functional convergence of the GAS5/miR-23b-3p/GSK-3β/PTEN pathway on multiple pathologies, suggesting a candidate therapeutic target in Alzheimer's disease.展开更多
Mitogen-activated protein kinase(MAPK)cascades regulate a myriad of plant biological processes,including disease resistance.Plant genomes encode a large number of MAPK kinase kinases(MAPKKKs)that can be divided into t...Mitogen-activated protein kinase(MAPK)cascades regulate a myriad of plant biological processes,including disease resistance.Plant genomes encode a large number of MAPK kinase kinases(MAPKKKs)that can be divided into two subfamilies,namely MEKK-like kinases and Raf-like kinases.Thus far,the func-tions of MEKK-like MAPKKKs have been relatively well characterized,but the roles of Raf-like MAPKKKs in.plant MAPK cascades remain less understood.Here,we report the role of OsEDR1,a Raf-like MAPKKK,in the regulation of the MAPK cascade in rice response tp the bacterial pathogen Xanthomonas oryzae pv.oryzicola(Xoc).We found that OsEDR1 inhibits OsMPKK10.2(a MAPK kinase)activity through physical interaction.Upon Xoc infection,OsMPKK10.2 is phosphorylated at S304 to activate OsMPK6(a MAPK).Interestingly,activated OsMPK6 phosphorylates OsEDR1 at S861,which destabilizes OsEDR1 and thus releases the inhibition of OsMPKK10.2,leading to increased OsMPKK10.2 activity and enhanced resistance of rice plants to Xoc.Taken together,these results provide new insights into the functions of Raf-like ki-nases in the regulation of the MAPK cascade in plant immunity.展开更多
Plants employ receptor-like kinases (RLKs)and receptor-like proteins for rapid recognition of invading pathogens,and RLKs then transmit signals to receptor-like cytoplasmic kinases (RLCKs)to activate immune responses....Plants employ receptor-like kinases (RLKs)and receptor-like proteins for rapid recognition of invading pathogens,and RLKs then transmit signals to receptor-like cytoplasmic kinases (RLCKs)to activate immune responses.RLKs are under fine regulation mediated by subcellular trafficking,which contributes to proper activation of plant immunity.In this study,we show that Arabidopsisthaliana RECEPTOR-LIKE KINASE 902 (RLK902)plays important roles in resistance to the bacterial pathogen Pseudomonas syringae, but not to the fungal powdery mildew pathogen Golovinomyces cichoracearum.RLK902 localizes at the plasma membrane and associates with ENHANCED DISEASE RESISTANCE 4 (EDR4),a protein involved in clathrin-mediated trafficking pathways.EDR4 and CLATHRIN HEAVY CHAIN 2 (CHC2)regulate the subcellular trafficking and accumulation of RLK902 protein.Furthermore,we found that RLKg02 directly associates with the RLCK BRASSINOSTEROID-SIGNALING KINASE1 (BSK1),a key component of plant immunity,but not with other members of the FLAGELLIN SENSING 2 immune complex.RLK902 phosphorylates BSK1,and its Ser-230 is a key phosphorylation site critical for RLK902-mediated defense signaling. Taken together,our data indicate that EDR4 regulates plant immunity by modulating the subcellular trafficking and protein accumulation of RLK902,and that RLK902 transmits immune signals by phosphorylating BSK1.展开更多
Double fertilization in angiosperms requires the targeted delivery of immotile sperm to the eggs through pollen tubes. The polarity of tip-growing pollen tubes is maintained through dynamic association of active Rho G...Double fertilization in angiosperms requires the targeted delivery of immotile sperm to the eggs through pollen tubes. The polarity of tip-growing pollen tubes is maintained through dynamic association of active Rho GTPases of plants （ROP-GTP） with the apical plasma membrane. Guanine nucleotide exchange factors for ROPs （RopGEFs） catalyze the activation of ROPs and thereby affect spatiotemporal ROP signaling. Whereas RopGEFs have been found to be phosphorylated proteins, the kinases responsible for their phos- phorylation in v/vo and biological consequences of RopGEF phosphorylation in pollen tube growth remain unclear. We report here that the Arabidopsis AGC1.5 subfamily of cytoplasmic kinases is critical for the restricted localization of ROP-GTP during pollen tube growth. Loss of AGCI.5 and AGC1.7 functions resulted in the mistargeting of active ROPs and defective events downstream of ROP signaling in pollen tubes. AGCI.5 interacts with RopGEFs via their catalytic PRONE domain and phosphorylates RopGEFs at a conserved Ser residue of PRONE domain. Loss of AGC1.5 and AGC1.7 functions resulted in the mistargeting of RopGEFs in pollen tubes, similar to the phenotype caused by the mutation that renders RopGEFs non-phosphorylatable by AGC1.5. Collectively, our results provide mechanistic insights into the spatiotem- poral activation of ROPs during the polar growth of pollen tubes.展开更多
Aluminum(Al)toxicity can seriously restrict crop production on acidic soils,which comprise 40%of the world’s potentially arable land.The zinc finger transcription factor STOP1 has a conserved and essential function i...Aluminum(Al)toxicity can seriously restrict crop production on acidic soils,which comprise 40%of the world’s potentially arable land.The zinc finger transcription factor STOP1 has a conserved and essential function in mediating plant Al resistance.Al stress induces STOP1 accumulation via post-transcriptional regulatory mechanisms.However,the upstream signaling pathway involved in Al-triggered STOP1 accumulation remains unclear.Here,we report that the MEKK1-MKK1/2-MPK4 cascade positively regulates STOP1 phosphorylation and stability.Mutations of MEKK1,MKK1/2,or MPK4 lead to decreased STOP1 stability and Al resistance.Al stress induces the kinase activity of MPK4,which interacts with and phosphorylates STOP1.The phosphorylation of STOP1 reduces its interaction with the F-box protein RAE1 that mediates STOP1 degradation,thereby leading to enhanced STOP1 stability and Al resistance.Taken together,our results suggest that the MEKK1-MKK1/2-MPK4 cascade is important for Al signaling and confers Al resistance through phosphorylation-mediated enhancement of STOP1 accumulation in Arabidopsis.展开更多
Plants recognize pathogens and activate immune responses,which usually involve massive transcriptional reprogramming.The evolutionarily conserved kinase,Sucrose non-fermenting-related kinase 1(SnRK1),functions as a me...Plants recognize pathogens and activate immune responses,which usually involve massive transcriptional reprogramming.The evolutionarily conserved kinase,Sucrose non-fermenting-related kinase 1(SnRK1),functions as a metabolic regulator that is essential for plant growth and stress responses.Here,we identify barley SnRK1 and a WRKY3 transcription factor by screening a cDNA library.SnRK1 interacts with WRKY3 in yeast,as confirmed by pull-down and luciferase complementation assays.Förster resonance energy transfer combined with noninvasive fluorescence lifetime imaging analysis indicates that the interaction occurs in the barley nucleus.Transient expression and virus-induced gene silencing analyses indicate that WRKY3 acts as a repressor of disease resistance to the Bgh fungus.Barley plants overexpressing WRKY3 have enhanced fungal microcolony formation and sporulation.Phosphorylation assays show that SnRK1 phosphorylates WRKY3 mainly at Ser83 and Ser112 to destabilize the repressor,and WRKY3 non-phosphorylation-null mutants at these two sites are more stable than the wild-type protein.SnRK1-overexpressing barley plants display enhanced disease resistance to Bgh.Transient expression of SnRK1 reduces fungal haustorium formation in barley cells,which probably requires SnRK1 nuclear localization and kinase activity.Together,these findings suggest that SnRK1 is directly involved in plant immunity through phosphorylation and destabilization of the WRKY3 repressor,revealing a new regulatory mechanism of immune derepression in plants.展开更多
RCAN1, also known as DSCR1, is an endogenous regulator of calcineurin, a serine/threonine protein phosphatase that plays a critical role in many physiological processes. In this report, we demonstrate that p38a MAP ki...RCAN1, also known as DSCR1, is an endogenous regulator of calcineurin, a serine/threonine protein phosphatase that plays a critical role in many physiological processes. In this report, we demonstrate that p38a MAP kinase can phosphorylate RCAN1 at multiple sites in vitro and show that phospho-RCAN1 is a good protein substrate for calcineurin. In addition, we found that unphosphorylated RCANI noncompetitively inhibits calcineurin protein phosphatase activity and that the phosphorylation of RCAN1 by p38a MAP kinase decreases the binding affinity of RCAN1 for calcineurin. These findings reveal the molecular mechanism by which p38a MAP kinase regulates the function of RCAN1/calcineurin through phosphorylation.展开更多
Seeds establish dormancy to delay germination until the arrival of a favorable growing season.In this study,we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 th...Seeds establish dormancy to delay germination until the arrival of a favorable growing season.In this study,we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 that is responsible for the seed state transition from dormancy to germination.We show that dormancy-breaking factors activate the MKK3–MPK7 module,which affects the expression of some a-EXPANSIN(EXPA)genes to control seed dormancy.Furthermore,we identify a direct downstream substrate of this module,ERF4,which suppresses the expression of these EXPAs by directly binding to the GCC boxes in their exon regions.The activated MKK3–MPK7 module phosphorylates ERF4,leading to its rapid degradation and thereby releasing its inhibitory effect on the expression of these EXPAs.Collectively,our work identifies a signaling chain consisting of protein phosphorylation,degradation,and gene transcription,by which the germination promoters within the embryo sense and are activated by germination signals from ambient conditions.展开更多
Spinal cord injuries impose a notably economic burden on society,mainly because of the severe after-effects they cause.Despite the ongoing development of various therapies for spinal cord injuries,their effectiveness ...Spinal cord injuries impose a notably economic burden on society,mainly because of the severe after-effects they cause.Despite the ongoing development of various therapies for spinal cord injuries,their effectiveness remains unsatisfactory.However,a deeper understanding of metabolism has opened up a new therapeutic opportunity in the form of metabolic reprogramming.In this review,we explore the metabolic changes that occur during spinal cord injuries,their consequences,and the therapeutic tools available for metabolic reprogramming.Normal spinal cord metabolism is characterized by independent cellular metabolism and intercellular metabolic coupling.However,spinal cord injury results in metabolic disorders that include disturbances in glucose metabolism,lipid metabolism,and mitochondrial dysfunction.These metabolic disturbances lead to corresponding pathological changes,including the failure of axonal regeneration,the accumulation of scarring,and the activation of microglia.To rescue spinal cord injury at the metabolic level,potential metabolic reprogramming approaches have emerged,including replenishing metabolic substrates,reconstituting metabolic couplings,and targeting mitochondrial therapies to alter cell fate.The available evidence suggests that metabolic reprogramming holds great promise as a next-generation approach for the treatment of spinal cord injury.To further advance the metabolic treatment of the spinal cord injury,future efforts should focus on a deeper understanding of neurometabolism,the development of more advanced metabolomics technologies,and the design of highly effective metabolic interventions.展开更多
Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this condition.The aims of this study were to...Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this condition.The aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive impairment.We found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic stroke.In addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic stroke.Serum phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic stroke.Furthermore,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein levels.Although ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein levels.Taken together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.展开更多
Regulatory T(Treg)cells are pivotal for maintaining immune homeostasis and play essential roles in various diseases,such as autoimmune diseases,graft-versus-host disease(GVHD),tumors,and infectious diseases.Treg cells...Regulatory T(Treg)cells are pivotal for maintaining immune homeostasis and play essential roles in various diseases,such as autoimmune diseases,graft-versus-host disease(GVHD),tumors,and infectious diseases.Treg cells exert suppressive function via distinct mechanisms,including inhibitory cytokines,granzyme or perforin-mediated cytolysis,metabolic disruption,and suppression of dendritic cells.Forkhead Box P3(FOXP3),the characteristic transcription factor,is essential for Treg cell function and plasticity.Cumulative evidence has demonstrated that FOXP3 activity and Treg cell function are modulated by a variety of post-translational modifications(PTMs),including ubiquitination,acetylation,phosphorylation,methylation,glycosylation,poly(ADP-ribosyl)ation,and uncharacterized modifications.This review describes Treg cell suppressive mechanisms and summarizes the current evidence on PTM regulation of FOXP3 and Treg cell function.Understanding the regulatory role of PTMs in Treg cell plasticity and function will be helpful in designing therapeutic strategies for autoimmune diseases,GVHD,tumors,and infectious diseases.展开更多
Objective:Cytotoxic T lymphocytes(CTLs)play a crucial role in the therapeutic approach to hepatocellular carcinoma(HCC).Recent research has indicated that junctional adhesion molecule-like protein(JAML)enhances the an...Objective:Cytotoxic T lymphocytes(CTLs)play a crucial role in the therapeutic approach to hepatocellular carcinoma(HCC).Recent research has indicated that junctional adhesion molecule-like protein(JAML)enhances the antitumor activity of CD8+T cells.Our study investigates the role of JAML+CD8+T cells in HCC.Methods:We utilized time-of-flight mass cytometry and an orthotopic mouse model of HCC to examine histone modifications in tumor-infiltrating immune cells undergoing immunotherapy.Flow cytometry was used to assess CD4+T cells differentiation and JAML expression in CD8+T cells infiltrating HCC.Correlation analysis revealed a strong positive correlation between lactate dehydrogenase A+(LDHA+)CD4+T cells and JAML+CD8+T cells.Subsequently,we evaluated the therapeutic effects of an agonistic anti-JAML antibody,both alone and combined with immunotherapy.Finally,RNA sequencing was conducted to identify potential regulatory mechanisms.Results:Immunotherapy significantly increased the percentage of CD8+T cells infiltrating HCC and induced histone modifications,such as H3K18 lactylation(H3K18la)in CD4+T cells.Flow cytometry analysis revealed that lactate promotes the differentiation of CD4+T cells into Th1 cells.LDHA,an enzyme that converts pyruvate to lactate,plays a key role in this process.Correlation analysis revealed a strong positive relationship between LDHA+CD4+T cells and JAML+CD8+T cells in patients who responded to immunotherapy.Moreover,high JAML expression in CD8+T cells was associated with a more favorable prognosis.In vivo experiments demonstrated that agonistic anti-JAML antibody therapy reduced tumor volume and significantly prolonged the survival of tumor-bearing mice,independent of the effects of anti-programmed cell death protein ligand-1 antibody(αPD-L1)-mediated immunotherapy.Pathway enrichment analysis further revealed that JAML enhances CTL responses through the oxidative phosphorylation pathway.Conclusions:Activation of JAML enhances CTL responses in HCC treatment,independent ofαPD-L1-mediated immunotherapy,providing a promising strategy for advanced HCC.展开更多
BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression result...BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression results in a loss of this capacity to facilitate cyclin E degradation.The ubiquitination and degradation of cyclin E1 may be associated with phosphorylation at specific sites on the protein,with Cx43 potentially enhancing this process by facilitating the phosphorylation of these critical residues.AIM To investigate the correlation between expression of Cx43,SKP1/Cullin1/F-box(SCF)FBXW7,p-cyclin E1(ser73,thr77,thr395)and clinicopathological indexes in colon cancer.METHODS Expression levels of Cx43,SCF^(FBXW7),p-cyclin E1(ser73,thr77,thr395)in 38 clinical colon cancer samples were detected by immunohistochemistry and were analyzed by statistical methods to discuss their correlations.RESULTS Positive rate of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in detected samples were 76.32%,76.32%,65.79%,5.26%and 55.26%respectively.Positive expressions of these proteins were not related to the tissue type,degree of tissue differentiation or lymph node metastasis.Cx43 and SCF^(FBXW7)(r=0.749),p-cyclin E1(Ser73)(r=0.667)and p-cyclin E1(Thr395)(r=0.457),SCF^(FBXW7) and p-cyclin E1(Ser73)(r=0.703)and p-cyclin E1(Thr395)(0.415)were correlated in colon cancer(P<0.05),and expressions of the above proteins were positively correlated in colon cancer.CONCLUSION Cx43 may facilitate the phosphorylation of cyclin E1 at the Ser73 and Thr195 sites through its interaction with SCF^(FBXW7),thereby influencing the ubiquitination and degradation of cyclin E1.展开更多
Meiotic resumption in mammalian oocytes involves nuclear and organelle structural changes,notably the chromatin configuration transition from a non-surrounding nucleolus(NSN)to surrounding nucleolus(SN)in germinal ves...Meiotic resumption in mammalian oocytes involves nuclear and organelle structural changes,notably the chromatin configuration transition from a non-surrounding nucleolus(NSN)to surrounding nucleolus(SN)in germinal vesicle oocytes.In the current study,we found that nuclear speckles(NSs),a subnuclear structure mainly composed of serine-arginine(SR)proteins,changed from a diffuse spotted distribution in mouse NSN oocytes to an aggregated pattern in SN oocytes.We also found that the SR protein-specific kinase 1(SRPK1),an enzyme that phosphorylates SR proteins,co-localized with NSs at the SN stage,and that NSN oocytes failed to transition to SN oocytes after the inhibition of SRPK1 activity.Furthermore,the typical structure of the chromatin ring around the nucleolus in SN oocytes collapsed after treatment with an SRPK1 inhibitor.Mechanistically,phosphorylated SR proteins were found to be related to chromatin as shown by a salt extraction experiment,and in situ DNaseⅠassay showed that the accessibility of chromatin was enhanced in SN oocytes when SRPK1 was inhibited,accompanied by a decreased repressive modification on histone and the abnormal recurrence of a transcriptional signal.In conclusion,our results indicated that SRPK1-regulated phosphorylation of SR proteins was involved in the NSN-SN transition and played an important role in maintaining the condensed nucleus of SN oocytes via interacting with chromatin.展开更多
基金the National Natural Sciences Foundation of China (No. 30770664)a grant from Educational Committee of Anhui Province, China (No. ZD2008008-2).
文摘Objective Machado-Joseph disease （MJD）/Spinocerebellar ataxia type 3 （SCA3） is an autosomal dominant neurodegenerative disorder caused by an expansion of polyglutamine tract near the C-terminus of the MJD1 gene product, ataxin-3. The precise mechanism of the MJD/SCA3 pathogenesis remains unclear. A growing body of evidence demonstrates that phosphorylation plays an important role in the pathogenesis of many neurodegenerative diseases. However, few kinases are known to phosphorylate ataxin-3. The present study is to explore whether ataxin-3 is a substrate of casein kinase 2 （CK2）. Methods The interaction between ataxin-3 and CK2 was identified by glutathione S-transferase （GST） pull-down assay and co-immunoprecipition assay. The phosphorylation of ataxin-3 by CK2 was measured by in vitro phosphorylation assays. Results （1） Both wild type and expanded ataxin-3 interacted with CK2α and CK2β in vitro. （2） In 293 cells, both wild type and expanded ataxin-3 interacted with CK2β, but not CK2α. （3） CK2 phosphorylated wild type and expanded ataxin-3. Conclusion Ataxin-3 is a substrate of protein kinase CK2.
基金supported by the National Basic Re-search Program of China (No. 2006CB100100)the National High Technology Research and Development Program of China (863 Programme) (No. 2003AA210100)
文摘NPR1 （Nonexpressor of Pathogenesis-Related gene 1） is a major co-activator of plant defense. Phosphorylations of NPR1 play important roles in fine-tuning its activity, however a kinase corresponding to such modification remains uncharacterized. Here, we report that NPR1 interacts with PKS5 （SOS2-1ike Protein Kinase 5）. The AKR （AnKyrin Repeats） motif of NPR1 is required for this interaction. PKS5 phosphorylates NPR1 at the C-terminal region. Expression of PKS5 is induced quickly by Pseudomonas syringae pv. tomato DC3000. Expression level of two NPR1 target genes, WRKY38 and WRKY62, is reduced and/or delayed in pks5 mutants. Moreover, the expression of WRKY38 and WRKY62 displays a similar pattern in nprl-lpks5-1 double mutant comparing to that in nprl-1. Our results suggest that PKS5 functions at the upstream of NPR1 and might mediate expression of WRKY38 and WRKY62 possibly by interacting with and phosphorylating NPR 1.
基金Supported by the National Natural Science Foundation of China(Nos.30370294and30640064).
文摘Increasing evidence suggests that Cyclin A-Cdk2 activity is required in the apoptosis process induced by various stimuli.To determine a specific substrate of Cyclin A-Cdk2 for apoptosis,in this study,we carried out an in vitro kinase assay using immunoprecipitated complex Cyclin A-Cdk2 as an enzyme source,and recombinant protein GST-Bad as a substrate.Our study showed that Bad was clearly phosphorylated by Cyclin A-Cdk2 in vitro.To examine whether protein Bad can also be phosphorylated by Cyclin A-Cdk2 kinase in vivo,we transiently overexpressed protein Bad with Cyclin A or Cdk2-dn,a dominant negative version of Cdk2,in Hela cells and determined the phosphorylation status of protein Bad.The test showed that protein Bad was clearly phosphorylated in Cyclin A overexpressed cells,but not in Cdk2-dn or mock transfectent.Moreover,etoposide also caused the phosphorylation of endogenetic Bad.In conclusion,here we provide first time evidence that protein Bad can be a substrate of Cyclin A-Cdk2 apoptosis for in vitro and in vivo.
基金funded by the National Key R&D Program of China(2018YFD1000703 and 2018YFD1000700)the Strategic Priority Research Program of Chinese Academy of Sciences(XDPB16)National Program on Research and Development of Transgenic Plants(2016ZX08009-003-001).
文摘Mitogen-activated protein kinase(MAPK)cascades play important roles in disease resistance in model plant species.However,the functions of MAPK signaling pathways in crop disease resistance are largely unknown.Here we report the function of HvMKK1-HvMPK4-HvWRKY1 module in barley immune system.HvMPK4 is identified to play a negative role in barley immune response against Bgh,as virus-induced gene silencing of HvMPK4 results in enhanced disease resistance whilst stably overexpressing HvMPK4 leads to super-susceptibility to Bgh infection.Furthermore,the barley MAPK kinase HvMKK1 is found to specifically interact with HvMPK4,and the activated HvMKK1^(DD) variant specifically phosphorylates HvMPK4 in vitro.Moreover,the transcription factor HvWRKY1 is identified to be a downstream target of HvMPK4 and phosphorylated by HvMPK4 in vitro in the presence of HvMKK1^(DD).Phosphorylation assay coupled with mutagenesis analyses identifies S122,T284,and S347 in HvWRKY1 as the major residues phosphorylated by HvMPK4.HvWRKY1 is phosphorylated in barley at the early stages of Bgh infection,which enhances its suppression on barley immunity likely due to enhanced DNA-binding and transcriptional repression activity.Our data suggest that the HvMKK1-HvMPK4 kinase pair acts upstream of HvWRKY1 to negatively regulate barley immunity against powdery mildew.
基金supported by National Key Research and Development Program of China(2023YFD2300603,2022YFF1003100)the National Natural Science Foundation of China(32322073)+2 种基金Foundation of Hubei Hongshan Laboratory(2021hszd016)Fundamental Research Funds for the Central Universities(2662023PY011)the Huazhong Agricultural University(start-up funding to C.L.)。
文摘Fruit taste quality is greatly influenced by the content of soluble sugars,which are predominantly stored in the vacuolar lumen.However,the accumulation and regulation mechanisms of sugars in most fruits remain unclear.Recently,we established the citrus fruit vacuole proteome and discovered the major transporters localized in the vacuole membrane.Here,we demonstrated that the expression of tonoplast sugar transporter 2(CsTST2)is closely associated with sugar accumulation during sweet orange(Citrus sinensis)ripening.It was further demonstrated that CsTST2 had the function of transporting hexose and sucrose into the vacuole.Overexpression of CsTST2 resulted in an elevation of sugar content in citrus juice sac,calli,and tomato fruit,whereas the downregulation of its expression led to the reduction in sugar levels.CsTST2 was identified as interacting with CsCIPK23,which binds to the upstream calcium signal sensor protein CsCBL1.The phosphorylation of the three serine residues(Ser277,Ser337,and Ser354)in the loop region of CsTST2 by CsCIPK23 is crucial for maintaining the sugar transport activity of CsTST2.Additionally,the expression of CsCIPK23 is positively correlated with sugar content.Genetic evidence further confirmed that calcium and CsCIPK23-mediated increase in sugar accumulation depends on CsTST2 and its phosphorylation level.These findings not only unveil the functional mechanism of CsTST2 in sugar accumulation,but also explore a vital calcium signal regulation module of CsCBL1/CIPK23 for citrus sweetness quality.
文摘Subject Code:C06With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Deng Xingwang(邓兴旺)from the State Key Laboratory of Protein and Plant Gene Research,Peking-Tsinghua Center for Life Sciences,School of Advanced Agriculture Sciences and School of
基金supported by the National Natural Science Foundation of China,Nos. 82173806 and U1803281Chinese Academy of Medical Sciences (CAMS) Innovation Fund for Medical Science,Nos. 2021-I2M-1-030 and 2022-I2M-2-002Non-Profit Central Research Institute Fund of Chinese Academy of Medical Sciences,No. 2022-JKCS-08 (all to RL)。
文摘Long noncoding RNA and microRNA are regulatory noncoding RNAs that are implicated in Alzheimer's disease, but the role of long noncoding RNA-associated competitive endogenous RNA has not been fully elucidated. The long noncoding RNA growth arrest-specific 5(GAS5) is a member of the 5′-terminal oligopyrimidine gene family that may be involved in neurological disorders, but its role in Alzheimer's disease remains unclear. This study aimed to investigate the function of GAS5 and construct a GAS5-associated competitive endogenous RNA network comprising potential targets. RNA sequencing results showed that GAS5 was upregulated in five familial Alzheimer's disease(5×FAD) mice, APPswe/PSEN1dE9(APP/PS1) mice, Alzheimer's disease-related APPswe cells, and serum from patients with Alzheimer's disease. Functional experiments with targeted overexpression and silencing demonstrated that GAS5 played a role in cognitive dysfunction and multiple Alzheimer's disease-associated pathologies, including tau hyperphosphorylation, amyloid-beta accumulation, and neuronal apoptosis. Mechanistic studies indicated that GAS5 acted as an endogenous sponge by competing for microRNA-23b-3p(miR-23b-3p) binding to regulate its targets glycogen synthase kinase 3beta(GSK-3β) and phosphatase and tensin homologue deleted on chromosome 10(PTEN) expression in an Argonaute 2-induced RNA silencing complex(RISC)-dependent manner. GAS5 inhibited miR-23b-3p-mediated GSK-3β and PTEN cascades with a feedforward PTEN/protein kinase B(Akt)/GSK-3β linkage. Furthermore, recovery of GAS5/miR-23b-3p/GSK-3β/PTEN pathways relieved Alzheimer's disease-like symptoms in vivo, indicated by the amelioration of spatial cognition, neuronal degeneration, amyloid-beta load, and tau phosphorylation. Together, these findings suggest that GAS5 promotes Alzheimer's disease pathogenesis. This study establishes the functional convergence of the GAS5/miR-23b-3p/GSK-3β/PTEN pathway on multiple pathologies, suggesting a candidate therapeutic target in Alzheimer's disease.
基金This work was supported by grants from the National Natural Science Foundation of China(31772145 and 31901865)Huazhong Agricultural University Scientific&Technological Self-innovation Foundation(2012YB02).
文摘Mitogen-activated protein kinase(MAPK)cascades regulate a myriad of plant biological processes,including disease resistance.Plant genomes encode a large number of MAPK kinase kinases(MAPKKKs)that can be divided into two subfamilies,namely MEKK-like kinases and Raf-like kinases.Thus far,the func-tions of MEKK-like MAPKKKs have been relatively well characterized,but the roles of Raf-like MAPKKKs in.plant MAPK cascades remain less understood.Here,we report the role of OsEDR1,a Raf-like MAPKKK,in the regulation of the MAPK cascade in rice response tp the bacterial pathogen Xanthomonas oryzae pv.oryzicola(Xoc).We found that OsEDR1 inhibits OsMPKK10.2(a MAPK kinase)activity through physical interaction.Upon Xoc infection,OsMPKK10.2 is phosphorylated at S304 to activate OsMPK6(a MAPK).Interestingly,activated OsMPK6 phosphorylates OsEDR1 at S861,which destabilizes OsEDR1 and thus releases the inhibition of OsMPKK10.2,leading to increased OsMPKK10.2 activity and enhanced resistance of rice plants to Xoc.Taken together,these results provide new insights into the functions of Raf-like ki-nases in the regulation of the MAPK cascade in plant immunity.
文摘Plants employ receptor-like kinases (RLKs)and receptor-like proteins for rapid recognition of invading pathogens,and RLKs then transmit signals to receptor-like cytoplasmic kinases (RLCKs)to activate immune responses.RLKs are under fine regulation mediated by subcellular trafficking,which contributes to proper activation of plant immunity.In this study,we show that Arabidopsisthaliana RECEPTOR-LIKE KINASE 902 (RLK902)plays important roles in resistance to the bacterial pathogen Pseudomonas syringae, but not to the fungal powdery mildew pathogen Golovinomyces cichoracearum.RLK902 localizes at the plasma membrane and associates with ENHANCED DISEASE RESISTANCE 4 (EDR4),a protein involved in clathrin-mediated trafficking pathways.EDR4 and CLATHRIN HEAVY CHAIN 2 (CHC2)regulate the subcellular trafficking and accumulation of RLK902 protein.Furthermore,we found that RLKg02 directly associates with the RLCK BRASSINOSTEROID-SIGNALING KINASE1 (BSK1),a key component of plant immunity,but not with other members of the FLAGELLIN SENSING 2 immune complex.RLK902 phosphorylates BSK1,and its Ser-230 is a key phosphorylation site critical for RLK902-mediated defense signaling. Taken together,our data indicate that EDR4 regulates plant immunity by modulating the subcellular trafficking and protein accumulation of RLK902,and that RLK902 transmits immune signals by phosphorylating BSK1.
基金This research was supported by the National Natural Science Foundation of China （31471304 to Y.Z. 31771558 to S.L.）, Natural Science Foundation of Shandong Province （ZR2014CM027 to S.L.）, China Postdoctoral Science Foundation （2018M632698 to E.L.）, and Research Grants Council of Hong Kong （AoE/M-05/12 and C4011-14R）. Y.Z. was partially supported by the Tai-Shan Scholar program from the Shandong Provinciak Government.
文摘Double fertilization in angiosperms requires the targeted delivery of immotile sperm to the eggs through pollen tubes. The polarity of tip-growing pollen tubes is maintained through dynamic association of active Rho GTPases of plants （ROP-GTP） with the apical plasma membrane. Guanine nucleotide exchange factors for ROPs （RopGEFs） catalyze the activation of ROPs and thereby affect spatiotemporal ROP signaling. Whereas RopGEFs have been found to be phosphorylated proteins, the kinases responsible for their phos- phorylation in v/vo and biological consequences of RopGEF phosphorylation in pollen tube growth remain unclear. We report here that the Arabidopsis AGC1.5 subfamily of cytoplasmic kinases is critical for the restricted localization of ROP-GTP during pollen tube growth. Loss of AGCI.5 and AGC1.7 functions resulted in the mistargeting of active ROPs and defective events downstream of ROP signaling in pollen tubes. AGCI.5 interacts with RopGEFs via their catalytic PRONE domain and phosphorylates RopGEFs at a conserved Ser residue of PRONE domain. Loss of AGC1.5 and AGC1.7 functions resulted in the mistargeting of RopGEFs in pollen tubes, similar to the phenotype caused by the mutation that renders RopGEFs non-phosphorylatable by AGC1.5. Collectively, our results provide mechanistic insights into the spatiotem- poral activation of ROPs during the polar growth of pollen tubes.
基金supported by the National Natural Science Foundation of China(grant nos.32170261 and 31870223 to C.-F.H.)the National Key Laboratory of Plant Molecular Genetics.
文摘Aluminum(Al)toxicity can seriously restrict crop production on acidic soils,which comprise 40%of the world’s potentially arable land.The zinc finger transcription factor STOP1 has a conserved and essential function in mediating plant Al resistance.Al stress induces STOP1 accumulation via post-transcriptional regulatory mechanisms.However,the upstream signaling pathway involved in Al-triggered STOP1 accumulation remains unclear.Here,we report that the MEKK1-MKK1/2-MPK4 cascade positively regulates STOP1 phosphorylation and stability.Mutations of MEKK1,MKK1/2,or MPK4 lead to decreased STOP1 stability and Al resistance.Al stress induces the kinase activity of MPK4,which interacts with and phosphorylates STOP1.The phosphorylation of STOP1 reduces its interaction with the F-box protein RAE1 that mediates STOP1 degradation,thereby leading to enhanced STOP1 stability and Al resistance.Taken together,our results suggest that the MEKK1-MKK1/2-MPK4 cascade is important for Al signaling and confers Al resistance through phosphorylation-mediated enhancement of STOP1 accumulation in Arabidopsis.
基金supported by the National Key R&D Program of China(2016YFD0100602,2018YFD1000703)the National Natural Science Foundation of China(31530061)the Ministry of Agriculture and Rural Affairs of China(2016ZX08009-003-001).
文摘Plants recognize pathogens and activate immune responses,which usually involve massive transcriptional reprogramming.The evolutionarily conserved kinase,Sucrose non-fermenting-related kinase 1(SnRK1),functions as a metabolic regulator that is essential for plant growth and stress responses.Here,we identify barley SnRK1 and a WRKY3 transcription factor by screening a cDNA library.SnRK1 interacts with WRKY3 in yeast,as confirmed by pull-down and luciferase complementation assays.Förster resonance energy transfer combined with noninvasive fluorescence lifetime imaging analysis indicates that the interaction occurs in the barley nucleus.Transient expression and virus-induced gene silencing analyses indicate that WRKY3 acts as a repressor of disease resistance to the Bgh fungus.Barley plants overexpressing WRKY3 have enhanced fungal microcolony formation and sporulation.Phosphorylation assays show that SnRK1 phosphorylates WRKY3 mainly at Ser83 and Ser112 to destabilize the repressor,and WRKY3 non-phosphorylation-null mutants at these two sites are more stable than the wild-type protein.SnRK1-overexpressing barley plants display enhanced disease resistance to Bgh.Transient expression of SnRK1 reduces fungal haustorium formation in barley cells,which probably requires SnRK1 nuclear localization and kinase activity.Together,these findings suggest that SnRK1 is directly involved in plant immunity through phosphorylation and destabilization of the WRKY3 repressor,revealing a new regulatory mechanism of immune derepression in plants.
基金supported in part by Ministry of Science and Technology of China (Grant 2011CB910803)
文摘RCAN1, also known as DSCR1, is an endogenous regulator of calcineurin, a serine/threonine protein phosphatase that plays a critical role in many physiological processes. In this report, we demonstrate that p38a MAP kinase can phosphorylate RCAN1 at multiple sites in vitro and show that phospho-RCAN1 is a good protein substrate for calcineurin. In addition, we found that unphosphorylated RCANI noncompetitively inhibits calcineurin protein phosphatase activity and that the phosphorylation of RCAN1 by p38a MAP kinase decreases the binding affinity of RCAN1 for calcineurin. These findings reveal the molecular mechanism by which p38a MAP kinase regulates the function of RCAN1/calcineurin through phosphorylation.
基金supported by the National Natural Science Foundation of China(grant nos.32000250 and 32170364)the China Postdoctoral Science Foundation(grant no.2020M682997)+2 种基金the Key Area Research and Development Program of Guangdong Province(grant no.2021B0707010006)the Science,Technology and Innovation Commission of Shenzhen Municipality(grant nos.KCXFZ-20201221173203009 and KCXFZ20211020164207012)the Dapeng New District Science and Technology Program(grant nos.KJYF202101-09 and RCTD20180102)。
文摘Seeds establish dormancy to delay germination until the arrival of a favorable growing season.In this study,we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 that is responsible for the seed state transition from dormancy to germination.We show that dormancy-breaking factors activate the MKK3–MPK7 module,which affects the expression of some a-EXPANSIN(EXPA)genes to control seed dormancy.Furthermore,we identify a direct downstream substrate of this module,ERF4,which suppresses the expression of these EXPAs by directly binding to the GCC boxes in their exon regions.The activated MKK3–MPK7 module phosphorylates ERF4,leading to its rapid degradation and thereby releasing its inhibitory effect on the expression of these EXPAs.Collectively,our work identifies a signaling chain consisting of protein phosphorylation,degradation,and gene transcription,by which the germination promoters within the embryo sense and are activated by germination signals from ambient conditions.
基金supported by the National Natural Science Foundation of China,No.82202681(to JW)the Natural Science Foundation of Zhejiang Province,Nos.LZ22H090003(to QC),LR23H060001(to CL).
文摘Spinal cord injuries impose a notably economic burden on society,mainly because of the severe after-effects they cause.Despite the ongoing development of various therapies for spinal cord injuries,their effectiveness remains unsatisfactory.However,a deeper understanding of metabolism has opened up a new therapeutic opportunity in the form of metabolic reprogramming.In this review,we explore the metabolic changes that occur during spinal cord injuries,their consequences,and the therapeutic tools available for metabolic reprogramming.Normal spinal cord metabolism is characterized by independent cellular metabolism and intercellular metabolic coupling.However,spinal cord injury results in metabolic disorders that include disturbances in glucose metabolism,lipid metabolism,and mitochondrial dysfunction.These metabolic disturbances lead to corresponding pathological changes,including the failure of axonal regeneration,the accumulation of scarring,and the activation of microglia.To rescue spinal cord injury at the metabolic level,potential metabolic reprogramming approaches have emerged,including replenishing metabolic substrates,reconstituting metabolic couplings,and targeting mitochondrial therapies to alter cell fate.The available evidence suggests that metabolic reprogramming holds great promise as a next-generation approach for the treatment of spinal cord injury.To further advance the metabolic treatment of the spinal cord injury,future efforts should focus on a deeper understanding of neurometabolism,the development of more advanced metabolomics technologies,and the design of highly effective metabolic interventions.
基金supported by the Scientific Research Project of China Rehabilitation Research Center,No.2021zx-23the National Natural Science Foundation of China,No.32100925the Beijing Nova Program,No.Z211100002121038。
文摘Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this condition.The aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive impairment.We found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic stroke.In addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic stroke.Serum phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic stroke.Furthermore,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein levels.Although ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein levels.Taken together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.
基金supported by grants from the National Key R&D Program of China(2022YFC2403000 and 2021YFC2400500)the National Natural Science Foundation of China(32200728 and 32170925)+3 种基金the Clinical Research Project of Shenzhen Medical Academy of Research and Translation(C2301008)Shenzhen Science and Technology Program(JCYJ20220531100406014,JCYJ2022081800807016,RCBS20221008093336088,KQTD20210811090115019)Guangdong Basic and Applied Basic Research Foundation(2021A1515110375)the Innovative Research Team of High-level Local Universities in Shanghai(SHSMU-ZDCX20210601).
文摘Regulatory T(Treg)cells are pivotal for maintaining immune homeostasis and play essential roles in various diseases,such as autoimmune diseases,graft-versus-host disease(GVHD),tumors,and infectious diseases.Treg cells exert suppressive function via distinct mechanisms,including inhibitory cytokines,granzyme or perforin-mediated cytolysis,metabolic disruption,and suppression of dendritic cells.Forkhead Box P3(FOXP3),the characteristic transcription factor,is essential for Treg cell function and plasticity.Cumulative evidence has demonstrated that FOXP3 activity and Treg cell function are modulated by a variety of post-translational modifications(PTMs),including ubiquitination,acetylation,phosphorylation,methylation,glycosylation,poly(ADP-ribosyl)ation,and uncharacterized modifications.This review describes Treg cell suppressive mechanisms and summarizes the current evidence on PTM regulation of FOXP3 and Treg cell function.Understanding the regulatory role of PTMs in Treg cell plasticity and function will be helpful in designing therapeutic strategies for autoimmune diseases,GVHD,tumors,and infectious diseases.
基金funded by the Major Research Plan of the National Natural Science Foundation of China(No.92159202)the National Key Research and Development Program of China(No.2021YFA1100500)+1 种基金the Leading Innovation Team Project of Hangzhou Medical College(No.CXLJ202401)the Key Research and Development Plan of Zhejiang Provincial Department of Science and Technology(No.2024C03051)。
文摘Objective:Cytotoxic T lymphocytes(CTLs)play a crucial role in the therapeutic approach to hepatocellular carcinoma(HCC).Recent research has indicated that junctional adhesion molecule-like protein(JAML)enhances the antitumor activity of CD8+T cells.Our study investigates the role of JAML+CD8+T cells in HCC.Methods:We utilized time-of-flight mass cytometry and an orthotopic mouse model of HCC to examine histone modifications in tumor-infiltrating immune cells undergoing immunotherapy.Flow cytometry was used to assess CD4+T cells differentiation and JAML expression in CD8+T cells infiltrating HCC.Correlation analysis revealed a strong positive correlation between lactate dehydrogenase A+(LDHA+)CD4+T cells and JAML+CD8+T cells.Subsequently,we evaluated the therapeutic effects of an agonistic anti-JAML antibody,both alone and combined with immunotherapy.Finally,RNA sequencing was conducted to identify potential regulatory mechanisms.Results:Immunotherapy significantly increased the percentage of CD8+T cells infiltrating HCC and induced histone modifications,such as H3K18 lactylation(H3K18la)in CD4+T cells.Flow cytometry analysis revealed that lactate promotes the differentiation of CD4+T cells into Th1 cells.LDHA,an enzyme that converts pyruvate to lactate,plays a key role in this process.Correlation analysis revealed a strong positive relationship between LDHA+CD4+T cells and JAML+CD8+T cells in patients who responded to immunotherapy.Moreover,high JAML expression in CD8+T cells was associated with a more favorable prognosis.In vivo experiments demonstrated that agonistic anti-JAML antibody therapy reduced tumor volume and significantly prolonged the survival of tumor-bearing mice,independent of the effects of anti-programmed cell death protein ligand-1 antibody(αPD-L1)-mediated immunotherapy.Pathway enrichment analysis further revealed that JAML enhances CTL responses through the oxidative phosphorylation pathway.Conclusions:Activation of JAML enhances CTL responses in HCC treatment,independent ofαPD-L1-mediated immunotherapy,providing a promising strategy for advanced HCC.
基金Supported by Innovative Practice Platform for Undergraduate Students,School of Public Health Xiamen University,No.2021001.
文摘BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression results in a loss of this capacity to facilitate cyclin E degradation.The ubiquitination and degradation of cyclin E1 may be associated with phosphorylation at specific sites on the protein,with Cx43 potentially enhancing this process by facilitating the phosphorylation of these critical residues.AIM To investigate the correlation between expression of Cx43,SKP1/Cullin1/F-box(SCF)FBXW7,p-cyclin E1(ser73,thr77,thr395)and clinicopathological indexes in colon cancer.METHODS Expression levels of Cx43,SCF^(FBXW7),p-cyclin E1(ser73,thr77,thr395)in 38 clinical colon cancer samples were detected by immunohistochemistry and were analyzed by statistical methods to discuss their correlations.RESULTS Positive rate of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in detected samples were 76.32%,76.32%,65.79%,5.26%and 55.26%respectively.Positive expressions of these proteins were not related to the tissue type,degree of tissue differentiation or lymph node metastasis.Cx43 and SCF^(FBXW7)(r=0.749),p-cyclin E1(Ser73)(r=0.667)and p-cyclin E1(Thr395)(r=0.457),SCF^(FBXW7) and p-cyclin E1(Ser73)(r=0.703)and p-cyclin E1(Thr395)(0.415)were correlated in colon cancer(P<0.05),and expressions of the above proteins were positively correlated in colon cancer.CONCLUSION Cx43 may facilitate the phosphorylation of cyclin E1 at the Ser73 and Thr195 sites through its interaction with SCF^(FBXW7),thereby influencing the ubiquitination and degradation of cyclin E1.
基金National Natural Science Foundation of China(Grant Nos.32070838 and 82301874)Open Fund of State Key Laboratory of Reproductive Medicine,Nanjing Medical University(Grant No.SKLRM K202102)。
文摘Meiotic resumption in mammalian oocytes involves nuclear and organelle structural changes,notably the chromatin configuration transition from a non-surrounding nucleolus(NSN)to surrounding nucleolus(SN)in germinal vesicle oocytes.In the current study,we found that nuclear speckles(NSs),a subnuclear structure mainly composed of serine-arginine(SR)proteins,changed from a diffuse spotted distribution in mouse NSN oocytes to an aggregated pattern in SN oocytes.We also found that the SR protein-specific kinase 1(SRPK1),an enzyme that phosphorylates SR proteins,co-localized with NSs at the SN stage,and that NSN oocytes failed to transition to SN oocytes after the inhibition of SRPK1 activity.Furthermore,the typical structure of the chromatin ring around the nucleolus in SN oocytes collapsed after treatment with an SRPK1 inhibitor.Mechanistically,phosphorylated SR proteins were found to be related to chromatin as shown by a salt extraction experiment,and in situ DNaseⅠassay showed that the accessibility of chromatin was enhanced in SN oocytes when SRPK1 was inhibited,accompanied by a decreased repressive modification on histone and the abnormal recurrence of a transcriptional signal.In conclusion,our results indicated that SRPK1-regulated phosphorylation of SR proteins was involved in the NSN-SN transition and played an important role in maintaining the condensed nucleus of SN oocytes via interacting with chromatin.
