AIM： To investigate the clinical significance of BMP and activin membrane-bound inhibitor （BAMBI） which is a pseudoreceptor of transforming growth factorbeta （TGF-β） type 1 receptors and acts as a negative regul...AIM： To investigate the clinical significance of BMP and activin membrane-bound inhibitor （BAMBI） which is a pseudoreceptor of transforming growth factorbeta （TGF-β） type 1 receptors and acts as a negative regulator of TGF-β signaling and expression aberrantly elevated in colorectal cancers （CRCs）. We studied BAMBI expression in CRCs. METHODS： We studied BAMBI expression in 183 surgically resected CRCs by immunochemical and immunoblotting analyses using a generated monoclonal anti-BAMBI antibody. Commercially available anti-β- catenin and anti-p53 antibodies were also applied for immunochemical analyses as a comparison control.RESULTS： Immunohistochemical analysis revealed that BAMBI expression was observed in 148 （80.8%）, and strong BAMBI expression was observed in 46% of the CRCs. Strong BAMBI expression was positively correlated with histological type, depth of invasion, lymph node metastases, and tumor node metastasis （TNM） stage （P 〈 0.05）. Clear associations were found between BAMBI and β-catenin （P = 0.035） and p53 （P =0.049） expression. In curatively resected CRC, 5-year recurrence-free survival was 51.9% （P = 0.037） for strong BAMBI expression compared to 79.8% for weak BAMBI expression. In the Cox＇s multivariate analysis, lymph node metastases （relative risk 6.685; P 〈 0.001） and depth of invasion （RR 14.0; P = 0.013） were significant indicators for recurrence, and strong BAMBI expression （RR 2.26; P = 0.057） tended to be significant. CONCLUSION： BAMBI was linked to a potentially aggressive tumor phenotype and predicted tumor recurrence and cancer-related death in CRC. BAMBI expression might be applicable in the routine clinical setting of CRC.展开更多
Levan produced by Gluconobacter spp.has great potential in biotechnological applications.However,Gluconobacter spp.can synthesize organic acids during fermentation,resulting in environmental acidification.Few studies ...Levan produced by Gluconobacter spp.has great potential in biotechnological applications.However,Gluconobacter spp.can synthesize organic acids during fermentation,resulting in environmental acidification.Few studies have focused on the effects of environmental acidification on levan synthesis.This study revealed that the organic acids,mainly gluconic acid(GA)and 2-keto-gluconic acid(2KGA)secreted by Gluconobacter sp.MP2116 created a highly acidic environment(pH<3)that inhibited levan biosynthesis.The levansucrase derived from strain MP2116 had high enzyme activity at pH 4.0~pH 6.5.When the ambient pH was less than 3,the enzyme activity decreased by 67%.Knocking out the mgdh gene of membrane-bound glucose dehydrogenase(mGDH)in the GA and 2KGA synthesis pathway in strain MP2116 eliminated the inhibitory effect of high acid levels on levansucrase function.As a result,the levan yield increased from 7.4 g/l(wild-type)to 18.8 g/l(Δmgdh)during fermentation without pH control.This study provides a new strategy for improving levan production by preventing the inhibition of polysaccharide synthesis by environmental acidification.展开更多
The insecticidal Cry proteins produced by the bacterium Bacillus thuringiensis(Bt)are extensively used for pest control in formulated sprays and in genetically modified crops,but resistance to Bt toxins threatens thei...The insecticidal Cry proteins produced by the bacterium Bacillus thuringiensis(Bt)are extensively used for pest control in formulated sprays and in genetically modified crops,but resistance to Bt toxins threatens their sustainable use in agriculture.Understanding the molecular mechanisms involved in Bt pathogenesis is crucial for the development of effective resistance management strategies.Previously,we showed a strong correlation between Cry1Ac resistance in Plutella xylostella(L.)and down-regulation of the glycosylphosphatidylinositol(GPI)-anchored membrane-bound alkaline phosphatase(mALP)and aminopeptidase(APN)and members of the ATP-binding cassette(ABC)transporter subfamily C(ABCC),but we do not yet have a clear understanding of the relative contribution of each midgut receptor type.Here,a P.xylostella strain homozygous for the PxmALP gene knockout was generated using CRISPR/Cas9 and the results showed that this strain had a 294-fold resistance to Cry1Ac toxin and 394-fold cross-resistance to Cry1Ab.Moreover,a triple knockout strain lacking PxmALP,Px-ABCC2,and PxABCC3 exhibited 9,660-fold resistance to Cry1Ac and 5,662-fold cross-resistance to Cry1Ab.These resistance levels surpassed those observed in the previously described double PxABCC2 and PxABCC3 knockout mutant,revealing a functional redundancy between ABC transporters and PxmALP.In addition,the activity of Cry1A toxins against Sf9 cells expressing PxmALP,PxABCC2 or PxABCC3 confirmed that each of these can act as a functional receptor.Our findings are crucial for unraveling the relative role of multiple receptors and the molecular mechanisms underlying Bt resistance in insects.展开更多
Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in t...Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in the cellular membrane, storing as dormant forms. Upon exposure to environmental and developmental cues, these transcription factors are released from the membrane and translocated to the nucleus, where they regulate associated target genes. As this process skips both transcriptional and translational regulations, it guarantees prompt response to external and internal signals. Membrane- bound transcription factors （MTFs） undergo several unique steps that are not involved in the action of canonical nuclear transcription factors： proteolytic processing and intracellular movement. Recently, alternative splicing has also emerged as a mechanism to liberate MTFs from the cellular membranes, establishing an additional activation scheme independent of proteolytic processing. Multiple layers of MTF regulation add complexity to transcriptional regulatory scheme and ensure elaborate action of MTFs. In this review, we provide an overview of recent findings on MTFs in plants and highlight the molecular mechanisms underlying MTF liberation from cellular membranes with an emphasis on intracellular movement.展开更多
The biological activity of the multifunctional cytokine interleukin-1 （IL-1） is mediated by its receptors. The aim of this study was to determine if an association exists between single nucleotide polymorphisms （S...The biological activity of the multifunctional cytokine interleukin-1 （IL-1） is mediated by its receptors. The aim of this study was to determine if an association exists between single nucleotide polymorphisms （SNPs） in the IL-1 type I and 2 receptor genes （ILIR1 and ILIR2） and the expression level of membrane-bound ILIRs on subpopulations of mononuclear cells or serum levels of soluble IL-1 receptors. It was observed that healthy individuals with the genotype TT in SNP rs2234650.C〉T had a lower percentage of intact CD14＋ monocytes expressing ILIR1 on their surface. The SNP rs4141134-T〉C in ILIR2 has also been associated with the percentage of intact CD3＋ T cells expressing ILIR2. Furthermore, individuals carrying the CC allele of SNP rs4141134.T〉C and the TT allele of SNP rs2071008-T〉G in ILIR2 had a lower density of ILIR2s on the surface of CD14＋ monocytes in lipopolysaccharide （LPS）-stimulated PBMC cultures. In summary, this study demonstrated that IL-1 receptor gene polymorphisms could be one of the factors influencing the expression of membrane-bound IL-1 receptors （ILIR） on immunocompetent cells.展开更多
Maize plant architecture influences planting density and,in turn,grain yield.Most of the plant architecture-related traits can be described as organ size.We describe a miniature maize mutant,Tiny plant 4(Tip4),which e...Maize plant architecture influences planting density and,in turn,grain yield.Most of the plant architecture-related traits can be described as organ size.We describe a miniature maize mutant,Tiny plant 4(Tip4),which exhibits reduced size of multiple organs and exhibits a semi-dominant monofactorial inheritance characteristic.Positional cloning confirmed that a 4-bp deletion in the NAC TF with transmembrane motif 1-Like(NTL)gene ZmNTL2,denoted as ZmNTL2^(Δ),confers the Tip4 mutation.qRT-PCR showed that ZmNTL2 was expressed in all tested tissues.ZmNTL2 functions as a transcriptional activator and is located in both the nucleus and biomembranes.The mutation does not affect the mRNA abundance of ZmNTL2 locus,but it does result in the loss of transmembrane domain and confines the ZmNTL2^(Δ)protein to the nucleus.Knocking out ZmNTL2 has no effect on maize organ size development,indicating that the 4-bp deletion might be a gain-of-function mutation in organ size regulation.Combining transcriptome sequencing with cytokinin and auxin content determination suggests that the decreased organ size may be possibly mediated by changes in hormone homeostasis.展开更多
In analyses of protein families that may serve as drug targets,membrane-associated G-protein-coupled receptors(GPCRs)dominate,followed by ion channels,transporters,and—to a lesser extent—membrane-bound enzymes.Howev...In analyses of protein families that may serve as drug targets,membrane-associated G-protein-coupled receptors(GPCRs)dominate,followed by ion channels,transporters,and—to a lesser extent—membrane-bound enzymes.However,various challenges put such membrane proteins among key groups of underutilized opportunities for the application of therapeutic antibodies.Antibodies hold the promise of exquisite specificity,as they are able to target even specific conformations of a particular membrane protein,as well as adaptability through engineering into various antibody formats.However,the ease of raising and isolating specific,effective antibodies targeting membrane proteins depends on many factors.In particular,the generation of specific antibodies is easier when targeting larger,simpler,extracellular domains with greater uniqueness of amino acid sequence.The rareness of such ideal conditions is illustrated by the limited number of approved biologics for targeting GPCRs and other complex membrane proteins.Challenges in developing antibodies to complex membrane proteins such as GPCRs,ion channels,transporters,and membrane-bound enzymes can be addressed by the design of the antigen,antibody-generation strategies,lead optimization technologies,and antibody modalities.A better understanding of the membrane proteins being targeted would facilitate mechanism-based drug discovery.This review describes the advantages and challenges of targeting complex membrane proteins with antibodies and discusses the preparation of membrane protein antigens and antibody generation,illustrated by select examples of success.展开更多
Nonobstructive azoospermia(NOA)is a common cause of infertility and is defined as the complete absence of sperm in ejaculation due to defective spermatogenesis.The aim of this study was to identify the genetic etiolog...Nonobstructive azoospermia(NOA)is a common cause of infertility and is defined as the complete absence of sperm in ejaculation due to defective spermatogenesis.The aim of this study was to identify the genetic etiology of NOA in an infertile male from a Chinese consanguineous family.A homozygous missense variant of the membrane-bound O-acyltransferase domain-containing 1(MBOAT1)gene(c.770C>T,p.Thr257Met)was found by whole-exome sequencing(WES).Bioinformatic analysis also showed that this variant was a pathogenic variant and that the amino acid residue in MBOAT1 was highly conserved in mammals.Quantitative polymerase chain reaction(Q-PCR)analysis showed that the mRNA level of MBOAT1 in the patient was 22.0%lower than that in his father.Furthermore,we screened variants of MBOAT1 in a broader population and found an additional homozygous variant of the MBOAT1 gene in 123 infertile men.Our data identified homozygous variants of the MBOAT1 gene associated with male infertility.This study will provide new insights for researchers to understand the molecular mechanisms of male infertility and will help clinicians make accurate diagnoses.展开更多
4-Hydroxyphenylpyruvic acid （4-HPPA）, a kind of α-keto acid, is an intermediate in the metabolism of tyrosine and has a wide range of application in food, pharmaceutical and chemical industry. Using amino acids as ...4-Hydroxyphenylpyruvic acid （4-HPPA）, a kind of α-keto acid, is an intermediate in the metabolism of tyrosine and has a wide range of application in food, pharmaceutical and chemical industry. Using amino acids as raw material to prod uce the corresponding α-keto acid is thought to be both economic and efficient. Among the enzymes that convert amino acid to α-keto acid, membrane bound L-amino acid deaminase （mL-AAD）, which is anchored to the outer side of the cytomembrane, becomes an ideal enzyme to prepare α-keto acid since there is no cofactors needed and H2O2 production during the reaction. In this study, the mL-AAD from Proteus vulgaris was used to prepare whole-cell catalysts to produce 4-HPPA from L-tyrosine. The secretory efficiency of mL-AAD conducted by its own twin-arginine signal peptide （twin-arginine translocation pathway, Tat） and integrated pelB （the general secretory pathway, Sec）-Tat signal peptide was determined and compared firstly, using two pET systems （pET28a and pET20b）. It was found that the Tat pathway （pET28a-mlaad） resulted in higher cell-associated mL-AAD activity and cell biomass, and was more beneficial to prepare biocatalyst. In addition, expression hosts BI21 （DE3） and 0.05 mmol. L- 1 IPTG were found to be suitable for mL-AAD expression. The reaction conditions for mL-AAD were optimized and 72.72 mmol,L 1 4-HPPA was obtained from 100 mmol.L 1 tyrosine in 10 h under the optimized conditions. This bioprocess, which is more eco-friendly and economical than the traditional chemical synthesis ways, has great potential for industrial application.展开更多
Folic acid is a fully oxidized synthetic folate with high bioavailability and stability which has been extensively prescribed to prevent congenital disabilities.Here we revealed the immunosuppressive effect of folic a...Folic acid is a fully oxidized synthetic folate with high bioavailability and stability which has been extensively prescribed to prevent congenital disabilities.Here we revealed the immunosuppressive effect of folic acid by targeting splenic marginal zone B(MZB)cells.Folic acid demonstrates avid binding with the Fc domain of immunoglobulin M(IgM),targeting IgM positive MZB cells in vivo to destabilize IgM-B cell receptor(BCR)complex and block immune responses.The induced anergy of MZB cells by folic acid provides an immunological escaping window for antigens.Covalent conjugation of folic acid with therapeutic proteins and antibodies induces immunological evasion to mitigate the production of anti-drug antibodies,which is a major obstacle to the long-term treatment of biologics by reducing curative effects and/or causing adverse reactions.Folic acid acts as a safe and effective immunosuppressant via IgM-mediated MZB cells targeting to boost the clinical outcomes of biologics by inhibiting the production of anti-drug antibodies,and also holds the potential to treat other indications that adverse immune responses need to be transiently shut off.展开更多
Callose,aβ-1,3-glucan plant cell wall polymer,regulates symplasmic channel size at plasmodesmata(PD)and plays a crucial role in a variety of plant processes.However,elucidating the molecular mechanism of PD callose h...Callose,aβ-1,3-glucan plant cell wall polymer,regulates symplasmic channel size at plasmodesmata(PD)and plays a crucial role in a variety of plant processes.However,elucidating the molecular mechanism of PD callose homeostasis is limited.We screened and identified an Arabidopsis mutant plant with excessive callose deposition at PD and found that the mutated gene wasα1-COP,a member of the coat protein I(COPI)coatomer complex.We report that loss of function ofα1-COP elevates the callose accumulation at PD by affecting subcellular protein localization of callose degradation enzyme Pd BG2.This process is linked to the functions of ERH1,an inositol phosphoryl ceramide synthase,and glucosylceramide synthase through physical interactions with theα1-COP protein.Additionally,the loss of function ofα1-COP alters the subcellular localization of ERH1 and GCS proteins,resulting in a reduction of Glc Cers and Glc HCers molecules,which are key sphingolipid(SL)species for lipid raft formation.Our findings suggest thatα1-COP protein,together with SL modifiers controlling lipid raft compositions,regulates the subcellular localization of GPI-anchored PDBG2 proteins,and hence the callose turnover at PD and symplasmic movement of biomolecules.Our findings provide the first key clue to link the COPI-mediated intracellular trafficking pathway to the callose-mediated intercellular signaling pathway through PD.展开更多
Zeste white 10(ZW10)was first identified as a centromere/kinetochore protein encoded by the ZW10 gene in Drosophila.ZW10 guides the spindle assembly checkpoint signaling during mitotic chromosome segregation in metazo...Zeste white 10(ZW10)was first identified as a centromere/kinetochore protein encoded by the ZW10 gene in Drosophila.ZW10 guides the spindle assembly checkpoint signaling during mitotic chromosome segregation in metazoans.Recent studies have shown that ZW10 is also involved in membrane-bound organelle interactions during interphase and plays a vital role in membrane transport between the endoplasmic reticulum and Golgi apparatus.Despite these findings,the precise molecular mechanisms by which ZW10 regulates interactions between membrane-bound organelles in interphase and the assembly of membraneless organelle kinetochore in mitosis remain elusive.Here,we highlight how ZW10 forms context-dependent protein complexes during the cell cycle.These complexes are essential for mediating membrane trafficking in interphase and ensuring the accurate segregation of chromosomes in mitosis.展开更多
Dehydration of a surface is the first step for the interaction between biomolecules and the surface. In this study, we systemati- cally investigated the influence of cholesterol analog 6-ketocholestanol （6-KC） on th...Dehydration of a surface is the first step for the interaction between biomolecules and the surface. In this study, we systemati- cally investigated the influence of cholesterol analog 6-ketocholestanol （6-KC） on the dehydration of model cell membrane, using sum frequency generation vibrational spectroscopy. In pure DI water environment, two separate dehydration dynamic components were observed in neutrally charged and isotopically labeled 1,2-dimyristoyl-sn-glycero-3-phosphocholine （DMPC） and positively charged 1,2-dimyristoyl-sn-glycero-3-ethylphosphocholine（chloride salt） （DMEPC） bilayer： a large-amplitude fast component and a small-amplitude slow component, which originated from the water molecules with a weak and a strong water-membrane bound strengths, respectively. Dehydration of a negatively charged mixed DMPC/DMPG bilayer lead to the membrane-bound water being reorganized to ordered structures quickly. It is evident that the water-membrane bound strengths depend largely on the charge status of the lipid and has an order of neutrally charged membrane〈〈positively charged mem- brane〈〈negatively charged membrane. In an ionic environment, KC1 solution can not only dehydrate DMPC bilayer, but also prevent the 6-KC fiom further dehydrating this model cell membrane. We observed that the dehydration dynamics behavior of DMPC bilayer in the presence of the chaotropic anions is similar to that of the negatively charged DMPG bilayer because of the penetration of chaotropic anions into the DMPC bilayer. The degree of dehydration difficulty in kosmotropic anions fol- lows a Hofmeister series and linearly correlates with the hydration Gibbs free energy of the anions. Our results provide a molecular basis for the interpretation of the Hofmeister effect of kosmotropic anions on ion transport proteins.展开更多
Cytochrome P450(CYP)enzymes play crucial roles during the evolution and diversification of ancestral monocel-lular eukaryotes into multicellular eukaryotic organisms due to their essential functionalities including ca...Cytochrome P450(CYP)enzymes play crucial roles during the evolution and diversification of ancestral monocel-lular eukaryotes into multicellular eukaryotic organisms due to their essential functionalities including catalysis of housekeeping biochemical reactions,synthesis of diverse metabolites,detoxification of xenobiotics,and con-tribution to environmental adaptation.Eukaryotic CYPs with versatile functionalities are undeniably regarded as promising biocatalysts with great potential for biotechnological,pharmaceutical and chemical industry applica-tions.Nevertheless,the modes of action and the challenges associated with these membrane-bound proteins have hampered the effective utilization of eukaryotic CYPs in a broader range.This review is focused on comprehen-sive and consolidated approaches to address the core challenges in heterologous expression of membrane-bound eukaryotic CYPs in different surrogate microbial cell factories,aiming to provide key insights for better studies and applications of diverse eukaryotic CYPs in the future.We also highlight the functional significance of the previously underrated cytochrome P450 reductases(CPRs)and provide a rational justification on the progression of CPR from auxiliary redox partner to function modulator in CYP catalysis.展开更多
基金Grants from the Japan Science and Technology Agency, No. 17014011The Harunasou Foundation Cancer Research Subsidizing Fund+3 种基金The Kanetsu Chuo Hospital Research Fundresearch funds from the Uchida Clinic in Inamachi, SaitamaThe Katoh Clinic, Maebashi Norte Hospital in Maebashi, GunmaKeiaido Hospital in Midori, Gunma
文摘AIM： To investigate the clinical significance of BMP and activin membrane-bound inhibitor （BAMBI） which is a pseudoreceptor of transforming growth factorbeta （TGF-β） type 1 receptors and acts as a negative regulator of TGF-β signaling and expression aberrantly elevated in colorectal cancers （CRCs）. We studied BAMBI expression in CRCs. METHODS： We studied BAMBI expression in 183 surgically resected CRCs by immunochemical and immunoblotting analyses using a generated monoclonal anti-BAMBI antibody. Commercially available anti-β- catenin and anti-p53 antibodies were also applied for immunochemical analyses as a comparison control.RESULTS： Immunohistochemical analysis revealed that BAMBI expression was observed in 148 （80.8%）, and strong BAMBI expression was observed in 46% of the CRCs. Strong BAMBI expression was positively correlated with histological type, depth of invasion, lymph node metastases, and tumor node metastasis （TNM） stage （P 〈 0.05）. Clear associations were found between BAMBI and β-catenin （P = 0.035） and p53 （P =0.049） expression. In curatively resected CRC, 5-year recurrence-free survival was 51.9% （P = 0.037） for strong BAMBI expression compared to 79.8% for weak BAMBI expression. In the Cox＇s multivariate analysis, lymph node metastases （relative risk 6.685; P 〈 0.001） and depth of invasion （RR 14.0; P = 0.013） were significant indicators for recurrence, and strong BAMBI expression （RR 2.26; P = 0.057） tended to be significant. CONCLUSION： BAMBI was linked to a potentially aggressive tumor phenotype and predicted tumor recurrence and cancer-related death in CRC. BAMBI expression might be applicable in the routine clinical setting of CRC.
基金supported by the Shandong Provincial Natural Science Foundation(ZR2023MC113)Taishan Scholar Construction Foundation of Shandong Province(tshw20130963).
文摘Levan produced by Gluconobacter spp.has great potential in biotechnological applications.However,Gluconobacter spp.can synthesize organic acids during fermentation,resulting in environmental acidification.Few studies have focused on the effects of environmental acidification on levan synthesis.This study revealed that the organic acids,mainly gluconic acid(GA)and 2-keto-gluconic acid(2KGA)secreted by Gluconobacter sp.MP2116 created a highly acidic environment(pH<3)that inhibited levan biosynthesis.The levansucrase derived from strain MP2116 had high enzyme activity at pH 4.0~pH 6.5.When the ambient pH was less than 3,the enzyme activity decreased by 67%.Knocking out the mgdh gene of membrane-bound glucose dehydrogenase(mGDH)in the GA and 2KGA synthesis pathway in strain MP2116 eliminated the inhibitory effect of high acid levels on levansucrase function.As a result,the levan yield increased from 7.4 g/l(wild-type)to 18.8 g/l(Δmgdh)during fermentation without pH control.This study provides a new strategy for improving levan production by preventing the inhibition of polysaccharide synthesis by environmental acidification.
基金supported by the National Natural Science Foundation of China(32172458,32302354,32221004,32372600)the Beijing Key Laboratory for Pest Control and Sustainable Cultivation of Vegetables and the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-CSCB-202303).
文摘The insecticidal Cry proteins produced by the bacterium Bacillus thuringiensis(Bt)are extensively used for pest control in formulated sprays and in genetically modified crops,but resistance to Bt toxins threatens their sustainable use in agriculture.Understanding the molecular mechanisms involved in Bt pathogenesis is crucial for the development of effective resistance management strategies.Previously,we showed a strong correlation between Cry1Ac resistance in Plutella xylostella(L.)and down-regulation of the glycosylphosphatidylinositol(GPI)-anchored membrane-bound alkaline phosphatase(mALP)and aminopeptidase(APN)and members of the ATP-binding cassette(ABC)transporter subfamily C(ABCC),but we do not yet have a clear understanding of the relative contribution of each midgut receptor type.Here,a P.xylostella strain homozygous for the PxmALP gene knockout was generated using CRISPR/Cas9 and the results showed that this strain had a 294-fold resistance to Cry1Ac toxin and 394-fold cross-resistance to Cry1Ab.Moreover,a triple knockout strain lacking PxmALP,Px-ABCC2,and PxABCC3 exhibited 9,660-fold resistance to Cry1Ac and 5,662-fold cross-resistance to Cry1Ab.These resistance levels surpassed those observed in the previously described double PxABCC2 and PxABCC3 knockout mutant,revealing a functional redundancy between ABC transporters and PxmALP.In addition,the activity of Cry1A toxins against Sf9 cells expressing PxmALP,PxABCC2 or PxABCC3 confirmed that each of these can act as a functional receptor.Our findings are crucial for unraveling the relative role of multiple receptors and the molecular mechanisms underlying Bt resistance in insects.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2013R1A1A1004831)research funds of Chonbuk National University in 2012
文摘Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in the cellular membrane, storing as dormant forms. Upon exposure to environmental and developmental cues, these transcription factors are released from the membrane and translocated to the nucleus, where they regulate associated target genes. As this process skips both transcriptional and translational regulations, it guarantees prompt response to external and internal signals. Membrane- bound transcription factors （MTFs） undergo several unique steps that are not involved in the action of canonical nuclear transcription factors： proteolytic processing and intracellular movement. Recently, alternative splicing has also emerged as a mechanism to liberate MTFs from the cellular membranes, establishing an additional activation scheme independent of proteolytic processing. Multiple layers of MTF regulation add complexity to transcriptional regulatory scheme and ensure elaborate action of MTFs. In this review, we provide an overview of recent findings on MTFs in plants and highlight the molecular mechanisms underlying MTF liberation from cellular membranes with an emphasis on intracellular movement.
文摘The biological activity of the multifunctional cytokine interleukin-1 （IL-1） is mediated by its receptors. The aim of this study was to determine if an association exists between single nucleotide polymorphisms （SNPs） in the IL-1 type I and 2 receptor genes （ILIR1 and ILIR2） and the expression level of membrane-bound ILIRs on subpopulations of mononuclear cells or serum levels of soluble IL-1 receptors. It was observed that healthy individuals with the genotype TT in SNP rs2234650.C〉T had a lower percentage of intact CD14＋ monocytes expressing ILIR1 on their surface. The SNP rs4141134-T〉C in ILIR2 has also been associated with the percentage of intact CD3＋ T cells expressing ILIR2. Furthermore, individuals carrying the CC allele of SNP rs4141134.T〉C and the TT allele of SNP rs2071008-T〉G in ILIR2 had a lower density of ILIR2s on the surface of CD14＋ monocytes in lipopolysaccharide （LPS）-stimulated PBMC cultures. In summary, this study demonstrated that IL-1 receptor gene polymorphisms could be one of the factors influencing the expression of membrane-bound IL-1 receptors （ILIR） on immunocompetent cells.
基金supported by The National Key Research and Development Program of China(2022YFD1200704--3)Crop Varietal Improvement and Insect Pests Control by Nuclear Radiation,Platform for Mutation Breeding by Radiation of Sichuan(2021YFYZ0011)+1 种基金Natural Science Foundation of Sichuan Province(2022NSFSC1635)Applied Basic Research Programs of Sichuan Provincial Science and Technology Department(2020YJ0249)。
文摘Maize plant architecture influences planting density and,in turn,grain yield.Most of the plant architecture-related traits can be described as organ size.We describe a miniature maize mutant,Tiny plant 4(Tip4),which exhibits reduced size of multiple organs and exhibits a semi-dominant monofactorial inheritance characteristic.Positional cloning confirmed that a 4-bp deletion in the NAC TF with transmembrane motif 1-Like(NTL)gene ZmNTL2,denoted as ZmNTL2^(Δ),confers the Tip4 mutation.qRT-PCR showed that ZmNTL2 was expressed in all tested tissues.ZmNTL2 functions as a transcriptional activator and is located in both the nucleus and biomembranes.The mutation does not affect the mRNA abundance of ZmNTL2 locus,but it does result in the loss of transmembrane domain and confines the ZmNTL2^(Δ)protein to the nucleus.Knocking out ZmNTL2 has no effect on maize organ size development,indicating that the 4-bp deletion might be a gain-of-function mutation in organ size regulation.Combining transcriptome sequencing with cytokinin and auxin content determination suggests that the decreased organ size may be possibly mediated by changes in hormone homeostasis.
基金This work was partly supported by the Cancer Prevention and Research Institute of Texas,USA(PR150551 and RP190561)the Welch Foundation(AU-0042-20030616)+1 种基金The work was also supported by the National Natural Science Foundation of China(31700778 and 31320103918)Jiangsu Province’s Key Laboratory of Medicine(XK201135).
文摘In analyses of protein families that may serve as drug targets,membrane-associated G-protein-coupled receptors(GPCRs)dominate,followed by ion channels,transporters,and—to a lesser extent—membrane-bound enzymes.However,various challenges put such membrane proteins among key groups of underutilized opportunities for the application of therapeutic antibodies.Antibodies hold the promise of exquisite specificity,as they are able to target even specific conformations of a particular membrane protein,as well as adaptability through engineering into various antibody formats.However,the ease of raising and isolating specific,effective antibodies targeting membrane proteins depends on many factors.In particular,the generation of specific antibodies is easier when targeting larger,simpler,extracellular domains with greater uniqueness of amino acid sequence.The rareness of such ideal conditions is illustrated by the limited number of approved biologics for targeting GPCRs and other complex membrane proteins.Challenges in developing antibodies to complex membrane proteins such as GPCRs,ion channels,transporters,and membrane-bound enzymes can be addressed by the design of the antigen,antibody-generation strategies,lead optimization technologies,and antibody modalities.A better understanding of the membrane proteins being targeted would facilitate mechanism-based drug discovery.This review describes the advantages and challenges of targeting complex membrane proteins with antibodies and discusses the preparation of membrane protein antigens and antibody generation,illustrated by select examples of success.
基金This research was supported by the National Key Research and Development Project(2019YFA0802600)the National Natural Science Foundation of China(81971333).
文摘Nonobstructive azoospermia(NOA)is a common cause of infertility and is defined as the complete absence of sperm in ejaculation due to defective spermatogenesis.The aim of this study was to identify the genetic etiology of NOA in an infertile male from a Chinese consanguineous family.A homozygous missense variant of the membrane-bound O-acyltransferase domain-containing 1(MBOAT1)gene(c.770C>T,p.Thr257Met)was found by whole-exome sequencing(WES).Bioinformatic analysis also showed that this variant was a pathogenic variant and that the amino acid residue in MBOAT1 was highly conserved in mammals.Quantitative polymerase chain reaction(Q-PCR)analysis showed that the mRNA level of MBOAT1 in the patient was 22.0%lower than that in his father.Furthermore,we screened variants of MBOAT1 in a broader population and found an additional homozygous variant of the MBOAT1 gene in 123 infertile men.Our data identified homozygous variants of the MBOAT1 gene associated with male infertility.This study will provide new insights for researchers to understand the molecular mechanisms of male infertility and will help clinicians make accurate diagnoses.
基金Supported by the National Natural Science Foundation of China(31470793,31670804)China Postdoctoral Science Foundation(2016M592003)+1 种基金the Natural Science Foundation of Zhejiang Province(LZ13B060002)the General Scientific Research Project of Zhejiang Provincial Education Department(Y201432760)
文摘4-Hydroxyphenylpyruvic acid （4-HPPA）, a kind of α-keto acid, is an intermediate in the metabolism of tyrosine and has a wide range of application in food, pharmaceutical and chemical industry. Using amino acids as raw material to prod uce the corresponding α-keto acid is thought to be both economic and efficient. Among the enzymes that convert amino acid to α-keto acid, membrane bound L-amino acid deaminase （mL-AAD）, which is anchored to the outer side of the cytomembrane, becomes an ideal enzyme to prepare α-keto acid since there is no cofactors needed and H2O2 production during the reaction. In this study, the mL-AAD from Proteus vulgaris was used to prepare whole-cell catalysts to produce 4-HPPA from L-tyrosine. The secretory efficiency of mL-AAD conducted by its own twin-arginine signal peptide （twin-arginine translocation pathway, Tat） and integrated pelB （the general secretory pathway, Sec）-Tat signal peptide was determined and compared firstly, using two pET systems （pET28a and pET20b）. It was found that the Tat pathway （pET28a-mlaad） resulted in higher cell-associated mL-AAD activity and cell biomass, and was more beneficial to prepare biocatalyst. In addition, expression hosts BI21 （DE3） and 0.05 mmol. L- 1 IPTG were found to be suitable for mL-AAD expression. The reaction conditions for mL-AAD were optimized and 72.72 mmol,L 1 4-HPPA was obtained from 100 mmol.L 1 tyrosine in 10 h under the optimized conditions. This bioprocess, which is more eco-friendly and economical than the traditional chemical synthesis ways, has great potential for industrial application.
基金supported by the National Natural Science Foundation of China(82125035,81973245 and 82373817,China)Shanghai Education Commission Major Project(2021-01-07-00-07-E00081,China)。
文摘Folic acid is a fully oxidized synthetic folate with high bioavailability and stability which has been extensively prescribed to prevent congenital disabilities.Here we revealed the immunosuppressive effect of folic acid by targeting splenic marginal zone B(MZB)cells.Folic acid demonstrates avid binding with the Fc domain of immunoglobulin M(IgM),targeting IgM positive MZB cells in vivo to destabilize IgM-B cell receptor(BCR)complex and block immune responses.The induced anergy of MZB cells by folic acid provides an immunological escaping window for antigens.Covalent conjugation of folic acid with therapeutic proteins and antibodies induces immunological evasion to mitigate the production of anti-drug antibodies,which is a major obstacle to the long-term treatment of biologics by reducing curative effects and/or causing adverse reactions.Folic acid acts as a safe and effective immunosuppressant via IgM-mediated MZB cells targeting to boost the clinical outcomes of biologics by inhibiting the production of anti-drug antibodies,and also holds the potential to treat other indications that adverse immune responses need to be transiently shut off.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)(Grant Nos.NRF 2018R1A2A1A05077295,2020M3A9I4038352,2022R1A2C3010331,2020R1A6A1A03044344,and 2022R1A 5A1031361)a grant from the New Breeding Technologies Development Program(Grant No.PJ01653202),Rural Development Administration(RDA),Republic of Korea。
文摘Callose,aβ-1,3-glucan plant cell wall polymer,regulates symplasmic channel size at plasmodesmata(PD)and plays a crucial role in a variety of plant processes.However,elucidating the molecular mechanism of PD callose homeostasis is limited.We screened and identified an Arabidopsis mutant plant with excessive callose deposition at PD and found that the mutated gene wasα1-COP,a member of the coat protein I(COPI)coatomer complex.We report that loss of function ofα1-COP elevates the callose accumulation at PD by affecting subcellular protein localization of callose degradation enzyme Pd BG2.This process is linked to the functions of ERH1,an inositol phosphoryl ceramide synthase,and glucosylceramide synthase through physical interactions with theα1-COP protein.Additionally,the loss of function ofα1-COP alters the subcellular localization of ERH1 and GCS proteins,resulting in a reduction of Glc Cers and Glc HCers molecules,which are key sphingolipid(SL)species for lipid raft formation.Our findings suggest thatα1-COP protein,together with SL modifiers controlling lipid raft compositions,regulates the subcellular localization of GPI-anchored PDBG2 proteins,and hence the callose turnover at PD and symplasmic movement of biomolecules.Our findings provide the first key clue to link the COPI-mediated intracellular trafficking pathway to the callose-mediated intercellular signaling pathway through PD.
基金supported by grants from the Ministry of Science and Technology of China and the National Natural Science Foundation of China(2022YFA1303100,32090040,92254302,2022YFA0806800,W2411017,32450537,91953000,92153302,32170733,and 22177106)Plans for Major Provincial Science&Technology Projects of Anhui Province(202303a0702003)+2 种基金the Ministry of Education(IRT_17R102)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB19040000)the Fundamental Research Funds for the Central Universities(KB9100000007,KB9100000006,and KB9100000013).
文摘Zeste white 10(ZW10)was first identified as a centromere/kinetochore protein encoded by the ZW10 gene in Drosophila.ZW10 guides the spindle assembly checkpoint signaling during mitotic chromosome segregation in metazoans.Recent studies have shown that ZW10 is also involved in membrane-bound organelle interactions during interphase and plays a vital role in membrane transport between the endoplasmic reticulum and Golgi apparatus.Despite these findings,the precise molecular mechanisms by which ZW10 regulates interactions between membrane-bound organelles in interphase and the assembly of membraneless organelle kinetochore in mitosis remain elusive.Here,we highlight how ZW10 forms context-dependent protein complexes during the cell cycle.These complexes are essential for mediating membrane trafficking in interphase and ensuring the accurate segregation of chromosomes in mitosis.
基金supported by the National Natural Science Foundation of China(21273217,91127042,21161160557)the National Basic Research Program of China(2010CB923300)+2 种基金the Key Research Program of the Chinese Academy of Sciencesthe Scientific Research Foundation for the Returned Overseas Chinese Scholars(State Education Ministry)the Fundamental Research Funds for the Central Universities
文摘Dehydration of a surface is the first step for the interaction between biomolecules and the surface. In this study, we systemati- cally investigated the influence of cholesterol analog 6-ketocholestanol （6-KC） on the dehydration of model cell membrane, using sum frequency generation vibrational spectroscopy. In pure DI water environment, two separate dehydration dynamic components were observed in neutrally charged and isotopically labeled 1,2-dimyristoyl-sn-glycero-3-phosphocholine （DMPC） and positively charged 1,2-dimyristoyl-sn-glycero-3-ethylphosphocholine（chloride salt） （DMEPC） bilayer： a large-amplitude fast component and a small-amplitude slow component, which originated from the water molecules with a weak and a strong water-membrane bound strengths, respectively. Dehydration of a negatively charged mixed DMPC/DMPG bilayer lead to the membrane-bound water being reorganized to ordered structures quickly. It is evident that the water-membrane bound strengths depend largely on the charge status of the lipid and has an order of neutrally charged membrane〈〈positively charged mem- brane〈〈negatively charged membrane. In an ionic environment, KC1 solution can not only dehydrate DMPC bilayer, but also prevent the 6-KC fiom further dehydrating this model cell membrane. We observed that the dehydration dynamics behavior of DMPC bilayer in the presence of the chaotropic anions is similar to that of the negatively charged DMPG bilayer because of the penetration of chaotropic anions into the DMPC bilayer. The degree of dehydration difficulty in kosmotropic anions fol- lows a Hofmeister series and linearly correlates with the hydration Gibbs free energy of the anions. Our results provide a molecular basis for the interpretation of the Hofmeister effect of kosmotropic anions on ion transport proteins.
基金supported by the National Key Research and Develop-ment Program of China(2019YFA0706900)the National Natural Sci-ence Foundation of China(32025001 and 21472204)the Shandong Provincial Natural Science Foundation(ZR2019ZD20).
文摘Cytochrome P450(CYP)enzymes play crucial roles during the evolution and diversification of ancestral monocel-lular eukaryotes into multicellular eukaryotic organisms due to their essential functionalities including catalysis of housekeeping biochemical reactions,synthesis of diverse metabolites,detoxification of xenobiotics,and con-tribution to environmental adaptation.Eukaryotic CYPs with versatile functionalities are undeniably regarded as promising biocatalysts with great potential for biotechnological,pharmaceutical and chemical industry applica-tions.Nevertheless,the modes of action and the challenges associated with these membrane-bound proteins have hampered the effective utilization of eukaryotic CYPs in a broader range.This review is focused on comprehen-sive and consolidated approaches to address the core challenges in heterologous expression of membrane-bound eukaryotic CYPs in different surrogate microbial cell factories,aiming to provide key insights for better studies and applications of diverse eukaryotic CYPs in the future.We also highlight the functional significance of the previously underrated cytochrome P450 reductases(CPRs)and provide a rational justification on the progression of CPR from auxiliary redox partner to function modulator in CYP catalysis.
