Osteoclast-development patterns and their alterations across Ankylosing Spondylitis(AS)conditions are mysterious,making AS treatment difficult.Our study aims to clarify osteoclast-precursor(OCP)development patterns fr...Osteoclast-development patterns and their alterations across Ankylosing Spondylitis(AS)conditions are mysterious,making AS treatment difficult.Our study aims to clarify osteoclast-precursor(OCP)development patterns from monocytes and their variations under AS conditions.We performed single-cell transcriptomics in peripheral blood mononuclear cells(PBMCs)from healthy donors and AS patients in the early,aggravated and remission stages.After monocytic reclustering,OCP-development patterns and the alterations upon AS onset and different outcomes were revealed based on single-cell trajectory.The trajectories revealed two monocyte states with strong OCP features,and AS pathogenesis was characterized by their reduction.Ribosome synthesis was considered the essential function for the development towards OCP-featured states,and this function and its representative molecule,RPS17,showed a decreasing trend with AS onset and outcomes.Histology assessment showed that RPS17underexpression participated in AS inflammatory osteogenesis and ankylosing destruction.Conditional knockout of RPS17ameliorated ovariectomy-induced bone loss and enhanced osteoclastogenesis,and RPS17 overexpression improved the phenotype of AS-like mice.Importantly,local injection of RPS17-overexpressed monocytic OCPs markedly ameliorated the joint alterations of AS-like mice without promoting bone loss;this was associated with enhanced osteoclastogenesis adjacent to the articular surface and T-cell-suppressive property in monocytic OCPs.Overall,the evolution of monocytes towards OCP-lineage fate mainly depends on ribosome synthesis,and OCP-development disorder participates in AS lesions due to a reduction in RPS17-dependent ribosome synthesis.Notably,RPS17-overexpressed monocytic OCPs have translational potential in preventing and treating AS peripheral lesions.展开更多
Pigeons and certain other avian species produce a milklike secretion in their crop sacs to nourish offspring,yet the detailed processes involved are not fully elucidated.This study investigated the crop sacs of 225-da...Pigeons and certain other avian species produce a milklike secretion in their crop sacs to nourish offspring,yet the detailed processes involved are not fully elucidated.This study investigated the crop sacs of 225-day-old unpaired non-lactating male pigeons(MN)and males initiating lactation on the first day after incubation(ML).Using RNA sequencing,ribosomeprofiling,andsingle-cell transcriptome sequencing(scRNA-seq),we identified a significant up-regulation of genes associated with ribosome assembly and protein synthesis in ML compared to MN.Results from scRNA-seq analysis identified 12distinct cell types and 22 clusters,with secretory epithelial cells(SECs)exhibiting marked expression of plasma cell markers,including IGLL1 and MZB1.RNA fluorescence in situ hybridization(RNA FISH)and IgY quantification confirmed the critical role of SECs in producing endogenous IgY during lactation.We propose that fibroblast-derived BAFF signals activate SECs,mimicking B cell transformation and enhancing protein production through the unfolded protein response(UPR).These findings shed light on the cellular dynamics of pigeon milk production and contribute to a broader understanding of avian biology.展开更多
Soybean meal(SBM)prepared by soybean crushing is the most popular protein source in the poultry and livestock industries(Cai et al.,2015)due to its economic manufacture,high protein content,and good nutritional value....Soybean meal(SBM)prepared by soybean crushing is the most popular protein source in the poultry and livestock industries(Cai et al.,2015)due to its economic manufacture,high protein content,and good nutritional value.Despite these benefits,SBM contains various antigen proteins such as glycinin andβ-conglycinin,which account for approximately 70%of the total proteins of the SBM and reduce digestibility and damage intestinal function(Peng et al.,2018).展开更多
Cytoplasmic accumulation of TDP-43 is a pathological hallmark of amyotrophic lateral sclerosis(ALS)and other neurodegenerative diseases.While current studies have primarily focused on gene regulation mediated by full-...Cytoplasmic accumulation of TDP-43 is a pathological hallmark of amyotrophic lateral sclerosis(ALS)and other neurodegenerative diseases.While current studies have primarily focused on gene regulation mediated by full-length nuclear TDP-43,the potential effects of cytoplasmic TDP-43 fragments remain less explored.Our previous findings demonstrated that primate-specific cleavage of TDP-43 contributes to its cytoplasmic localization,prompting further investigation into its pathological effects.In the cynomolgus monkey brain,we observed that mutant or truncated TDP-43 was transported onto the ribosome organelle.Ribosome-associated transcriptomic analysis revealed dysregulation of apoptosis-and lysosome-related genes,indicating that cytoplasmic TDP-43 induces neurotoxicity by binding to ribosomes and disrupting mRNA expression.These findings provide mechanistic insights into the gain-of-function effects of pathological TDP-43.展开更多
In eukaryotic cells, initiation of protein translation is to recruit the ribosome to a specific mRNA, which is generally dependent on the 5＇ cap structure. However, protein translation can also be initiated in a cap-...In eukaryotic cells, initiation of protein translation is to recruit the ribosome to a specific mRNA, which is generally dependent on the 5＇ cap structure. However, protein translation can also be initiated in a cap-independent manner by using a cis-regulatory element termed the internal ribosome entry site （IRES）. The first experimentally validated IRES was reported in the poliovirus （Pelletier and Sonenberg, 1988）. Then eukaryotic cellular mRNAs were also validated to contain IRES elements.展开更多
Many plants contain ribosome inactivating proteins (RIPs) with N-glycosidase activity, which depurinate large ribosomal RNA and arrest protein synthesis. RIPs so far tested inhibit replication of mRNA as well as DNA v...Many plants contain ribosome inactivating proteins (RIPs) with N-glycosidase activity, which depurinate large ribosomal RNA and arrest protein synthesis. RIPs so far tested inhibit replication of mRNA as well as DNA viruses and these proteins, isolated from plants, are found to be effective against a broad range of viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV). Most of the research work related to RIPs has been focused on antiviral activity against HIV; however, the exact mechanism of antiviral activity is still not clear. The mechanism of antiviral activity was thought to follow inactivation of the host cell ribosome, leading to inhibition of viral protein translation and host cell death. Enzymatic activity of RIPs is not limited to depurination of the large rRNA, in addition they can depurinate viral DNA as well as RNA. Recently, Phase I/II clinical trials have demonstrated the potential use of RIPs for treating patients with HIV disease. The aim of this review is to focus on various RIPs from plants associated with anti-HIV activity.展开更多
Ribosome biogenesis is essential for the cell growth and division. Disruptions in ribosome biogenesis result in developmental defects and a group of diseases, known as ribosomopathies. Here, we report a mutation in ze...Ribosome biogenesis is essential for the cell growth and division. Disruptions in ribosome biogenesis result in developmental defects and a group of diseases, known as ribosomopathies. Here, we report a mutation in zebrafish urb1, which encodes an essential ribosome biogenesis protein. The urb1 cq31 mutant exhibits hypoplastic digestive organs, which is caused by impaired cell proliferation with the differentiation of digestive organ progenitors unaffected. Knockdown of mtor or raptor leads to similar hypoplastic phenotypes and reduced expression of urb1 in the digestive organs. Overexpression of Urb1 results in overgrowth of digestive organs, and can efficiently rescue the hypoplastic liver and pancreas in the mtor and raptor morphants. Reduced syntheses of free ribosomal subunits and impaired assembly of polysomes are observed in the urb1 mutant as well as in the mtor and raptor morphants, which can be rescued by the Urb1 overexpression. These data demonstrate that Urb1 plays an important role in governing ribosome biogenesis and protein synthesis downstream of mammalian/mechanistic target of rapamycin complex 1（mTORC1）, thus regulating the development of digestive organs. Our study indicates the requirement of hyperactive protein synthesis for the digestive organ development.展开更多
Gene therapy appears as a promising strategy to treatincurable diseases. In particular, combined gene therapy has shown improved therapeutic efficiency. Internal ribosome entry sites(IRESs), RNA elements naturally pre...Gene therapy appears as a promising strategy to treatincurable diseases. In particular, combined gene therapy has shown improved therapeutic efficiency. Internal ribosome entry sites(IRESs), RNA elements naturally present in the 5' untranslated regions of a few m RNAs, constitute a powerful tool to co-express several genes of interest. IRESs are translational enhancers allowing the translational machinery to start protein synthesis by internal initiation. This feature allowed the design of multi-cistronic vectors expressing several genes from a single m RNA. IRESs exhibit tissue specificity, and drive translation in stress conditions when the global cell translation is blocked, which renders them useful for gene transfer in hypoxic conditions occurring in ischemic diseases and cancer. IRES-based viral and non viral vectors have been used successfully in preclinical and clinical assays of combined gene therapy and resulted in therapeutic benefits for various pathologies including cancers, cardiovascular diseases and degenerative diseases.展开更多
Ribosome biogenesis in the nucleolus requires numerous nucleolar proteins and small non-coding RNAs.Among them is ribosome biogenesis factor Bmsl,which is highly conserved from yeast to human.In yeast,Bmsl initiates r...Ribosome biogenesis in the nucleolus requires numerous nucleolar proteins and small non-coding RNAs.Among them is ribosome biogenesis factor Bmsl,which is highly conserved from yeast to human.In yeast,Bmsl initiates ribosome biogenesis through recruiting Rcll to pre-ribosomes.However,little is known about the biological function of Bmsl in vertebrates.Here we report that Bmsl plays an essential role in zebrafish liver development.We identified a zebrafish bms1l^（sq163） mutant which carries a T to A mutation in the gene bmsl-like（bms1l）.This mutation results in L^（152） to Q^（152） substitution in a GTPase motif in Bmsll.Surprisingly,bmsll^（sq163） mutation confers hypoplasia specifically in the liver,exocrine pancreas and intestine after 3 days post-fertilization（dpf）.Consistent with the bmsll^（sq163） mutant phenotypes,whole-mount in situ hybridization（WISH） on wild type embryos showed that bmsll transcripts are abundant in the entire digestive tract and its accessory organs.Immunostaining for phospho-Histone 3（P-H3） and TUNEL assay revealed that impairment of hepatoblast proliferation rather than cell apoptosis is one of the consequences of bms1l（sq163） giving rise to an under-developed liver.Therefore,our findings demonstrate that Bmsll is necessary for zebrafish liver development.展开更多
Recent improvement in the technologies for efficient delivery of DNA vaccines has renewed interest in the DNA-based vaccines. Several DNA-based vaccines against human enterovirus 71 (EV71), the causative agent for han...Recent improvement in the technologies for efficient delivery of DNA vaccines has renewed interest in the DNA-based vaccines. Several DNA-based vaccines against human enterovirus 71 (EV71), the causative agent for hand, foot and mouth disease (HFMD) have been developed. Here we examined the potential of improving the vaccines by inserting the EV71 5’ untranslated region (5’ UTR) containing the full length internal ribosome entry site (IRES) sequence to the EV71 VP1-based DNA vaccine constructs. Four vaccine constructs designated as 5’ UTR-VP1/EGFP, VP1/EGFP, 5’ UTR-VP1/pVAX and VP1/pVAX, were designed using the pEGFP-N1 and pVAX-1 expression vectors, respectively. Transfection of Vero cells with the vaccine constructs with the 5’-UTR (5’-UTR-VP1/EGFP and 5’ UTR-VP1/pVAX) resulted in higher percentages of cells expressing the recombinant protein in comparison to cells transfected with vectors without the 5’-UTR (67% and 57%, respectively). Higher IgG responses (29%) were obtained from mice immunized with the DNA vaccine construct with the full length 5’ UTR. The same group of mice when challenged with life EV71 produced significantly higher neutralizing antibody (NAb) titers (>5-fold). These results suggest that insertion of the EV71 5’ UTR sequence consisting of the full length IRES to the EV71 DNA vaccine constructs improved the efficacy of the constructs with enhanced elicitation of the neutralizing antibody responses.展开更多
The decoding release factor （RF） triggers termination of protein synthesis by functionally mimicking a tRNA to span the decoding centre and the peptidyl transferase centre （PTC） of the ribosome. Structurally, it m...The decoding release factor （RF） triggers termination of protein synthesis by functionally mimicking a tRNA to span the decoding centre and the peptidyl transferase centre （PTC） of the ribosome. Structurally, it must fit into a site crafted for a tRNA and surrounded by five other RNAs, namely the adjacent peptidyl tRNA carrying the completed polypeptide, the mRNA and the three rRNAs. This is achieved by extending a structural domain from the body of the protein that results in a critical conformational change allowing it to contact the PTC. A structural model of the bacterial termination complex with the accommodated RF shows that it makes close contact with the first, second and third bases of the stop codon in the mRNA with two separate loops of structure＂ the anticodon loop and the loop at the tip of helix orS. The anticodon loop also makes contact with the base following the stop codon that is known to strongly influence termination efficiency. It confirms the close contact of domain 3 of the protein with the key RNA structures of the PTC. The mRNA signal for termination includes sequences upstream as well as downstream of the stop codon, and this may reflect structural restrictions for specific combinations of tRNA and RF to be bound onto the ribosome together. An unbiased SELEX approach has been investigated as a tool to identify potential rRNA-binding contacts of the bacterial RF in its different binding conformations within the active centre of the ribosome.展开更多
Genomic DNA for Jatropha curcas ribosome inactivating protein （JRIP） was cloned from total DNA of its leaves by polymerase chain reaction （PCR）. The no intron character was confirmed. The plant expression vector p...Genomic DNA for Jatropha curcas ribosome inactivating protein （JRIP） was cloned from total DNA of its leaves by polymerase chain reaction （PCR）. The no intron character was confirmed. The plant expression vector pBI121-JRIP was constructed by inserting the JRIP gene into pBI121 plasmid. The recombinant Agrobacterium EHA105 strain harboring pBI121-JRIP was constructed by conducting pBI121-JRIP to strain EHA 105. PCR and Southern blotting were carried out, and the results proved that the JRIP gene was integrated into tobacco genome. It might provide a new material for disease resistance tobacco species breeding.展开更多
Elongation factor 4（EF4） is one of the highly conserved translational GTPases, whose functions are largely unknown. Structures of EF4 bound ribosomal PRE-translocation and POST-translocation complexes have both been...Elongation factor 4（EF4） is one of the highly conserved translational GTPases, whose functions are largely unknown. Structures of EF4 bound ribosomal PRE-translocation and POST-translocation complexes have both been visualized. On top of cellular, structural, and biochemical studies, several controversial models have been raised to rationalize functions of EF4. However, how EF4 modulates elongation through its interactions with ribosomes has not been revealed. Here, using single-molecule fluorescence resonance energy transfer assays, we directly captured short-lived EF4·GTP bound ribosomal PRE and POST translocation complexes, which may adopt slightly different conformations from structures prepared using GDP, GDPNP, or GDPCP. Furthermore, we revealed that EF4·GTP severely impairs delivery of aminoacyl-tRNA into the A-site of the ribosome and moderately accelerates translocation. We proposed that functions of EF4 are to slow overall elongation and to stall majority of ribosomes in POST states under stress conditions.展开更多
In the present experiments the changes in levels of ribosome,polysome and 3H-leucine incorporation rate in liver post-mitochondrial supernatant (PM-supernatant) were investigated in Sedericient and Se-supplented rats....In the present experiments the changes in levels of ribosome,polysome and 3H-leucine incorporation rate in liver post-mitochondrial supernatant (PM-supernatant) were investigated in Sedericient and Se-supplented rats.The results demonstrated that the amounts of ribosome and polysome as well as the ratio of polysome to ribosome in liver PM-supernatant from the Se-deficient rats were all remarkahly decreased.In the meantime,the rate of protein synthesis expressed as radioactivity or 3H-leucine incorporated into protein in the PM-supernatant system also decreased significantly.The results suggest that the decreases of ribosomes and proportion of ribosomal aggregates in PM-supernatant may be responsible for the decrease of the protein synthesis activity in liver of the Se-deficient animals.展开更多
LepA, the highly conserved translational GTPase (trGTPase), triggers one-codon back-movement of the elongating ribosome. Here we identify a new enzymatic activity
AIM: To investigate the subcellular localization and the function of mouse transducin β-like 3(Tbl3).METHODS: The coding sequence of mouse Tbl3 was cloned from the c DNAs of a promyelocyte cell line by reverse transc...AIM: To investigate the subcellular localization and the function of mouse transducin β-like 3(Tbl3).METHODS: The coding sequence of mouse Tbl3 was cloned from the c DNAs of a promyelocyte cell line by reverse transcription-polymerase chain reaction. Fusion constructs of Tbl3 and enhanced green fluorescent protein(EGFP) were transfected into fibroblasts and examined by fluorescence microscopy to reveal the subcellular localization of tbl3. To search for nucleolar targeting sequences, scanning deletions of Tbl3-EGFP were constructed and transfected into fibroblasts. To explore the possible function of Tbl3, small hairpin RNAs(sh RNAs) were used to knock down endogenous Tbl3 in mouse promyelocytes and fibroblasts. The effects of Tbl3 knockdown on ribosomal RNA(r RNAs) synthesis or processing were studied by labeling cells with 5,6-3H-uridine followed by a chase with fresh medium for various periods. Total RNAs were purified from treated cells and subjected to gel electrophoresis and Northern analysis. Ribosome profiling by sucrose gradient centrifugation was used to compare the amounts of 40 S and 60 S ribosome subunits as well as the 80 S monosome. The impact of Tbl3 knockdown on cell growth and proliferation was examined by growth curves and colony assays.RESULTS: The largest open reading frame of mouse Tbl3 encodes a protein of 801 amino acids(AA) with an apparent molecular weight of 89-90 kilodalton. It contains thirteen WD40 repeats(an ancient protein-protein interaction motif) and a carboxyl terminus that is highly homologous to the corresponding region of the yeast nucleolar protein, utp13. Virtually nothing is known about the biological function of Tbl3. All cell lines surveyed expressed Tbl3 and the level of expression correlated roughly with cell proliferation and/or biosynthetic activity. Using Tbl3-EGFP fusion constructs we obtained the first direct evidence that Tbl3 is targeted to the nucleoli in mammalian cells. However, no previously described nucleolar targeting sequences were found in Tbl3, suggesting that the WD40 motif and/or other topological features are responsible for nucleolar targeting. Partial knockdown(by 50%-70%) of mouse Tbl3 by shR NA had no discernable effects on the processing of the 47 S pre-ribosomal RNA(pre-r RNA) or the steady-state levels of the mature 28 S, 18 S and 5.8S r RNAs but consistently increased the expression level of the 47 S pre-rR NA by two to four folds. The results of the current study corroborated the previous finding that there was no detectable rR NA processing defects in zebra fish embryos with homozygous deletions of zebra fish Tbl3. As ribosome production consumes the bulk of cellular energy and biosynthetic precursors, dysregulation of pre-rR NA synthesis can have negative effects on cell growth, proliferation and differentiation. Indeed, partial knockdown of Tbl3 in promyelocytes severely impaired their proliferation. The inhibitory effect of Tbl3 knockdown was also observed in fibroblasts, resulting in an 80% reduction in colony formation. Taken together, these results indicate that Tbl3 is a newly recognized nucleolar protein with regulatory roles at very early stages of ribosome biogenesis, perhaps at the level of rR NA gene transcription. CONCLUSION: Tbl3 is a newly recognized nucleolar protein with important regulatory roles in ribosome biogenesis.展开更多
Ribosome biogenesis is a multi-step process that initiates within the nucleolus,terminates in the cytoplasm,and determines the rate of protein synthesis.Ribosome biogenesis is essential for maintaining liver function....Ribosome biogenesis is a multi-step process that initiates within the nucleolus,terminates in the cytoplasm,and determines the rate of protein synthesis.Ribosome biogenesis is essential for maintaining liver function.In eukaryotes,it involves producing and assembling approximately 200 factors and 80 ribosomal proteins.Mutations in ribosome proteins,ribosomal RNA processing,and ribosome assembly factors in the liver can result in liver disease.Hepatitis C virus causes acute or chronic infection and liver disease,which can progress to liver cirrhosis,cancer,and death.This review provides an overview of the effects of ribosomal biogenesis,including ribosomal RNA,ribosomal proteins,and ribosome biogenesis factors,on liver regeneration,hepatitis C virus,nonalcoholic fatty liver disease,liver fibrosis,cirrhosis,and liver cancer.It lists drugs that exploit ribosome biogenesis to treat liver cancer.Targeting ribosome biogenesis shows promise as a therapeutic approach.A better understanding of this process will contribute to developing effective and targeted therapeutic strategies for ribosome biogenesis disorders.展开更多
The roles of concealed microproteins encoded by long noncoding RNAs(lncRNAs)are gradually being exposed,but their functions in tumorigenesis are still largely unclear.Here,we identify and characterize a conserved 99-a...The roles of concealed microproteins encoded by long noncoding RNAs(lncRNAs)are gradually being exposed,but their functions in tumorigenesis are still largely unclear.Here,we identify and characterize a conserved 99-amino acid microprotein named KRASIM that is encoded by the putative lncRNA NCBP2-AS2.KRASIM is differentially expressed in normal hepatocytes and hepatocellular carcinoma(HCC)cells and can suppress HCC cell growth and proliferation.Mechanistically,KRASIM interacts and colocalizes with the KRAS protein in the cytoplasm of human HuH-7 hepatoma cells.More importantly,the overexpression of KRASIM decreases the KRAS protein level,leading to the inhibition of ERK signaling activity in HCC cells.These results demonstrate a novel microprotein repressor of the KRAS pathway for the first time and provide new insights into the regulatory mechanisms of oncogenic signaling and HCC therapy.展开更多
Dear Editor,Streptomyces can produce a large variety of secondary metabolites as a major source of anti-infective, antitumor or immune-suppressive agents widely applied in clinical treatment. Antibiotics-resistant bac...Dear Editor,Streptomyces can produce a large variety of secondary metabolites as a major source of anti-infective, antitumor or immune-suppressive agents widely applied in clinical treatment. Antibiotics-resistant bacteria are spreading at alarming rates.展开更多
A new ribosome-inactivating protein （RIP） with a molecular weight of 31 kDa induced by Cinchonaglycoside C （1） designated CIP31, was isolated from tobacco leaves. Analysis of this protein sequence indicated that i...A new ribosome-inactivating protein （RIP） with a molecular weight of 31 kDa induced by Cinchonaglycoside C （1） designated CIP31, was isolated from tobacco leaves. Analysis of this protein sequence indicated that it belongs to the RIP family and it was distinct from the other plant RIPs reported previously at its N-terminal amino acid sequence. CIP31 can directly impair synthesis of coat protein （CP） of tobacco mosaic virus （TMV）, which resulted in inhibition of TMV long distance movement and multiplication in tobacco plants at concentrations of ng/mL. Furthermore, no toxicity was shown to the growth and fertility of the plants. CIP31 was synthesized only in the presence of Cinchonaglycoside C （1） and was independent of the salicylic acid （SA） signal pathway. We provided evidence for the SA-independent biological induction of resistance.展开更多
基金supported by National Natural Science Foundation of China(82472473,81991510,81991511 and 81820108020)Major Scientific Research Project of Health in Fujian Province(20212D01003)+3 种基金Fujian Province Joint Fund Project for Science and Technology Innovation(2021Y9023,2023Y9601)China Postdoctoral Science Foundation(2022M710702)Fujian Provincial Natural Science Foundation Projects(2023J01177,2023J011209,2023J01172)Fujian Provincial Health Technology Project(2023GGA004)。
文摘Osteoclast-development patterns and their alterations across Ankylosing Spondylitis(AS)conditions are mysterious,making AS treatment difficult.Our study aims to clarify osteoclast-precursor(OCP)development patterns from monocytes and their variations under AS conditions.We performed single-cell transcriptomics in peripheral blood mononuclear cells(PBMCs)from healthy donors and AS patients in the early,aggravated and remission stages.After monocytic reclustering,OCP-development patterns and the alterations upon AS onset and different outcomes were revealed based on single-cell trajectory.The trajectories revealed two monocyte states with strong OCP features,and AS pathogenesis was characterized by their reduction.Ribosome synthesis was considered the essential function for the development towards OCP-featured states,and this function and its representative molecule,RPS17,showed a decreasing trend with AS onset and outcomes.Histology assessment showed that RPS17underexpression participated in AS inflammatory osteogenesis and ankylosing destruction.Conditional knockout of RPS17ameliorated ovariectomy-induced bone loss and enhanced osteoclastogenesis,and RPS17 overexpression improved the phenotype of AS-like mice.Importantly,local injection of RPS17-overexpressed monocytic OCPs markedly ameliorated the joint alterations of AS-like mice without promoting bone loss;this was associated with enhanced osteoclastogenesis adjacent to the articular surface and T-cell-suppressive property in monocytic OCPs.Overall,the evolution of monocytes towards OCP-lineage fate mainly depends on ribosome synthesis,and OCP-development disorder participates in AS lesions due to a reduction in RPS17-dependent ribosome synthesis.Notably,RPS17-overexpressed monocytic OCPs have translational potential in preventing and treating AS peripheral lesions.
基金supported by the Department of Agriculture and Rural Affairs of Jiangxi Province,China (JXARS-09)Science and Technology Program of Guangdong Province,China (2020B1212060060)。
文摘Pigeons and certain other avian species produce a milklike secretion in their crop sacs to nourish offspring,yet the detailed processes involved are not fully elucidated.This study investigated the crop sacs of 225-day-old unpaired non-lactating male pigeons(MN)and males initiating lactation on the first day after incubation(ML).Using RNA sequencing,ribosomeprofiling,andsingle-cell transcriptome sequencing(scRNA-seq),we identified a significant up-regulation of genes associated with ribosome assembly and protein synthesis in ML compared to MN.Results from scRNA-seq analysis identified 12distinct cell types and 22 clusters,with secretory epithelial cells(SECs)exhibiting marked expression of plasma cell markers,including IGLL1 and MZB1.RNA fluorescence in situ hybridization(RNA FISH)and IgY quantification confirmed the critical role of SECs in producing endogenous IgY during lactation.We propose that fibroblast-derived BAFF signals activate SECs,mimicking B cell transformation and enhancing protein production through the unfolded protein response(UPR).These findings shed light on the cellular dynamics of pigeon milk production and contribute to a broader understanding of avian biology.
基金supported by the Ten-thousand Talents Plan of Zhejiang Province(No.2022R52021)the Key Research and Development Program of Zhejiang Province(No.2021C04016)the Pioneer and Leading Goose R&D Program of Zhejiang(No.2022C04020),China.
文摘Soybean meal(SBM)prepared by soybean crushing is the most popular protein source in the poultry and livestock industries(Cai et al.,2015)due to its economic manufacture,high protein content,and good nutritional value.Despite these benefits,SBM contains various antigen proteins such as glycinin andβ-conglycinin,which account for approximately 70%of the total proteins of the SBM and reduce digestibility and damage intestinal function(Peng et al.,2018).
基金supported by the National Natural Science Foundation of China(32270564 to P.Y.,82394422 to X.J.L.,82371178 to B.L.)Guangdong Basic and Applied Basic Research(2022A1515011205 and 2023A1515010811 to P.Y.,2021ZT09Y007 and 2018B030337001 to X.J.L.)。
文摘Cytoplasmic accumulation of TDP-43 is a pathological hallmark of amyotrophic lateral sclerosis(ALS)and other neurodegenerative diseases.While current studies have primarily focused on gene regulation mediated by full-length nuclear TDP-43,the potential effects of cytoplasmic TDP-43 fragments remain less explored.Our previous findings demonstrated that primate-specific cleavage of TDP-43 contributes to its cytoplasmic localization,prompting further investigation into its pathological effects.In the cynomolgus monkey brain,we observed that mutant or truncated TDP-43 was transported onto the ribosome organelle.Ribosome-associated transcriptomic analysis revealed dysregulation of apoptosis-and lysosome-related genes,indicating that cytoplasmic TDP-43 induces neurotoxicity by binding to ribosomes and disrupting mRNA expression.These findings provide mechanistic insights into the gain-of-function effects of pathological TDP-43.
基金supported by the grants from National Natural Science Foundation of China (Nos. 61571223 and 61171191)
文摘In eukaryotic cells, initiation of protein translation is to recruit the ribosome to a specific mRNA, which is generally dependent on the 5＇ cap structure. However, protein translation can also be initiated in a cap-independent manner by using a cis-regulatory element termed the internal ribosome entry site （IRES）. The first experimentally validated IRES was reported in the poliovirus （Pelletier and Sonenberg, 1988）. Then eukaryotic cellular mRNAs were also validated to contain IRES elements.
基金Indo-Swiss Joint research Program (ISJRP)#17/2011
文摘Many plants contain ribosome inactivating proteins (RIPs) with N-glycosidase activity, which depurinate large ribosomal RNA and arrest protein synthesis. RIPs so far tested inhibit replication of mRNA as well as DNA viruses and these proteins, isolated from plants, are found to be effective against a broad range of viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV). Most of the research work related to RIPs has been focused on antiviral activity against HIV; however, the exact mechanism of antiviral activity is still not clear. The mechanism of antiviral activity was thought to follow inactivation of the host cell ribosome, leading to inhibition of viral protein translation and host cell death. Enzymatic activity of RIPs is not limited to depurination of the large rRNA, in addition they can depurinate viral DNA as well as RNA. Recently, Phase I/II clinical trials have demonstrated the potential use of RIPs for treating patients with HIV disease. The aim of this review is to focus on various RIPs from plants associated with anti-HIV activity.
基金supported by the National Key Basic Research Program of China(2015CB942800)the National Natural Science Foundation of China(Nos.31330051 and 31730060)+2 种基金the 111 Program(B14037)the Natural Science Foundation Project of Chongqing(cstc2014jcyj A10088)the Fundamental Research Funds for the Central Universities(XDJK2015B011)
文摘Ribosome biogenesis is essential for the cell growth and division. Disruptions in ribosome biogenesis result in developmental defects and a group of diseases, known as ribosomopathies. Here, we report a mutation in zebrafish urb1, which encodes an essential ribosome biogenesis protein. The urb1 cq31 mutant exhibits hypoplastic digestive organs, which is caused by impaired cell proliferation with the differentiation of digestive organ progenitors unaffected. Knockdown of mtor or raptor leads to similar hypoplastic phenotypes and reduced expression of urb1 in the digestive organs. Overexpression of Urb1 results in overgrowth of digestive organs, and can efficiently rescue the hypoplastic liver and pancreas in the mtor and raptor morphants. Reduced syntheses of free ribosomal subunits and impaired assembly of polysomes are observed in the urb1 mutant as well as in the mtor and raptor morphants, which can be rescued by the Urb1 overexpression. These data demonstrate that Urb1 plays an important role in governing ribosome biogenesis and protein synthesis downstream of mammalian/mechanistic target of rapamycin complex 1（mTORC1）, thus regulating the development of digestive organs. Our study indicates the requirement of hyperactive protein synthesis for the digestive organ development.
文摘Gene therapy appears as a promising strategy to treatincurable diseases. In particular, combined gene therapy has shown improved therapeutic efficiency. Internal ribosome entry sites(IRESs), RNA elements naturally present in the 5' untranslated regions of a few m RNAs, constitute a powerful tool to co-express several genes of interest. IRESs are translational enhancers allowing the translational machinery to start protein synthesis by internal initiation. This feature allowed the design of multi-cistronic vectors expressing several genes from a single m RNA. IRESs exhibit tissue specificity, and drive translation in stress conditions when the global cell translation is blocked, which renders them useful for gene transfer in hypoxic conditions occurring in ischemic diseases and cancer. IRES-based viral and non viral vectors have been used successfully in preclinical and clinical assays of combined gene therapy and resulted in therapeutic benefits for various pathologies including cancers, cardiovascular diseases and degenerative diseases.
基金supported by the grants from the National Natural Science Foundation of China(NSFC)(No.31171391) to LJLan NSFC grant(No. 30825025) to JRP and a grant from the National Research Foundation of Singapore(R-154-000-529-281) to YHH
文摘Ribosome biogenesis in the nucleolus requires numerous nucleolar proteins and small non-coding RNAs.Among them is ribosome biogenesis factor Bmsl,which is highly conserved from yeast to human.In yeast,Bmsl initiates ribosome biogenesis through recruiting Rcll to pre-ribosomes.However,little is known about the biological function of Bmsl in vertebrates.Here we report that Bmsl plays an essential role in zebrafish liver development.We identified a zebrafish bms1l^（sq163） mutant which carries a T to A mutation in the gene bmsl-like（bms1l）.This mutation results in L^（152） to Q^（152） substitution in a GTPase motif in Bmsll.Surprisingly,bmsll^（sq163） mutation confers hypoplasia specifically in the liver,exocrine pancreas and intestine after 3 days post-fertilization（dpf）.Consistent with the bmsll^（sq163） mutant phenotypes,whole-mount in situ hybridization（WISH） on wild type embryos showed that bmsll transcripts are abundant in the entire digestive tract and its accessory organs.Immunostaining for phospho-Histone 3（P-H3） and TUNEL assay revealed that impairment of hepatoblast proliferation rather than cell apoptosis is one of the consequences of bms1l（sq163） giving rise to an under-developed liver.Therefore,our findings demonstrate that Bmsll is necessary for zebrafish liver development.
文摘Recent improvement in the technologies for efficient delivery of DNA vaccines has renewed interest in the DNA-based vaccines. Several DNA-based vaccines against human enterovirus 71 (EV71), the causative agent for hand, foot and mouth disease (HFMD) have been developed. Here we examined the potential of improving the vaccines by inserting the EV71 5’ untranslated region (5’ UTR) containing the full length internal ribosome entry site (IRES) sequence to the EV71 VP1-based DNA vaccine constructs. Four vaccine constructs designated as 5’ UTR-VP1/EGFP, VP1/EGFP, 5’ UTR-VP1/pVAX and VP1/pVAX, were designed using the pEGFP-N1 and pVAX-1 expression vectors, respectively. Transfection of Vero cells with the vaccine constructs with the 5’-UTR (5’-UTR-VP1/EGFP and 5’ UTR-VP1/pVAX) resulted in higher percentages of cells expressing the recombinant protein in comparison to cells transfected with vectors without the 5’-UTR (67% and 57%, respectively). Higher IgG responses (29%) were obtained from mice immunized with the DNA vaccine construct with the full length 5’ UTR. The same group of mice when challenged with life EV71 produced significantly higher neutralizing antibody (NAb) titers (>5-fold). These results suggest that insertion of the EV71 5’ UTR sequence consisting of the full length IRES to the EV71 DNA vaccine constructs improved the efficacy of the constructs with enhanced elicitation of the neutralizing antibody responses.
文摘The decoding release factor （RF） triggers termination of protein synthesis by functionally mimicking a tRNA to span the decoding centre and the peptidyl transferase centre （PTC） of the ribosome. Structurally, it must fit into a site crafted for a tRNA and surrounded by five other RNAs, namely the adjacent peptidyl tRNA carrying the completed polypeptide, the mRNA and the three rRNAs. This is achieved by extending a structural domain from the body of the protein that results in a critical conformational change allowing it to contact the PTC. A structural model of the bacterial termination complex with the accommodated RF shows that it makes close contact with the first, second and third bases of the stop codon in the mRNA with two separate loops of structure＂ the anticodon loop and the loop at the tip of helix orS. The anticodon loop also makes contact with the base following the stop codon that is known to strongly influence termination efficiency. It confirms the close contact of domain 3 of the protein with the key RNA structures of the PTC. The mRNA signal for termination includes sequences upstream as well as downstream of the stop codon, and this may reflect structural restrictions for specific combinations of tRNA and RF to be bound onto the ribosome together. An unbiased SELEX approach has been investigated as a tool to identify potential rRNA-binding contacts of the bacterial RF in its different binding conformations within the active centre of the ribosome.
基金Project supported by Tenth Five Years Key Program Foundation of the State Science and Technology Commission of China (GrantNo .2002BA901A15)
文摘Genomic DNA for Jatropha curcas ribosome inactivating protein （JRIP） was cloned from total DNA of its leaves by polymerase chain reaction （PCR）. The no intron character was confirmed. The plant expression vector pBI121-JRIP was constructed by inserting the JRIP gene into pBI121 plasmid. The recombinant Agrobacterium EHA105 strain harboring pBI121-JRIP was constructed by conducting pBI121-JRIP to strain EHA 105. PCR and Southern blotting were carried out, and the results proved that the JRIP gene was integrated into tobacco genome. It might provide a new material for disease resistance tobacco species breeding.
基金supported by funds from the National Natural Science Foundation of China (No. 31570754)Tsinghua-Peking Joint Center for Life Sciences and Beijing Advanced Innovation Center for Structural Biology to C. ChenLab Innovation Funding from Lab and Instrument Department, Tsinghua University to W. Wang
文摘Elongation factor 4（EF4） is one of the highly conserved translational GTPases, whose functions are largely unknown. Structures of EF4 bound ribosomal PRE-translocation and POST-translocation complexes have both been visualized. On top of cellular, structural, and biochemical studies, several controversial models have been raised to rationalize functions of EF4. However, how EF4 modulates elongation through its interactions with ribosomes has not been revealed. Here, using single-molecule fluorescence resonance energy transfer assays, we directly captured short-lived EF4·GTP bound ribosomal PRE and POST translocation complexes, which may adopt slightly different conformations from structures prepared using GDP, GDPNP, or GDPCP. Furthermore, we revealed that EF4·GTP severely impairs delivery of aminoacyl-tRNA into the A-site of the ribosome and moderately accelerates translocation. We proposed that functions of EF4 are to slow overall elongation and to stall majority of ribosomes in POST states under stress conditions.
文摘In the present experiments the changes in levels of ribosome,polysome and 3H-leucine incorporation rate in liver post-mitochondrial supernatant (PM-supernatant) were investigated in Sedericient and Se-supplented rats.The results demonstrated that the amounts of ribosome and polysome as well as the ratio of polysome to ribosome in liver PM-supernatant from the Se-deficient rats were all remarkahly decreased.In the meantime,the rate of protein synthesis expressed as radioactivity or 3H-leucine incorporated into protein in the PM-supernatant system also decreased significantly.The results suggest that the decreases of ribosomes and proportion of ribosomal aggregates in PM-supernatant may be responsible for the decrease of the protein synthesis activity in liver of the Se-deficient animals.
文摘LepA, the highly conserved translational GTPase (trGTPase), triggers one-codon back-movement of the elongating ribosome. Here we identify a new enzymatic activity
基金Supported by In part by a grant from the St.Perres Fund,No.11-02011
文摘AIM: To investigate the subcellular localization and the function of mouse transducin β-like 3(Tbl3).METHODS: The coding sequence of mouse Tbl3 was cloned from the c DNAs of a promyelocyte cell line by reverse transcription-polymerase chain reaction. Fusion constructs of Tbl3 and enhanced green fluorescent protein(EGFP) were transfected into fibroblasts and examined by fluorescence microscopy to reveal the subcellular localization of tbl3. To search for nucleolar targeting sequences, scanning deletions of Tbl3-EGFP were constructed and transfected into fibroblasts. To explore the possible function of Tbl3, small hairpin RNAs(sh RNAs) were used to knock down endogenous Tbl3 in mouse promyelocytes and fibroblasts. The effects of Tbl3 knockdown on ribosomal RNA(r RNAs) synthesis or processing were studied by labeling cells with 5,6-3H-uridine followed by a chase with fresh medium for various periods. Total RNAs were purified from treated cells and subjected to gel electrophoresis and Northern analysis. Ribosome profiling by sucrose gradient centrifugation was used to compare the amounts of 40 S and 60 S ribosome subunits as well as the 80 S monosome. The impact of Tbl3 knockdown on cell growth and proliferation was examined by growth curves and colony assays.RESULTS: The largest open reading frame of mouse Tbl3 encodes a protein of 801 amino acids(AA) with an apparent molecular weight of 89-90 kilodalton. It contains thirteen WD40 repeats(an ancient protein-protein interaction motif) and a carboxyl terminus that is highly homologous to the corresponding region of the yeast nucleolar protein, utp13. Virtually nothing is known about the biological function of Tbl3. All cell lines surveyed expressed Tbl3 and the level of expression correlated roughly with cell proliferation and/or biosynthetic activity. Using Tbl3-EGFP fusion constructs we obtained the first direct evidence that Tbl3 is targeted to the nucleoli in mammalian cells. However, no previously described nucleolar targeting sequences were found in Tbl3, suggesting that the WD40 motif and/or other topological features are responsible for nucleolar targeting. Partial knockdown(by 50%-70%) of mouse Tbl3 by shR NA had no discernable effects on the processing of the 47 S pre-ribosomal RNA(pre-r RNA) or the steady-state levels of the mature 28 S, 18 S and 5.8S r RNAs but consistently increased the expression level of the 47 S pre-rR NA by two to four folds. The results of the current study corroborated the previous finding that there was no detectable rR NA processing defects in zebra fish embryos with homozygous deletions of zebra fish Tbl3. As ribosome production consumes the bulk of cellular energy and biosynthetic precursors, dysregulation of pre-rR NA synthesis can have negative effects on cell growth, proliferation and differentiation. Indeed, partial knockdown of Tbl3 in promyelocytes severely impaired their proliferation. The inhibitory effect of Tbl3 knockdown was also observed in fibroblasts, resulting in an 80% reduction in colony formation. Taken together, these results indicate that Tbl3 is a newly recognized nucleolar protein with regulatory roles at very early stages of ribosome biogenesis, perhaps at the level of rR NA gene transcription. CONCLUSION: Tbl3 is a newly recognized nucleolar protein with important regulatory roles in ribosome biogenesis.
基金supported by the National Natural Science Foundation of China(No.82272421)the Changzhou's 14th Five-Year Plan Project to Train High-Level Health Professionals(Jiangsu,China)(No.2022CZLJ027)+1 种基金Changzhou Special Program for the Introduction of Foreign Talents(No.CQ20240052)Open project of Jiangsu Provincial Key Laboratory of Key Laboratory of Laboratory Medicine(No.JSKLM-Z-2024-001,JSKLM-Z-2024-002).
文摘Ribosome biogenesis is a multi-step process that initiates within the nucleolus,terminates in the cytoplasm,and determines the rate of protein synthesis.Ribosome biogenesis is essential for maintaining liver function.In eukaryotes,it involves producing and assembling approximately 200 factors and 80 ribosomal proteins.Mutations in ribosome proteins,ribosomal RNA processing,and ribosome assembly factors in the liver can result in liver disease.Hepatitis C virus causes acute or chronic infection and liver disease,which can progress to liver cirrhosis,cancer,and death.This review provides an overview of the effects of ribosomal biogenesis,including ribosomal RNA,ribosomal proteins,and ribosome biogenesis factors,on liver regeneration,hepatitis C virus,nonalcoholic fatty liver disease,liver fibrosis,cirrhosis,and liver cancer.It lists drugs that exploit ribosome biogenesis to treat liver cancer.Targeting ribosome biogenesis shows promise as a therapeutic approach.A better understanding of this process will contribute to developing effective and targeted therapeutic strategies for ribosome biogenesis disorders.
基金This work was supported by the National Key Research and Development Program of China(2017YFA0504400)the National Natural Science Foundation of China(31370791,31671349,31770879)+2 种基金Fundamental Research Funds for the Central Universities(14lgjc18)This research was supported in part by the Guangdong Province Key Laboratory of Computational Science(13lgjc05)the Guangdong Province Computational Science Innovative Research Team(14lgjc18).
文摘The roles of concealed microproteins encoded by long noncoding RNAs(lncRNAs)are gradually being exposed,but their functions in tumorigenesis are still largely unclear.Here,we identify and characterize a conserved 99-amino acid microprotein named KRASIM that is encoded by the putative lncRNA NCBP2-AS2.KRASIM is differentially expressed in normal hepatocytes and hepatocellular carcinoma(HCC)cells and can suppress HCC cell growth and proliferation.Mechanistically,KRASIM interacts and colocalizes with the KRAS protein in the cytoplasm of human HuH-7 hepatoma cells.More importantly,the overexpression of KRASIM decreases the KRAS protein level,leading to the inhibition of ERK signaling activity in HCC cells.These results demonstrate a novel microprotein repressor of the KRAS pathway for the first time and provide new insights into the regulatory mechanisms of oncogenic signaling and HCC therapy.
基金supported by grants from the Ministry of Science and Technology of China (2015CB150600)the National Natural Science Foundation of China (31571281 and 31771378)
文摘Dear Editor,Streptomyces can produce a large variety of secondary metabolites as a major source of anti-infective, antitumor or immune-suppressive agents widely applied in clinical treatment. Antibiotics-resistant bacteria are spreading at alarming rates.
基金the NationaI NaturaI Science Foundation of China(30370957)the NaturaI Science Foundation of Yunnan Province(2003C0061M).
文摘A new ribosome-inactivating protein （RIP） with a molecular weight of 31 kDa induced by Cinchonaglycoside C （1） designated CIP31, was isolated from tobacco leaves. Analysis of this protein sequence indicated that it belongs to the RIP family and it was distinct from the other plant RIPs reported previously at its N-terminal amino acid sequence. CIP31 can directly impair synthesis of coat protein （CP） of tobacco mosaic virus （TMV）, which resulted in inhibition of TMV long distance movement and multiplication in tobacco plants at concentrations of ng/mL. Furthermore, no toxicity was shown to the growth and fertility of the plants. CIP31 was synthesized only in the presence of Cinchonaglycoside C （1） and was independent of the salicylic acid （SA） signal pathway. We provided evidence for the SA-independent biological induction of resistance.
