A full-length cDNA encoding translationally controlled tumor protein of marine flatfish turbot （Scophthalmus maximus）, SmTCTP, was isolated with rapid amplification of cDNA Ends （RACE）. SmTCTP consisted of a 5＇ u...A full-length cDNA encoding translationally controlled tumor protein of marine flatfish turbot （Scophthalmus maximus）, SmTCTP, was isolated with rapid amplification of cDNA Ends （RACE）. SmTCTP consisted of a 5＇ untranslated region （UTR） of 84 bp, a 3＇ UTR of 451 bp and an open reading frame （ORF） of 513 bp, encoding a protein of 170 amino acid residues, which contained two signature sequences of TCTP family. The 5＇UTR of SmTCTP started with a 5＇-terminal oligopyrimidine tract （5＇-TOP）, a typical feature for translationally controlled mRNAs. The deduced amino acid sequence of SmTCTP was similar to the other known vertebrate TCTPs in a range of 58.8% to 64.1%. The length of fish TCTPs was diverse among species, e.g., TCTP of turbot and sea perch （Lateolabraxjaponicus） is 170 aa in length, while that of zebrafish （Danio rerio） and rohu （Labeo rohita） is 171 aa in length. Northern blot analysis revealed that SmTCTP has only one type of mRNA. Its expression level in albino skin was slightly higher than that in normal skin. We constructed the pET3Oa-SmTCTP expression plasmid. The recombinant protein of His-tag SmTCTP was over-expressed in E. coli, purified and identified with peptide mass fingerprinting. These results may pave the way of further investigation of the biological function of TCTP in fish.展开更多
Translationally controlled tumor protein(TCTP) is a highly conserved multifunctional protein localized in the cytoplasm and nucleus of eukaryotic cells. It is secreted through exosomes and its degradation is associate...Translationally controlled tumor protein(TCTP) is a highly conserved multifunctional protein localized in the cytoplasm and nucleus of eukaryotic cells. It is secreted through exosomes and its degradation is associated with the ubiquitin-proteasome system(UPS), heat shock protein 27(Hsp27), and chaperone-mediated autophagy(CMA). Its structure contains three α-helices and eleven β-strands, and features a helical hairpin as its hallmark. TCTP shows a remarkable similarity to the methionine-R-sulfoxide reductase B(Msr B) and mammalian suppressor of Sec4(Mss4/Dss4) protein families, which exerts guanine nucleotide exchange factor(GEF) activity on small guanosine triphosphatase(GTPase) proteins, suggesting that some functions of TCTP may at least depend on its GEF action. Indeed, TCTP exerts GEF activity on Ras homolog enriched in brain(Rheb) to boost the growth and proliferation of Drosophila cells. TCTP also enhances the expression of cell division control protein 42 homolog(Cdc42) to promote cancer cell invasion and migration. Moreover, TCTP regulates cytoskeleton organization by interacting with actin microfilament(MF) and microtubule(MT) proteins and inducing the epithelial-mesenchymal transition(EMT) process. In essence, TCTP promotes cancer cell movement. It is usually highly expressed in cancerous tissues and thus reduces patient survival;meanwhile, drugs can target TCTP to reduce this effect. In this review, we summarize the mechanisms of TCTP in promoting cancer invasion and migration, and describe the current inhibitory strategy to target TCTP in cancerous diseases.展开更多
Controlled gene regulation during gamete development is vital for maintaining reproductive potential. During the complex process of mammalian spermatogenesis, male germ cells experience extended periods of the inactiv...Controlled gene regulation during gamete development is vital for maintaining reproductive potential. During the complex process of mammalian spermatogenesis, male germ cells experience extended periods of the inactive transcription despite heavy translational requirements for continued growth and differentiation. Hence, spermatogenesis is highly reliant on mechanisms of posttranscriptional regulation of gene expression, facilitated by RNA binding proteins （RBPs）, which remain abundantly expressed throughout this process. One such group of proteins is the Musashi family, previously identified as critical regulators of testis germ cell development and meiosis in Drosophila, and also shown to be vital to sperm development and reproductive potential in the mouse. This review describes the role and function of RBPs our recent knowledge of the Musashi proteins in spermatogenesis. within the scope of male germ cell development, focusing on The functional mechanisms utilized by RBPs within the cell are outlined in depth, and the significance of sub-cellular localization and stage-specific expression in relation to the mode and impact of posttranscriptional regulation is also highlighted. We emphasize the historical role of the Musashi family of RBPs in stem cell function and cell fate determination, as originally characterized in Drosophila and Xenopus, and conclude with our current understanding of the differential roles and functions of the mammalian Musashi proteins, Musashi-1 and Musashi-2, with a primary focus on our findings in spermatogenesis. This review highlights both the essential contribution of RBPs to posttranscriptional regulation and the importance of the Musashi family as master regulators of male gamete development.展开更多
The eukaryotic transcription factor NF-Y consists of three subunits （A, B, and C）, which are encoded in Ara- bidopsis thaliana in multigene families consisting of 10, 13, and 13 genes, respectively. In principle, al...The eukaryotic transcription factor NF-Y consists of three subunits （A, B, and C）, which are encoded in Ara- bidopsis thaliana in multigene families consisting of 10, 13, and 13 genes, respectively. In principle, all potential combi- nations of the subunits are possible for the assembly of the heterotrimeric complex. We aimed at assessing the probability of each subunit to participate in the assembly of NF-Y. The evaluation of physical interactions among all members of the NF-Y subunit families indicate a strong requirement for NF-YB/NF-YC heterodimerization before the entire complex can be accomplished. By means of a modified yeast two-hybrid system assembly of all three subunits to a heterotrimeric complex was demonstrated. Using GFP fusion constructs, NF-YA and NF-YC localization in the nucleus was demonstrated, while NF- YB is solely imported into the nucleus as a NF-YC-associated heterodimer NF-YC. This piggyback transport of the two Arabidopsis subunits differs from the import of the NF-Y heterotrimer of heterotrophic organisms. Based on a peptide structure model of the histone-fold-motifs, disulfide bonding among intramolecular conserved cysteine residues of NF-YB, which is responsible for the redox-regulated assembly of NF-YB and NF-YC in human and Aspergillus nidulans, can be excluded for Arabidopsis NF-YB.展开更多
Glycogen synthase kinase 3(GSK3)signaling plays important and broad roles in regulating neural development in vitro and in vivo.Here,we reviewed recent findings of GSK3-regulated axon regeneration in vivo in both the ...Glycogen synthase kinase 3(GSK3)signaling plays important and broad roles in regulating neural development in vitro and in vivo.Here,we reviewed recent findings of GSK3-regulated axon regeneration in vivo in both the peripheral and central nervous systems and discussed a few controversial findings in the field.Overall,current evidence indicates that GSK3βsignaling serves as an important downstream mediator of the PI3K–AKT pathway to regulate axon regeneration in parallel with the mTORC1 pathway.Specifically,the mTORC1 pathway supports axon regeneration mainly through its role in regulating cap-dependent protein translation,whereas GSK3βsignaling might be involved in regulating N6-methyladenosine mRNA methylation-mediated,cap-independent protein translation.In addition,GSK3 signaling also plays a key role in reshaping the neuronal transcriptomic landscape during neuralregeneration.Finally,we proposed some research directions to further elucidate the molecular mechanisms underlying the regulatory function of GSK3 signaling and discover novel GSK3 signaling-related therapeutic targets.Together,we hope to provide an updated and insightful overview of how GSK3 signaling regulates neural regeneration in vivo.展开更多
文摘A full-length cDNA encoding translationally controlled tumor protein of marine flatfish turbot （Scophthalmus maximus）, SmTCTP, was isolated with rapid amplification of cDNA Ends （RACE）. SmTCTP consisted of a 5＇ untranslated region （UTR） of 84 bp, a 3＇ UTR of 451 bp and an open reading frame （ORF） of 513 bp, encoding a protein of 170 amino acid residues, which contained two signature sequences of TCTP family. The 5＇UTR of SmTCTP started with a 5＇-terminal oligopyrimidine tract （5＇-TOP）, a typical feature for translationally controlled mRNAs. The deduced amino acid sequence of SmTCTP was similar to the other known vertebrate TCTPs in a range of 58.8% to 64.1%. The length of fish TCTPs was diverse among species, e.g., TCTP of turbot and sea perch （Lateolabraxjaponicus） is 170 aa in length, while that of zebrafish （Danio rerio） and rohu （Labeo rohita） is 171 aa in length. Northern blot analysis revealed that SmTCTP has only one type of mRNA. Its expression level in albino skin was slightly higher than that in normal skin. We constructed the pET3Oa-SmTCTP expression plasmid. The recombinant protein of His-tag SmTCTP was over-expressed in E. coli, purified and identified with peptide mass fingerprinting. These results may pave the way of further investigation of the biological function of TCTP in fish.
基金funded by the National Natural Science Foundation of China(No.31672377)。
文摘Translationally controlled tumor protein(TCTP) is a highly conserved multifunctional protein localized in the cytoplasm and nucleus of eukaryotic cells. It is secreted through exosomes and its degradation is associated with the ubiquitin-proteasome system(UPS), heat shock protein 27(Hsp27), and chaperone-mediated autophagy(CMA). Its structure contains three α-helices and eleven β-strands, and features a helical hairpin as its hallmark. TCTP shows a remarkable similarity to the methionine-R-sulfoxide reductase B(Msr B) and mammalian suppressor of Sec4(Mss4/Dss4) protein families, which exerts guanine nucleotide exchange factor(GEF) activity on small guanosine triphosphatase(GTPase) proteins, suggesting that some functions of TCTP may at least depend on its GEF action. Indeed, TCTP exerts GEF activity on Ras homolog enriched in brain(Rheb) to boost the growth and proliferation of Drosophila cells. TCTP also enhances the expression of cell division control protein 42 homolog(Cdc42) to promote cancer cell invasion and migration. Moreover, TCTP regulates cytoskeleton organization by interacting with actin microfilament(MF) and microtubule(MT) proteins and inducing the epithelial-mesenchymal transition(EMT) process. In essence, TCTP promotes cancer cell movement. It is usually highly expressed in cancerous tissues and thus reduces patient survival;meanwhile, drugs can target TCTP to reduce this effect. In this review, we summarize the mechanisms of TCTP in promoting cancer invasion and migration, and describe the current inhibitory strategy to target TCTP in cancerous diseases.
文摘Controlled gene regulation during gamete development is vital for maintaining reproductive potential. During the complex process of mammalian spermatogenesis, male germ cells experience extended periods of the inactive transcription despite heavy translational requirements for continued growth and differentiation. Hence, spermatogenesis is highly reliant on mechanisms of posttranscriptional regulation of gene expression, facilitated by RNA binding proteins （RBPs）, which remain abundantly expressed throughout this process. One such group of proteins is the Musashi family, previously identified as critical regulators of testis germ cell development and meiosis in Drosophila, and also shown to be vital to sperm development and reproductive potential in the mouse. This review describes the role and function of RBPs our recent knowledge of the Musashi proteins in spermatogenesis. within the scope of male germ cell development, focusing on The functional mechanisms utilized by RBPs within the cell are outlined in depth, and the significance of sub-cellular localization and stage-specific expression in relation to the mode and impact of posttranscriptional regulation is also highlighted. We emphasize the historical role of the Musashi family of RBPs in stem cell function and cell fate determination, as originally characterized in Drosophila and Xenopus, and conclude with our current understanding of the differential roles and functions of the mammalian Musashi proteins, Musashi-1 and Musashi-2, with a primary focus on our findings in spermatogenesis. This review highlights both the essential contribution of RBPs to posttranscriptional regulation and the importance of the Musashi family as master regulators of male gamete development.
文摘The eukaryotic transcription factor NF-Y consists of three subunits （A, B, and C）, which are encoded in Ara- bidopsis thaliana in multigene families consisting of 10, 13, and 13 genes, respectively. In principle, all potential combi- nations of the subunits are possible for the assembly of the heterotrimeric complex. We aimed at assessing the probability of each subunit to participate in the assembly of NF-Y. The evaluation of physical interactions among all members of the NF-Y subunit families indicate a strong requirement for NF-YB/NF-YC heterodimerization before the entire complex can be accomplished. By means of a modified yeast two-hybrid system assembly of all three subunits to a heterotrimeric complex was demonstrated. Using GFP fusion constructs, NF-YA and NF-YC localization in the nucleus was demonstrated, while NF- YB is solely imported into the nucleus as a NF-YC-associated heterodimer NF-YC. This piggyback transport of the two Arabidopsis subunits differs from the import of the NF-Y heterotrimer of heterotrophic organisms. Based on a peptide structure model of the histone-fold-motifs, disulfide bonding among intramolecular conserved cysteine residues of NF-YB, which is responsible for the redox-regulated assembly of NF-YB and NF-YC in human and Aspergillus nidulans, can be excluded for Arabidopsis NF-YB.
文摘Glycogen synthase kinase 3(GSK3)signaling plays important and broad roles in regulating neural development in vitro and in vivo.Here,we reviewed recent findings of GSK3-regulated axon regeneration in vivo in both the peripheral and central nervous systems and discussed a few controversial findings in the field.Overall,current evidence indicates that GSK3βsignaling serves as an important downstream mediator of the PI3K–AKT pathway to regulate axon regeneration in parallel with the mTORC1 pathway.Specifically,the mTORC1 pathway supports axon regeneration mainly through its role in regulating cap-dependent protein translation,whereas GSK3βsignaling might be involved in regulating N6-methyladenosine mRNA methylation-mediated,cap-independent protein translation.In addition,GSK3 signaling also plays a key role in reshaping the neuronal transcriptomic landscape during neuralregeneration.Finally,we proposed some research directions to further elucidate the molecular mechanisms underlying the regulatory function of GSK3 signaling and discover novel GSK3 signaling-related therapeutic targets.Together,we hope to provide an updated and insightful overview of how GSK3 signaling regulates neural regeneration in vivo.
