Aim： To determine the possible roles of the t-complex testis expressed gene 5 （Tctex5） on sperm functions, the fulllength sequence of mRNA was studied and compared in the testis between the normal wild-type and the...Aim： To determine the possible roles of the t-complex testis expressed gene 5 （Tctex5） on sperm functions, the fulllength sequence of mRNA was studied and compared in the testis between the normal wild-type and the sterile t-haplotype mutant mice. Methods： We applied rapid amplification of cDNA ends, Northern blot and reverse transcription polymerase chain reaction to analyze the full length of Tctex5 mRNAs isolated from testes of the wild-type and the t-haplotype mice. Reverse transcription polymerase chain reaction was used to semi-quantitatively compare expression of Tctex5 transcripts in the 16 tissues and 9.5 day stage embryos in the wild-type mice. E-translation was applied to estimate the amino acid sequences. Results： One long and one short transcript of Tctex5 mRNA were discovered in mouse testis of wild-type （Tctex5^long-＋ and Tctex5^short-＋） and t-haplotype （Tctex5^long-＋ and Tctex5^short-＋） mice, respectively. Being enhanced only in the testis, Tctex5^long-＋ had 17 point mutations and one 15-bp-deletion in the exon 1 region, comparing with the Tctex5^long-＋, whereas the Tctex5^short-＋ was similar to the Tctex5^short-＋. The short isoforms of Tctex5 mRNAs in the two models encoded exactly the same peptides, but the long isoforms did not. The estimated peptide encoded by Tctex5^long-＋ had significant mutations on putative sites of phosphorylation and PP1 binding. Conclusion： We established that mutations that occur in the Tctex5 long transcript of the t-haplotype mice are important for normal sperm function, whereas the short transcript of Tctex5 might have a conserved function among different tissues. （Asian J Androl 2008 Mar; 10： 219-226）展开更多
The cytosolic chaperonin T-complex protein 1-ring complex(TRiC)or chaperonin containing T-complex protein 1(CCT)is essential in de novo folding of approximately 10%of the eukaryotic,newly translated polypeptides as we...The cytosolic chaperonin T-complex protein 1-ring complex(TRiC)or chaperonin containing T-complex protein 1(CCT)is essential in de novo folding of approximately 10%of the eukaryotic,newly translated polypeptides as well as misfolded proteins.There is a close link between the TRiC/CCT cytosolic chaperonin and neurodegenerative diseases(Lopez et al.,2015).A lot of research suggests that CCT plays neuroprotective roles in neurodegenerative diseases including Huntington’s disease(Lopez et al.,2015).Either overexpression of a single or all eight subunits(CCT1-8)or treatment of the substrate-binding apical domain of yeast CCT1(ApiCCT1)prevented mutant Huntingtin aggregation and improved cellular and neuronal functions(Zhao et al.,2016).Importantly,our recent study has demonstrated that both CCT and ApiCCT could reduce mutant Huntingtin level and enhance both anterograde and retrograde axonal transport of brain-derived neurotrophic factor.These results led to restoration of the trophic status of striatal neurons from a bacterial artificial chromosome transgenic mouse model of Huntington’s disease(Zhao et al.,2016).Axonal transport is regulated by many factors including microtubule-associated protein tau,which promotes tubulin polymerization and stabilizes microtubules.Impaired interaction between tau and microtubules plays a vital role in the pathogenesis of multiple neurodegenerative diseases(Wang and Mandelkow,2016).Interestingly,tau phosphorylation is also observed in brains of several Huntington’s disease mouse models and Huntington’s disease patients(Gratuze et al.,2016).In a recent study,we explored if CCT subunit has any effect on axonal transport in a tau-dependent pathway(Chen et al.,2018b).We focused on the retrograde axonal transport of brain-derived neurotrophic factor,as neurotrophic factor-mediated signaling in the form of signaling endosome is essential in both the developing and the mature nervous system and dysregulation of trafficking of neurotrophic factors is tightly linked to disorders of the nervous system(Chen et al.,2018a).We found that the expression of a single CCT subunit(CCT5)significantly promoted retrograde axonal transport of brain-derived neurotrophic factor in primary cortical neurons.Mechanically,CCT regulated the level of cyclin-dependent kinase 5(CDK5)/p35/p25 and,subsequently contributed to CCT-induced tau phosphorylation,which induced detachment of tau from microtubules(Chen et al.,2018b)(Figure 1).展开更多
文摘Aim： To determine the possible roles of the t-complex testis expressed gene 5 （Tctex5） on sperm functions, the fulllength sequence of mRNA was studied and compared in the testis between the normal wild-type and the sterile t-haplotype mutant mice. Methods： We applied rapid amplification of cDNA ends, Northern blot and reverse transcription polymerase chain reaction to analyze the full length of Tctex5 mRNAs isolated from testes of the wild-type and the t-haplotype mice. Reverse transcription polymerase chain reaction was used to semi-quantitatively compare expression of Tctex5 transcripts in the 16 tissues and 9.5 day stage embryos in the wild-type mice. E-translation was applied to estimate the amino acid sequences. Results： One long and one short transcript of Tctex5 mRNA were discovered in mouse testis of wild-type （Tctex5^long-＋ and Tctex5^short-＋） and t-haplotype （Tctex5^long-＋ and Tctex5^short-＋） mice, respectively. Being enhanced only in the testis, Tctex5^long-＋ had 17 point mutations and one 15-bp-deletion in the exon 1 region, comparing with the Tctex5^long-＋, whereas the Tctex5^short-＋ was similar to the Tctex5^short-＋. The short isoforms of Tctex5 mRNAs in the two models encoded exactly the same peptides, but the long isoforms did not. The estimated peptide encoded by Tctex5^long-＋ had significant mutations on putative sites of phosphorylation and PP1 binding. Conclusion： We established that mutations that occur in the Tctex5 long transcript of the t-haplotype mice are important for normal sperm function, whereas the short transcript of Tctex5 might have a conserved function among different tissues. （Asian J Androl 2008 Mar; 10： 219-226）
文摘The cytosolic chaperonin T-complex protein 1-ring complex(TRiC)or chaperonin containing T-complex protein 1(CCT)is essential in de novo folding of approximately 10%of the eukaryotic,newly translated polypeptides as well as misfolded proteins.There is a close link between the TRiC/CCT cytosolic chaperonin and neurodegenerative diseases(Lopez et al.,2015).A lot of research suggests that CCT plays neuroprotective roles in neurodegenerative diseases including Huntington’s disease(Lopez et al.,2015).Either overexpression of a single or all eight subunits(CCT1-8)or treatment of the substrate-binding apical domain of yeast CCT1(ApiCCT1)prevented mutant Huntingtin aggregation and improved cellular and neuronal functions(Zhao et al.,2016).Importantly,our recent study has demonstrated that both CCT and ApiCCT could reduce mutant Huntingtin level and enhance both anterograde and retrograde axonal transport of brain-derived neurotrophic factor.These results led to restoration of the trophic status of striatal neurons from a bacterial artificial chromosome transgenic mouse model of Huntington’s disease(Zhao et al.,2016).Axonal transport is regulated by many factors including microtubule-associated protein tau,which promotes tubulin polymerization and stabilizes microtubules.Impaired interaction between tau and microtubules plays a vital role in the pathogenesis of multiple neurodegenerative diseases(Wang and Mandelkow,2016).Interestingly,tau phosphorylation is also observed in brains of several Huntington’s disease mouse models and Huntington’s disease patients(Gratuze et al.,2016).In a recent study,we explored if CCT subunit has any effect on axonal transport in a tau-dependent pathway(Chen et al.,2018b).We focused on the retrograde axonal transport of brain-derived neurotrophic factor,as neurotrophic factor-mediated signaling in the form of signaling endosome is essential in both the developing and the mature nervous system and dysregulation of trafficking of neurotrophic factors is tightly linked to disorders of the nervous system(Chen et al.,2018a).We found that the expression of a single CCT subunit(CCT5)significantly promoted retrograde axonal transport of brain-derived neurotrophic factor in primary cortical neurons.Mechanically,CCT regulated the level of cyclin-dependent kinase 5(CDK5)/p35/p25 and,subsequently contributed to CCT-induced tau phosphorylation,which induced detachment of tau from microtubules(Chen et al.,2018b)(Figure 1).
