Thiol-based redox post-translational modifications have emerged as important mechanisms of signaling and regulation in all organisms, and thioredoxin plays a key role by controlling the thiol-disulfide status of targe...Thiol-based redox post-translational modifications have emerged as important mechanisms of signaling and regulation in all organisms, and thioredoxin plays a key role by controlling the thiol-disulfide status of target proteins. Recent redox proteomic studies revealed hundreds of proteins regulated by glutathio- nylation and nitrosylation in the unicellular green alga Chlamydomonas reinhardtii, while much less is known about the thioredoxin interactome in this organism. By combining qualitative and quantitative proteomic analyses, we have comprehensively investigated the Chlamydomonas thioredoxome and 1188 targets have been identified. They participate in a wide range of metabolic pathways and cellular pro- cesses. This study broadens not only the redox regulation to new enzymes involved in well-known thiore- doxin-regulated metabolic pathways but also sheds light on cellular processes for which data supporting redox regulation are scarce （aromatic amino acid biosynthesis, nuclear transport, etc）. Moreover, we char- acterized 1052 thioredoxin-dependent regulatory sites and showed that these data constitute a valuable resource for future functional studies in Chlamydomonas. By comparing this thioredoxome with proteomic data for glutathionylation and nitrosylation at the protein and cysteine levels, this work confirms the existence of a complex redox regulation network in Chlamydomonas and provides evidence of a tremendous selectivity of redox post-translational modifications for specific cysteine residues.展开更多
Parthenogenetic embryonic stem(pES)cells isolated from parthenogenetic activation of oocytes and embryos,also called parthenogenetically induced pluripotent stem cells,exhibit pluripotency evidenced by both in vitro a...Parthenogenetic embryonic stem(pES)cells isolated from parthenogenetic activation of oocytes and embryos,also called parthenogenetically induced pluripotent stem cells,exhibit pluripotency evidenced by both in vitro and in vivo differentiation potential.Differential proteomic analysis was performed using differential in-gel electrophoresis and isotope-coded affinity tag-based quantitative proteomics to investigate the molecular mechanisms underlying the developmental pluripotency of pES cells and to compare the protein expression of pES cells generated from either the in vivo-matured ovulated(IVO)oocytes or from the in vitro-matured(IVM)oocytes with that of fertilized embryonic stem(fES)cells derived from fertilized embryos.A total of 76 proteins were upregulated and 16 proteins were downregulated in the IVM pES cells,whereas 91 proteins were upregulated and 9 were downregulated in the IVO pES cells based on a minimal 1.5-fold change as the cutoff value.No distinct pathways were found in the differentially expressed proteins except for those involved in metabolism and physiological processes.Notably,no differences were found in the protein expression of imprinted genes between the pES and fES cells,suggesting that genomic imprinting can be corrected in the pES cells at least at the early passages.The germline competent IVM pES cells may be applicable for germ cell renewal in aging ovaries if oocytes are retrieved at a younger age.展开更多
文摘Thiol-based redox post-translational modifications have emerged as important mechanisms of signaling and regulation in all organisms, and thioredoxin plays a key role by controlling the thiol-disulfide status of target proteins. Recent redox proteomic studies revealed hundreds of proteins regulated by glutathio- nylation and nitrosylation in the unicellular green alga Chlamydomonas reinhardtii, while much less is known about the thioredoxin interactome in this organism. By combining qualitative and quantitative proteomic analyses, we have comprehensively investigated the Chlamydomonas thioredoxome and 1188 targets have been identified. They participate in a wide range of metabolic pathways and cellular pro- cesses. This study broadens not only the redox regulation to new enzymes involved in well-known thiore- doxin-regulated metabolic pathways but also sheds light on cellular processes for which data supporting redox regulation are scarce （aromatic amino acid biosynthesis, nuclear transport, etc）. Moreover, we char- acterized 1052 thioredoxin-dependent regulatory sites and showed that these data constitute a valuable resource for future functional studies in Chlamydomonas. By comparing this thioredoxome with proteomic data for glutathionylation and nitrosylation at the protein and cysteine levels, this work confirms the existence of a complex redox regulation network in Chlamydomonas and provides evidence of a tremendous selectivity of redox post-translational modifications for specific cysteine residues.
基金supported by MOST National Major Basic Research Program(Grant Nos.2010CB94500,2009CB941000(to LL),and 2010CB833703(to FY)).
文摘Parthenogenetic embryonic stem(pES)cells isolated from parthenogenetic activation of oocytes and embryos,also called parthenogenetically induced pluripotent stem cells,exhibit pluripotency evidenced by both in vitro and in vivo differentiation potential.Differential proteomic analysis was performed using differential in-gel electrophoresis and isotope-coded affinity tag-based quantitative proteomics to investigate the molecular mechanisms underlying the developmental pluripotency of pES cells and to compare the protein expression of pES cells generated from either the in vivo-matured ovulated(IVO)oocytes or from the in vitro-matured(IVM)oocytes with that of fertilized embryonic stem(fES)cells derived from fertilized embryos.A total of 76 proteins were upregulated and 16 proteins were downregulated in the IVM pES cells,whereas 91 proteins were upregulated and 9 were downregulated in the IVO pES cells based on a minimal 1.5-fold change as the cutoff value.No distinct pathways were found in the differentially expressed proteins except for those involved in metabolism and physiological processes.Notably,no differences were found in the protein expression of imprinted genes between the pES and fES cells,suggesting that genomic imprinting can be corrected in the pES cells at least at the early passages.The germline competent IVM pES cells may be applicable for germ cell renewal in aging ovaries if oocytes are retrieved at a younger age.
