Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of th...Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of the Smc1-Smc3-Scc1 cohesin ring, is phosphorylated on S/T-Q residues. This event depended on the Mec1 checkpoint kinase as well as on cell cycle arrest triggered by the DNA damage checkpoint network. This phosphorylation event also took place during mitosis of an unperturbed cell cycle. The present finding that S. cerevisiae Scc3 is phosphorylated during mitosis represents a potentially important new regulatory step in cohesin’s mitotic functions.展开更多
The meiotic cohesin complex of S. cerevisiae shares with the mitotic one the Irr1/Scc3, Smc1, and Smc3 subunits, while the meiosis-specific subunit Rec8 replaces mitotic subunit Scc1/Mcd1. We noticed earlier that the ...The meiotic cohesin complex of S. cerevisiae shares with the mitotic one the Irr1/Scc3, Smc1, and Smc3 subunits, while the meiosis-specific subunit Rec8 replaces mitotic subunit Scc1/Mcd1. We noticed earlier that the irr1-1 mutation (F658G) severely affected meiosis. The irr1 1/IRR1 cells were entering meiosis before having completed mitotic cell division. Using meiotic two-hybrid assay and co-immunoprecipitation we show that in cells arrested in pachytene due to a lack of a gene-regulatory factor Ndt80, the Irr1 protein interacts with Rec8p and the irr1-1 mutation abolishes this interaction. These findings indicate an important role of Irr1p in early stages of meiosis.展开更多
RBM46 is a germ cell-specific RNA-binding protein required for gametogenesis,but the targets and molecular functions of RBM46 remain unknown.Here,we demonstrate that RBM46 binds at specific motifs in the 3'UTRs of...RBM46 is a germ cell-specific RNA-binding protein required for gametogenesis,but the targets and molecular functions of RBM46 remain unknown.Here,we demonstrate that RBM46 binds at specific motifs in the 3'UTRs of mRNAs encoding multiple meiotic cohesin subunits and show that RBM46 is required for normal synaptonemal complex formation during meiosis initiation.Using a recently reported,high-resolution technique known as LACE-seq and working with low-input cells,we profiled the targets of RBM46 at single-nucleotide resolution in leptotene and zygotene stage gametes.We found that RBM46 preferentially binds target mRNAs containing GCCUAU/GUUCGA motifs in their 3'UTRs regions.In Rbm46 knockout mice,the RBM46-target cohesin subunits displayed unaltered mRNA levels but had reduced translation,resulting in the failed assembly of axial elements,synapsis disruption,and meiotic arrest.Our study thus provides mechanistic insights into the molecular functions of RBM46 in gametogenesis and illustrates the power of LACE-seq for investigations of RNA-binding protein functions when working with low-abundance input materials.展开更多
Objective： To evaluate the effect of Heyan Kuntai Capsule （和颜坤泰胶囊, HYKT） on the ovarian function of aged mice and expressions of cohesion complexes in oocytes. Methods： Twenty-five 9-month-old female C57BL/6...Objective： To evaluate the effect of Heyan Kuntai Capsule （和颜坤泰胶囊, HYKT） on the ovarian function of aged mice and expressions of cohesion complexes in oocytes. Methods： Twenty-five 9-month-old female C57BL/6J mice were randomly divided into 5 groups by block randomization method （n=5 per group）, including the control group （saline）, 17β-estradiol group [E2, 100 μg/（kg·d）], and low-, medium-, and high- dose of HYKT groups [0.3, 0.9, 2.7 g/（kg·d）, respectively]. All mice were treated by intragastric administration for 4 weeks. Hematoxylin and eosin staining and anti-VASA staining were used to detect the amounts of follicles. The apoptosis of follicles was measured by anti-gamma H2A histone family member X （γ, H2AX） staining and TdT-mediated dUTP Nick-End Labeling （TUNEL） assay. The density of cohesin subunits, REC8 meiotic recombination protein （REC8）, structural maintenance of chromosome （SMC） 1 β and SMC3 in oocytes were evaluated by immunofluorescent staining. Results： After administration of E2 and high-dose of HYKT, the total number of follicles as well as the number of primordial and primary follicles were significantly increased （P〈0.05）. Anti-γ/H2AX staining and TUNEL assay demonstrated that high-dose of HYKT and E2 partly suppressed the apoptosis of follicles （P〈0.05）. Furthermore, it showed an increased trend in the levels of REC8 and SMC1 β, after administration with E2 and HYKT, and no obvious change in the level of SMC3. Conclusion： HYKT could enhance the number of follicles, suppress apoptosis of oocytes and have a trend to elevate the meiotic-specific cohesin subunits （REC8 and SMC1 β） in oocytes of aged mice, indicating a beneficial effect on the ovarian function in terms of the quantity and quality of follicles.展开更多
a-kleisins are core components of meiotic and mitotic cohesin complexes. Arabidopsis contains genes encoding four a-kleisins. SYN1, a REC8 ortholog, is essential for meiosis, while SYN2 and SYN4 appear to be SCCI orth...a-kleisins are core components of meiotic and mitotic cohesin complexes. Arabidopsis contains genes encoding four a-kleisins. SYN1, a REC8 ortholog, is essential for meiosis, while SYN2 and SYN4 appear to be SCCI orthologs and function in mitosis. SYN3 is enriched in the nucleolus of meiotic and mitotic cells and is essential for megagametogenesis. It was recently shown that expression of SYN3-RNAi constructs in buds cause changes in meiotic gene expression that result in meiotic alterations. In this report we show that expression of SYN3 from the 35S promoter with either a c-terminal Myc or FAST tag causes a reduction in SYN1 mRNA levels that results in al- terations in sister chromatid cohesion, homologous chromosome synapsis female meiosis. and synaptonemal complex formation during both male and展开更多
Age-related chromosomal aneuploidy is associated with the reduction of cohesin in meiosis.There are many complicated factors affecting the metabolism of cohesion,including the hyperactive separase,abnormal Shugoshin p...Age-related chromosomal aneuploidy is associated with the reduction of cohesin in meiosis.There are many complicated factors affecting the metabolism of cohesion,including the hyperactive separase,abnormal Shugoshin protein degradation,oxidative damage,increased intracellular pH in oocytes,abnormal metabolism of spindle assembly checkpoint,anaphase-promoting complex,and age-related reproductive hormones,which are summarized in the review.展开更多
文摘Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of the Smc1-Smc3-Scc1 cohesin ring, is phosphorylated on S/T-Q residues. This event depended on the Mec1 checkpoint kinase as well as on cell cycle arrest triggered by the DNA damage checkpoint network. This phosphorylation event also took place during mitosis of an unperturbed cell cycle. The present finding that S. cerevisiae Scc3 is phosphorylated during mitosis represents a potentially important new regulatory step in cohesin’s mitotic functions.
基金supported in part by the Ministry of Science and Higher Education,grants 0038/P01/2009/36 and 4568/B/P01/2010/38.
文摘The meiotic cohesin complex of S. cerevisiae shares with the mitotic one the Irr1/Scc3, Smc1, and Smc3 subunits, while the meiosis-specific subunit Rec8 replaces mitotic subunit Scc1/Mcd1. We noticed earlier that the irr1-1 mutation (F658G) severely affected meiosis. The irr1 1/IRR1 cells were entering meiosis before having completed mitotic cell division. Using meiotic two-hybrid assay and co-immunoprecipitation we show that in cells arrested in pachytene due to a lack of a gene-regulatory factor Ndt80, the Irr1 protein interacts with Rec8p and the irr1-1 mutation abolishes this interaction. These findings indicate an important role of Irr1p in early stages of meiosis.
基金supported by grants from the National Key R&D Program of China(2021YFC2700200)Academic Promotion Programme of Shandong First Medical University(2019U001)+5 种基金General Research Fund from Research Grants Council of Hong Kong(14103418)Basic Science Center Program of NFSC(31988101)the Shandong Provincial Key Research and Development Program(2020ZLYS02)a fund from A-Smart Group to support CUHKSDU Joint Laboratory on Reproductive Genetics of CUHK,Major Innovation Projects in Shandong Province(2021ZDSYS16)the Science Foundation for Distinguished Yong Scholars of Shandong(ZR2021JQ27)Taishan Scholars Program for Young Experts of Shandong Province(tsqn202103192).
文摘RBM46 is a germ cell-specific RNA-binding protein required for gametogenesis,but the targets and molecular functions of RBM46 remain unknown.Here,we demonstrate that RBM46 binds at specific motifs in the 3'UTRs of mRNAs encoding multiple meiotic cohesin subunits and show that RBM46 is required for normal synaptonemal complex formation during meiosis initiation.Using a recently reported,high-resolution technique known as LACE-seq and working with low-input cells,we profiled the targets of RBM46 at single-nucleotide resolution in leptotene and zygotene stage gametes.We found that RBM46 preferentially binds target mRNAs containing GCCUAU/GUUCGA motifs in their 3'UTRs regions.In Rbm46 knockout mice,the RBM46-target cohesin subunits displayed unaltered mRNA levels but had reduced translation,resulting in the failed assembly of axial elements,synapsis disruption,and meiotic arrest.Our study thus provides mechanistic insights into the molecular functions of RBM46 in gametogenesis and illustrates the power of LACE-seq for investigations of RNA-binding protein functions when working with low-abundance input materials.
基金Supported by the National Natural Science Foundation of China(No.31571196,81401171,30801502)the 2015 Program to Guide Medicine of the Shanghai Municipal Science and Technology Commission(No.15401932200)+4 种基金the FY2008 JSPS Postdoctoral Fellowship for Foreign Researchers(No.P08471)the Shanghai Pujiang Program(No.11PJ1401900)the Development Project of Shanghai Peak Disciplines-Integrated Chinese and Western Medicinethe Program for Outstanding Medical Academic LeaderDevelopment Project of Shanghai Peak Disciplines-Integrated Chinese and Western Medicine(No.20150407)
文摘Objective： To evaluate the effect of Heyan Kuntai Capsule （和颜坤泰胶囊, HYKT） on the ovarian function of aged mice and expressions of cohesion complexes in oocytes. Methods： Twenty-five 9-month-old female C57BL/6J mice were randomly divided into 5 groups by block randomization method （n=5 per group）, including the control group （saline）, 17β-estradiol group [E2, 100 μg/（kg·d）], and low-, medium-, and high- dose of HYKT groups [0.3, 0.9, 2.7 g/（kg·d）, respectively]. All mice were treated by intragastric administration for 4 weeks. Hematoxylin and eosin staining and anti-VASA staining were used to detect the amounts of follicles. The apoptosis of follicles was measured by anti-gamma H2A histone family member X （γ, H2AX） staining and TdT-mediated dUTP Nick-End Labeling （TUNEL） assay. The density of cohesin subunits, REC8 meiotic recombination protein （REC8）, structural maintenance of chromosome （SMC） 1 β and SMC3 in oocytes were evaluated by immunofluorescent staining. Results： After administration of E2 and high-dose of HYKT, the total number of follicles as well as the number of primordial and primary follicles were significantly increased （P〈0.05）. Anti-γ/H2AX staining and TUNEL assay demonstrated that high-dose of HYKT and E2 partly suppressed the apoptosis of follicles （P〈0.05）. Furthermore, it showed an increased trend in the levels of REC8 and SMC1 β, after administration with E2 and HYKT, and no obvious change in the level of SMC3. Conclusion： HYKT could enhance the number of follicles, suppress apoptosis of oocytes and have a trend to elevate the meiotic-specific cohesin subunits （REC8 and SMC1 β） in oocytes of aged mice, indicating a beneficial effect on the ovarian function in terms of the quantity and quality of follicles.
基金supported by a grant from the National Science Foundation of USA(No.MCB0718191)
文摘a-kleisins are core components of meiotic and mitotic cohesin complexes. Arabidopsis contains genes encoding four a-kleisins. SYN1, a REC8 ortholog, is essential for meiosis, while SYN2 and SYN4 appear to be SCCI orthologs and function in mitosis. SYN3 is enriched in the nucleolus of meiotic and mitotic cells and is essential for megagametogenesis. It was recently shown that expression of SYN3-RNAi constructs in buds cause changes in meiotic gene expression that result in meiotic alterations. In this report we show that expression of SYN3 from the 35S promoter with either a c-terminal Myc or FAST tag causes a reduction in SYN1 mRNA levels that results in al- terations in sister chromatid cohesion, homologous chromosome synapsis female meiosis. and synaptonemal complex formation during both male and
文摘Age-related chromosomal aneuploidy is associated with the reduction of cohesin in meiosis.There are many complicated factors affecting the metabolism of cohesion,including the hyperactive separase,abnormal Shugoshin protein degradation,oxidative damage,increased intracellular pH in oocytes,abnormal metabolism of spindle assembly checkpoint,anaphase-promoting complex,and age-related reproductive hormones,which are summarized in the review.
