Resolution of chiasmata in oocytes requires separase-mediated proteolysis
Resolution of chiasmata in oocytes requires separase-mediated proteolysis
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DOI：
10.1016/j.cell.2006.05.033
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发表时间：
2006-07-14
期刊：
影响因子：
64.5
通讯作者：
Nasmyth, Kim
中科院分区：
文献类型：
--
作者：
Kudo, Nobuaki R.;Wassmann, Katja;Nasmyth, Kim
在酵母中，减数分裂I中交叉的分解需要分离酶沿着粘着蛋白Rec 8亚基的染色体臂进行蛋白水解裂解沿着。由于激活分离酶的后期促进复合物（APC/C）被认为是不需要的减数分裂在非洲爪蟾卵母细胞I，它已被建议，动物细胞可能会解决交叉的分离独立的机制有关的所谓的“前期途径”，消除粘连蛋白从染色体臂在有丝分裂。通过表达Cre重组酶从透明质酸启动子，我们已经删除了一个floxed等位基因的分离酶特异性在小鼠卵母细胞。这阻止了Rec 8从染色体臂上的去除和交叉的分解。它还阻碍第一极体（PBE）的排出，导致女性不育。编码野生型但非无催化活性的分离酶的mRNA恢复交叉分辨。这两种类型的mRNA恢复PBE。因此，分离酶的蛋白水解活性对于从染色体臂中去除Rec 8和交叉分辨是必不可少的，但对于PBE不是。
In yeast, resolution of chiasmata in meiosis I requires proteolytic cleavage along chromosome arms of cohesin's Rec8 subunit by separase. Since activation of separase by the anaphase-promoting complex (APC/C) is supposedly not required for meiosis I in Xenopus oocytes, it has been suggested that animal cells might resolve chiasmata by a separase-independent mechanism related to the so-called "prophase pathway" that removes cohesin from chromosome arms during mitosis. By expressing Cre recombinase from a zona pellucida promoter, we have deleted a floxed allele of separase specifically in mouse oocytes. This prevents removal of Rec8 from chromosome arms and resolution of chiasmata. It also hinders extrusion of the first polar body (PBE) and causes female sterility. mRNA encoding wild-type but not catalytically inactive separase restores chiasma resolution. Both types of mRNA restore PBE. Proteolytic activity of separase is therefore essential for Rec8's removal from chromosome arms and for chiasma resolution but not for PBE.