PP2A(Cdc55)'s role in reductional chromosome segregation during achiasmate meiosis in budding yeast is independent of its FEAR function.
PP2A(Cdc55)'s role in reductional chromosome segregation during achiasmate meiosis in budding yeast is independent of its FEAR function.
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DOI：
10.1038/srep30397
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发表时间：
2016-07-26
影响因子：
4.6
通讯作者：
Arumugam P
中科院分区：
文献类型：
--
作者：
Kerr GW;Wong JH;Arumugam P
PP 2ACdc 55是一种高度保守的丝氨酸-苏氨酸蛋白磷酸酶，参与多种细胞过程。在芽殖酵母中，缺乏PP 2ACdc 55活性的减数分裂细胞经历过早退出减数分裂I，这导致未能形成双极纺锤体和分裂核。这种缺陷主要是由于其在负调节Cdc 14早期后期释放（FEAR）途径中的作用。PP 2ACdc 55通过抵消Cdk对核仁蛋白Net 1的磷酸化作用，阻止Cdk（细胞周期蛋白依赖性激酶）拮抗磷酸酶Cdc 14的核仁释放。在通过分离spo 11 Δ spo 12 Δ致死性抑制子进行的单核蛋白遗传筛选中鉴定了Cdc 55，表明Cdc 55可能在减数分裂染色体分离中起作用。我们通过分离抑制spo 11 Δ spo 12 Δ致死性的cdc 55等位基因来研究这种可能性，并表明这种抑制与PP 2ACdc 55的FEAR功能无关。虽然cdc 55中的抑制突变在没有重组的情况下影响减数分裂染色体分离，但它们对野生型减数分裂期间的染色体分离没有影响。我们认为，Cdc 55是所需的减少染色体分离过程中的非交叉减数分裂，这是独立的FEAR功能。
PP2ACdc55 is a highly conserved serine-threonine protein phosphatase that is involved in diverse cellular processes. In budding yeast, meiotic cells lacking PP2ACdc55 activity undergo a premature exit from meiosis I which results in a failure to form bipolar spindles and divide nuclei. This defect is largely due to its role in negatively regulating the Cdc Fourteen Early Anaphase Release (FEAR) pathway. PP2ACdc55 prevents nucleolar release of the Cdk (Cyclin-dependent kinase)-antagonising phosphatase Cdc14 by counteracting phosphorylation of the nucleolar protein Net1 by Cdk. CDC55 was identified in a genetic screen for monopolins performed by isolating suppressors of spo11Δ spo12Δ lethality suggesting that Cdc55 might have a role in meiotic chromosome segregation. We investigated this possibility by isolating cdc55 alleles that suppress spo11Δ spo12Δ lethality and show that this suppression is independent of PP2ACdc55’s FEAR function. Although the suppressor mutations in cdc55 affect reductional chromosome segregation in the absence of recombination, they have no effect on chromosome segregation during wild type meiosis. We suggest that Cdc55 is required for reductional chromosome segregation during achiasmate meiosis and this is independent of its FEAR function.