The half-bridge component Kar1 promotes centrosome separation and duplication during budding yeast meiosis.
The half-bridge component Kar1 promotes centrosome separation and duplication during budding yeast meiosis.
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DOI：
10.1091/mbc.e18-03-0163
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发表时间：
2018-08-01
影响因子：
3.3
通讯作者：
Yu HG
中科院分区：
文献类型：
--
作者：
Agarwal M;Jin H;McClain M;Fan J;Koch BA;Jaspersen SL;Yu HG
出芽酵母的中心体，通常被称为纺锤体极体（SPB），在细胞分裂过程中为染色体分离形成微管核。一种被称为半桥的附属结构附着在SPB的一侧，调节SPB的复制和分离。与DNA一样，SPB在每个细胞周期中仅复制一次。然而，在减数分裂过程中，在一轮DNA复制之后，两轮SPB复制和分离分别与减数第一次分裂中的同源染色体分离以及减数第二次分裂中的姐妹染色单体分离相偶联。减数分裂过程中SPB的复制和分离是如何被调节的仍有待阐明，并且减数分裂中的调节是否不同于有丝分裂中的调节也不清楚。在此我们表明，半桥成分Kar1的过量产生会导致减数分裂过程中SPB过早分离。此外，过量的Kar1会诱导SPB过度复制，形成多余的SPB，从而导致染色体错误分离和子囊孢子形成错误。Kar1介导的SPB复制绕过了Sfi1去磷酸化的需求，Sfi1是另一种先前被确定为许可因子的半桥成分。因此，我们的结果揭示了Kar1在许可减数分裂SPB复制中的意外作用，并表明了出芽酵母减数分裂过程中SPB调节的一种独特机制。
The budding yeast centrosome, often called the spindle pole body (SPB), nucleates microtubules for chromosome segregation during cell division. An appendage, called the half bridge, attaches to one side of the SPB and regulates SPB duplication and separation. Like DNA, the SPB is duplicated only once per cell cycle. During meiosis, however, after one round of DNA replication, two rounds of SPB duplication and separation are coupled with homologue segregation in meiosis I and sister-chromatid segregation in meiosis II. How SPB duplication and separation are regulated during meiosis remains to be elucidated, and whether regulation in meiosis differs from that in mitosis is unclear. Here we show that overproduction of the half-bridge component Kar1 leads to premature SPB separation during meiosis. Furthermore, excessive Kar1 induces SPB overduplication to form supernumerary SPBs, leading to chromosome missegregation and erroneous ascospore formation. Kar1-mediated SPB duplication bypasses the requirement of dephosphorylation of Sfi1, another half-bridge component previously identified as a licensing factor. Our results therefore reveal an unexpected role of Kar1 in licensing meiotic SPB duplication and suggest a unique mechanism of SPB regulation during budding yeast meiosis.
DOI：
10.1007/978-1-4939-6545-8_9
发表时间：
2017
期刊：
Methods in molecular biology (Clifton, N.J.)
影响因子：
--
作者：
Fan J;Jin H;Yu HG
通讯作者：
Yu HG