F-Actin nucleated on chromosomes coordinates their capture by microtubules in oocyte meiosis.
F-Actin nucleated on chromosomes coordinates their capture by microtubules in oocyte meiosis.
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DOI：
10.1083/jcb.201802080
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发表时间：
2018-08-06
期刊：
影响因子：
--
通讯作者：
Lénárt P
中科院分区：
文献类型：
--
作者：
Burdyniuk M;Callegari A;Mori M;Nédélec F;Lénárt P
肌动蛋白网络在不对称分裂过程中将染色体移动到卵母细胞的皮质。Burdyniuk等人表明，在海星卵母细胞中，肌动蛋白以RanGTP和Arp 2/3依赖的方式在染色体周围成核。这些F-肌动蛋白“补丁”协调染色体捕获在大卵母细胞，防止过早的形成着丝粒微管附件。 纺锤体微管捕获每一条染色体对于防止染色体丢失和非整倍体是必不可少的。在体细胞中，星状微管搜寻并捕获染色体，形成与动粒的侧向附着。然而，在大卵母细胞中，这种机制是不够的。我们之前已经证明，收集分散在70 μm海星卵母细胞核中的染色体还需要一个可收缩的F-肌动蛋白网络。这种F-肌动蛋白驱动的机制如何与微管捕获协调仍然未知。在这里，我们表明，核膜破裂后Arp 2/3-有核的F-肌动蛋白“补丁”周围的染色体形成的Ran-GTP依赖的方式，我们建议，这些结构的空间位阻kinetochore-microtubule附件。一旦F-肌动蛋白驱动的染色体运输完成，协调拆卸F-肌动蛋白补丁允许同步捕获的微管。我们的观察表明，这种协调是必要的，因为早期捕获的染色体微管会干扰F-肌动蛋白驱动的运输，导致染色体丢失和形成非整倍体卵子。
An actin network moves chromosomes to the cortex of oocytes during asymmetric division. Burdyniuk et al. show that in starfish oocytes actin is nucleated around chromosomes in a RanGTP- and Arp2/3-dependent manner. These F-actin “patches” coordinate chromosome capture in the large oocyte by preventing the formation of premature kinetochore–microtubule attachments. Capture of each and every chromosome by spindle microtubules is essential to prevent chromosome loss and aneuploidy. In somatic cells, astral microtubules search and capture chromosomes forming lateral attachments to kinetochores. However, this mechanism alone is insufficient in large oocytes. We have previously shown that a contractile F-actin network is additionally required to collect chromosomes scattered in the 70-µm starfish oocyte nucleus. How this F-actin–driven mechanism is coordinated with microtubule capture remained unknown. Here, we show that after nuclear envelope breakdown Arp2/3-nucleated F-actin “patches” form around chromosomes in a Ran-GTP–dependent manner, and we propose that these structures sterically block kinetochore–microtubule attachments. Once F-actin–driven chromosome transport is complete, coordinated disassembly of F-actin patches allows synchronous capture by microtubules. Our observations indicate that this coordination is necessary because early capture of chromosomes by microtubules would interfere with F-actin–driven transport leading to chromosome loss and formation of aneuploid eggs.
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影响因子：
7.7
作者：
Bun, Philippe;Dmitrieff, Serge;Lenart, Peter
通讯作者：
Lenart, Peter
DOI：
10.1126/science.aaf1709
发表时间：
2016-05-20
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Henty-Ridilla JL;Rankova A;Eskin JA;Kenny K;Goode BL
通讯作者：
Goode BL
影响因子：
56.9
作者：
Mogessie, Binyam;Schuh, Melina
通讯作者：
Schuh, Melina
影响因子：
11.8
作者：
Deng, Manqi;Suraneni, Praveen;Li, Rong
通讯作者：
Li, Rong
影响因子：
11.4
作者：
DASSO, M;SEKI, T;NISHIMOTO, T
通讯作者：
NISHIMOTO, T