Reorganization of actin filaments by ADF/cofilin is involved in formation of microtubule structures during Xenopus oocyte maturation.
Reorganization of actin filaments by ADF/cofilin is involved in formation of microtubule structures during Xenopus oocyte maturation.
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DOI：
10.1091/mbc.e15-01-0035
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发表时间：
2015-12-01
影响因子：
3.3
通讯作者：
Abe H
中科院分区：
文献类型：
--
作者：
Yamagishi Y;Abe H
在非洲爪蟾卵母细胞成熟过程中，微管组织中心和瞬时微管阵列和减数分裂纺锤体的形成需要非洲爪蟾ADF/cofilin动态重组细胞质和核内肌动蛋白丝，通过ADF/cofilin特异性磷酸酶，弹弓调节。我们研究了非洲爪蟾卵母细胞成熟过程中肌动蛋白丝和微管的重组。围绕未成熟卵母细胞的生殖囊泡（GV），细胞质肌动蛋白丝重组，积累下方的植物侧的GV，微管组织中心和瞬时微管阵列（MTOC-TMA）组装，就在GV击穿（GVBD）。GVBD后，爪蟾ADF/cofilin（XAC）及其磷酸酶Slingshot（XSSH）均聚集于细胞核内，随着GV的收缩，核内肌动蛋白丝从植物侧解体。由于MTOC-TMA发育良好，细胞质肌动蛋白丝保留在MTOC-TMA基底区。通过注射抗XSSH抗体抑制XAC去磷酸化抑制了肌动蛋白丝重组以及MTOC-TMA和减数分裂纺锤体的适当形成和定位。鬼笔环肽的肌动蛋白丝的稳定化也抑制了MTOC-TMA的形成和核内肌动蛋白丝的分解，而不影响核收缩。诺考达唑还引起MTOC-TMA和其基部区域的细胞质肌动蛋白丝消失，这进一步阻碍了从植物侧的核内肌动蛋白丝的分解。XAC似乎重组细胞质肌动蛋白丝所需的精确组装的MTOC和，连同MTOC-TMA，调节核内肌动蛋白丝拆卸必要的减数分裂纺锤体的形成。
During Xenopus oocyte maturation, the formation of the microtubule-organizing center and transient microtubule array and meiotic spindles requires dynamic reorganization of cytoplasmic and intranuclear actin filaments by Xenopus ADF/cofilin, regulated through an ADF/cofilin-specific phosphatase, Slingshot. We examined the reorganization of actin filaments and microtubules during Xenopus oocyte maturation. Surrounding the germinal vesicle (GV) in immature oocytes, the cytoplasmic actin filaments reorganized to accumulate beneath the vegetal side of the GV, where the microtubule-organizing center and transient microtubule array (MTOC-TMA) assembled, just before GV breakdown (GVBD). Immediately after GVBD, both Xenopus ADF/cofilin (XAC) and its phosphatase Slingshot (XSSH) accumulated into the nuclei and intranuclear actin filaments disassembled from the vegetal side with the shrinkage of the GV. As the MTOC-TMA developed well, cytoplasmic actin filaments were retained at the MTOC-TMA base region. Suppression of XAC dephosphorylation by anti-XSSH antibody injection inhibited both actin filament reorganization and proper formation and localization of both the MTOC-TMA and meiotic spindles. Stabilization of actin filaments by phalloidin also inhibited formation of the MTOC-TMA and disassembly of intranuclear actin filaments without affecting nuclear shrinkage. Nocodazole also caused the MTOC-TMA and the cytoplasmic actin filaments at its base region to disappear, which further impeded disassembly of intranuclear actin filaments from the vegetal side. XAC appears to reorganize cytoplasmic actin filaments required for precise assembly of the MTOC and, together with the MTOC-TMA, regulate the intranuclear actin filament disassembly essential for meiotic spindle formation.