PAR-3 defines a central subdomain of the cortical actin cap in mouse eggs
PAR-3 defines a central subdomain of the cortical actin cap in mouse eggs
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DOI：
10.1016/j.ydbio.2004.12.034
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发表时间：
2005-04-01
影响因子：
2.7
通讯作者：
Williams, CJ
中科院分区：
文献类型：
--
作者：
Duncan, FE;Moss, SB;Williams, CJ
进化上保守的分配缺陷（PAR）蛋白PAR-3是建立和维持细胞极性的关键。在哺乳动物卵母细胞成熟过程中，径向对称的卵母细胞转化为高度极化的中期II（MII）停滞卵。因此，我们研究了几个方面的PAR-3表达在卵母细胞成熟。我们克隆了两个新的PAR-3转录本从卵母细胞库，可能编码蛋白质的M-r = 73 K和133 K，在成熟过程中磷酸化。PAR-3，这是整个GV完整的卵母细胞中发现，成为不对称定位在减数分裂过程中。萌发囊泡破裂后，PAR-3围绕在凝聚的染色体周围，并与减数分裂纺锤体结合。在发射第一和第二极体之前，PAR-3位于极化肌动蛋白帽的中心子域内，该帽覆盖纺锤体。这种皮质PAR-3定位依赖于完整的微丝。这些结果表明，PAR-3在建立不对称的鸡蛋，并在定义未来的网站极体排放的作用。(c)2005年爱思唯尔公司All rights reserved.
The evolutionarily conserved partitioning defective (PAR) protein PAR-3 is pivotal for establishing and maintaining cell polarity. During mammalian oocyte maturation, the radially symmetric oocyte is transformed into a highly polarized metaphase II (MII)-arrested egg. We therefore examined several aspects of PAR-3 expression during oocyte maturation. We cloned two novel PAR-3 transcripts from an oocyte library that likely encode proteins of M-r = 73 K and 133 K that are phosphorylated during maturation. PAR-3, which is found throughout the GV-intact oocyte, becomes asymmetrically localized during meiosis. Following germinal vesicle breakdown, PAR-3 surrounds the condensing chromosomes and associates with the meiotic spindles. Prior to emission of the first and second polar bodies, PAR-3 is located within a central subdomain of the polarized actin cap, which overlies the spindle. This cortical PAR-3 localization depends on intact microfilaments. These results suggest a role for PAR-3 in establishing asymmetry in the egg and in defining the future site of polar body emission. (c) 2005 Elsevier Inc. All rights reserved.