Chromosomal association of Ran during meiotic and mitotic divisions
Chromosomal association of Ran during meiotic and mitotic divisions
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DOI：
10.1242/jcs.00136
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发表时间：
2002-12-01
影响因子：
4
通讯作者：
Terasaki, M
中科院分区：
文献类型：
--
作者：
Hinkle, B;Slepchenko, B;Terasaki, M
最近在非洲爪蟾卵提取物中的研究表明，小G蛋白Ran在纺锤体组装和核膜重组中具有核心作用。我们确定了Ran在M期细胞中的定位和动力学。通过免疫荧光，RAN积累在减数分裂-II-逮捕爪蟾卵的染色体上。在活细胞中，荧光标记的RAN与非洲爪蟾的染色体相关联，并在卵子被人工激活的后期保持关联。荧光RAN与小鼠卵子中的染色体，在海星的减数分裂成熟和早期胚胎分裂，并在较低程度上在培养的哺乳动物细胞系的有丝分裂。染色体Ran经历恒定的流动。在未成熟海星卵母细胞的光漂白实验中，染色体Ran的k（off）近似为0.06秒（-1），结合分析表明存在一个单一的主要位点。染色体的相互作用可能有助于保持Ran-GTP在染色体附近的纺锤体组装和核膜重组。
Recent studies in Xenopus egg extracts indicate that the small G protein Ran has a central role in spindle assembly and nuclear envelope reformation. We determined Ran localization and dynamics in cells during M phase. By immunofluorescence, Ran is accumulated on the chromosomes of meiosis-II-arrested Xenopus eggs. In living cells, fluorescently labeled Ran associated with the chromosomes in Xenopus and remained associated during anaphase when eggs were artificially activated. Fluorescent Ran associated with chromosomes in mouse eggs, during meiotic maturation and early embryonic divisions in starfish, and to a lesser degree during mitosis of a cultured mammalian cell line. Chromosomal Ran undergoes constant flux. From photobleach experiments in immature starfish oocytes, chromosomal Ran has a k(off) of similar to0.06 second(-1), and binding analysis suggests that there is a single major site. The chromosomal interactions may serve to keep Ran-GTP in the vicinity of the chromosomes for spindle assembly and nuclear envelope reformation.