Chikashige Yuji, Haraguchi Tokuko, Hiraoka Yasushi
Kobe Advanced ICT Research Center, National Institute of Information and Communications Technology, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe, 651-2492, Japan.
Chromosoma. 2007 Dec;116(6):497-505. doi: 10.1007/s00412-007-0114-8. Epub 2007 Jul 18.
A typical way of moving chromosomes is exemplified by mitotic segregation, in which the centromere is directly captured by spindle microtubules. In this study, we highlight another way of moving chromosomes remotely from outside the nucleus, which involves SUN and KASH domain nuclear envelope proteins. SUN and KASH domain protein families are known to connect the nucleus to cytoskeletal networks and play a role in migration and positioning of the nucleus. Recent studies in the fission yeast Schizossacharomyces pombe demonstrated an additional role for the SUN-KASH protein complex in chromosome movements. During meiotic prophase, telomeres are moved to rearrange chromosomes within the nucleus. The SUN-KASH protein complex located in the nuclear envelope is involved in this process. Telomeres are connected to the SUN protein on the nucleoplasmic side, and the dynein motor complex binds to the KASH protein on the cytoplasmic side. Telomeres are then moved along the nuclear envelope using cytoplasmic microtubules. These findings illustrate a general mechanism for transmitting a cytoskeletal driving force to chromosomes across the nuclear envelope.
有丝分裂分离就是染色体移动的一种典型方式，在此过程中，着丝粒直接被纺锤体微管捕获。在本研究中，我们着重介绍了另一种使染色体从细胞核外部远距离移动的方式，这涉及SUN和KASH结构域的核膜蛋白。已知SUN和KASH结构域蛋白家族可将细胞核与细胞骨架网络相连，并在细胞核的迁移和定位中发挥作用。最近在裂殖酵母粟酒裂殖酵母中的研究表明，SUN - KASH蛋白复合物在染色体移动中还有额外作用。在减数分裂前期，端粒会移动以重排细胞核内的染色体。位于核膜中的SUN - KASH蛋白复合物参与了这一过程。端粒在核质侧与SUN蛋白相连，动力蛋白复合物在细胞质侧与KASH蛋白结合。然后，端粒利用细胞质微管沿着核膜移动。这些发现阐明了一种将细胞骨架驱动力通过核膜传递给染色体的通用机制。
