Wilhelmsen Kevin, Ketema Mirjam, Truong Hoa, Sonnenberg Arnoud
Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
J Cell Sci. 2006 Dec 15;119(Pt 24):5021-9. doi: 10.1242/jcs.03295.
The nucleus in eukaryotic cells can move within the cytoplasm, and its position is crucial for many cellular events, including migration and differentiation. Nuclear anchorage and movement can be achieved through association of outer nuclear membrane (ONM) proteins with the three cytoskeletal systems. Two decades ago studies described C. elegans mutants with defects in such events, but only recently has it been shown that the strategies for nuclear positioning are indeed conserved in C. elegans, Drosophila, mammals and potentially all eukaryotes. The integral ONM proteins implicated in these processes thus far all contain a conserved Klarsicht/ANC-1/Syne homology (KASH) domain at their C-terminus that can associate with Sad1p/UNC-84 (SUN)-domain proteins of the inner nuclear membrane within the periplasmic space of the nuclear envelope (NE). The complex thus formed is responsible not only for association with cytoplasmic elements but also for the integrity of the NE itself.
真核细胞中的细胞核能够在细胞质内移动，其位置对于包括迁移和分化在内的许多细胞活动至关重要。核锚定和移动可通过外核膜（ONM）蛋白与三种细胞骨架系统的结合来实现。二十年前的研究描述了秀丽隐杆线虫中在此类活动中存在缺陷的突变体，但直到最近才表明，核定位策略在秀丽隐杆线虫、果蝇、哺乳动物以及可能所有真核生物中确实是保守的。迄今为止，参与这些过程的完整ONM蛋白在其C末端均含有一个保守的Klarsicht/ANC-1/Syne同源（KASH）结构域，该结构域可与核膜（NE）周质空间内内核膜的Sad1p/UNC-84（SUN）结构域蛋白结合。由此形成的复合物不仅负责与细胞质成分的结合，还负责NE自身的完整性。
