Wiese Christiane, Zheng Yixian
Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA.
J Cell Sci. 2006 Oct 15;119(Pt 20):4143-53. doi: 10.1242/jcs.03226.
Centrosomes and their fungal equivalents, spindle pole bodies (SPBs), are the main microtubule (MT)-organizing centers in eukaryotic cells. Several proteins have been implicated in microtubule formation by centrosomes and SPBs, including microtubule-minus-end-binding proteins and proteins that bind along the length or stabilize the plus ends of microtubules. Recent work has improved our understanding of the molecular mechanisms of MT formation. In particular, it has shown that gamma-tubulin and its associated proteins play key roles in microtubule nucleation and spindle assembly in evolutionarily distant species ranging from fungi to mammals. Other work indicates that gamma-tubulin-mediated microtubule nucleation, although necessary, is not sufficient for mitotic spindle assembly but requires additional proteins that regulate microtubule nucleation independently of centrosomes.
中心体及其在真菌中的对应物纺锤极体（SPB）是真核细胞中主要的微管（MT）组织中心。几种蛋白质已被证明与中心体和纺锤极体形成微管有关，包括微管负端结合蛋白以及沿微管长度结合或稳定微管正端的蛋白质。最近的研究工作增进了我们对微管形成分子机制的理解。特别是，研究表明γ-微管蛋白及其相关蛋白在从真菌到哺乳动物等进化距离较远的物种的微管成核和纺锤体组装中起关键作用。其他研究表明，γ-微管蛋白介导的微管成核虽然是必要的，但对于有丝分裂纺锤体组装并不充分，还需要其他独立于中心体调节微管成核的蛋白质。
