Immunostructural evidence for the template mechanism of microtubule nucleation

被引:91
作者
Keating, TJ [1 ]
Borisy, GG [1 ]
机构
[1] Univ Wisconsin, Mol Biol Lab, Madison, WI 53706 USA
关键词
D O I
10.1038/35014045
中图分类号
Q2 [细胞生物学];
学科分类号
071009 ; 090102 ;
摘要
Two opposing models have been proposed to explain how the gamma-tubulin ring complex (gamma TuRC) induces microtubule nucleation. In the 'protofilament' model, the gamma TuRC induces nucleation as a partially or completely straightened protofilament that is incorporated longitudinally into the wall of the nascent microtubule, whereas the 'template' model proposes that the gamma TuRC acts as a helical template that constitutes the base of the newly-formed polymer. Here we appraise these two models, using high-resolution structural and immunolocalization methods. We show that components of the gamma TuRC localize to a narrow zone at the extreme minus end of the microtubule and that these ends terminate in a pointed cap. Together, these results strongly favour the template model of microtubule nucleation.
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收藏
页码:352 / 357
页数:6
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