β-tubulin C354 mutations that severely decrease microtubule dynamics do not prevent nuclear migration in yeast
β-tubulin C354 mutations that severely decrease microtubule dynamics do not prevent nuclear migration in yeast
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DOI：
10.1091/mbc.e02-01-0003
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发表时间：
2002-08-01
影响因子：
3.3
通讯作者：
Himes, RH
中科院分区：
文献类型：
--
作者：
Gupta, ML;Bode, CJ;Himes, RH
微管动力学受微管与细胞因子的相互作用以及微管蛋白分子一级序列变化的影响。酵母β-微管蛋白C354位于某些抗有丝分裂化合物的结合位点附近，其突变可使体内和体外微管动力学降低90%以上。由此产生的内在稳定的微管使我们能够确定哪些细胞过程（如果有的话）依赖于动态微管。胞质微管的平均数量从野生型的3个减少到突变型细胞的1个。单个微管在芽萌发前有效地定位芽位。虽然纺锤体在后期开始时位于芽颈附近，但突变体细胞缺乏前期纺锤体沿沿着母芽轴的排列。纺锤体微管动力学和纺锤体伸长率也严重抑郁的突变体。通过细胞周期的细胞质微管动力学调节的模式和程度可能揭示支持生长所需的最小动力学特性。改变内在微管动力学和确定表达突变微管蛋白的细胞的体内表型的能力在评估必需基因功能的动态要求方面提供了关键的进展。
Microtubule dynamics are influenced by interactions of microtubules with cellular factors and by changes in the primary sequence of the tubulin molecule. Mutations of yeast beta-tubulin C354, which is located near the binding site of some antimitotic compounds, reduce microtubule dynamicity greater than 90% in vivo and in vitro. The resulting intrinsically stable microtubules allowed us to determine which, if any, cellular processes are dependent on dynamic microtubules. The average number of cytoplasmic microtubules decreased from 3 in wild-type to 1 in mutant cells. The single microtubule effectively located the bud site before bud emergence. Although spindles were positioned near the bud neck at the onset of anaphase, the mutant cells were deficient in preanaphase spindle alignment along the mother-bud axis. Spindle microtubule dynamics and spindle elongation rates were also severely depressed in the mutants. The pattern and extent of cytoplasmic microtubule dynamics modulation through the cell cycle may reveal the minimum dynamic properties required to support growth. The ability to alter intrinsic microtubule dynamics and determine the in vivo phenotype of cells expressing the mutant tubulin provides a critical advance in assessing the dynamic requirements of an essential gene function.