beta-Tubulin mutation suppresses microtubule dynamics in vitro and slows mitosis in vivo.
beta-Tubulin mutation suppresses microtubule dynamics in vitro and slows mitosis in vivo.
复制标题
β-微管蛋白突变会抑制体外微管动力学并减缓体内有丝分裂。
DOI：
10.1002/cm.970300406
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Farrell,KW
中科院分区：
文献类型：
--
作者：
Sage,CR;Davis,AS;Dougherty,CA;Sullivan,K;Farrell,KW
微管(MT)在细胞内的动态在空间和时间上都不同，被认为对MT细胞的正常功能很重要。由于MT动力学似乎与β-微管蛋白亚基的鸟苷三磷酸酶(GTP酶)活性密切相关，因此我们研究了MT动力学在芽殖酵母中的重要性。通过在单个β微管蛋白基因TUB2的一个区域引入T107K点突变，在体外影响MTS装配依赖的GTP酶活性。用视频增强差示干涉显微镜对MT的动态行为进行分析，发现T107K亚基在体外减慢了单个MT的生长速度和灾难性的解体速度。在单倍体细胞Stub2-T107K是致命的；但tub2-T107K/tub2-590杂合子突变是活的，显性的，通过有丝分裂减缓细胞周期进展，而不会导致细胞MTS的大规模中断。MTS在体外的缓慢生长和缩短速率与体内较慢的有丝分裂之间的相关性表明，MT动态在萌芽酵母中是重要的，并可能调节核移动和分离的速度。突变细胞中较慢的有丝分裂不会导致过早的胞质分裂和细胞死亡，这进一步表明，细胞周期控制机制可能通过直接监测MT动态来“感觉”有丝分裂放缓。©1995 Wiley-Liss公司
Microtubule (MT) dynamics vary both spatially and temporally within cells and are thought to be important for proper MT cellular function. Because MT dynamics appear to be closely tied to the guanosine triphosphatase (GTPase) activity of β‐tubulin subunits, we examined the importance of MT dynamics in the budding yeastS. cerevisiaeby introducing aT107Kpoint mutation into a region of the single β‐tubulin gene,TUB2, known to affect the assembly‐dependent GTPase activity of MTs in vitro. Analysis of MT dynamic behavior by video‐enhanced differential interference contrast microscopy, revealed thatT107Ksubunits slowed both the growth rates and catastrophic disassembly rates of individual MTs in vitro. In haploid cellstub2‐T107Kis lethal; but intub2‐T107K/tub2‐590heterozygotes the mutation is viable, dominant, and slows cell‐cycle progression through mitosis, without causing wholesale disruption of cellular MTs. The correlation between the slower growing and shortening rates of MTs in vitro, and the slower mitosis in vivo suggests that MT dynamics are important in budding yeast and may regulate the rate of nuclear movement and segregation. The slower mitosis in mutant celis did not result in premature cytokinesis and cell death, further suggesting that cell‐cycle control mechanisms “sense” the mitotic slowdown, possibly by monitoring MT dynamics directly. © 1995 Wiley‐Liss, Inc.