Polarized growth controls cell shape and bipolar bud site selection in Saccharomyces cerevisiae
Polarized growth controls cell shape and bipolar bud site selection in Saccharomyces cerevisiae
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DOI：
10.1128/mcb.20.14.5235-5247.2000
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发表时间：
2000-07-01
影响因子：
5.3
通讯作者：
Snyder, M
中科院分区：
文献类型：
--
作者：
Sheu, YJ;Barral, Y;Snyder, M
我们研究了极化生长和分裂位点选择之间的关系，这两个基本过程对真核生物的正常发育很重要。二倍体酿酒酵母细胞表现出椭圆体形状和特定的分裂模式（双极出芽模式）。我们发现极性基因SPA 2、PEA 2、BUD 6和BNI 1参与了芽形态发生的关键步骤--顶端生长。删除这些基因的结果在圆形细胞和减少芽伸长突变体表现出显着的顶端生长。极化分泌标记Sec 4的分布的检查表明，spa 2三角洲，pea 2三角洲，bud 6三角洲，和bni 1三角洲突变体不能集中Sec 4在芽尖在顶端生长过程中，并在分裂的网站在复极化细胞质分裂之前。此外，在这些突变体中，细胞表面扩展不限于芽的远端。此外，我们发现，p21激活的激酶同源物Ste 20也是重要的顶端生长和双极芽的网站选择。我们进一步研究了极化生长的持续时间如何影响双极芽位点的选择，通过使用细胞周期调节因子的突变来控制生长阶段的时间。grr 1 Delta突变通过稳定G（1）细胞周期蛋白增强顶端生长，并增加二倍体中的远极出芽。通过破坏G（2）/M细胞周期蛋白基因CLB 2延长极化生长期，增强了野生型、spa 2 Delta和ste 20 Delta细胞中芽位点选择的准确性，而通过删除SWE 1缩短极化生长期，降低了双极出芽的保真度。本研究报告的鉴定所需的组件顶端的增长，并证明了两极芽的网站选择极化增长的关键作用。我们建议，顶端的生长和复极化在胞质分裂的网站是至关重要的建立空间线索所使用的二倍体酵母细胞定位分裂平面。
We examined the relationship between polarized growth and division site selection, two fundamental processes important for proper development of eukaryotes. Diploid Saccharomyces cerevisiae cells exhibit an ellipsoidal shape and a specific division pattern (a bipolar budding pattern). We found that the polarity genes SPA2, PEA2, BUD6, and BNI1 participate in a crucial step of bud morphogenesis, apical growth. Deleting these genes results in round cells and diminishes bud elongation in mutants that exhibit pronounced apical growth. Examination of distribution of the polarized secretion marker Sec4 demonstrates that spa2 Delta, pea2 Delta, bud6 Delta, and bni1 Delta mutants fail to concentrate Sec4 at the bud tip during apical growth and at the division site during repolarization just prior to cytokinesis. Moreover, cell surface expansion is not confined to the distal tip of the bud in these mutants. In addition, we found that the p21-activated kinase homologue Ste20 is also important for both apical growth and bipolar bud site selection. We further examined how the duration of polarized growth affects bipolar bud site selection by using mutations in cell cycle regulators that control the timing of growth phases. The grr1 Delta mutation enhances apical growth by stabilizing G(1) cyclins and increases the distal-pole budding in diploids. Prolonging polarized growth phases by disrupting the G(2)/M cyclin gene CLB2 enhances the accuracy of bud site selection in wild-type, spa2 Delta, and ste20 Delta cells, whereas shortening the polarized growth phases by deleting SWE1 decreases the fidelity of bipolar budding. This study reports the identification of components required for apical growth and demonstrates the critical role of polarized growth in bipolar bud site selection. We propose that apical growth and repolarization at the site of cytokinesis are crucial for establishing spatial cues used by diploid yeast cells to position division planes.