Fission yeast mod5p regulates polarized growth through anchoring of tea1p at cell tips
Fission yeast mod5p regulates polarized growth through anchoring of tea1p at cell tips
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DOI：
10.1038/nature01672
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发表时间：
2003-06-05
期刊：
影响因子：
64.8
通讯作者：
Sawin, KE
中科院分区：
文献类型：
--
作者：
Snaith, HA;Sawin, KE
微管在真核细胞极性中起核心作用（1），部分通过微管末端结合蛋白和细胞皮质之间的相互作用（2，3）。在裂殖酵母裂殖酵母中，微管和极性调节剂tea 1 p保持圆柱形细胞形状和严格的反足细胞生长（4-7）。tea 1 p蛋白通过与生长中的微管正末端（8）相结合被转运到细胞尖端;一旦到达细胞尖端，tea 1 p从微管末端释放并与细胞皮质相结合，在那里它协调极化生长（4，6）。在这里，我们描述了一种皮质蛋白，mod 5 p，它调节tea 1 p的动态行为。在mod 5Delta细胞中，tea 1 p在微管上被有效地运输到细胞尖端，但不能正确地锚在皮层，因此不能积累到正常水平。MOD 5 p含有羧基末端异戊烯化的信号，并且在野生型细胞中与细胞尖端的质膜结合。然而，在tea 1Delta细胞中，尽管mod 5 p仍然定位于质膜，但mod 5 p不再局限于细胞尖端。我们认为tea 1 p和mod 5 p在微管介导的细胞极性调节中起正反馈作用。
Microtubules have a central role in eukaryotic cell polarity(1), in part through interactions between microtubule end-binding proteins and the cell cortex(2,3). In the fission yeast Schizosaccharomyces pombe, microtubules and the polarity modulator tea1p maintain cylindrical cell shape and strictly antipodal cell growth(4-7). The tea1p protein is transported to cell tips by association with growing microtubule plus ends(8); once at cell tips, tea1p releases from microtubule ends and associates with the cell cortex, where it coordinates polarized growth(4,6). Here we describe a cortical protein, mod5p, that regulates the dynamic behaviour of tea1p. In mod5Delta cells, tea1p is efficiently transported on microtubules to cell tips but fails to anchor properly at the cortex and thus fails to accumulate to normal levels. mod5p contains a signal for carboxy-terminal prenylation and in wildtype cells is associated with the plasma membrane at cell tips. However, in tea1Delta cells, although mod5p remains localized to the plasma membrane, mod5p is no longer restricted to the cell tips. We propose that tea1p and mod5p act in a positive-feedback loop in the microtubule-mediated regulation of cell polarity.