The small GTPase Rho3 and the diaphanous/formin For3 function in polarized cell growth in fission yeast
The small GTPase Rho3 and the diaphanous/formin For3 function in polarized cell growth in fission yeast
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DOI：
10.1242/jcs.00150
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发表时间：
2002-12-01
影响因子：
4
通讯作者：
Mabuchi, I
中科院分区：
文献类型：
--
作者：
Nakano, K;Imai, J;Mabuchi, I
我们在裂殖酵母裂殖酵母中发现了一个新的Rho基因rho 3（+），并研究了它与裂殖酵母中的transphanous/transphanous for 3（+）的相互作用。rho 3 null细胞和for 3 null细胞不仅在肌动蛋白细胞骨架的组织中表现出缺陷，而且在细胞质微管（MT）中也表现出缺陷。rho 3for 3双无效细胞具有比每个单个无效细胞更严重的缺陷：极化生长在双无效细胞中是缺陷的。For 3的功能需要高度保守的FH 1和F112结构域、含有Rho结合结构域的N端区域和C端区域。For 3与Rho 3和Cdc 42的活性形式结合，但不与Rho 1结合。For 3以点状分布于间期细胞的末端和分裂细胞的中部。这种定位可能依赖于它与Rho蛋白的相互作用。过表达的For 3产生巨大的肿胀细胞含有去极化的F-肌动蛋白补丁和厚厚的细胞质NIT束。此外，组成型活性Rho 3Q 71 L的过表达诱导了胞质分裂的强烈缺陷。综上所述，我们提出Rho 3-For 3信号系统通过控制肌动蛋白细胞骨架和MT在裂殖酵母的极化细胞生长中起作用。
We identified a novel Rho gene rho3(+) and studied its interaction with diaphanous/formin for3(+) in the fission yeast Schizosaccharomyces pombe. Both rho3 null cells and for3 null cells showed defects in organization of not only actin cytoskeleton but also cytoplasmic microtubules (MTs). rho3 for3 double null cells had defects that were more severe than each single null cell: polarized growth was deficient in the double null cells. Function of For3 needed the highly conserved FH1 and F112 domains, an N-terminal region containing a Rho-binding domain, and the C-terminal region. For3 bound to active forms of both Rho3 and Cdc42 but not to that of Rho1. For3 was localized as dots to the ends of interphase cells and to the mid-region in dividing cells. This localization was probably dependent on its interaction with Rho proteins. Overexpression of For3 produced huge swollen cells containing depolarized F-actin patches and thick cytoplasmic NIT bundles. In addition, overexpression of a constitutively active Rho3Q71L induced a strong defect in cytokinesis. In conclusion, we propose that the Rho3-For3 signaling system functions in the polarized cell growth of fission yeast by controlling both actin cytoskeleton and MTs.