Wsh3/Tea4 is a novel cell-end factor essential for bipolar distribution of Tea1 and protects cell polarity under environmental stress in S-pombe
Wsh3/Tea4 is a novel cell-end factor essential for bipolar distribution of Tea1 and protects cell polarity under environmental stress in S-pombe
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DOI：
10.1016/j.cub.2005.04.061
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发表时间：
2005-06-07
期刊：
影响因子：
9.2
通讯作者：
Shiozaki, K
中科院分区：
文献类型：
--
作者：
Tatebe, H;Shimada, K;Shiozaki, K
背景资料：裂殖酵母粟酒裂殖酵母具有圆柱形细胞形状，其生长严格限于两端，并且用作细胞极性测定的遗传分析的优良模型系统。先前的研究确定了一种细胞末端标记蛋白Teal，它由细胞质微管转运到细胞尖端，并招募其他细胞末端因子，包括Dyrk家族的Pom 1激酶。Delta tea 1突变体细胞不能以双极方式生长，热休克后显示T形形态。结果：我们确定Wsh 3/Tea 4作为一种新的蛋白质，与应激激活的MAP激酶级联反应中的Win 1 MAP激酶激酶激酶激酶（MAPKKK）相互作用。Wsh 3与Teal形成复合物，并通过生长的微管转运到细胞尖端。Delta wsh 3突变体显示单极生长，在非生长细胞末端具有异常Teal聚集体;这种异常聚集体无法招募Pom 1激酶。与观察到的Win和Wsh 3之间的相互作用一致，缺乏Wsh 3或Teal的细胞在渗透压和热应激刺激下显示出更严重的细胞极性缺陷，已知这些刺激会激活应激MAPK级联反应。此外，突变体的压力MAPK也表现出细胞极性缺陷时，暴露于相同的stress.Conclusions：Wsh 3/Tea 4是一个必不可少的组成部分Teal细胞末端复合物。除了在正常细胞周期中的双极生长中的作用外，Wsh 3-Tea 1复合物与应激信号MAPK级联反应一起有助于在应激条件下维持细胞极性。
Background: The fission yeast Schizosaccharomyces pombe has a cylindrical cell shape, for which growth is strictly limited to both ends, and serves as an excellent model system for genetic analysis of cell-polarity determination. Previous studies identified a cell-end marker protein, Teal, that is transported by cytoplasmic microtubules to cell tips and recruits other cell-end factors, including the Dyrk-family Pom1 kinase. The Delta tea1 mutant cells cannot grow in a bipolar fashion and show T-shaped morphology after heat shock.Results: We identified Wsh3/Tea4 as a novel protein that interacts with Win1 MAP kinase kinase kinase (MAPKKK) of the stress-activated MAP kinase cascade. Wsh3 forms a complex with Teal and is transported to cell tips by growing microtubules. The Delta wsh3 mutant shows monopolar growth with abnormal Teal aggregate at the non-growing cell end; this abnormal aggregate fails to recruit Pom1 kinase. Consistent with the observed interaction between Win and Wsh3, cells lacking Wsh3 or Teal show more severe cell-polarity defects under osmolarity and heat-stress stimuli that are known to activate the stress MAPK cascade. Furthermore, mutants of the stress MAPK also exhibit cell-polarity defects when exposed to the same stress.Conclusions: Wsh3/Tea4 is an essential component of the Teal cell-end complex. In addition to its role in bipolar growth during the normal cell cycle, the Wsh3-Tea1 complex, together with the stress-signaling MAPK cascade, contributes to cell-polarity maintenance under stress conditions.