Multistep and multimode cortical anchoring of tea1p at cell tips in fission yeast
Multistep and multimode cortical anchoring of tea1p at cell tips in fission yeast
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DOI：
10.1038/sj.emboj.7600838
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发表时间：
2005-11-02
期刊：
影响因子：
11.4
通讯作者：
Sawin, KE
中科院分区：
文献类型：
--
作者：
Snaith, HA;Samejima, I;Sawin, KE
裂殖酵母细胞极性调节剂 tea1p 通过与生长的微管末端结合而靶向细胞尖端。 Tea1p 随后通过一种未知机制锚定在细胞尖端的细胞皮质上，该机制需要 tea1p 羧基末端和膜蛋白 mod5p。在这里，我们证明了与 tea1p 相关的蛋白质 tea3p 独立地与 mod5p 和 tea1p 结合，并且 tea1p 和 mod5p 也可以独立于 tea3p 直接相互作用。尽管结构相关，但 tea1p 和 tea3p 的不同区域需要各自与 mod5p 的重要中心区域相互作用。我们证明，tea3p 是 tea1p 正确皮质定位所必需的，特别是在非生长细胞尖端，并且 tea1p 和 mod5p 是 tea3p 定位独立所需的。此外，我们发现与 GFP 或 mCherry 融合的 tea3p 与 tea1p 通过微管共同转运至细胞尖端，但这仅在 mod5p 不存在的情况下发生。这些结果表明，tea1p、tea3p 和 mod5p 之间独立的蛋白质-蛋白质相互作用共同有助于 tea1p 通过多步骤和多模式机制锚定在细胞尖端。
The fission yeast cell-polarity regulator tea1p is targeted to cell tips by association with growing microtubule ends. Tea1p is subsequently anchored at the cell cortex at cell tips via an unknown mechanism that requires both the tea1p carboxy-terminus and the membrane protein mod5p. Here, we show that a tea1p-related protein, tea3p, binds independently to both mod5p and tea1p, and that tea1p and mod5p can also interact directly, independent of tea3p. Despite their related structures, different regions of tea1p and tea3p are required for their respective interactions with an essential central region of mod5p. We demonstrate that tea3p is required for proper cortical localization of tea1p, specifically at nongrowing cell tips, and that tea1p and mod5p are independently required for tea3p localization. Further, we find that tea3p fused to GFP or mCherry is cotransported with tea1p by microtubules to cell tips, but this occurs only in the absence of mod5p. These results suggest that independent protein-protein interactions among tea1p, tea3p and mod5p collectively contribute to tea1p anchoring at cell tips via a multistep and multimode mechanism.