Pan1p, End3p, and Sla1p, Three Yeast Proteins Required for Normal Cortical Actin Cytoskeleton Organization, Associate with Each Other and Play Essential Roles in Cell Wall Morphogenesis
Pan1p, End3p, and Sla1p, Three Yeast Proteins Required for Normal Cortical Actin Cytoskeleton Organization, Associate with Each Other and Play Essential Roles in Cell Wall Morphogenesis
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DOI：
10.1128/mcb.20.1.12-25.2000
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发表时间：
2000-01
影响因子：
5.3
通讯作者：
Hsin-Yao Tang;Jinghuai Xu;M. Cai
中科院分区：
文献类型：
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作者：
Hsin-Yao Tang;Jinghuai Xu;M. Cai
摘要芽殖酵母EH结构域蛋白Pan 1 p和End 3 p在体内形成复合物，在肌动蛋白细胞骨架的组织和胞吞过程中起重要作用。在这份报告中，我们描述了有关Pan 1 p-End 3 p复合物功能的新发现。首先，我们发现Pan 1 p-End 3 p复合物与Sla 1 p相关，Sla 1 p是另一种已知的皮质肌动蛋白结构组装所需的蛋白质。Sla 1 p与Pan 1 p的第一个长重复区和End 3 p的N-末端EH结构域相互作用，从而使Pan 1 p-End 3 p相互作用不受干扰，这需要Pan 1 p的第二个长重复区和End 3 p的C-末端重复区。其次，Pan 1 p、End 3 p和Sla 1 p也是正常细胞壁形态发生所必需的。Pan 1 -4、sla 1 Δ和end 3 Δ突变体均显示出先前报道的act 1 -1突变体的异常细胞壁形态。这些细胞壁缺陷也表现为野生型细胞过度产生负责与Pan 1 p和End 3 p相互作用的Sla 1 p的C末端区域。这些结果表明，Pan 1 p，End 3 p和Sla 1 p在细胞壁形态发生中的功能可能取决于异源三聚体复合物的形成。有趣的是，这些细胞表现出的细胞壁异常是独立的肌动蛋白细胞骨架组织的细胞皮质，因为它们表现出，尽管存在明显正常的皮质肌动蛋白细胞骨架。对几个act 1突变体的研究也支持这一结论。这些观察结果表明，Pan 1 p-End 3 p-Sla 1 p复合物不仅是正常肌动蛋白细胞骨架组织所需的，也是酵母细胞壁形态发生所需的。
ABSTRACT The EH domain proteins Pan1p and End3p of budding yeast have been known to form a complex in vivo and play important roles in organization of the actin cytoskeleton and endocytosis. In this report, we describe new findings concerning the function of the Pan1p-End3p complex. First, we found that the Pan1p-End3p complex associates with Sla1p, another protein known to be required for the assembly of cortical actin structures. Sla1p interacts with the first long repeat region of Pan1p and the N-terminal EH domain of End3p, thus leaving the Pan1p-End3p interaction, which requires the second long repeat of Pan1p and the C-terminal repeat region of End3p, undisturbed. Second, Pan1p, End3p, and Sla1p are also required for normal cell wall morphogenesis. Each of the Pan1-4, sla1Δ, andend3Δ mutants displays the abnormal cell wall morphology previously reported for the act1-1 mutant. These cell wall defects are also exhibited by wild-type cells overproducing the C-terminal region of Sla1p that is responsible for interactions with Pan1p and End3p. These results indicate that the functions of Pan1p, End3p, and Sla1p in cell wall morphogenesis may depend on the formation of a heterotrimeric complex. Interestingly, the cell wall abnormalities exhibited by these cells are independent of the actin cytoskeleton organization on the cell cortex, as they manifest despite the presence of apparently normal cortical actin cytoskeleton. Examination of several act1 mutants also supports this conclusion. These observations suggest that the Pan1p-End3p-Sla1p complex is required not only for normal actin cytoskeleton organization but also for normal cell wall morphogenesis in yeast.