A mutant plasma membrane ATPase, Pma1-10, is defective in stability at the yeast cell surface
A mutant plasma membrane ATPase, Pma1-10, is defective in stability at the yeast cell surface
复制标题
DOI：
10.1073/pnas.161282998
复制
发表时间：
2001-07-31
影响因子：
11.1
通讯作者：
Chang, A
中科院分区：
文献类型：
--
作者：
Gong, XH;Chang, A
Pma1是一种质膜ht - atp酶，其在细胞表面的活性对细胞生存至关重要。在本文中，我们描述了一个温度敏感的pma1等位基因pma1-10（在pma1的第一个细胞质环上有两个点突变），其中新合成的突变蛋白在37度时不能在细胞表面保持稳定。相反，Pma1-10似乎以依赖于End4、Vps27、Doa4和Pep4的方式进行液泡降解的内在化。与野生型Pma1相比，突变型Pma1-10是低磷酸化的，并且在37度时不能与triton不溶性部分结合，这表明不能进入脂筏。动力学分析表明，在允许的温度下，新合成的Pma1-10在稳定之前获得了triton不溶性。我们认为磷酸化和脂筏结合可能在维持质膜蛋白稳定性方面发挥重要作用。
Pma1 is a plasma membrane HT-ATPase whose activity at the cell surface is essential for cell viability. In this paper we describe a temperature-sensitive pma1 allele, pma1-10 (with two point mutations in the first cytoplasmic loop of Pma1}, in which the newly synthesized mutant protein fails to remain stable at the cell surface at 37 degreesC. Instead, Pma1-10 appears to undergo internalization for vacuolar degradation in a manner dependent on End4, Vps27, Doa4, and Pep4. By contrast with wild-type Pma1, mutant Pma1-10 is hypophosphorylated and fails to associate with a Triton-insoluble fraction at 37 degreesC, suggesting failure to enter lipid rafts. Kinetic analysis reveals that, at the permissive temperature, newly synthesized Pma1-10 acquires Triton-insolubility before becoming stabilized. We suggest that phosphorylation and lipid raft association may play important rotes in maintaining protein stability at the plasma membrane.