The interaction of ATP11C-b with ezrin contributes to its polarized localization
The interaction of ATP11C-b with ezrin contributes to its polarized localization
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DOI：
10.1242/jcs.258523
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发表时间：
2021-10-01
影响因子：
4
通讯作者：
Shin, Hye-Won
中科院分区：
文献类型：
--
作者：
Inoue, Hiroki;Takatsu, Hiroyuki;Shin, Hye-Won
ATP 11 C是P4-ATP酶家族的成员，在质膜上转运磷脂酰丝氨酸和磷脂酰乙醇胺。我们以前发现，其C-末端剪接变体ATP 11 C-b在运动细胞系中表现出极化定位，如MDA-MB-231和Ba/F3。在本研究中，我们发现ATP 11 C-b的C-末端胞质区域特异性地与ezrin相互作用。值得注意的是，ATP 11 C-b C-末端区域中的LLxY基序对于其与埃兹蛋白的相互作用以及其在质膜上的极化定位至关重要。一个组成型的活性，C-末端拟磷酸突变体ezrin与ATP 11 C-b在极化运动细胞共定位。ATP 11 C-b在单独消耗ezrin的细胞中部分错误定位，并且在同时消耗家族成员ezrin、根蛋白和膜突蛋白（ERM）的细胞中表现出更大的错误定位，这表明ERM蛋白，特别是ezrin，有助于ATP 11 C-b的极化定位。此外，Atp 11 c敲除导致C-端磷酸化的ERM蛋白的错误定位，这是由ATP 11 C-b而不是ATP 11 C-a的外源表达恢复。这些观察结果共同表明，ATP 11 C-b和ezrin的活性形式的质膜的极化定位是相互依赖地稳定的。
ATP11C, a member of the P4-ATPase family, translocates phosphatidylserine and phosphatidylethanolamine at the plasma membrane. We previously revealed that its C-terminal splice variant ATP11C-b exhibits polarized localization in motile cell lines, such as MDA-MB-231 and Ba/F3. In the present study, we found that the C-terminal cytoplasmic region of ATP11C-b interacts specifically with ezrin. Notably, the LLxY motif in the ATP11C-b C-terminal region is crucial for its interaction with ezrin as well as its polarized localization on the plasma membrane. A constitutively active, C-terminal phosphomimetic mutant of ezrin was colocalized with ATP11C-b in polarized motile cells. ATP11C-b was partially mislocalized in cells depleted of ezrin alone, and exhibited greater mislocalization in cells simultaneously depleted of the family members ezrin, radixin and moesin (ERM), suggesting that ERM proteins, particularly ezrin, contribute to the polarized localization of ATP11C-b. Furthermore, Atp11c knockout resulted in C-terminally phosphorylated ERM protein mislocalization, which was restored by exogenous expression of ATP11C-b but not ATP11C-a. These observations together indicate that the polarized localizations of ATP11C-b and the active form of ezrin to the plasma membrane are interdependently stabilized.