Laboratoire des Colloïdes, Verres et Nanomatériaux, UMR CNRS-UM2 no. 5587, Université Montpellier 2, Place E. Bataillon, Montpellier Cedex 5, France.
Biochemistry. 2010 Nov 2;49(43):9318-27. doi: 10.1021/bi101141d.
The plasma membrane-cytoskeleton interface is a dynamic structure involved in a variety of cellular events. Ezrin, a protein from the ERM family, provides a direct linkage between the cytoskeleton and the membrane via its interaction with phosphatidylinositol 4,5-bisphosphate (PIP₂). In this paper, we investigate the interaction between PIP₂ and ezrin in vitro using PIP₂ dispersed in a unimolecular way in buffer. We compared the results obtained with full-length ezrin to those obtained with an ezrin mutant, which was previously found not to be localized at the cell membrane, and with the N-terminal membrane binding domain (FERM domain) of ezrin. We show that PIP₂ induced a conformational change in full-length ezrin. PIP₂ was also found to induce, in vitro, the formation of oligomers of wild-type ezrin, but not of mutant ezrin. These oligomers had previously been observed in vivo, but their role is yet to be clarified. Our finding hints at a possible role for PIP₂ in the formation of ezrin oligomers.
质膜-细胞骨架界面是一种动态结构，参与多种细胞事件。埃兹蛋白（Ezrin）是ERM 家族的一种蛋白质，通过与磷脂酰肌醇 4,5-二磷酸（PIP₂）的相互作用，为细胞骨架和膜之间提供直接连接。在本文中，我们使用在缓冲液中以单分子形式分散的 PIP₂，在体外研究 PIP₂与 ezrin 之间的相互作用。我们将所得结果与全长 ezrin 与先前发现未定位于细胞膜的 ezrin 突变体以及 ezrin 的 N 端膜结合结构域（FERM 结构域）进行了比较。我们表明 PIP₂ 诱导全长 ezrin 发生构象变化。还发现 PIP₂ 在体外诱导野生型 ezrin 形成寡聚体，但突变型 ezrin 则不会。这些寡聚体先前在体内观察到，但它们的作用尚未阐明。我们的发现暗示 PIP₂ 可能在 ezrin 寡聚体的形成中起作用。
