Interactions with the Environment Program, Immune System Development and Function Unit, Centro de Biología Molecular "Severo Ochoa" (CBMSO). CSIC-UAM, 28049 Madrid, Spain.
Int J Mol Sci. 2020 Feb 22;21(4):1502. doi: 10.3390/ijms21041502.
Ezrin, radixin and moesin proteins (ERMs) are plasma membrane (PM) organizers that link the actin cytoskeleton to the cytoplasmic tail of transmembrane proteins, many of which are adhesion receptors, in order to regulate the formation of F-actin-based structures (e.g., microspikes and microvilli). ERMs also effect transmission of signals from the PM into the cell, an action mainly exerted through the compartmentalized activation of the small Rho GTPases Rho, Rac and Cdc42. Ezrin and moesin are the ERMs more highly expressed in leukocytes, and although they do not always share functions, both are mainly regulated through phosphatidylinositol 4,5-bisphosphate (PIP) binding to the N-terminal band 4.1 protein-ERM (FERM) domain and phosphorylation of a conserved Thr in the C-terminal ERM association domain (C-ERMAD), exerting their functions through a wide assortment of mechanisms. In this review we will discuss some of these mechanisms, focusing on how they regulate polarization and migration in leukocytes, and formation of actin-based cellular structures like the phagocytic cup-endosome and the immune synapse in macrophages/neutrophils and lymphocytes, respectively, which represent essential aspects of the effector immune response.
埃兹蛋白、根蛋白和膜突蛋白（ERM）是质膜（PM）组织者，将肌动蛋白细胞骨架与跨膜蛋白的细胞质尾巴连接起来，其中许多是粘附受体，以调节基于 F-肌动蛋白的结构的形成（例如，微刺和微绒毛）。ERM 还通过将 PM 中的信号传递到细胞内，从而发挥作用，主要通过小 Rho GTPases Rho、Rac 和 Cdc42 的分隔激活来发挥作用。埃兹蛋白和膜突蛋白是白细胞中表达较高的 ERM，尽管它们并不总是具有相同的功能，但它们主要通过与 N 端带 4.1 蛋白-ERM（FERM）结构域结合的磷脂酰肌醇 4,5-二磷酸（PIP）和 C 端 ERM 结合结构域（C-ERMAD）中的保守 Thr 磷酸化来调节，通过广泛的机制发挥其功能。在这篇综述中，我们将讨论其中的一些机制，重点讨论它们如何调节白细胞的极化和迁移，以及在巨噬细胞/中性粒细胞和淋巴细胞中分别形成基于肌动蛋白的细胞结构，如吞噬杯-内体和免疫突触，这是效应免疫反应的重要方面。
