Structure and Functions: ERM Protein Family

Abstract

Preservation of the structural integrity of the cell depends on the plasma membrane in eukaryotic cells. Interaction between plasma membrane, cytoskeleton and proper anchorage influence regular cellular processes. The needed regulated connection between the membrane and the underlying actin cytoskeleton is therefore made available by the ERM (Ezrin, Radixin, and Moesin) family of proteins. ERM proteins also afford the required environment for the diffusion of signals in reactions to extracellular signals. Other studies have confirmed the importance of ERM proteins in different mode organisms and in cultured cells to emphasize the generation and maintenance of specific domains of the plasma membrane. An essential attribute of almost all cells are the specialized membrane domains. They are specifically important to tissues like the intestinal brush border epithelium, with a highly organized cell cortex including a compound array of apical microvilli, an apical junctional complex, and a basolateral membrane domain. This paper critically looks at the structure and functions of the ERM proteins and briefly presents the activation and deactivation mechanism through careful analysis on works done on this protein and its prospects. It is obvious from the discussion presented in this paper that the ERM (Ezrin, Radixin, and Moesin) proteins play very vital roles in mediating signal transduction and maintaining cellular integrity from a variety of extracellular inputs through their interaction with different receptor tyrosine kinases (RTKs) such as EGFR and HGFR, adhesion and adaptor proteins such as E-cadherin, ICAM-1,2,3, NHERF and CD44, and other signaling pathways such as PI3K/Akt, cAMP/PKA and the Rho GTPases, all of which have been implicated in tumorigenesis; thus, making ERM proteins a crucial target in development of novel therapeutics in fighting cancer progression and other related disease conditions where the protein is implicated. Further analysis on the structure and reaction mechanism of this protein is needed to exploit its full potential for clinical and other uses.