Moesin: Proteins and Enzymes

Moesin (membrane-organizing extension spike protein) has previously been characterized as a possible receptor protein for heparan sulfate and also as a cytoskeletal linker protein that stabilizes cell surface microvilli, filopodia and lamellipodia. Data indicate that moesin is identical to the 77-kDa band that copurifies with ezrin in its isolation from human placenta (1). Members of the ezrin-radixin-moesin (ERM) family of membrane-cytoskeletal linking proteins have NH2- and COOH-terminal domains that associate with the plasma membrane and the actin cytoskeleton, respectively (2). It has been demonstrated that ezrin-radixin-moesin proteins are rapidly inactivated after antigen recognition through a Vav1-Rac1 pathway. The resulting disanchoring of the cortical actin cytoskeleton from the plasma membrane decreased cellular rigidity, leading to more efficient T cell-antigen-presenting cell conjugate formation (3).