Cytoskeletal protein radixin activates integrin alpha(M)beta(2) by binding to its cytoplasmic tail.
Talin binding of integrins, via its band 4.1, ezrin, radixin, and moesin (FERM)-homologous domain, directly activates the integrin receptor. However, it is not known whether other FERM-containing proteins also possess such an integrin activating capability. We report here that radixin, one of the original FERM-domain proteins, binds to the membrane-proximal region of the integrin beta(2) but not alpha(M) cytoplasmic tail. Importantly, we show that radixin binding significantly enhances the adhesive activity of integrin alpha(M)beta(2). Given the distinct biological activities of radixin and talin, radixin may represent a novel talin-independent pathway for integrin activation under specific settings.
Tang
Pingtao
P
Center for Vascular and Inflammatory Diseases, Department of Physiology, University of Maryland School of Medicine, 800 W Baltimore Street, Baltimore, MD 21201, USA.
Cao
Chunzhang
C
Xu
Min
M
Zhang
Li
L
D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D002448:Cell Adhesion; D006224:Cricetinae; D003412:Cricetulus; D003593:Cytoplasm / Q000737:chemistry; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D016177:Macrophage-1 Antigen / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D011485:Protein Binding; D014162:Transfection
D003598:Cytoskeletal Proteins; D016177:Macrophage-1 Antigen; D008565:Membrane Proteins; C071776:radixin