학술논문

Specific integrin α and ß chain phosphorylations regulate LFA-1 activation through affinity-development and -independent mechanisms.
Document Type
Article
Source
Journal of Cell Biology. 11/21/2005, Vol. 171 Issue 4, p705-715. 11p.
Subject
*INTEGRINS
*PHOSPHORYLATION
*CHEMICAL reactions
*COHESION
*ADHESION
*ADSORPTION (Chemistry)
*GLYCOPROTEINS
*CELL adhesion molecules
*BIOMOLECULES
Language
ISSN
0021-9525
Abstract
Integrins are adhesion receptors that are crucial to the functions of multicellular organisms. Integrin-mediated adhesion is a complex process that involves both affinity regulation and cytoskeletal coupling, but the molecular mechanisms behind this process have remained incompletely understood. In this study, we report that the phosphorylation of each cytoplasmic domain of the leukocyte function-associated antigen-1 integrin mediates different modes of integrin activation. α Chain phosphorylation on Ser1140 is needed for conformational changes in the integrin after chemokine- or integrin ligand-induced activation or after activation induced by active Rap1 (Rap1V12). In contrast, the β chain Thr758 phosphorylation mediates selective binding to 14-3-3 proteins in response to inside-out activation through the T cell receptor, resulting in cytosketetal rearrangements. Thus, site-specific phosphorylation of the integrin cytoplasmic domains is important for the dynamic regulation of these complex receptors in cells. [ABSTRACT FROM AUTHOR]