Molecular Interaction of the src Gene Product with Cellular Adhesion Plaques

Abstract

Publisher Summary This chapter summarizes the observations concerning the location of pp6O src within adhesion plaques and discusses the possible significance of adhesion plaques in the transformation mechanism. The results with these and other partial transformation mutants suggest that there are at least two separate molecular events dealing with pp60 src and adhesion plaques or adhesion-plaque components. One event involves the phosphorylation of vinculin on tyrosine. It is likely, although not yet certain, that pp60 src directly phosphorylates vinculin on tyrosine. A second molecular event dealing with pp60 src and adhesion plaques involves the physical binding and presence of pp60 src at these sites. The pp60 src of most viruses studied in the chapter bound to and was detectable at the adhesion-plaque sites under permissive conditions. CU 12-CEC, as well as CEC infected with several other fusiform mutants of Rous sarcoma virus (RSV), did not contain pp60 src in adhesion plaques. Thus, a specific region of pp60 src must control adhesion plaque binding. These two molecular events associated with pp60 src also correlate with separate parameters of the transformed cell. The binding of pp60 src to the adhesion plaques occurs independently of the kinase activity and is correlated with the absence of fibronectin in the extracellular matrix.