Tissue-Specific Expression and Possible Functions of pp60^c-src

Abstract

Although some remarkable progress has been made in identifying the function of a few proto-oncogene products such as c-erbB, c-fms, c-sis (see Wagner and Müller; Beug et al.; Sherr and Stanley; Heldin and Westermark, all this Vol.), the function of the c-src protein pp60^c-src has remained an enigma despite the fact that it was the very first proto-oncogene product identified (Collett et al. 1978). The difficulty in studying pp60^c-src is that it occurs at a very low abundance and that it is not easily accessible to the investigator since it is neither secreted nor located at the cell surface (as are the proto-oncogene products listed above). Nevertheless, several analyses of pp60^c-src expression in various tissues and stages of embryogenesis have recently been carried out, and the results promise to shed new light on the regulation of cell growth and differentiation. In the present review, I discuss the significance of these findings for a functional role of the c-src gene product.