Identification of a 32K plasma membrane protein that binds to the myristylated amino-terminal sequence of p60^v-src

Abstract

THE transforming protein of Rous sarcoma virus, p60^v-src, is a myristylated membrane-bound phosphoprotein^1–3. Interaction of p60^v-src with the plasma membrane is essential for transforming activity^4–5, and is mediated by association with a membrane-bound Src receptor protein⁶. Evidence for the existence of an Src receptor is based on the ability of a myristylated peptide containing the N-terminal Src sequence to inhibit binding of p60^v-src to plasma membranes in vitro: binding of p60^v-src to a plasma membrane receptor is therefore mediated by N-terminal Src sequences⁶. Here we report that a myristyl-Src peptide, but not the corresponding non-myristylated peptide, can be specifically crosslinked to a plasma membrane protein of relative molecular mass 32,000 (M_r 32K). The 32K protein represents an Src-binding protein in the plasma membrane that is likely to be a component of the myristyl-Src receptor, and which could be involved in cellular transformation.