The insulin receptor-kinase complex: an integrated system for transmembrane hormone signalling.

receptor as well as phosphorylation of certain intracellular proteins. The intracellular messenger system that transmits the mitogenic signal from the receptor and to the nucleus is still largely unknown. Recent observations have indicated that the cellular homologue to the oncogene myc might be involved; stimulation of cells with PDGF leads to increased expression of rnyc with a maximum after 2 h (Kelley et al., 1983). A possible function for the PDGF-receptor-associated kinase may then be to activate proteins which specifically regulate the transcription of myc or of other genes coding for proteins involved in the regulation of mitogenesis.