Platelet-derived growth factor receptors expressed by cDNA transfection couple to a diverse group of cellular responses associated with cell proliferation

Abstract

We have expressed the mouse platelet-derived growth factor (PDGF) receptor cDNA under transcriptional control of simian virus 40 promoter in Chinese hamster ovary cells, a cell type that lacks PDGF receptors. Stable transfectants expressed receptor protein that was recognized by antireceptor antibodies. PDGF stimulated a diverse group of responses in the transfected cells including tyrosine phosphorylation of the receptor and a 32-kDa cellular substrate, receptor internalization, phosphoinositide turnover, cytoplasmic alkalinization, changes in the intracellular calcium concentration, thymidine uptake into DNA, and cell division. There were no responses to PDGF in the control Chinese hamster ovary cells. After prolonged exposure to PDGF, the transfectants became refractory to subsequent PDGF stimulation and the receptor protein was no longer detectable. These data validate the authenticity of the PDGF receptor cDNA, show that transfection of a single type of receptor cDNA sequence confers PDGF sensitivity to a diverse group of cellular responses, and demonstrate that effector molecules that mediate the PDGF responses are present in cells that lack PDGF receptors.