firstly , activation of protein kinase c in intact quiescent fibroblasts is one of the earliest events elicited by a variety of growth-promoting agents including serum , platelet-derived growth factor ( pdgf ) , vasopressin and bombesin , as judged by the increase in the phosphorylation of a cellular protein characterized by an mr of 80 000 and a pi of 5 .
C0016030
fibroblasts
C0007634
cellular