Epidermal growth factor activates phosphoinositide turnover and protein kinase C in BALB/MK keratinocytes.

TitleEpidermal growth factor activates phosphoinositide turnover and protein kinase C in BALB/MK keratinocytes.
Publication TypeJournal Article
Year of Publication1988
AuthorsMoscat J, Molloy CJ, Fleming TP, Aaronson SA
JournalMol Endocrinol
Date Published1988 Sep
KeywordsAnimals, Dose-Response Relationship, Drug, Epidermal Growth Factor, Epidermis, Keratins, Mice, Mice, Inbred BALB C, Phosphatidylinositols, Phosphorylation, Protein Kinase C, Thymidine

BALB/MK is a nontransformed epithelial cell line derived from primary BALB/c mouse keratinocytes that requires epidermal growth factor (EGF) for growth. Using a defined-medium culture system, we investigated the role of physiological concentrations of EGF on phosphoinositide metabolism in these cells. The results show that EGF rapidly activates phospholipase-C mediated phosphoinositide metabolism resulting in the generation of the second messengers inositol 1,4,5-trisphosphate and diacylglycerol. These metabolites control intracellular Ca2+ levels and activate protein kinase C, respectively. Protein kinase C activation in response to EGF was evidenced by the phosphorylation of the acidic 80 kilodalton endogenous protein substrate (p80) specific for this kinase. In contrast, insulin, which acts in concert with EGF to cause BALB/MK cell proliferation, had no effect on phosphoinositide metabolism nor led to any additional stimulation when added in combination with EGF. Taken together, our results show that rapid alterations in phosphoinositide metabolism and protein kinase C activation are associated with the normal mitogenic response of keratinocytes to EGF.

Alternate JournalMol Endocrinol
PubMed ID2459606
Related Faculty: 
Jorge Moscat, Ph.D.

Pathology & Laboratory Medicine 1300 York Avenue New York, NY 10065 Phone: (212) 746-6464
Surgical Pathology: (212) 746-2700