Open AccessTyrosine phosphorylation is an early and specific event involved in primary keratinocyte differentiation.
Author(s) -
Ellen Filvaroff,
David F. Stern,
G. Paolo Dotto
Publication year - 1990
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.10.3.1164
Subject(s) - tyrosine phosphorylation , biology , phosphorylation , tyrosine , protein tyrosine phosphatase , tyrosine kinase , keratinocyte , receptor tyrosine kinase , microbiology and biotechnology , platelet derived growth factor receptor , cancer research , biochemistry , signal transduction , growth factor , in vitro , receptor
Very little is known about early molecular events triggering epithelial cell differentiation. We have examined the possible role of tyrosine phosphorylation in this process, as observed in cultures of primary mouse keratinocytes after exposure to calcium or 12-O-tetradecanoylphorbol-13-acetate (TPA). Immunoblotting with phosphotyrosine-specific antibodies as well as direct phosphoamino acid analysis revealed that induction of tyrosine phosphorylation occurs as a very early and specific event in keratinocyte differentiation. Very little or no induction of tyrosine phosphorylation was observed in a keratinocyte cell line resistant to the differentiating effects of calcium. Treatment of cells with tyrosine kinase inhibitors prevented induction of tyrosine phosphorylation by calcium and TPA and interfered with the differentiative effects of these agents. These results suggest that specific activation of tyrosine kinase(s) may play an important regulatory role in keratinocyte differentiation.