Nerve growth factor stimulates the tyrosine phosphorylation of MAP2 kinase in PC12 cells.
NGF treatment of PC12 cells results in the rapid activation of MAP2 kinase. We report here that the induction of enzyme activity was correlated with the phosphorylation of MAP2 kinase, detected by metabolic labeling of the enzyme and with anti-phosphotyrosine antibodies. NGF stimulated the phosphorylation of MAP2 kinase on tyrosine, as well as serine and threonine residues. Western blot analysis using a polyclonal anti-phosphotyrosine antibody demonstrated that the tyrosine phosphorylation of MAP2 kinase was maximal within 2 min following NGF exposure and preceded the induction of MAP2 kinase activity. The NGF-stimulated tyrosine phosphorylation of an identified substrate provides direct evidence for the participation of a tyrosine kinase in the mechanism of action of NGF.
Schanen-King
C
C
Medical Scientist Training Program, Medical University of South Carolina, Charleston 29425.
Nel
A
A
Williams
L K
LK
Landreth
G
G
D000310:Adrenal Gland Neoplasms; D000818:Animals; D015153:Blotting, Western; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002460:Cell Line; D007700:Kinetics; D008970:Molecular Weight; D009414:Nerve Growth Factors / Q000494:pharmacology*; D010673:Pheochromocytoma; D010750:Phosphoproteins / Q000302:isolation & purification; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D014443:Tyrosine
D009414:Nerve Growth Factors; D010750:Phosphoproteins; D014443:Tyrosine; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases