The phosphorylation and activation of B-raf in PC12 cells stimulated by nerve growth factor.
Treatment of PC12 cells with nerve growth factor does not alter the levels of B-raf mRNA, but does induce rapid phosphorylation of B-raf proteins. Phosphorylation was observed after 1.5 min and reached a maximum by 10-15 min. B-raf protein was phosphorylated almost exclusively on serine residues; no tyrosine phosphorylation was detected. Nerve growth factor-induced phosphorylation was not affected by depletion of protein kinase C or by removal of extracellular calcium but was inhibited by K-252a. Concomitant with the increase in serine phosphorylation, nerve growth factor treatment also increased the serine/threonine kinase activity of B-raf protein within 1-2 min.
Oshima
M
M
Section on Growth Factors, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
Sithanandam
G
G
Rapp
U R
UR
Guroff
G
G
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D002227:Carbazoles / Q000494:pharmacology; D026121:Indole Alkaloids; D007700:Kinetics; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009842:Oligopeptides / Q000138:chemical synthesis / Q000276:immunology; D016716:PC12 Cells; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D019908:Proto-Oncogene Proteins c-raf; D013379:Substrate Specificity
D000906:Antibodies; D002227:Carbazoles; D026121:Indole Alkaloids; D009414:Nerve Growth Factors; D009842:Oligopeptides; D011518:Proto-Oncogene Proteins; C049985:staurosporine aglycone; D011494:Protein Kinases; D019908:Proto-Oncogene Proteins c-raf; D011493:Protein Kinase C