Human colony stimulating factor-1 receptor activates the C-raf-1 proto-oncogene kinase.
The proto-oncogene c-raf-1 encodes a 74 kD serine/threonine kinase. Recently, it has been shown that Raf kinase activity is stimulated by platelet derived growth factor (PDGF) treatment of receptor bearing cells, and that p74 is a direct substrate for PDGF receptor. CSF-1 treatment of BeWo cells, a human choriocarcinoma cell line, and mouse NIH 3T3 cells expressing a transfected human CSF-1 receptor cDNA, was associated with a 3-4 fold increase in phosphorylation of a 74 kD protein immunoprecipitated with affinity purified Raf-1 antibody. The kinase activity of p74 was increased 2-3 fold against two exogenous substrates following CSF-1 treatment of the transfected cells. These observations suggest that Raf-1 protein is a downstream second messenger molecule in CSF-1 mediated signal transduction.
Choudhury
G G
GG
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio 78284-7762.
Sylvia
V L
VL
Pfeifer
A
A
Wang
L M
LM
Smith
E A
EA
Sakaguchi
A Y
AY
D000818:Animals; D002460:Cell Line; D005786:Gene Expression Regulation; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D051379:Mice; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D019908:Proto-Oncogene Proteins c-raf; D011519:Proto-Oncogenes; D016184:Receptors, Colony-Stimulating Factor / Q000235:genetics / Q000502:physiology*; D014162:Transfection
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D016184:Receptors, Colony-Stimulating Factor; D016173:Macrophage Colony-Stimulating Factor; D011505:Protein-Tyrosine Kinases; D019908:Proto-Oncogene Proteins c-raf