A point mutation at tyrosine-809 in the human colony-stimulating factor 1 receptor impairs mitogenesis without abrogating tyrosine kinase activity, association with phosphatidylinositol 3-kinase, or induction of c-fos and junB genes.
Substitution of phenylalanine for tyrosine-809 in the human colony-stimulating factor 1 receptor (CSF-1R) inhibited its ability to transduce ligand-dependent mitogenic signals in mouse NIH 3T3 cells. When combined with an "activating" mutation at codon 301 that induces constitutive CSF-1R tyrosine kinase activity, the codon 809 mutation suppressed ligand-independent cell transformation. Comparative mapping of tryptic phosphopeptides from mutant and wild-type CSF-1R indicated that tyrosine-809 is a site of ligand-dependent receptor phosphorylation in vivo. The mutant receptor was active as a tyrosine kinase in vitro and in vivo, underwent CSF-1-dependent association with a phosphatidylinositol 3-kinase, and induced expression of the protooncogenes c-fos and junB, underscoring its ability to trigger some of the known cellular responses to CSF-1. The mutant receptor is likely to be impaired in its ability to interact with critical cellular effectors whose activity is required for mitogenesis.
Roussel
M F
MF
Department of Tumor Cell Biology, Saint Jude Children's Research Hospital, Memphis, TN 38104.
Shurtleff
S A
SA
Downing
J R
JR
Sherr
C J
CJ
D000818:Animals; D001483:Base Sequence; D002455:Cell Division; D002460:Cell Line; D003062:Codon / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D015345:Oligonucleotide Probes; D010449:Peptide Mapping; D019869:Phosphatidylinositol 3-Kinases; D010748:Phosphopeptides / Q000302:isolation & purification; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D011519:Proto-Oncogenes; D016186:Receptor, Macrophage Colony-Stimulating Factor; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics*; D014443:Tyrosine
D003062:Codon; D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes; D010748:Phosphopeptides; D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors; D014443:Tyrosine; D010770:Phosphotransferases; D019869:Phosphatidylinositol 3-Kinases; D011505:Protein-Tyrosine Kinases; D016186:Receptor, Macrophage Colony-Stimulating Factor