Expression of a novel form of the fyn proto-oncogene in hematopoietic cells.
The fyn proto-oncogene encodes a 59-kD membrane-associated protein-tyrosine kinase that is implicated in the control of cell growth. We report here that there are two distinct fyn-encoded transcripts that exhibit mutually exclusive expression patterns; one form is found in thymocytes, splenocytes, and some hematolymphoid cell lines, while a second form accumulates principally in brain. The thymocyte and brain forms of p59fyn differ in their kinase domains, and are generated by mutually exclusive alternative splicing of a single exon. Immunoprecipitation followed by in vitro autophosphorylation demonstrates that both forms of p59fyn are enzymatically active. Our results define a novel form of the p59fyn protein-tyrosine kinase, with an altered catalytic domain, that apparently participates in a specialized signal transduction pathway in hematopoietic cells.
Cooke
M P
MP
Howard Hughes Medical Institute, University of Washington, Seattle 98195.
Perlmutter
R M
RM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000201:enzymology*; D002460:Cell Line; D004790:Enzyme Induction; D005091:Exons; D016391:Genes, src; D006801:Humans; D007527:Isoenzymes / Q000235:genetics* / Q000502:physiology; D008221:Lymphoid Tissue / Q000737:chemistry / Q000166:cytology; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000235:genetics* / Q000502:physiology; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000502:physiology; D051076:Proto-Oncogene Proteins c-fyn; D012326:RNA Splicing; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D013601:T-Lymphocytes / Q000201:enzymology*
D007527:Isoenzymes; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; C494957:FYN protein, human; C494960:Fyn protein, mouse; D051076:Proto-Oncogene Proteins c-fyn