Autophosphorylation activity and association with Src family kinase of Sky receptor tyrosine kinase.
"Sky" is a putative receptor tyrosine kinase predominantly expressed in the brain. Sky, like Axl/Ufo/Ark and c-Eyk, has an extracellular domain composed of two immunoglobulin-like domains and two fibronectin type III domains. Immunoblot analysis using an antibody raised against a C-terminal peptide of Sky identified a 98-kDa Sky protein in COS cells transfected with sky cDNA (COS/sky cells). A 98-kDa protein in the immunoprecipitates with anti-Sky antibody was autophosphorylated on tyrosine, by in vitro kinase reaction. When the lysates of COS/sky cells were immunoprecipitated with anti-Sky antibody and immunoblotted with an anti-phosphotyrosine antibody, a 60-kDa phosphotyrosine-containing protein, in addition to the tyrosine-phosphorylated Sky, was detected. Using the anti-Src antibody, which is reactive to Src, Fyn and Yes, we obtained evidence for an association between the Src family tyrosine kinase and the tyrosine-phosphorylated Sky receptor. These results suggest that the Src family kinase may play an important role in signal transduction of the Sky receptor.
Toshima
J
J
Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.
Ohashi
K
K
Iwashita
S
S
Mizuno
K
K
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D006801:Humans; D066298:In Vitro Techniques; D008024:Ligands; D008969:Molecular Sequence Data; D005810:Multigene Family; D010455:Peptides / Q000737:chemistry; D010766:Phosphorylation; D011233:Precipitin Tests; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000737:chemistry; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D015398:Signal Transduction
D008024:Ligands; D010455:Peptides; D020794:Receptor Protein-Tyrosine Kinases; C084944:TYRO3 protein, human; D016392:Proto-Oncogene Proteins pp60(c-src)