Identification of a new in vitro substrate of tyrosine protein kinase.
Recent studies in our laboratory [Tokuda, M., Khanna, N.C., Aurora, A., & Waisman, D. M. (1986) Biochem. Biophys. Res. Commun. 139, 910-917] have identified in membranes of rat spleen two tyrosine protein kinases named TPK-I and TPK-II. In this paper the identification of the Ca2+ binding protein CAB-48 as a major in vitro substrate of TPK-II is reported. TPK-II catalyzed the incorporation of 0.73 mol of phosphate/mol of CAB-48. Phosphoamino acid analysis revealed that phosphorylation of CAB-48 was specific for tyrosine residues. Phosphorylation of CAB-48 by TPK-I (rat spleen), protein kinase C, casein kinase I, casein kinase II, cAMP-dependent protein kinase, or calcium calmodulin dependent protein kinase was not observed.
Tokuda
M
M
Department of Medical Biochemistry, University of Calgary, Alberta, Canada.
Kong
S K
SK
Khanna
N C
NC
Waisman
D M
DM
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001921:Brain; D002417:Cattle; D007700:Kinetics; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D013154:Spleen / Q000201:enzymology; D013379:Substrate Specificity
D000596:Amino Acids; D011505:Protein-Tyrosine Kinases