Possible endogenous substrate proteins for cytosolic protein-tyrosine kinase from porcine spleen.
1. Endogenous phosphate acceptor proteins by cytosolic protein-tyrosine kinase from porcine spleen (CPTK-40) were studied using subcellular fractions of porcine spleen and supernatant fraction of rat various tissues. 2. At least 13 phosphate acceptor proteins ranging from 94 to 26 kDa were observed in all but mitochondrial subcellular fractions. 3. Among the supernatant fraction of rat tissues, brain, testis and spleen contained many phosphate acceptor proteins. 4. The most heavily phosphorylated band of around 55 kDa which was commonly recognized among various tissues was confirmed as tubulin by the immunoreactivity with anti-tubulin antibody. 5. The results obtained in this paper indicate that CPTK-40 has the potential to catalyze the phosphorylation of numerous endogenous proteins including tubulin.
Shimomura
R
R
Department of Biochemistry, Fukui Medical School, Japan.
Taniguchi
T
T
Sakai
K
K
Asahi
M
M
Inazu
T
T
Yamamura
H
H
D000818:Animals; D001923:Brain Chemistry; D003600:Cytosol / Q000201:enzymology*; D008297:Male; D008928:Mitochondria / Q000201:enzymology; D008970:Molecular Weight; D010710:Phosphates / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D051381:Rats; D013154:Spleen / Q000737:chemistry / Q000201:enzymology* / Q000648:ultrastructure; D013379:Substrate Specificity; D013552:Swine; D013737:Testis / Q000737:chemistry
D010710:Phosphates; D010750:Phosphoproteins; D011505:Protein-Tyrosine Kinases