Phospholipids differently modulate the activity of cytosolic protein-tyrosine kinase from porcine spleen.
Effect of membrane phospholipids on the activity of cytosolic protein-tyrosine kinase from porcine spleen (CPTK-40) has been studied. Using poly(Glu Na, Tyr)4:1 as a substrate, phosphatidylethanolamine, phosphatidylcholine and phosphatidylserine had stimulatory effects on that phosphorylation activity, however phosphatidic acid had inhibitory and phosphatidylinositol had no effects. Similar results were obtained using[Val5]angiotensin II as a substrate. On the other hand using basic protein (H2B histone and myelin basic protein) as substrates, phosphatidic acid stimulated the activity of CPTK-40, while phosphatidylinositol inhibited the activity. Phosphatidylethanolamine, phosphatidylcholine and phosphatidylserine caused different effect on the activity of CPTK-40 depending on the substrate employed. However using acidic protein (tubulin and casein) as substrates, the activity of CPTK-40 was neither stimulated nor inhibited by any phospholipids. These results suggest that phospholipids may modulate the activity of CPTK-40.
Sakai
K
K
Department of Biochemistry, Fukui Medical School, Japan.
Taniguchi
T
T
Shimomura
R
R
Asahi
M
M
Kobayashi
T
T
Inazu
T
T
Nakamura
S
S
Yamamura
H
H
D000818:Animals; D003600:Cytosol / Q000201:enzymology; D007700:Kinetics; D008051:Lipid Bilayers; D010743:Phospholipids / Q000494:pharmacology*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D013154:Spleen / Q000201:enzymology*; D013552:Swine
D008051:Lipid Bilayers; D010743:Phospholipids; D011505:Protein-Tyrosine Kinases