Tyrosyl phosphorylation and activation of a type II phosphatidylinositol 4-kinase by p56(lck) in concanavalin A stimulated rat splenic lymphocytes.
Recent evidence suggests that concanavalin A modulates tyrosyl phosphorylation and activation of a type II PtdIns 4-kinase in rat splenic lymphocytes. However, the regulatory protein tyrosine kinase(s) remain to be elusive. The present manuscript provides evidence that a type II PtdIns 4-kinase associates with p56(lck) in Con A stimulated rat splenic lymphocytes. In vitro phosphorylation studies suggest that p56(lck) regulates phosphorylation and activation of type II PtdIns 4-kinase. Inhibition of p56(lck) activity in vivo has shown to reduce tyrosyl phosphorylation and activation of PtdIns 4-kinase by Con A. These results suggest that p56(lck) may be the physiological regulator of type II PtdIns 4-kinase.
Fernandis
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Biotechnology Centre, Indian Institute of Technology, Bombay Powai, PIN 400076, Mumbal, India.
Subrahmanyam
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D019870:1-Phosphatidylinositol 4-Kinase / Q000145:classification / Q000378:metabolism*; D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology; D004789:Enzyme Activation; D066298:In Vitro Techniques; D007700:Kinetics; D008213:Lymphocyte Activation; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000378:metabolism*; D008214:Lymphocytes / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology*; D015739:Nocodazole / Q000494:pharmacology; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction; D014443:Tyrosine / Q000378:metabolism
D003208:Concanavalin A; D014443:Tyrosine; D019870:1-Phosphatidylinositol 4-Kinase; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D015739:Nocodazole