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Inhibition of Neuroblastoma Cell Phosphatidylinositol 3‐Kinase by CDP‐Diacylglycerol and Phosphatidate
Author(s) -
Lavie Yaakov,
Agranoff Bernard W.
Publication year - 1996
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1996.66020811.x
Subject(s) - diacylglycerol kinase , phosphatidate , phosphatidylinositol , kinase , microbiology and biotechnology , pi , signal transduction , biology , protein kinase c , biochemistry , chemistry
Phosphatidylinositol (PI) 3‐kinase is activated by a variety of agents, including various growth factors, and has been proposed to play a role in initiation of cell growth, proliferation, and differentiation. We here investigate the effect of various membrane lipids on PI 3‐kinase immunopurified from human SH‐SY5Y neuroblastoma cells. CDP‐diacylglycerol (CDP‐DAG) inhibited PI 3‐kinase activity with an IC 50 of 6 µ M . Phosphatidate (PA) was also inhibitory (IC 50 = 38 µ M ) as was lysophosphatidate. Neither DAG nor any of the other phospholipids examined affected PI 3‐kinase activity. The results offer the possibility that CDP‐DAG or PA at critical membrane sites may exert functionally significant metabolic regulation at the point of convergence of the PI 3‐kinase‐directed and the PI 4‐kinase‐directed phosphoinositide signal transduction pathways.