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Phosphatidylinositol 4,5‐bisphosphate stimulates protein kinaseC‐mediated phosphorylation of soluble brain proteins
Author(s) -
Chauhan Ved P.S.
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)80457-t
Subject(s) - phosphatidylinositol , phosphatidylinositol 4,5 bisphosphate , phosphorylation , chemistry , protein phosphorylation , biochemistry , microbiology and biotechnology , biophysics , protein kinase a , biology
Phosphatidylinositol 4,5‐bisphosphate (PIP 2 ) at 0.1 mol% activated the protein kinase C (PKC)‐mediated phosphorylation of 87‐, 55‐ and 47‐kDa brain proteins. Neomycin, an aminoglycoside antibiotic that binds PIP 2 with a high affinity, inhibited PIP 2 ·PKC activity in a concentration‐dependent manner. Low concentrations of neomycin (< 2 mM) did not affect DG·PKC activity; however, 4 mM neomycin inhibited 50% of this activity. This inhibition of DG‐stimulated activity at high neomycin concentration may be the result of its binding to Ca 2+ and ATP in the assay system. These results suggest that PIP 2 is a physiological activator of PKC, and show that neomycin can be an inhibitor of PIP 2 ·PKC activity at concentrations where DG·PKC activity is not affected.