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Guanine nucleotides stimulate hydrolysis of phosphatidylinositol and polyphosphoinositides in permeabilized Swiss 3T3 cells
Author(s) -
Taylor Colin W.,
Blakeley Diane M.,
Brown Kenneth D.
Publication year - 1988
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(88)80193-5
Subject(s) - phosphatidylinositol , inositol , nucleotide , diacylglycerol kinase , biochemistry , hydrolysis , dephosphorylation , gtp' , guanine , sugar phosphates , inositol phosphate , chemistry , inositol trisphosphate , phosphatidylinositol 4,5 bisphosphate , gq alpha subunit , intracellular , phosphate , g protein , phosphorylation , phosphatase , enzyme , signal transduction , protein kinase c , receptor , gene
Hydrolysis‐resistant analogues of GTP specifically stimulate the formation of [ 3 H]inositol mono‐, bis‐ and trisphosphates by saponin‐permeabilized Swiss 3T3 cells prelabelled with [ 3 H]inositol. Each inositol phosphate is formed largely by hydrolysis of its parent lipid and not by dephosphorylation of inositol 1,4,5‐trisphosphate [(1,4,5)IP 3 ]. Although hydrolysis of phosphatidylinositol 4,5‐bisphosphate (PIP 2 ) is most sensitive to guanine nucleotides, hydrolysis of phosphatidylinositol (PI) and phosphatidylinositol 4‐phosphate (PIP) is quantitatively more important. These results suggest that a guanine nucleotide‐dependent regulatory protein(s) (G‐protein) is involved in regulating the hydrolysis of PI and PIP, as well as PIP 2 , and so may allow formation of diacylglycerol (DG) without simultaneous production of (1,4,5)IP 3 and mobilization of intracellular Ca 2+ .