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Published on: August 13, 2017
A novel phosphoinositide 3 kinase activity in myeloid-derived cells is activated by G protein beta gamma subunits
L Stephens1, A Smrcka, F T Cooke
1Agricultural and Food Research Council, Babraham Institute, Cambridge, England.
Abstract:
Phosphoinositide 3 kinase (PI3K) is a key signaling enzyme implicated in receptor-stimulated mitogenesis, oxidative bursting in neutrophils, membrane ruffling, and glucose uptake. A PI3K has already been purified, cloned, and shown to be regulated by receptors that act via tyrosine kinase-dependent regulatory mechanisms. We report that an immunologically, pharmacologically, and chromatographically distinct form of PI3K activity present in neutrophils and U937 cells is specifically activated by G protein beta gamma subunits. This data suggests PI3Ks conform to the paradigm set by receptor regulation of phosphoinositidase Cs: different receptor transduction systems specifically regulate dedicated isoforms of effector protein.
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