Overview
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Alomone Labs Wortmannin inhibits AKT phosphorylation via PI3-kinase in NIH-3T3 cells.Cells were preincubated for 30 min in different concentrations of LY 294002 (#L-300) or Wortmannin (#W-400) and then stimulated with PDGF (3 ng/ml) for 20 min. Cell proteins were resolved by SDS-PAGE and probed with (A) anti-phospho-AKT antibody, followed by stripping and reprobed with (B) anti-Akt antibody.
PI 3 Kinase is an enzyme implicated in growth factor signal transduction by associating with receptor and non-receptory tyrosine kinases. Wortmannin, a fungal metabolite (Penicillium fumiculosum), is a potent and specific inhibitor of phosphatidylinositol 3-kinase (PI-3K).1 It is highly cell-permeable, binds to the catalytic subunit of PI-3K and inhibits the enzyme activity in vitro and in vivo.2,3
In purified preparations and cell-free cytosolic fractions it is active at 5 nM. In fibroblasts Wortmannin abolishes PDGF-mediated Inositol(3,4,5) P3 formation (IC50 = 5 nM).4 In guinea pig neutrophils it inhibits fMLP induced PIP3 and superoxide anion production (IC50 = 50 nM), and also phospholipase D activation.5,6 In PC12 cells treated with NGF, Wortmannin blocks the elongation of neurites.7 In rat basophilic leukemia (RBL-2H3) cells it inhibits IgE mediated histamine secretion.8 At higher concentrations Wortmanin inhibits other kinases such as myosin light chain kinase (IC50 = 200 nM)9 and MAP kinase activation (IC50 = 200-300 nM) induced by platelet activating factor.10
