Selective, reversible, and cell-permeable inhibitor of MAP kinase kinase (MEK) that acts by inhibiting the activation of MAP kinase and subsequent phosphorylation of MAP kinase substrates. Pretreatment of PC-12 cells with PD 98059 completely blocks the 4-fold increase in MAP kinase activity produced by nerve growth factor (NGF; IC
50 = 2 μM); however, it has no effect on NGF-dependent tyrosine phosphorylation of the p140
trk receptor or its substrate Shc and does not block NGF-dependent activation of PI 3-kinase. Blocks LPS-induced activation of TNF-α gene expression. Inhibits cell growth and reverses the phenotype of
ras-transformed BALB3T3 mouse fibroblasts and rat kidney cells. A 5 mg/ml solution of PD 98059 (Cat. No.
513001) in anhydrous DMSO is also available.