Description
PF-4708671 is a cell-permeable inhibitor of p70 ribosomal S6 kinase (S6K1 isoform) with Ki/IC50 of 20 nM/160 nM, 400-fold greater selectivity for S6K1 than S6K2, and 4- and >20-fold selectivity FOR S6K1than MSK1 and RSK1/2, respectively. First S6K1-specific inhibitor to be reported.
Storage
2 years -20 centigrade Powder; 2 weeks 4 centigrade in DMSO; 6 months -80 centigrade in DMSO.
Molecular Formula
C19H21F3N6
Chemical Name
1H-Benzimidazole, 2-[[4-(5-ethyl-4-pyrimidinyl)-1-piperazinyl]methyl]-6-(trifluoromethyl)-
Solubility
DMSO 30 mg/mL; Water <1 mg/mL; Ethanol 8 mg/mL
In vitro
PF-4708671 is a piperazinyl-pyrimidine analogue and the first S6K1-specific inhibitor. PF-4708671 does not significantly inhibit the activity of the closely related S6K2 isoform or a number of other AGC kinases (Akt1, Akt2, PKA, PKCα, PKCϵ, PRK2, ROCK2, RSK1, RSK2 or SGK1) . PF-4708671 prevents the S6K1-mediated phosphorylation of S6 protein in response to IGF-1 (insulin-like growth factor 1), while having no effect upon the PMA-induced phosphorylation of substrates of the highly related RSK (p90 ribosomal S6 kinase) and MSK (mitogen- and stress-activated kinase) kinases. PF-4708671 is also found to induce phosphorylation of the T-loop and hydrophobic motif of S6K1, an effect that is dependent upon mTORC1 (mTOR complex 1). PF-4708671 does not affect activity of mTORC1.