S6K1 Inhibitor, PF-4708671

Toxicity: Standard Handling (A)

A cell-permeable piperazinyl-pyrimidine compound that acts as an inhibitor against S6K1 (K_i = 20 nM; IC₅₀ = 160 nM) and MSK1 (IC₅₀ = 950 nM) kinase activity, exhibiting little or much reduced potency against a panel of 75 other protein kinases (IC₅₀ = 4.7, 9.2, 65 µM, respectively, against RSK1, RSK2, and S6K2; ≤27% inhibition of the rest at 1 µM) and 10 lipid kinases (≤6% inhibition at 10 µM). Inhibits IGF1-induced phosphorylation of cellular S6K1 substrates S6 (Ser^235/236 and Ser^240/244), mTOR (Ser²⁴⁴⁸), and Rictor (Thr¹¹³⁵) in serum-starved HEK-293 cultures, but not the phoshorylation of MSK or RSK cellular substrates (CREB Ser¹³³ and GSK3α/β Ser²¹/ Ser⁹, respectively) upon PMA stimulation even at concentrations as high as 10 µM. Inhibition of S6K1 activation by rapamycin (Cat. Nos. 553210, 553211, & 553212) or S6K1 activity by PF-4708671 (75/mg/kg/daily i.p.) are both shown to alleviate heart remodeling and functional damage following left coronary artery ligation-induced MI (myocardial infarction) in mice in vivo. Cellular PF-4708671 treatment is also reported to result in increased S6K1 phosphorylation, likely due to a blockage of down-stream negative feedback mechanism.

Di, R., et al. 2012. Biochem. J.441, 199.
Pearce, L.R., et al. 2010. Biochem. J.431, 245.

Packaged under inert gas

Following reconstitution, aliquot and freeze (-20°C.) Stock solutions are stable for up to 6 months at -20°C.

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