Biochem/physiol Actions

PF-670462 is a selective inhibitor of the δ- and ε-isoforms of casein kinase I, with IC₅₀ values of 7.7 and 14 nM respectively, and >30 selectivity relative to 42 other kinases tested. Casein kinase Iε phosphorylates PER proteins, which are involved in setting the period of the circadian pacemaker or clock. PF-670462 is potent (IC₅₀ 7.7 nM) and effective in vivo (i.e. it induces profound phase delays in circadian periodicity).