Background:

PT 1 is a selective activator of AMPK with EC50 value of 0.3 μM for AMPK α1β1γ1 [1].

AMP-activated protein kinase (AMPK) is serine/threonine protein kinase that involved in cellular energy homeostasis and acts as an energy sensor. AMPK is a heterotrimer and increases ATP generation [1].

PT 1 is a selective AMPK activator. PT1 activated human AMPK α_x0001_1394, AMPK α2398 and AMPK(α1β1γ1) with EC50 values of 8, 12 and 0.3 μM, respectively. PT1 exhibited maximum activity against AMPK(α1β1γ1) at concentration up to 5 μM. PT1 exhibited high selectivity for AMPK_x0001_ α catalytic subunit. PT1 activated truncated AMPK α_x0001_1 subunit proteins including 313-335 aa with EC50 values of 8 μM, which was autoinhibitory domain. In HeLa cells without LKB1, PT1 induced AMPK and ACC phosphorylation, which were independent of LKB1. In human hepatoma HepG2 cells, PT1 dose-dependently reduced triacylglycerol and cholesterol content and induced AMPK and ACC phosphorylation [1]. In incubated mouse muscle, PT-1 increased γ1-containing AMPK activity and increased the AMPK-dependent phosphorylation of ULK1 on Ser555. However, in HEK293 cells expressing human γ1-, γ2- or γ3-AMPK, PT-1 activated them equally [2].

参考文献:
[1].  Pang T, Zhang ZS, Gu M, et al. Small molecule antagonizes autoinhibition and activates AMP-activated protein kinase in cells. J Biol Chem, 2008, 283(23): 16051-16060.
[2].  Jensen TE, Ross FA, Kleinert M, et al. PT-1 selectively activates AMPK-γ1 complexes in mouse skeletal muscle, but activates all three γ subunit complexes in cultured human cells by inhibiting the respiratory chain. Biochem J, 2015, 467(3): 461-472.