PMID: 29657085

Authors:

Ngoei KRW, Langendorf CG, Ling NXY, Hoque A, Varghese S, Camerino MA, Walker SR, Bozikis YE, Dite TA, Ovens AJ, Smiles WJ, Jacobs R, Huang H, Parker MW, Scott JW, Rider MH, Foitzik RC, Kemp BE, Baell JB, Oakhill JS

Title:

Structural Determinants for Small-Molecule Activation of Skeletal Muscle AMPK alpha2beta2gamma1 by the Glucose Importagog SC4.

Journal:

Cell Chem Biol. 2018 Apr 12. pii: S2451-9456(18)30110-7. doi:, 10.1016/j.chembiol.2018.03.008.

Abstract:

The AMP-activated protein kinase (AMPK) alphabetagamma heterotrimer regulates cellular energy homeostasis with tissue-specific isoform distribution. Small-molecule activation of skeletal muscle alpha2beta2 AMPK complexes may prove a valuable treatment strategy for type 2 diabetes and insulin resistance. Herein, we report the small-molecule SC4 is a potent, direct AMPK activator that preferentially activates alpha2 complexes and stimulates skeletal muscle glucose uptake. In parallel with the term secretagog, we propose "importagog" to define a substance that induces or augments cellular uptake of another substance. Three-dimensional structures of the glucose importagog SC4 bound to activated alpha2beta2gamma1 and alpha2beta1gamma1 complexes reveal binding determinants, in particular a key interaction between the SC4 imidazopyridine 4'-nitrogen and beta2-Asp111, which provide a design paradigm for beta2-AMPK therapeutics. The alpha2beta2gamma1/SC4 structure reveals an interaction between a beta2 N-terminal alpha helix and the alpha2 autoinhibitory domain. Our results provide a structure-function guide to accelerate development of potent, but importantly tissue-specific, beta2-AMPK therapeutics.