title: Small molecule drug A-769662 and AMP synergistically activate naive AMPK independent of upstream kinase signaling.
abstract: The AMP-activated protein kinase (AMPK) is a metabolic stress-sensing αβγ heterotrimer responsible for energy homeostasis, making it a therapeutic target for metabolic diseases such as type 2 diabetes and obesity. AMPK signaling is triggered by phosphorylation on the AMPK α subunit activation loop Thr172 by upstream kinases. Dephosphorylated, naive AMPK is thought to be catalytically inactive and insensitive to allosteric regulation by AMP and direct AMPK-activating drugs such as A-769662. Here we show that A-769662 activates AMPK independently of α-Thr172 phosphorylation, provided β-Ser108 is phosphorylated. Although neither A-769662 nor AMP individually stimulate the activity of dephosphorylated AMPK, together they stimulate >1,000-fold, bypassing the requirement for β-Ser108 phosphorylation. Consequently A-769662 and AMP together activate naive AMPK entirely allosterically and independently of upstream kinase signaling. These findings have important implications for development of AMPK-targeting therapeutics and point to possible combinatorial therapeutic strategies based on AMP and AMPK drugs.
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia. Electronic address: jscott@svi.edu.au.
authors.forename: John W
authors.initials: JW
authors.lastname: Scott
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia.
authors.forename: Naomi
authors.initials: N
authors.lastname: Ling
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia.
authors.forename: Samah M A
authors.initials: SM
authors.lastname: Issa
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia.
authors.forename: Toby A
authors.initials: TA
authors.lastname: Dite
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: O'Brien
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia.
authors.forename: Zhi-Ping
authors.initials: ZP
authors.lastname: Chen
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Galic
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Langendorf
authors.affiliation: Divisions of Endocrinology and Metabolism, Department of Medicine, and Division of Biochemistry and Biomedical Sciences, Department of Pediatrics, McMaster University, 1200 Main Street W., Hamilton, ON L8N 3Z5, Canada.
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Steinberg
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia.
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Kemp
authors.affiliation: Protein Chemistry & Metabolism, St. Vincent's Institute of Medical Research, University of Melbourne, 41 Victoria Parade, Fitzroy VIC 3065, Australia. Electronic address: joakhill@svi.edu.au.
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Oakhill
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000249:Adenosine Monophosphate / Q000494:pharmacology*; D000818:Animals; D001713:Biphenyl Compounds; D019556:COS Cells; D002522:Chlorocebus aethiops; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D008970:Molecular Weight; D010766:Phosphorylation / Q000187:drug effects; D011753:Pyrones / Q000737:chemistry / Q000494:pharmacology*; D012694:Serine / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013329:Structure-Activity Relationship; D013876:Thiophenes / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D001713:Biphenyl Compounds; D011753:Pyrones; D013876:Thiophenes; D000249:Adenosine Monophosphate; D012694:Serine; D055372:AMP-Activated Protein Kinases; C512408:4-hydroxy-3-(4-(2-hydroxyphenyl)phenyl)-6-oxo-7H-thieno(2,3-b)pyridine-5-carbonitrile