title: AMP-activated protein kinase subunit interactions: beta1:gamma1 association requires beta1 Thr-263 and Tyr-267.
abstract: AMP-activated protein kinase (AMPK) plays multiple roles in the body's overall metabolic balance and response to exercise, nutritional stress, hormonal stimulation, and the glucose-lowering drugs metformin and rosiglitazone. AMPK consists of a catalytic alpha subunit and two non-catalytic subunits, beta and gamma, each with multiple isoforms that form active 1:1:1 heterotrimers. Here we show that recombinant human AMPK alpha1beta1gamma1 expressed in insect cells is monomeric and displays specific activity and AMP responsiveness similar to rat liver AMPK. The previously determined crystal structure of the core of mammalian alphabetagamma complex shows that beta binds alpha and gamma. Here we show that a beta1(186-270)gamma1 complex can form in the absence of detectable alpha subunit. Moreover, using alanine mutagenesis we show that beta1 Thr-263 and Tyr-267 are required for betagamma association but not alphabeta association.
authors: St. Vincent's Institute, Fitzroy, Victoria 3065, Australia.
authors: Tristan J
authors: TJ
authors: Iseli
authors: Jonathan S
authors: JS
authors: Oakhill
authors: Michael F
authors: MF
authors: Bailey
authors: Sheena
authors: S
authors: Wee
authors: Mark
authors: M
authors: Walter
authors: Bryce J
authors: BJ
authors: van Denderen
authors: Laura A
authors: LA
authors: Castelli
authors: Frosa
authors: F
authors: Katsis
authors: Lee A
authors: LA
authors: Witters
authors: David
authors: D
authors: Stapleton
authors: S Lance
authors: SL
authors: Macaulay
authors: Belinda J
authors: BJ
authors: Michell
authors: Bruce E
authors: BE
authors: Kemp
mesh_terms: D055372:AMP-Activated Protein Kinases; D000818:Animals; D019556:COS Cells; D020134:Catalytic Domain / Q000235:genetics; D002522:Chlorocebus aethiops; D015444:Exercise / Q000502:physiology; D005947:Glucose / Q000378:metabolism; D006728:Hormones / Q000494:pharmacology; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology; D008099:Liver / Q000201:enzymology*; D008687:Metformin / Q000494:pharmacology; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020836:Protein Structure, Quaternary; D051381:Rats; D000077154:Rosiglitazone; D013312:Stress, Physiological / Q000201:enzymology; D045162:Thiazolidinediones / Q000494:pharmacology
chemical_list: D006728:Hormones; D007004:Hypoglycemic Agents; D009097:Multienzyme Complexes; D045162:Thiazolidinediones; D000077154:Rosiglitazone; D008687:Metformin; C526182:PRKAB1 protein, human; C526222:PRKAG1 protein, human; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D005947:Glucose