AMP-activated protein kinase subunit interactions: beta1:gamma1 association requires beta1 Thr-263 and Tyr-267.
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.
Iseli
Tristan J
TJ
St. Vincent's Institute, Fitzroy, Victoria 3065, Australia.
Oakhill
Jonathan S
JS
Bailey
Michael F
MF
Wee
Sheena
S
Walter
Mark
M
van Denderen
Bryce J
BJ
Castelli
Laura A
LA
Katsis
Frosa
F
Witters
Lee A
LA
Stapleton
David
D
Macaulay
S Lance
SL
Michell
Belinda J
BJ
Kemp
Bruce E
BE
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
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