AMP-activated protein kinase is physiologically regulated by inositol polyphosphate multikinase.
The AMP-activated kinase (AMPK) senses the energy status of cells and regulates fuel availability, whereas hypothalamic AMPK regulates food intake. We report that inositol polyphosphate multikinase (IPMK) regulates glucose signaling to AMPK in a pathway whereby glucose activates phosphorylation of IPMK at tyrosine 174 enabling the enzyme to bind to AMPK and regulate its activation. Thus, refeeding fasted mice rapidly and markedly stimulates transcriptional enhancement of IPMK expression while down-regulating AMPK. Also, AMPK is up-regulated in mice with genetic depletion of hypothalamic IPMK. IPMK physiologically binds AMPK, with binding enhanced by glucose treatment. Regulation by glucose of phospho-AMPK in hypothalamic cell lines is prevented by blocking AMPK-IPMK binding. These findings imply that IPMK inhibitors will be beneficial in treating obesity and diabetes.
Department of Psychiatry, Center for Neurobiology and Behavior, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Sookhee
S
Bang
Seyun
S
Kim
Megan J
MJ
Dailey
Yong
Y
Chen
Timothy H
TH
Moran
Solomon H
SH
Snyder
Sangwon F
SF
Kim
D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism*; D047468:Immunoprecipitation; D051379:Mice; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D014443:Tyrosine / Q000378:metabolism
D014443:Tyrosine; D017853:Phosphotransferases (Alcohol Group Acceptor); C434257:inositol polyphosphate multikinase; D055372:AMP-Activated Protein Kinases; D005947:Glucose