AMP-Activated protein kinase is activated by the stimulations of G(q)-coupled receptors.
The AMP-activated protein kinase (AMPK) functions as a metabolic sensor that monitors cellular AMP and ATP levels. Platelet-activating factor (PAF) activates endogeneous AMPKalpha1 in Chinese hamster ovary cells expressing the PAF receptor coupled with both G(i) and G(q), but its activity was not inhibited after treatment with islet-activating protein. Norepinephrine and bradykinin also activated AMPKalpha1 in cells expressing the G(q)-coupled alpha(1b)-adrenergic receptor and bradykinin receptor, respectively. Stimulations of the G(i)-coupled alpha(2A)-adrenergic receptor, fMet-Leu-Phe receptor, prostaglandin EP3alpha receptor, and G(s)-coupled beta(2)-adrenergic receptor did not activate AMPKalpha1. AMPKalpha1 thus is activated specifically by stimulation of G(q)-coupled receptors. G(q)-coupled receptors transmit the signal for GLUT4 translocation and glucose uptake through an insulin-independent pathway. However, direct activation of AMPKalpha1 with treatment of 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside did not trigger GLUT4 translocation nor stimulate glucose uptake in our cells. Thus, activation of AMPKalpha1 via G(q) is not sufficient to trigger GLUT4 translocation or stimulate glucose uptake.
Kishi
K
K
Division of Molecular Genetics, Institute for Enzyme Research, University of Tokushima, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan.
Yuasa
T
T
Minami
A
A
Yamada
M
M
Hagi
A
A
Hayashi
H
H
Kemp
B E
BE
Witters
L A
LA
Ebina
Y
Y
D055372:AMP-Activated Protein Kinases; D000818:Animals; D001692:Biological Transport; D016466:CHO Cells; D006224:Cricetinae; D004789:Enzyme Activation; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D009124:Muscle Proteins; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*; D018002:Receptors, Bradykinin / Q000378:metabolism*; D015398:Signal Transduction
D051275:Glucose Transporter Type 4; D009004:Monosaccharide Transport Proteins; D009097:Multienzyme Complexes; D009124:Muscle Proteins; D018340:Receptors, Adrenergic, alpha-1; D018002:Receptors, Bradykinin; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins; D005947:Glucose