title: Stimulation of glucose transport by AMP-activated protein kinase via activation of p38 mitogen-activated protein kinase.
abstract: Activation of AMP-activated protein kinase (AMPK) has been recently demonstrated to be associated with 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR)-stimulated glucose transport mediated by both GLUT1 and GLUT4 transporters. However, signaling events upstream and downstream of AMPK are unknown. Here we report that 1) p38 mitogen-activated protein kinase (MAPK) and mitogen-activated protein kinase kinase 3 (MKK3) were activated by AICAR in Clone 9 cells, which express only the GLUT1 transporters, and 2) activation of p38 was required for AICAR-stimulated glucose transport since treatment of the cells with p38 inhibitor SB203580 or overexpression of dominant negative p38 mutant inhibited glucose transport. Moreover, we found that overexpression of the constitutively active form of AMPK mutant also resulted in a significant activation of p38, and inhibition of p38 activity by SB203580 did not affect AICAR-stimulated activation of AMPK. These findings demonstrate that AICAR-stimulated activation of p38 is indeed mediated by AMPK, and the p38 MAPK cascade is downstream of AMPK in the signaling pathway of AICAR-stimulated glucose transport in Clone 9 cells.
authors.affiliation: Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4951, USA.
authors.forename: X
authors.initials: X
authors.lastname: Xi
authors.forename: J
authors.initials: J
authors.lastname: Han
authors.forename: J Z
authors.initials: JZ
authors.lastname: Zhang
mesh_terms: D055372:AMP-Activated Protein Kinases; D000595:Amino Acid Sequence; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D001692:Biological Transport; D017931:DNA Primers; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D007093:Imidazoles / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D012265:Ribonucleotides / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D017931:DNA Primers; D004791:Enzyme Inhibitors; D007093:Imidazoles; D009097:Multienzyme Complexes; D011725:Pyridines; D012265:Ribonucleotides; D000620:Aminoimidazole Carboxamide; D017346:Protein Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D055372:AMP-Activated Protein Kinases; C031143:AICA ribonucleotide; D005947:Glucose; C093642:SB 203580