A-kinase anchoring protein AKAP220 binds to glycogen synthase kinase-3beta (GSK-3beta ) and mediates protein kinase A-dependent inhibition of GSK-3beta.
Glycogen synthase kinase-3 (GSK-3) is regulated by various extracellular ligands and phosphorylates many substrates, thereby regulating cellular functions. Using yeast two-hybrid screening, we found that GSK-3beta binds to AKAP220, which is known to act as an A-kinase anchoring protein. GSK-3beta formed a complex with AKAP220 in intact cells at the endogenous level. Cyclic AMP-dependent protein kinase (PKA) and type 1 protein phosphatase (PP1) were also detected in this complex, suggesting that AKAP220, GSK-3beta, PKA, and PP1 form a quaternary complex. It has been reported that PKA phosphorylates GSK-3beta, thereby decreasing its activity. When COS cells were treated with dibutyryl cyclic AMP to activate PKA, the activity of GSK-3beta bound to AKAP220 decreased more markedly than the total GSK-3beta activity. Calyculin A, a protein phosphatase inhibitor, also inhibited the activity of GSK-3beta bound to AKAP220 more strongly than the total GSK-3beta activity. These results suggest that PKA and PP1 regulate the activity of GSK-3beta efficiently by forming a complex with AKAP220.
Tanji
Chie
C
Department of Biochemistry, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
Yamamoto
Hideki
H
Yorioka
Noriaki
N
Kohno
Nobuoki
N
Kikuchi
Kunimi
K
Kikuchi
Akira
A
D054758:A Kinase Anchor Proteins; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D003994:Bucladesine / Q000494:pharmacology; D016466:CHO Cells; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D006224:Cricetinae; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014162:Transfection
D054758:A Kinase Anchor Proteins; C099270:AKAP11 protein, human; D002352:Carrier Proteins; D010455:Peptides; D011994:Recombinant Proteins; D003994:Bucladesine; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D017868:Cyclic AMP-Dependent Protein Kinases; D038362:Glycogen Synthase Kinase 3; D010749:Phosphoprotein Phosphatases