Phosphorylation of the glycogen-binding subunit of protein phosphatase-1G in response to adrenalin.
The glycogen-binding (G) subunit of protein phosphatase-1 is phosphorylated in vivo. In rabbits injected with propranolol the serine residue termed site-1 was phosphorylated in 56% of the molecules isolated, and phosphorylation increased to 82% after administration of adrenalin. It is concluded that the G-subunit is a physiological substrate for cyclic AMP-dependent protein kinase. The G-subunit remained largely bound to glycogen even after injection of adrenalin, whereas half of the protein phosphatase-1 activity associated with glycogen was released into the cytosol. The results indicate that adrenalin induces dissociation of the catalytic subunit from the G-subunit in vivo.
MacKintosh
C
C
Department of Biochemistry, University of Dundee, Scotland.
Campbell
D G
DG
Hiraga
A
A
Cohen
P
P
D000595:Amino Acid Sequence; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D000242:Cyclic AMP / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology; D004837:Epinephrine / Q000494:pharmacology*; D006003:Glycogen / Q000378:metabolism*; D006007:Glycogen-Synthase-D Phosphatase / Q000378:metabolism*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009132:Muscles / Q000187:drug effects / Q000201:enzymology*; D010446:Peptide Fragments; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism; D054645:Protein Phosphatase 1; D011817:Rabbits; D014357:Trypsin
D010446:Peptide Fragments; D010768:Phosphoserine; D006003:Glycogen; D011433:Propranolol; D000242:Cyclic AMP; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D006007:Glycogen-Synthase-D Phosphatase; D014357:Trypsin; D004837:Epinephrine