Mutation of glycine 49 to valine in the alpha subunit of GS results in the constitutive elevation of cyclic AMP synthesis.
The G-protein GS couples hormone-activated receptors with adenylyl cyclase and stimulates increased cyclic AMP synthesis. Transient expression in COS-1 cells of cDNAs coding for the GS alpha-subunit (alpha S) or alpha S cDNAs having single amino acid mutations Gly49----Val or Gly225----Thr elevated cyclic AMP levels, resulting in the activation of cyclic AMP dependent protein kinase. Stable expression in Chinese hamster ovary cells of alpha S Val49 cDNA resulted in a small constitutive elevation of cyclic AMP that was sufficient to persistently activate cyclic AMP dependent protein kinase activity 1.5-2-fold over basal activity. Stable expression of wild-type alpha S or alpha S Thr225 in Chinese hamster ovary cells was less effective in sustaining elevated cyclic AMP synthesis and kinase activation compared to alpha SVal49.
Woon
C W
CW
Department of Biochemistry, University of Massachusetts Medical School, Worcester 01655.
Heasley
L
L
Osawa
S
S
Johnson
G L
GL
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D000242:Cyclic AMP / Q000096:biosynthesis*; D004247:DNA / Q000032:analysis; D004789:Enzyme Activation; D005260:Female; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005998:Glycine / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010957:Plasmids; D011494:Protein Kinases / Q000378:metabolism; D014162:Transfection; D014633:Valine / Q000235:genetics* / Q000378:metabolism
D004247:DNA; D000242:Cyclic AMP; D011494:Protein Kinases; D019204:GTP-Binding Proteins; D014633:Valine; D005998:Glycine