The N54 mutant of Galphas has a conditional dominant negative phenotype which suppresses hormone-stimulated but not basal cAMP levels.
The phenotype of a Ser to Asn mutation at position 54 of the alpha subunit of G(s)(N54-alpha(s)) was characterized in transient transfection experiments in COS and HEK293 cells. Expression of either wild type or N54-alpha(s) increased basal cAMP levels. In contrast, expression of wild type alpha(s), potentiated agonist-stimulated cAMP levels, while expression of N54-alpha(s)caused a decrease. Thus, the N54-alpha(s) mutant possesses a conditional dominant negative phenotype, suppressing preferentially hormone-stimulated effects.
Cleator
J H
JH
Medical University of South Carolina, Department of Cell and Molecular Pharmacology, Charleston 29425, USA.
Mehta
N D
ND
Kurtz
D T
DT
Hildebrandt
J D
JD
D000818:Animals; D019556:COS Cells; D002417:Cattle; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009154:Mutation; D010641:Phenotype; D051381:Rats; D011989:Receptors, Thyrotropin / Q000378:metabolism; D013972:Thyrotropin / Q000378:metabolism*