Three intragenic suppressors of a GTPase-deficient allele of GNAS associated with McCune-Albright syndrome.
Gain-of-function mutations in heterotrimeric G-protein α subunits are associated with a variety of human diseases. McCune-Albright syndrome (MAS) is caused by mutations in GNAS, the gene encoding Gs. Alterations at Arg201 significantly reduce the GTPase activity of the protein, rendering it constitutively active. In this study, we have constructed a library of random mutations in a constitutively active yeast GPA1 gene carrying a mutation homologous to the McCune-Albright allele (Arg297His). Intragenic suppressors found at sites with homology to the human Gs protein were tested for their ability to suppress the constitutive activity of an Arg201His mutation in Gs. Three intragenic suppressors, at Phe142, Arg231, and Leu266, were able to suppress elevated basal cAMP responses caused by Arg201His when expressed in HEK293 cells. A range of amino acid substitutions was introduced at each of these sites to investigate the chemical requirements for intragenic suppression. The ability of Gs proteins carrying the suppressor mutations alone to mediate receptor-induced cAMP production was measured. These results offer potential sites on Gs that could serve as drug targets for MAS therapies.
Department of Biological ScienceBenedictine University, 5700 College Road, Lisle, Illinois 60532, USA.
Kyle
K
Turcic
Department of Biological ScienceBenedictine University, 5700 College Road, Lisle, Illinois 60532, USA.
Raquel
R
Tobar-Rubin
Department of Biological ScienceBenedictine University, 5700 College Road, Lisle, Illinois 60532, USA.
Daniela
D
Janevska
Department of Biological ScienceBenedictine University, 5700 College Road, Lisle, Illinois 60532, USA.
Julie
J
Carroll
Department of Biological ScienceBenedictine University, 5700 College Road, Lisle, Illinois 60532, USA.
Eraj
E
Din
Department of Biological ScienceBenedictine University, 5700 College Road, Lisle, Illinois 60532, USA.
Rebecca
R
Alvarez
Department of Biological ScienceBenedictine University, 5700 College Road, Lisle, Illinois 60532, USA.
Jennifer
J
Haick
Department of Biological ScienceBenedictine University, 5700 College Road, Lisle, Illinois 60532, USA rrylaarsdam@ben.edu.
Robin
R
Pals-Rylaarsdam
D019943:Amino Acid Substitution; D045744:Cell Line, Tumor; D002864:Chromogranins; D000242:Cyclic AMP / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D005147:Facial Bones / Q000002:abnormalities; D005359:Fibrous Dysplasia, Polyostotic / Q000235:genetics*; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000235:genetics*; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000235:genetics*; D015723:Gene Library; D057809:HEK293 Cells; D006801:Humans; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D012886:Skull / Q000002:abnormalities; D013489:Suppression, Genetic
D002864:Chromogranins; D029701:Saccharomyces cerevisiae Proteins; D000242:Cyclic AMP; C406732:GNAS protein, human; C084293:GPA1 protein, S cerevisiae; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D019205:GTP-Binding Protein alpha Subunits, Gs
G-protein; McCune–Albright syndrome; cAMP; suppressor mutation