| Title: | Novobiocin and peptide analogs of alpha-factor are positive allosteric modulators of the yeast G protein-coupled receptor Ste2p |
| Author(s): | Rymer JK; Hauser M; Bourdon AK; Campagna SR; Naider F; Becker JM; |
| Address: | "Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States. Department of Chemistry, University of Tennessee, Knoxville, TN 37996, United States. Department of Chemistry and Macromolecular Assemblies Institute, College of Staten Island, CUNY, New York, NY 10314, United States; Graduate School and University Center, CUNY, New York, NY 10314, United States. Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States. Electronic address: jbecker@utk.edu" |
| DOI: | 10.1016/j.bbamem.2014.12.024 |
| ISSN/ISBN: | 0006-3002 (Print) 0006-3002 (Linking) |
| Abstract: | "G protein-coupled receptors (GPCRs) are the target of many drugs prescribed for human medicine and are therefore the subject of intense study. It has been recognized that compounds called allosteric modulators can regulate GPCR activity by binding to the receptor at sites distinct from, or overlapping with, that occupied by the orthosteric ligand. The purpose of this study was to investigate the nature of the interaction between putative allosteric modulators and Ste2p, a model GPCR expressed in the yeast Saccharomyces cerevisiae that binds the tridecapeptide mating pheromone alpha-factor. Biological assays demonstrated that an eleven amino acid alpha-factor analog and the antibiotic novobiocin were positive allosteric modulators of Ste2p. Both compounds enhanced the biological activity of alpha-factor, but did not compete with alpha-factor binding to Ste2p. To determine if novobiocin and the 11-mer shared a common allosteric binding site, a biologically-active analog of the 11-mer peptide ([Bio-DOPA]11-mer) was chemically cross-linked to Ste2p in the presence and absence of novobiocin. Immunoblots probing for the Ste2p-[Bio-DOPA]11-mer complex revealed that novobiocin markedly decreased cross-linking of the [Bio-DOPA]11-mer to the receptor, but cross-linking of the alpha-factor analog [Bio-DOPA]13-mer, which interacts with the orthosteric binding site of the receptor, was minimally altered. This finding suggests that both novobiocin and [Bio-DOPA]11-mer compete for an allosteric binding site on the receptor. These results indicate that Ste2p may provide an excellent model system for studying allostery in a GPCR" |
| Keywords: | "Allosteric Regulation/*drug effects Anti-Bacterial Agents/*pharmacology Binding Sites Binding, Competitive Cross-Linking Reagents Humans Immunoblotting Ligands Mating Factor Membrane Proteins/genetics/metabolism Novobiocin/*pharmacology Peptide Fragments/;" |
| Notes: | "MedlineRymer, Jeffrey K Hauser, Melinda Bourdon, Allen K Campagna, Shawn R Naider, Fred Becker, Jeffrey M eng R01 GM022087/GM/NIGMS NIH HHS/ GM022087/GM/NIGMS NIH HHS/ GM112496/GM/NIGMS NIH HHS/ R01 GM112496/GM/NIGMS NIH HHS/ R56 GM022087/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural Netherlands 2015/01/13 Biochim Biophys Acta. 2015 Apr; 1848(4):916-24. doi: 10.1016/j.bbamem.2014.12.024. Epub 2015 Jan 7" |
