| Title: | Functional coupling of a mammalian somatostatin receptor to the yeast pheromone response pathway |
| Author(s): | Price LA; Kajkowski EM; Hadcock JR; Ozenberger BA; Pausch MH; |
| Address: | "Cyanamid Agricultural Research Center, Princeton, New Jersey 08543-0400, USA" |
| ISSN/ISBN: | 0270-7306 (Print) 1098-5549 (Electronic) 0270-7306 (Linking) |
| Abstract: | "A detailed analysis of structural and functional aspects of G-protein-coupled receptors, as well as discovery of novel pharmacophores that exert their effects on members of this class of receptors, will be facilitated by development of a yeast-based bioassay. To that end, yeast strains that functionally express the rat somatostatin receptor subtype 2 (SSTR2) were constructed. High-affinity binding sites for somatostatin ([125I-Tyr-11]S-14) comparable to those in native tissues were detected in yeast membrane extracts at levels equivalent to the alpha-mating pheromone receptor (Ste2p). Somatostatin-dependent growth of strains modified by deletion of genes encoding components of the pheromone response pathway was detected through induction of a pheromone-responsive HIS3 reporter gene, enabling cells to grow on medium lacking histidine. Dose-dependent growth responses to S-14 and related SSTR2 subtype-selective agonists that were proportional to the affinity of the ligands for SSTR2 were observed. The growth response required SSTR2, G alpha proteins, and an intact signal transduction pathway. The sensitivity of the bioassay was affected by intracellular levels of the G alpha protein. A mutation in the SST2 gene, which confers supersensitivity to pheromone, was found to significantly enhance the growth response to S-14. In sst2 delta cells, SSTR2 functionally interacted with both a chimeric yeast/mammalian G alpha protein and the yeast G alpha protein, Gpa1p; to promote growth. These yeast strains should serve as a useful in vivo reconstitution system for examination of molecular interactions of the G-protein-coupled receptors and G proteins" |
| Keywords: | "Animals Base Sequence Biological Assay Cell Division Cell Membrane/metabolism DNA Primers/chemistry GTP-Binding Proteins/*physiology Molecular Sequence Data Pheromones/physiology Rats Receptors, Mating Factor Receptors, Peptide/physiology Receptors, Somat;" |
| Notes: | "MedlinePrice, L A Kajkowski, E M Hadcock, J R Ozenberger, B A Pausch, M H eng 1995/11/01 Mol Cell Biol. 1995 Nov; 15(11):6188-95. doi: 10.1128/MCB.15.11.6188" |
