| Title: | Multiple regulatory roles of the carboxy terminus of Ste2p a yeast GPCR |
| Author(s): | Kim KM; Lee YH; Akal-Strader A; Uddin MS; Hauser M; Naider F; Becker JM; |
| Address: | "Department of Pharmacology, College of Pharmacy, Chonnam National University, Kwang-Ju 500-757, Republic of Korea" |
| DOI: | 10.1016/j.phrs.2011.11.002 |
| ISSN/ISBN: | 1096-1186 (Electronic) 1043-6618 (Print) 1043-6618 (Linking) |
| Abstract: | "Signaling and internalization of Ste2p, a model G protein-coupled receptor (GPCR) from the yeast Saccharomyces cerevisiae, are reported to be regulated by phosphorylation status of serine (S) and threonine (T) residues located in the cytoplasmic C-terminus. Although the functional roles of S/T residues located in certain C-terminus regions are relatively well characterized, systemic analyses have not been conducted for all the S/T residues that are spread throughout the C-terminus. A point mutation to alanine was introduced into the S/T residues located within three intracellular loops and the C-terminus individually or in combination. A series of functional assays such as internalization, FUS1-lacZ induction, and growth arrest were conducted in comparison between WT- and mutant Ste2p. The Ste2p in which all S/T residues in the C-terminus were mutated to alanine was more sensitive to alpha-factor, suggesting that phosphorylation in the C-terminus exerts negative regulatory activities on the Ste2p signaling. C-terminal S/T residues proximal to the seventh transmembrane domain were important for ligand-induced G protein coupling but not for receptor internalization. Sites on the central region of the C-terminus regulated both constitutive and ligand-induced internalization. Residues on the distal part were important for constitutive desensitization and modulated the G protein signaling mediated through the proximal part of the C-terminus. This study demonstrated that the C-terminus contains multiple functional domains with differential and interdependent roles in regulating Ste2p function in which the S/T residues located in each domain play critical roles" |
| Keywords: | "Amino Acid Sequence Endocytosis Gene Expression Regulation, Fungal Genes, Reporter Genotype Lac Operon Ligands Mating Factor Membrane Proteins/genetics Molecular Sequence Data Peptides/metabolism Phenotype Phosphorylation Point Mutation Protein Structure, ;" |
| Notes: | "MedlineKim, Kyeong-Man Lee, Yong-Hun Akal-Strader, Ayca Uddin, M Seraj Hauser, Melinda Naider, Fred Becker, Jeffrey M eng R01 GM022087/GM/NIGMS NIH HHS/ R01 GM022087-34/GM/NIGMS NIH HHS/ GM 22086/GM/NIGMS NIH HHS/ GM 22087/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural Netherlands 2011/11/22 Pharmacol Res. 2012 Jan; 65(1):31-40. doi: 10.1016/j.phrs.2011.11.002. Epub 2011 Nov 10" |
