| Title: | Direct identification of a G protein ubiquitination site by mass spectrometry |
| Author(s): | Marotti LA; Newitt R; Wang Y; Aebersold R; Dohlman HG; |
| Address: | "Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, Connecticut 06536, USA" |
| ISSN/ISBN: | 0006-2960 (Print) 0006-2960 (Linking) |
| Abstract: | "Covalent attachment of ubiquitin is well-known to target proteins for degradation. Here, mass spectrometry was used to identify the site of ubiquitination in Gpa1, the G protein alpha subunit in yeast Saccharomyces cerevisiae. The modified residue is located at Lys165 within the alpha-helical domain of Galpha, a region of unknown function. Substitution of Lys165 with Arg (Gpa1(K165R)) results in a substantial decrease in ubiquitination. In addition, yeast expressing the Gpa1(K165R) mutant are moderately resistant to pheromone in growth inhibition assays-a phenotype consistent with enhanced Galpha signaling activity. These findings indicate that the alpha-helical domain may serve to regulate the turnover of Gpa1" |
| Keywords: | "Amino Acid Substitution/genetics Arginine/genetics Chromatography, Liquid Cysteine Endopeptidases/metabolism *GTP-Binding Protein alpha Subunits GTP-Binding Protein alpha Subunits, Gq-G11 Growth Inhibitors/pharmacology Heterotrimeric GTP-Binding Proteins/;neuroscience;" |
| Notes: | "MedlineMarotti, Louis A Jr Newitt, Rick Wang, Yuqi Aebersold, Ruedi Dohlman, Henrik G eng R01 GM055316/GM/NIGMS NIH HHS/ R01 GM059167/GM/NIGMS NIH HHS/ GM59167/GM/NIGMS NIH HHS/ GM55316/GM/NIGMS NIH HHS/ RR11823/RR/NCRR NIH HHS/ Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 2002/04/17 Biochemistry. 2002 Apr 23; 41(16):5067-74. doi: 10.1021/bi015940q" |
