CaltechAUTHORS
  A Caltech Library Service

A quantitative characterization of the yeast heterotrimeric G protein cycle

Yi, Tau-Mu and Kitano, Hiroaki and Simon, Melvin I. (2003) A quantitative characterization of the yeast heterotrimeric G protein cycle. Proceedings of the National Academy of Sciences of the United States of America, 100 (19). pp. 10764-10769. ISSN 0027-8424. http://resolver.caltech.edu/CaltechAUTHORS:YITpnas03

[img]
Preview
PDF
See Usage Policy.

474Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:YITpnas03

Abstract

The yeast mating response is one of the best understood heterotrimeric G protein signaling pathways. Yet, most descriptions of this system have been qualitative. We have quantitatively characterized the heterotrimeric G protein cycle in yeast based on direct in vivo measurements. We used fluorescence resonance energy transfer to monitor the association state of cyan fluorescent protein (CFP)-Galpha and Gbetagamma-yellow fluorescent protein (YFP), and we found that receptor-mediated G protein activation produced a loss of fluorescence resonance energy transfer. Quantitative time course and dose-response data were obtained for both wild-type and mutant cells possessing an altered pheromone response. These results paint a quantitative portrait of how regulators such as Sst2p and the C-terminal tail of a-factor receptor modulate the kinetics and sensitivity of G protein signaling. We have explored critical features of the dynamics including the rapid rise and subsequent decline of active G proteins during the early response, and the relationship between the G protein activation dose-response curve and the downstream dose-response curves for cell-cycle arrest and transcriptional induction. Fitting the data to a mathematical model produced estimates of the in vivo rates of heterotrimeric G protein activation and deactivation in yeast.


Item Type:Article
Additional Information:Copyright © 2003 by the National Academy of Sciences. Contributed by Melvin I. Simon, July 14, 2003. Published online before print September 5, 2003, 10.1073/pnas.1834247100 We thank Drs. Ray Deshaies and Chris Rao for critical reading of the manuscript; the Deshaies laboratory for yeast strains and vectors; and the Simon laboratory for valuable discussions. This work was supported by the Exploratory Research for Advanced Technology Kitano Symbiotic Systems Project of the Japanese Science and Technology Corporation.
Subject Keywords:ALPHA-PHEROMONE RECEPTOR, SACCHAROMYCES-CEREVISIAE, PHOTOTRANSDUCTION, ENDOCYTOSIS, DESENSITIZATION, ACTIVATION, MEMBRANE, SUBUNIT, SIGNAL, GPA1
Record Number:CaltechAUTHORS:YITpnas03
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:YITpnas03
Alternative URL:http://dx.doi.org/10.1073/pnas.1834247100
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1111
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:20 Dec 2005
Last Modified:26 Dec 2012 08:42

Repository Staff Only: item control page