Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Subscribe

Logo for

PNAS 103 (35): 13034-13039

Copyright © 2006 by the National Academy of Sciences.


BIOLOGICAL SCIENCES / BIOCHEMISTRY

Kelch-repeat proteins interacting with the G{alpha} protein Gpa2 bypass adenylate cyclase for direct regulation of protein kinase A in yeast

Tom Peeters, Wendy Louwet, Ruud Geladé, David Nauwelaers, Johan M. Thevelein, and Matthias Versele*

Laboratory of Molecular Cell Biology, Katholieke Universiteit Leuven, and Department of Molecular Microbiology, Flanders Interuniversity Institute of Biotechnology (VIB), Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Belgium

Edited by Gregory A. Petsko, Brandeis University, Waltham, MA, and approved July 5, 2006

Received for publication November 7, 2005.

Abstract: The cAMP–PKA pathway consists of an extracellular ligand-sensitive G protein-coupled receptor, a G protein signal transmitter, and the effector, adenylate cyclase, of which the product, cAMP, acts as an intracellular second messenger. cAMP activates PKA by dissociating the regulatory subunit from the catalytic subunit. Yeast cells (Saccharomyces cerevisiae) contain a glucose/sucrose-sensitive seven-transmembrane domain receptor, Gpr1, that was proposed to activate adenylate cyclase through the G{alpha} protein Gpa2. Consistently, we show here that adenylate cyclase binds only to active, GTP-bound Gpa2. Two related kelch-repeat proteins, Krh1/Gpb2 and Krh2/Gpb1, are associated with Gpa2 and were suggested to act as Gbeta mimics for Gpa2, based on their predicted seven-bladed beta-propeller structure. However, we find that although Krh1 associates with both GDP and GTP-bound Gpa2, it displays a preference for GTP-Gpa2. The strong down-regulation of PKA targets by Krh1 and Krh2 does not require Gpa2 but is strictly dependent on both the catalytic and the regulatory subunits of PKA. Krh1 directly interacts with PKA by means of the catalytic subunits, and Krh1/2 stimulate the association between the catalytic and regulatory subunits in vivo. Indeed, both a constitutively active GPA2 allele and deletion of KRH1/2 lower the cAMP requirement of PKA for growth. We propose that active Gpa2 relieves the inhibition imposed by the kelch-repeat proteins on PKA, thereby bypassing adenylate cyclase for direct regulation of PKA. Importantly, we show that Krh1/2 also enhance the association between mouse R and C subunits, suggesting that Krh control of PKA has been evolutionarily conserved.

Key Words: Saccharomyces cerevisiae • signal transduction • glucose


Freely available online through the PNAS open access option.

Author contributions: T.P., W.L., R.G., D.N., J.M.T., and M.V. designed research; T.P., W.L., R.G., D.N., and M.V. performed research; T.P., W.L., R.G., D.N., J.M.T., and M.V. analyzed data; and J.M.T. and M.V. wrote the paper.

Conflict of interest statement: No conflicts declared.

This paper was submitted directly (Track II) to the PNAS office.

*To whom correspondence should be addressed. E-mail: matthias.versele{at}bio.kuleuven.be

© 2006 by The National Academy of Sciences of the USA


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Harnessing gene expression to identify the genetic basis of drug resistance.
B.-J. Chen, H. C. Causton, D. Mancenido, N. L. Goddard, E. O. Perlstein, and D. Pe'er (2014)
Mol Syst Biol 5, 310
   Abstract »    Full Text »    PDF »
Regulation of Cation Balance in Saccharomyces cerevisiae.
M. S. Cyert and C. C. Philpott (2013)
Genetics 193, 677-713
   Abstract »    Full Text »    PDF »
Nutritional Control of Growth and Development in Yeast.
J. R. Broach (2012)
Genetics 192, 73-105
   Abstract »    Full Text »    PDF »
Diversity in Genetic In Vivo Methods for Protein-Protein Interaction Studies: from the Yeast Two-Hybrid System to the Mammalian Split-Luciferase System.
B. Stynen, H. Tournu, J. Tavernier, and P. Van Dijck (2012)
Microbiol. Mol. Biol. Rev. 76, 331-382
   Abstract »    Full Text »    PDF »
Regulation of Vacuolar H+-ATPase Activity by the Cdc42 Effector Ste20 in Saccharomyces cerevisiae.
M. Lin, S. C. Li, P. M. Kane, and T. Hofken (2012)
Eukaryot. Cell 11, 442-451
   Abstract »    Full Text »    PDF »
The Regulation of Filamentous Growth in Yeast.
P. J. Cullen and G. F. Sprague Jr. (2012)
Genetics 190, 23-49
   Abstract »    Full Text »    PDF »
Yeast 3-Phosphoinositide-dependent Protein Kinase-1 (PDK1) Orthologs Pkh1-3 Differentially Regulate Phosphorylation of Protein Kinase A (PKA) and the Protein Kinase B (PKB)/S6K Ortholog Sch9.
K. Voordeckers, M. Kimpe, S. Haesendonckx, W. Louwet, M. Versele, and J. M. Thevelein (2011)
J. Biol. Chem. 286, 22017-22027
   Abstract »    Full Text »    PDF »
Ras Signaling in Yeast.
F. Tamanoi (2011)
Genes & Cancer 2, 210-215
   Abstract »    Full Text »    PDF »
Nutrient Control of Yeast PKA Activity Involves Opposing Effects on Phosphorylation of the Bcy1 Regulatory Subunit.
R. Budhwar, A. Lu, and J. P. Hirsch (2010)
Mol. Biol. Cell 21, 3749-3758
   Abstract »    Full Text »    PDF »
A CUG codon adapted two-hybrid system for the pathogenic fungus Candida albicans.
B. Stynen, P. Van Dijck, and H. Tournu (2010)
Nucleic Acids Res. 38, e184
   Abstract »    Full Text »    PDF »
The RasGAP Proteins Ira2 and Neurofibromin Are Negatively Regulated by Gpb1 in Yeast and ETEA in Humans.
V. T. Phan, V. W. Ding, F. Li, R. J. Chalkley, A. Burlingame, and F. McCormick (2010)
Mol. Cell. Biol. 30, 2264-2279
   Abstract »    Full Text »    PDF »
Nutrient sensing G protein-coupled receptors: interesting targets for antifungals?.
P. V. Dijck (2009)
Med Mycol 47, 671-680
   Abstract »    Full Text »    PDF »
Glucose Sensing Network in Candida albicans: a Sweet Spot for Fungal Morphogenesis.
J. Sabina and V. Brown (2009)
Eukaryot. Cell 8, 1314-1320
   Full Text »    PDF »
Genetic Identification of Factors That Modulate Ribosomal DNA Transcription in Saccharomyces cerevisiae.
R. D. Hontz, R. O. Niederer, J. M. Johnson, and J. S. Smith (2009)
Genetics 182, 105-119
   Abstract »    Full Text »    PDF »
Saccharomyces cerevisiae Phospholipase C Regulates Transcription of Msn2p-Dependent Stress-Responsive Genes.
A. Demczuk, N. Guha, P. H. Nguyen, P. Desai, J. Chang, K. Guzinska, J. Rollins, C. C. Ghosh, L. Goodwin, and A. Vancura (2008)
Eukaryot. Cell 7, 967-979
   Abstract »    Full Text »    PDF »
The RACK1 Ortholog Asc1 Functions as a G-protein beta Subunit Coupled to Glucose Responsiveness in Yeast.
C. E. Zeller, S. C. Parnell, and H. G. Dohlman (2007)
J. Biol. Chem. 282, 25168-25176
   Abstract »    Full Text »    PDF »
Kelch Repeat Protein Interacts with the Yeast G{alpha} Subunit Gpa2p at a Site That Couples Receptor Binding to Guanine Nucleotide Exchange.
T. Niranjan, X. Guo, J. Victor, A. Lu, and J. P. Hirsch (2007)
J. Biol. Chem. 282, 24231-24238
   Abstract »    Full Text »    PDF »
Environmental Sensing and Signal Transduction Pathways Regulating Morphopathogenic Determinants of Candida albicans.
S. Biswas, P. Van Dijck, and A. Datta (2007)
Microbiol. Mol. Biol. Rev. 71, 348-376
   Abstract »    Full Text »    PDF »
Propping Up Our Knowledge of G Protein Signaling Pathways: Diverse Functions of Putative Noncanonical Gbeta Subunits in Fungi.
C. S. Hoffman (2007)
Sci. STKE 2007, pe3
   Abstract »    Full Text »    PDF »

To Advertise     Find Products


Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882