Cellular noise suppression by the regulator of G protein signaling Sst2.

G proteins and their associated receptors process information from a variety of environmental stimuli to induce appropriate cellular responses. Generally speaking, each cell in a population responds within defined limits, despite large variation in the expression of protein signaling components. Therefore, we postulated that noise suppression is encoded within the signaling system. Using the yeast mating pathway as a model, we evaluated the ability of a regulator of G protein signaling (RGS) protein to suppress noise. We found that the RGS protein Sst2 limits variability in transcription and morphogenesis in response to pheromone stimulation. While signal suppression is a result of both the GAP (GTPase accelerating) and receptor binding functions of Sst2, noise suppression requires only the GAP activity. Taken together, our findings reveal a hitherto overlooked role of RGS proteins as noise suppressors and demonstrate an ability to uncouple signal and noise in a prototypical stimulus-response pathway.

[1]  N. Hao,et al.  Genome-Scale Analysis Reveals Sst2 as the Principal Regulator of Mating Pheromone Signaling in the Yeast Saccharomyces cerevisiae , 2006, Eukaryotic Cell.

[2]  M. Thattai,et al.  Intrinsic noise in gene regulatory networks , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[3]  Prahlad T. Ram,et al.  G Protein Pathways , 2002, Science.

[4]  G. Sprague,,et al.  Assay of yeast mating reaction. , 1991, Methods in enzymology.

[5]  Henrik G. Dohlman,et al.  DEP-Domain-Mediated Regulation of GPCR Signaling Responses , 2006, Cell.

[6]  J. Hasty,et al.  Regulation of cell signaling dynamics by the protein kinase-scaffold Ste5. , 2008, Molecular cell.

[7]  J. Moskow,et al.  Role of Cdc42p in Pheromone-Stimulated Signal Transduction in Saccharomyces cerevisiae , 2000, Molecular and Cellular Biology.

[8]  Second site suppressor mutations of a GTPase-deficient G-protein alpha-subunit. Selective inhibition of Gbeta gamma-mediated signaling. , 1998, The Journal of biological chemistry.

[9]  Zhen Yan,et al.  RGS4 Modulates Serotonin Signaling in Prefrontal Cortex and Links to Serotonin Dysfunction in a Rat Model of Schizophrenia , 2007, Molecular Pharmacology.

[10]  C. Hansen,et al.  Dissecting genealogy and cell cycle as sources of cell-to-cell variability in MAPK signaling using high-throughput lineage tracking , 2013, Proceedings of the National Academy of Sciences.

[11]  A. Løbner-Olesen,et al.  Distribution of minichromosomes in individual Escherichia coli cells: implications for replication control , 1999, The EMBO journal.

[12]  A. E. Hirsh,et al.  Noise Minimization in Eukaryotic Gene Expression , 2004, PLoS biology.

[13]  J. Raser,et al.  Control of Stochasticity in Eukaryotic Gene Expression , 2004, Science.

[14]  J. Boeke,et al.  Designer deletion strains derived from Saccharomyces cerevisiae S288C: A useful set of strains and plasmids for PCR‐mediated gene disruption and other applications , 1998, Yeast.

[15]  J. Thorner,et al.  Regulation of G protein-initiated signal transduction in yeast: paradigms and principles. , 2001, Annual review of biochemistry.

[16]  A. Bretscher,et al.  Polarization of cell growth in yeast. , 2000, Journal of cell science.

[17]  David McMillen,et al.  Biochemical Network Stochastic Simulator (BioNetS): software for stochastic modeling of biochemical networks , 2004, BMC Bioinformatics.

[18]  Konstantinos Michalodimitrakis,et al.  Noise in transcription negative feedback loops: simulation and experimental analysis , 2006, Molecular systems biology.

[19]  Hana El-Samad,et al.  Coordinate control of gene expression noise and interchromosomal interactions in a MAPK pathway , 2010, Nature Cell Biology.

[20]  Benjamin B. Kaufmann,et al.  Contributions of low molecule number and chromosomal positioning to stochastic gene expression , 2005, Nature Genetics.

[21]  M. Snyder,et al.  Pheromone-regulated Genes Required for Yeast Mating Differentiation , 1998, The Journal of cell biology.

[22]  E. O’Shea,et al.  Global analysis of protein expression in yeast , 2003, Nature.

[23]  G. Lahav,et al.  Encoding and Decoding Cellular Information through Signaling Dynamics , 2013, Cell.

[24]  Simon V. Avery,et al.  Microbial cell individuality and the underlying sources of heterogeneity , 2006, Nature Reviews Microbiology.

[25]  L. Serrano,et al.  Engineering stability in gene networks by autoregulation , 2000, Nature.

[26]  H. Dohlman,et al.  Analysis of RGS proteins in Saccharomyces cerevisiae. , 2002, Methods in enzymology.

[27]  H. Dohlman,et al.  Second Site Suppressor Mutations of a GTPase-deficient G-Protein α-Subunit , 1998, The Journal of Biological Chemistry.

[28]  Leland H. Hartwell,et al.  Courtship in S. cerevisiae: Both cell types choose mating partners by responding to the strongest pheromone signal , 1990, Cell.

[29]  A. Arkin,et al.  It's a noisy business! Genetic regulation at the nanomolar scale. , 1999, Trends in genetics : TIG.

[30]  S. Leibler,et al.  Phenotypic Diversity, Population Growth, and Information in Fluctuating Environments , 2005, Science.

[31]  E. O’Shea,et al.  Living with noisy genes: how cells function reliably with inherent variability in gene expression. , 2007, Annual review of biophysics and biomolecular structure.

[32]  J. Thorner,et al.  Sst2, a negative regulator of pheromone signaling in the yeast Saccharomyces cerevisiae: expression, localization, and genetic interaction and physical association with Gpa1 (the G-protein alpha subunit) , 1996, Molecular and cellular biology.

[33]  H. Dohlman,et al.  Selective Uncoupling of RGS Action by a Single Point Mutation in the G Protein α-Subunit* , 1998, The Journal of Biological Chemistry.

[34]  Jeff Hasty.  Origins of extrinsic variability in eukaryotic gene expression , 2006 .

[35]  Christoph H. Borchers,et al.  A Systems-Biology Analysis of Feedback Inhibition in the Sho1 Osmotic-Stress-Response Pathway , 2007, Current Biology.

[36]  M. Thattai,et al.  Stochastic Gene Expression in Fluctuating Environments , 2004, Genetics.

[37]  A. Bretscher,et al.  Polarization of cell growth in yeast. I. Establishment and maintenance of polarity states. , 2000, Journal of cell science.

[38]  R. Neubig,et al.  Identification of Small-Molecule Inhibitors of RGS4 Using a High-Throughput Flow Cytometry Protein Interaction Assay , 2007, Molecular Pharmacology.

[39]  P. Swain,et al.  Stochastic Gene Expression in a Single Cell , 2002, Science.

[40]  D. Drubin,et al.  Spontaneous receptor-independent heterotrimeric G-protein signalling in an RGS mutant , 2003, Nature Cell Biology.

[41]  J. Raser,et al.  Noise in Gene Expression: Origins, Consequences, and Control , 2005, Science.

[42]  J. Segall,et al.  Polarization of yeast cells in spatial gradients of alpha mating factor. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[43]  M. Snyder,et al.  Cell polarity and morphogenesis in budding yeast. , 1998, Annual review of microbiology.

[44]  C. Pesce,et al.  Regulated cell-to-cell variation in a cell-fate decision system , 2005, Nature.

[45]  J. Derisi,et al.  Single-cell proteomic analysis of S. cerevisiae reveals the architecture of biological noise , 2006, Nature.