| Title: | Assigning quantitative function to post-translational modifications reveals multiple sites of phosphorylation that tune yeast pheromone signaling output |
| Author(s): | Pincus D; Ryan CJ; Smith RD; Brent R; Resnekov O; |
| Address: | "Molecular Sciences Institute, Berkeley, California, USA" |
| DOI: | 10.1371/journal.pone.0056544 |
| ISSN/ISBN: | 1932-6203 (Electronic) 1932-6203 (Linking) |
| Abstract: | "Cell signaling systems transmit information by post-translationally modifying signaling proteins, often via phosphorylation. While thousands of sites of phosphorylation have been identified in proteomic studies, the vast majority of sites have no known function. Assigning functional roles to the catalog of uncharacterized phosphorylation sites is a key research challenge. Here we present a general approach to address this challenge and apply it to a prototypical signaling pathway, the pheromone response pathway in Saccharomyces cerevisiae. The pheromone pathway includes a mitogen activated protein kinase (MAPK) cascade activated by a G-protein coupled receptor (GPCR). We used published mass spectrometry-based proteomics data to identify putative sites of phosphorylation on pheromone pathway components, and we used evolutionary conservation to assign priority to a list of candidate MAPK regulatory sites. We made targeted alterations in those sites, and measured the effects of the mutations on pheromone pathway output in single cells. Our work identified six new sites that quantitatively tuned system output. We developed simple computational models to find system architectures that recapitulated the quantitative phenotypes of the mutants. Our results identify a number of putative phosphorylation events that contribute to adjust the input-output relationship of this model eukaryotic signaling system. We believe this combined approach constitutes a general means not only to reveal modification sites required to turn a pathway on and off, but also those required for more subtle quantitative effects that tune pathway output. Our results suggest that relatively small quantitative influences from individual phosphorylation events endow signaling systems with plasticity that evolution may exploit to quantitatively tailor signaling outcomes" |
| Keywords: | "MAP Kinase Signaling System/*physiology Pheromones/*metabolism Phosphorylation/physiology Receptors, G-Protein-Coupled/*metabolism Saccharomyces cerevisiae/*physiology Saccharomyces cerevisiae Proteins/*metabolism;" |
| Notes: | "MedlinePincus, David Ryan, Christopher J Smith, Richard D Brent, Roger Resnekov, Orna eng P41 GM103493/GM/NIGMS NIH HHS/ 8P41 GM103493-10/GM/NIGMS NIH HHS/ R01 GM097479/GM/NIGMS NIH HHS/ P50 HG002370/HG/NHGRI NIH HHS/ P50 HG0023/HG/NHGRI NIH HHS/ Research Support, N.I.H., Extramural 2013/04/05 PLoS One. 2013; 8(3):e56544. doi: 10.1371/journal.pone.0056544. Epub 2013 Mar 12" |
