The Ca2+/calmodulin dependent protein phosphatase, calcineurin, is a critical component of Ca2+-dependent signal transduction. In mammals, calcineurin regulates immune cell function, promotes heart and blood vessel development, allows heart cells to respond to stress, and modulates learning and memory. In vitro, calcineurin catalytic activity requires only the addition of Ca2+ and calmodulin. However, in vivo the interaction of calcineurin with its substrates and with regulatory proteins has a profound impact on its activity. In budding yeast, calcineurin allows cells to adapt to several environmental stresses, including exposure to ions (Na+, Mn2+, OH-), cell wall damage, and prolonged incubation with mating factor. Under these conditions, calcineurin dephosphorylates the Crz1p transcription factor, and causes its rapid translocation from the cytosol to the nucleus where it activates gene expression. How are calcineurin-dependent responses modulated in vivo, and how are they coordinated with other signaling mechanisms to achieve the proper physiological response to a particular environmental condition? To address these questions, we will examine mechanisms that regulate calcineurin and/or Crz1 function, study the interactions of other signaling pathways with Crz1/calcineurin, and characterize the association of calcineurin and Crz1 p with other proteins during signaling. Specifically, we will 1) Identify protein kinases that phosphorylate Crz1 p and determine the role of these kinases in Crz1p regulation, 2) Identify and mutagenize Crz1p phosphorylation sites and determine their roles in regulating Crz1p localization and activity, 3) Examine the mechanism by which Skn7p, a key protein in the yeast response to oxidative stress, influences catcineurin/Crz1p function to mediate cross-talk between these signaling pathways, and 4) Characterize calcineurin- and Crz1 p-containing protein complexes to define the role of specific protein-protein interactions in modulating calcineurin and Crz1 p-dependent signaling in vivo. The broad goal of this research is to elucidate the mechanisms and functions of Ca2+/calcineurin dependent signal transduction. We address these questions using S. cerevisiae, because of the many experimental advantages offered by this organism. However, we believe our findings will establish general principles that will apply to calcineurin-dependent signaling in all cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM048729-13
Application #
6909898
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Anderson, Richard A
Project Start
1993-01-01
Project End
2006-06-30
Budget Start
2005-07-01
Budget End
2006-06-30
Support Year
13
Fiscal Year
2005
Total Cost
$417,620
Indirect Cost
Name
Stanford University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Ly, Nina; Cyert, Martha S (2017) Calcineurin, the Ca2+-dependent phosphatase, regulates Rga2, a Cdc42 GTPase-activating protein, to modulate pheromone signaling. Mol Biol Cell 28:576-586
Guiney, Evan L; Goldman, Aaron R; Elias, Joshua E et al. (2015) Calcineurin regulates the yeast synaptojanin Inp53/Sjl3 during membrane stress. Mol Biol Cell 26:769-85
Arsenault, Heather E; Roy, Jagoree; Mapa, Claudine E et al. (2015) Hcm1 integrates signals from Cdk1 and calcineurin to control cell proliferation. Mol Biol Cell 26:3570-7
Goldman, Aaron; Roy, Jagoree; Bodenmiller, Bernd et al. (2014) The calcineurin signaling network evolves via conserved kinase-phosphatase modules that transcend substrate identity. Mol Cell 55:422-435
Alvaro, Christopher G; O'Donnell, Allyson F; Prosser, Derek C et al. (2014) Specific ?-arrestins negatively regulate Saccharomyces cerevisiae pheromone response by down-modulating the G-protein-coupled receptor Ste2. Mol Cell Biol 34:2660-81
Cyert, Martha S; Philpott, Caroline C (2013) Regulation of cation balance in Saccharomyces cerevisiae. Genetics 193:677-713
Grigoriu, Simina; Bond, Rachel; Cossio, Pilar et al. (2013) The molecular mechanism of substrate engagement and immunosuppressant inhibition of calcineurin. PLoS Biol 11:e1001492
Holmes, Kristen J; Klass, Daniel M; Guiney, Evan L et al. (2013) Whi3, an S. cerevisiae RNA-binding protein, is a component of stress granules that regulates levels of its target mRNAs. PLoS One 8:e84060
Pina, Francisco J; O'Donnell, Allyson F; Pagant, Silvere et al. (2011) Hph1 and Hph2 are novel components of the Sec63/Sec62 posttranslational translocation complex that aid in vacuolar proton ATPase biogenesis. Eukaryot Cell 10:63-71
Roy, Jagoree; Cyert, Martha S (2009) Cracking the phosphatase code: docking interactions determine substrate specificity. Sci Signal 2:re9

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