title: Model-guided optogenetic study of PKA signaling in budding yeast.
abstract: In eukaryotes, protein kinase A (PKA) is a master regulator of cell proliferation and survival. The activity of PKA is subject to elaborate control and exhibits complex time dynamics. To probe the quantitative attributes of PKA dynamics in the yeast Saccharomyces cerevisiae, we developed an optogenetic strategy that uses a photoactivatable adenylate cyclase to achieve real-time regulation of cAMP and the PKA pathway. We capitalize on the precise and rapid control afforded by this optogenetic tool, together with quantitative computational modeling, to study the properties of feedback in the PKA signaling network and dissect the nonintuitive dynamic effects that ensue from perturbing its components. Our analyses reveal that negative feedback channeled through the Ras1/2 GTPase is delayed, pinpointing its time scale and its contribution to the dynamic features of the cAMP/PKA signaling network.
authors.affiliation: Department of Biochemistry and Biophysics, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94158 Jacob_Stewart-Ornstein@hms.harvard.edu hana.el-samad@ucsf.edu.|Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158.|Howard Hughes Medical Institute, St. Louis, MO 63110.
authors.forename: Jacob
authors.initials: J
authors.lastname: Stewart-Ornstein
authors.affiliation: Department of Biochemistry and Biophysics, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94158.
authors.forename: Susan
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Biochemistry and Biophysics, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94158.
authors.forename: Rajat
authors.initials: R
authors.lastname: Bhatnagar
authors.affiliation: Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158.|Howard Hughes Medical Institute, St. Louis, MO 63110.
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Weissman
authors.affiliation: Department of Biochemistry and Biophysics, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94158 Jacob_Stewart-Ornstein@hms.harvard.edu hana.el-samad@ucsf.edu.
authors.forename: Hana
authors.initials: H
authors.lastname: El-Samad
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D025461:Feedback, Physiological; D008954:Models, Biological; D062308:Optogenetics / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D004718:Saccharomycetales / Q000378:metabolism; D015398:Signal Transduction; D018631:ras Proteins / Q000378:metabolism
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D018631:ras Proteins; D000262:Adenylyl Cyclases