title: Role of phosphatidylserine in the activation of Rho1-related Pkc1 signaling in Saccharomyces cerevisiae.
abstract: Protein kinase C (PKC) belongs to a family of serine/threonine kinases and is evolutionary conserved among eukaryotes. It contains several functional domains, with the C1 domain being identified as a membrane-targeting module. Diacylglycerol (DAG) and phorbol esters bind to the C1 domain to enhance its kinase activity. The C1 domain is conserved in PKC (Pkc1) in the budding yeast Saccharomyces cerevisiae; however, its kinase activity does not respond to DAG. Although the C1 domain of Pkc1 physically interacts with the small GTPase Rho1, the interaction between C1 domain and lipids has not yet been characterized. We herein provide evidence to show the physical interaction between the C1 domain of Pkc1 and phosphatidylserine (PS), but not DAG. The stress-induced activation of Pkc1 signaling was abolished in a cho1 mutant, which was defective in PS synthase. The deletion of CHO1 perturbed the appropriate localization of Pkc1 at the bud tip, and impaired the physical interaction between Pkc1 and GTP-bound Rho1 in vivo. Our results suggest that PS is necessary for Pkc1 signaling due to its role in regulating the localization of Pkc1 as well as the physical interaction between Rho1 and Pkc1.
authors.affiliation: Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Nomura
authors.affiliation: Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan. Electronic address: y_inoue@kais.kyoto-u.ac.jp.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010718:Phosphatidylserines / Q000378:metabolism*; D000072417:Protein Domains; D011493:Protein Kinase C / Q000737:chemistry / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D011765:Pyruvaldehyde / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D010718:Phosphatidylserines; D029701:Saccharomyces cerevisiae Proteins; D011765:Pyruvaldehyde; C490702:PKC1 protein, S cerevisiae; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; C051302:RHO1 protein, S cerevisiae; D020741:rho GTP-Binding Proteins
keywords: Cell signaling; Phosphatidylserine; Protein kinase C; Rho1; Saccharomyces cerevisiae