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Salsaa M, Aziz K, Lazcano P, Schmidtke MW, Tarsio M, Hüttemann M, Reynolds CA, Kane PM, Greenberg ML. Valproate activates the Snf1 kinase in Saccharomyces cerevisiae by decreasing the cytosolic pH. J Biol Chem 2021; 297:101110. [PMID: 34428448 PMCID: PMC8449051 DOI: 10.1016/j.jbc.2021.101110] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 11/27/2022] Open
Abstract
Valproate (VPA) is a widely used mood stabilizer, but its therapeutic mechanism of action is not understood. This knowledge gap hinders the development of more effective drugs with fewer side effects. Using the yeast model to elucidate the effects of VPA on cellular metabolism, we determined that the drug upregulated expression of genes normally repressed during logarithmic growth on glucose medium and increased levels of activated (phosphorylated) Snf1 kinase, the major metabolic regulator of these genes. VPA also decreased the cytosolic pH (pHc) and reduced glycolytic production of 2/3-phosphoglycerate. ATP levels and mitochondrial membrane potential were increased, and glucose-mediated extracellular acidification decreased in the presence of the drug, as indicated by a smaller glucose-induced shift in pH, suggesting that the major P-type proton pump Pma1 was inhibited. Interestingly, decreasing the pHc by omeprazole-mediated inhibition of Pma1 led to Snf1 activation. We propose a model whereby VPA lowers the pHc causing a decrease in glycolytic flux. In response, Pma1 is inhibited and Snf1 is activated, resulting in increased expression of normally repressed metabolic genes. These findings suggest a central role for pHc in regulating the metabolic program of yeast cells.
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Affiliation(s)
- Michael Salsaa
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Kerestin Aziz
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Pablo Lazcano
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Michael W Schmidtke
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Maureen Tarsio
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Maik Hüttemann
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, Michigan, USA
| | - Christian A Reynolds
- Department of Emergency Medicine, School of Medicine, Wayne State University, Detroit, Michigan, USA; Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Patricia M Kane
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA.
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Disassembly of intermolecular hydrogen bond induced by cations on self-assembled monolayer. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.114476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Phosphatidic acid: an emerging versatile class of cellular mediators. Essays Biochem 2020; 64:533-546. [DOI: 10.1042/ebc20190089] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 12/11/2022]
Abstract
Abstract
Lipids function not only as the major structural components of cell membranes, but also as molecular messengers that transduce signals to trigger downstream signaling events in the cell. Phosphatidic acid (PA), the simplest and a minor class of glycerophospholipids, is a key intermediate for the synthesis of membrane and storage lipids, and also plays important roles in mediating diverse cellular and physiological processes in eukaryotes ranging from microbes to mammals and higher plants. PA comprises different molecular species that can act differently, and is found in virtually all organisms, tissues, and organellar membranes, with variations in total content and molecular species composition. The cellular levels of PA are highly dynamic in response to stimuli and multiple enzymatic reactions can mediate its production and degradation. Moreover, its unique physicochemical properties compared with other glycerophospholipids allow PA to influence membrane structure and dynamics, and interact with various proteins. PA has emerged as a class of new lipid mediators modulating various signaling and cellular processes via its versatile effects, such as membrane tethering, conformational changes, and enzymatic activities of target proteins, and vesicular trafficking.
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Case KC, Salsaa M, Yu W, Greenberg ML. Regulation of Inositol Biosynthesis: Balancing Health and Pathophysiology. Handb Exp Pharmacol 2020; 259:221-260. [PMID: 30591968 DOI: 10.1007/164_2018_181] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Inositol is the precursor for all inositol compounds and is essential for viability of eukaryotic cells. Numerous cellular processes and signaling functions are dependent on inositol compounds, and perturbation of their synthesis leads to a wide range of human diseases. Although considerable research has been directed at understanding the function of inositol compounds, especially phosphoinositides and inositol phosphates, a focus on regulatory and homeostatic mechanisms controlling inositol biosynthesis has been largely neglected. Consequently, little is known about how synthesis of inositol is regulated in human cells. Identifying physiological regulators of inositol synthesis and elucidating the molecular mechanisms that regulate inositol synthesis will contribute fundamental insight into cellular processes that are mediated by inositol compounds and will provide a foundation to understand numerous disease processes that result from perturbation of inositol homeostasis. In addition, elucidating the mechanisms of action of inositol-depleting drugs may suggest new strategies for the design of second-generation pharmaceuticals to treat psychiatric disorders and other illnesses.
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Affiliation(s)
- Kendall C Case
- Department of Biological Sciences, Wayne State University, Detroit, MI, USA
| | - Michael Salsaa
- Department of Biological Sciences, Wayne State University, Detroit, MI, USA
| | - Wenxi Yu
- Department of Biological Sciences, Wayne State University, Detroit, MI, USA
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, MI, USA.
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Huang X, Chen J, Yan C, Shao H. Probing a Reversible Cationic Switch on a Mixed Self-Assembled Monolayer Using Scanning Electrochemical Microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10772-10779. [PMID: 31361491 DOI: 10.1021/acs.langmuir.9b01429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Probing a switch on biomimic membrane surfaces would offer some references to the research on permeability of cytomembranes. In this work, a mixed 11-mercaptoundecanoic acid/1-undecanethiol self-assembled monolayer (MUA/UT SAM) was constructed as a model of a biomembrane. In this mixed SAM, the MUA molecules work as functional parts for the switch and the UT molecules work as diluents. The surface coverage, wetting property, and pKa of this mixed SAM all have been well-inspected. The mixed SAM exhibits excellent switchable properties for cations, which is well-monitored by scanning electrochemical microscopy. When the pH of a solution is higher than the pKa, protons would stimulate a shift of dissociation equilibrium of terminal carboxyl groups. The dissociated carboxylate ions would lead to a switch on the state of the SAM. Otherwise, the SAM shows an off state when the pH is lower than the pKa. In addition, the repeatability, applicability, and the mechanism of the switch all have been well-evaluated.
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Affiliation(s)
- Ximing Huang
- Beijing Key Laboratory of Photoelectronic and Electrophotonic Conversion Materials, Key Laboratory of Cluster Science (Ministry of Education), School of Chemistry and Chemical Engineering , Beijing Institute of Technology , Beijing 102488 , P. R. China
| | - Jingchao Chen
- Beijing Key Laboratory of Photoelectronic and Electrophotonic Conversion Materials, Key Laboratory of Cluster Science (Ministry of Education), School of Chemistry and Chemical Engineering , Beijing Institute of Technology , Beijing 102488 , P. R. China
| | - Chunxia Yan
- Beijing Key Laboratory of Photoelectronic and Electrophotonic Conversion Materials, Key Laboratory of Cluster Science (Ministry of Education), School of Chemistry and Chemical Engineering , Beijing Institute of Technology , Beijing 102488 , P. R. China
| | - Huibo Shao
- Beijing Key Laboratory of Photoelectronic and Electrophotonic Conversion Materials, Key Laboratory of Cluster Science (Ministry of Education), School of Chemistry and Chemical Engineering , Beijing Institute of Technology , Beijing 102488 , P. R. China
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Anaokar S, Kodali R, Jonik B, Renne MF, Brouwers JFHM, Lager I, de Kroon AIPM, Patton-Vogt J. The glycerophosphocholine acyltransferase Gpc1 is part of a phosphatidylcholine (PC)-remodeling pathway that alters PC species in yeast. J Biol Chem 2018; 294:1189-1201. [PMID: 30514764 DOI: 10.1074/jbc.ra118.005232] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 11/27/2018] [Indexed: 12/22/2022] Open
Abstract
Phospholipase B-mediated hydrolysis of phosphatidylcholine (PC) results in the formation of free fatty acids and glycerophosphocholine (GPC) in the yeast Saccharomyces cerevisiae GPC can be reacylated by the glycerophosphocholine acyltransferase Gpc1, which produces lysophosphatidylcholine (LPC), and LPC can be converted to PC by the lysophospholipid acyltransferase Ale1. Here, we further characterized the regulation and function of this distinct PC deacylation/reacylation pathway in yeast. Through in vitro and in vivo experiments, we show that Gpc1 and Ale1 are the major cellular GPC and LPC acyltransferases, respectively. Importantly, we report that Gpc1 activity affects the PC species profile. Loss of Gpc1 decreased the levels of monounsaturated PC species and increased those of diunsaturated PC species, whereas Gpc1 overexpression had the opposite effects. Of note, Gpc1 loss did not significantly affect phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine profiles. Our results indicate that Gpc1 is involved in postsynthetic PC remodeling that produces more saturated PC species. qRT-PCR analyses revealed that GPC1 mRNA abundance is regulated coordinately with PC biosynthetic pathways. Inositol availability, which regulates several phospholipid biosynthetic genes, down-regulated GPC1 expression at the mRNA and protein levels and, as expected, decreased levels of monounsaturated PC species. Finally, loss of GPC1 decreased stationary phase viability in inositol-free medium. These results indicate that Gpc1 is part of a postsynthetic PC deacylation/reacylation remodeling pathway (PC-DRP) that alters the PC species profile, is regulated in coordination with other major lipid biosynthetic pathways, and affects yeast growth.
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Affiliation(s)
- Sanket Anaokar
- Departments of Biological Sciences, Pittsburgh, Pennsylvania 15282
| | - Ravindra Kodali
- Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282
| | - Benjamin Jonik
- Departments of Biological Sciences, Pittsburgh, Pennsylvania 15282
| | - Mike F Renne
- Department of Membrane Biochemistry & Biophysics, Bijvoet Center and Institute of Biomembranes, 3584 CH Utrecht, The Netherlands
| | - Jos F H M Brouwers
- Department of Biochemistry and Cell Biology, Institute of Biomembranes, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Ida Lager
- Department of Plant Breeding, Swedish University of Agricultural Sciences, SE-230 53 Alnarp, Sweden
| | - Anton I P M de Kroon
- Department of Membrane Biochemistry & Biophysics, Bijvoet Center and Institute of Biomembranes, 3584 CH Utrecht, The Netherlands
| | - Jana Patton-Vogt
- Departments of Biological Sciences, Pittsburgh, Pennsylvania 15282.
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