title: CGI-58/ABHD5 is phosphorylated on Ser239 by protein kinase A: control of subcellular localization.
abstract: CGI-58/ABHD5 coactivates adipose triglyceride lipase (ATGL). In adipocytes, CGI-58 binds to perilipin 1A on lipid droplets under basal conditions, preventing interaction with ATGL. Upon activation of protein kinase A (PKA), perilipin 1A is phosphorylated and CGI-58 rapidly disperses into the cytoplasm, enabling lipase coactivation. Because the amino acid sequence of murine CGI-58 has a predicted PKA consensus sequence of RKYS(239)S(240), we hypothesized that phosphorylation of CGI-58 is involved in this process. We show that Ser239 of murine CGI-58 is a substrate for PKA using phosphoamino acid analysis, MS, and immuno-blotting approaches to study phosphorylation of recombinant CGI-58 and endogenous CGI-58 of adipose tissue. Phosphorylation of CGI-58 neither increased nor impaired coactivation of ATGL in vitro. Moreover, Ser239 was not required for CGI-58 function to increase triacylglycerol turnover in human neutral lipid storage disorder fibroblasts that lack endogenous CGI-58. Both CGI-58 and S239A/S240A-mutated CGI-58 localized to perilipin 1A-coated lipid droplets in cells. When PKA was activated, WT CGI-58 dispersed into the cytoplasm, whereas substantial S239A/S240A-mutated CGI-58 remained on lipid droplets. Perilipin phosphorylation also contributed to CGI-58 dispersion. PKA-mediated phosphorylation of CGI-58 is required for dispersion of CGI-58 from perilipin 1A-coated lipid droplets, thereby increasing CGI-58 availability for ATGL coactivation.
authors.affiliation: Research Unit Functional Proteomics and Metabolic Pathways, Institute of Pathology, Medical University of Graz, Graz, Austria A-8036, and Omics Center Graz, BioTechMed-Graz, Graz, Austria A-8010.
authors.forename: Anita
authors.initials: A
authors.lastname: Sahu-Osen
authors.affiliation: Rutgers Center for Lipid Research, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 Departments of Nutritional Sciences Rutgers, The State University of New Jersey, New Brunswick, NJ 08901.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Montero-Moran
authors.affiliation: Research Unit Functional Proteomics and Metabolic Pathways, Institute of Pathology, Medical University of Graz, Graz, Austria A-8036, and Omics Center Graz, BioTechMed-Graz, Graz, Austria A-8010.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schittmayer
authors.affiliation: Research Unit Functional Proteomics and Metabolic Pathways, Institute of Pathology, Medical University of Graz, Graz, Austria A-8036, and Omics Center Graz, BioTechMed-Graz, Graz, Austria A-8010.
authors.forename: Katarina
authors.initials: K
authors.lastname: Fritz
authors.affiliation: Rutgers Center for Lipid Research, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 Departments of Nutritional Sciences Rutgers, The State University of New Jersey, New Brunswick, NJ 08901.
authors.forename: Anna
authors.initials: A
authors.lastname: Dinh
authors.affiliation: Rutgers Center for Lipid Research, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 Food Science, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901.
authors.forename: Yu-Fang
authors.initials: YF
authors.lastname: Chang
authors.affiliation: Rutgers Center for Lipid Research, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 Departments of Nutritional Sciences Rutgers, The State University of New Jersey, New Brunswick, NJ 08901.
authors.forename: Derek
authors.initials: D
authors.lastname: McMahon
authors.affiliation: Institute of Molecular Biosciences, University of Graz, Graz, Austria A-8010.
authors.forename: Andras
authors.initials: A
authors.lastname: Boeszoermenyi
authors.affiliation: Institute of Molecular Biosciences, University of Graz, Graz, Austria A-8010.
authors.forename: Irina
authors.initials: I
authors.lastname: Cornaciu
authors.affiliation: Rutgers Center for Lipid Research, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 Departments of Nutritional Sciences Rutgers, The State University of New Jersey, New Brunswick, NJ 08901.
authors.forename: Deanna
authors.initials: D
authors.lastname: Russell
authors.affiliation: Institute of Molecular Biosciences, University of Graz, Graz, Austria A-8010.
authors.forename: Monika
authors.initials: M
authors.lastname: Oberer
authors.affiliation: Rutgers Center for Lipid Research, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 Food Science, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901.
authors.forename: George M
authors.initials: GM
authors.lastname: Carman
authors.affiliation: Research Unit Functional Proteomics and Metabolic Pathways, Institute of Pathology, Medical University of Graz, Graz, Austria A-8036, and Omics Center Graz, BioTechMed-Graz, Graz, Austria A-8010.
authors.forename: Ruth
authors.initials: R
authors.lastname: Birner-Gruenberger
authors.affiliation: Rutgers Center for Lipid Research, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 Departments of Nutritional Sciences Rutgers, The State University of New Jersey, New Brunswick, NJ 08901.
authors.forename: Dawn L
authors.initials: DL
authors.lastname: Brasaemle
mesh_terms: D051103:1-Acylglycerol-3-Phosphate O-Acyltransferase / Q000737:chemistry* / Q000378:metabolism*; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002352:Carrier Proteins / Q000378:metabolism; D002522:Chlorocebus aethiops; D005576:Colforsin / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism*; D008049:Lipase / Q000378:metabolism; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D000070778:Perilipin-1; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012694:Serine / Q000378:metabolism*; D000217:Acyltransferases
chemical_list: D051103:1-Acylglycerol-3-Phosphate O-Acyltransferase; D002352:Carrier Proteins; D005576:Colforsin; D017868:Cyclic AMP-Dependent Protein Kinases; D008049:Lipase; D000070778:Perilipin-1; D010750:Phosphoproteins; D011994:Recombinant Proteins; D012694:Serine; C439972:ABHD5 protein, human; C492986:Abhd5 protein, mouse; C494794:PNPLA2 protein, human; D000217:Acyltransferases; C494445:PNPLA2 protein, mouse
keywords: Chanarin Dorfman syndrome; adipocytes; adipose tissue; adipose triglyceride lipase; lipase; lipid droplets; lipolysis; perilipin