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Colaço-Gaspar M, Hofer P, Oberer M, Zechner R. Corrigendum to "PNPLA-mediated lipid hydrolysis and transacylation - At the intersection of catabolism and anabolism" [Biochim. Biophys. Acta (BBA) - Mol. Cell Biol. Lipids volume 1869, issue 2, March 2024, 159,410]. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159481. [PMID: 38490127 DOI: 10.1016/j.bbalip.2024.159481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Affiliation(s)
| | - Peter Hofer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria; BioTechMed-Graz, 8010 Graz, Austria.
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria; BioTechMed-Graz, 8010 Graz, Austria.
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2
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Colaço-Gaspar M, Hofer P, Oberer M, Zechner R. PNPLA-mediated lipid hydrolysis and transacylation - At the intersection of catabolism and anabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159410. [PMID: 37951382 DOI: 10.1016/j.bbalip.2023.159410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/24/2023] [Accepted: 10/30/2023] [Indexed: 11/14/2023]
Abstract
Patatin-like phospholipase domain containing proteins (PNPLAs) play diverse roles in lipid metabolism. In this review, we focus on the enzymatic properties and predicted 3D structures of PNPLA1-5. PNPLA2-4 exert both catabolic and anabolic functions. Whereas PNPLA1 is predominantly expressed in the epidermis and involved in sphingolipid biosynthesis, PNPLA2 and 4 are ubiquitously expressed and exhibit several enzymatic activities, including hydrolysis and transacylation of various (glycero-)lipid species. This review summarizes known biological roles for PNPLA-mediated hydrolysis and transacylation reactions and highlights open questions concerning their physiological function.
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Affiliation(s)
| | - Peter Hofer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria; BioTechMed-Graz, 8010 Graz, Austria.
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria; BioTechMed-Graz, 8010 Graz, Austria.
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3
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Kulminskaya N, Rodriguez Gamez CF, Hofer P, Cerk IK, Dubey N, Viertlmayr R, Sagmeister T, Pavkov-Keller T, Zechner R, Oberer M. Unmasking crucial residues in adipose triglyceride lipase for coactivation with comparative gene identification-58. J Lipid Res 2024; 65:100491. [PMID: 38135254 PMCID: PMC10828586 DOI: 10.1016/j.jlr.2023.100491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 12/04/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
Lipolysis is an essential metabolic process that releases unesterified fatty acids from neutral lipid stores to maintain energy homeostasis in living organisms. Adipose triglyceride lipase (ATGL) plays a key role in intracellular lipolysis and can be coactivated upon interaction with the protein comparative gene identification-58 (CGI-58). The underlying molecular mechanism of ATGL stimulation by CGI-58 is incompletely understood. Based on analysis of evolutionary conservation, we used site directed mutagenesis to study a C-terminally truncated variant and full-length mouse ATGL providing insights in the protein coactivation on a per-residue level. We identified the region from residues N209-N215 in ATGL as essential for coactivation by CGI-58. ATGL variants with amino acids exchanges in this region were still able to hydrolyze triacylglycerol at the basal level and to interact with CGI-58, yet could not be activated by CGI-58. Our studies also demonstrate that full-length mouse ATGL showed higher tolerance to specific single amino acid exchanges in the N209-N215 region upon CGI-58 coactivation compared to C-terminally truncated ATGL variants. The region is either directly involved in protein-protein interaction or essential for conformational changes required in the coactivation process. Three-dimensional models of the ATGL/CGI-58 complex with the artificial intelligence software AlphaFold demonstrated that a large surface area is involved in the protein-protein interaction. Mapping important amino acids for coactivation of both proteins, ATGL and CGI-58, onto the 3D model of the complex locates these essential amino acids at the predicted ATGL/CGI-58 interface thus strongly corroborating the significance of these residues in CGI-58-mediated coactivation of ATGL.
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Affiliation(s)
| | | | - Peter Hofer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Ines Kathrin Cerk
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Noopur Dubey
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Roland Viertlmayr
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Theo Sagmeister
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Tea Pavkov-Keller
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria.
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4
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Eliaš J, Fellner K, Hofer P, Oberer M, Schreiber R, Zechner R. The Potential Roles of Transacylation in Intracellular Lipolysis and Related Qssa Approximations. Bull Math Biol 2023; 85:82. [PMID: 37544001 PMCID: PMC10404580 DOI: 10.1007/s11538-023-01188-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 07/19/2023] [Indexed: 08/08/2023]
Abstract
Fatty acids (FAs) are crucial energy metabolites, signalling molecules, and membrane building blocks for a wide range of organisms. Adipose triglyceride lipase (ATGL) is the first and presumingly most crucial regulator of FA release from triacylglycerols (TGs) stored within cytosolic lipid droplets. However, besides the function of releasing FAs by hydrolysing TGs into diacylglycerols (DGs), ATGL also promotes the transacylation reaction of two DG molecules into one TG and one monoacylglycerol molecule. To date, it is unknown whether DG transacylation is a coincidental byproduct of ATGL-mediated lipolysis or whether it is physiologically relevant. Experimental evidence is scarce since both, hydrolysis and transacylation, rely on the same active site of ATGL and always occur in parallel in an ensemble of molecules. This paper illustrates the potential roles of transacylation. It shows that, depending on the kinetic parameters but also on the state of the hydrolytic machinery, transacylation can increase or decrease downstream products up to 80% respectively 30%. We provide an extensive asymptotic analysis including quasi-steady-state approximations (QSSA) with higher order correction terms and provide numerical simulation. We also argue that when assessing the validity of QSSAs one should include parameter sensitivity derivatives. Our results suggest that the transacylation function of ATGL is of biological relevance by providing feedback options and altogether stability to the lipolytic machinery in adipocytes.
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Affiliation(s)
- Ján Eliaš
- Boehringer Ingelheim RCV GmbH & Co KG, Dr. Boehringer-Gasse 5-11, 1121 Vienna, Austria
- Institute of Mathematics and Scientific Computing, University of Graz, Heinrichstraße 36, 8010 Graz, Austria
| | - Klemens Fellner
- Institute of Mathematics and Scientific Computing, University of Graz, Heinrichstraße 36, 8010 Graz, Austria
| | - Peter Hofer
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010 Graz, Austria
- BioTechMed Graz, 8010 Graz, Austria
- BioHealth Field of Excellence, University of Graz, 8010 Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010 Graz, Austria
- BioHealth Field of Excellence, University of Graz, 8010 Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010 Graz, Austria
- BioTechMed Graz, 8010 Graz, Austria
- BioHealth Field of Excellence, University of Graz, 8010 Graz, Austria
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5
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Pusch LM, Riegler-Berket L, Oberer M, Zimmermann R, Taschler U. α/β-Hydrolase Domain-Containing 6 (ABHD6)- A Multifunctional Lipid Hydrolase. Metabolites 2022; 12:761. [PMID: 36005632 PMCID: PMC9412472 DOI: 10.3390/metabo12080761] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/05/2022] [Accepted: 08/12/2022] [Indexed: 11/16/2022] Open
Abstract
α/β-hydrolase domain-containing 6 (ABHD6) belongs to the α/β-hydrolase fold superfamily and was originally discovered in a functional proteomic approach designed to discover monoacylglycerol (MAG) hydrolases in the mouse brain degrading the endocannabinoid 2-arachidonoylglycerol. Subsequent studies confirmed that ABHD6 acts as an MAG hydrolase regulating cannabinoid receptor-dependent and -independent signaling processes. The enzyme was identified as a negative modulator of insulin secretion and regulator of energy metabolism affecting the pathogenesis of obesity and metabolic syndrome. It has been implicated in the metabolism of the lysosomal co-factor bis(monoacylglycerol)phosphate and in the surface delivery of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptors. Finally, ABHD6 was shown to affect cancer cell lipid metabolism and tumor malignancy. Here, we provide new insights into the experimentally derived crystal structure of ABHD6 and its possible orientation in biological membranes, and discuss ABHD6's functions in health and disease.
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Affiliation(s)
- Lisa-Maria Pusch
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
| | - Lina Riegler-Berket
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria
| | - Ulrike Taschler
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
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6
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Patel R, Santoro A, Hofer P, Tan D, Oberer M, Nelson AT, Konduri S, Siegel D, Zechner R, Saghatelian A, Kahn BB. ATGL is a biosynthetic enzyme for fatty acid esters of hydroxy fatty acids. Nature 2022; 606:968-975. [PMID: 35676490 PMCID: PMC9242854 DOI: 10.1038/s41586-022-04787-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 04/21/2022] [Indexed: 12/16/2022]
Abstract
Branched fatty acid (FA) esters of hydroxy FAs (HFAs; FAHFAs) are recently discovered lipids that are conserved from yeast to mammals1,2. A subfamily, palmitic acid esters of hydroxy stearic acids (PAHSAs), are anti-inflammatory and anti-diabetic1,3. Humans and mice with insulin resistance have lower PAHSA levels in subcutaneous adipose tissue and serum1. PAHSA administration improves glucose tolerance and insulin sensitivity and reduces inflammation in obesity, diabetes and immune-mediated diseases1,4-7. The enzyme(s) responsible for FAHFA biosynthesis in vivo remains unknown. Here we identified adipose triglyceride lipase (ATGL, also known as patatin-like phospholipase domain containing 2 (PNPLA2)) as a candidate biosynthetic enzyme for FAHFAs using chemical biology and proteomics. We discovered that recombinant ATGL uses a transacylation reaction that esterifies an HFA with a FA from triglyceride (TG) or diglyceride to produce FAHFAs. Overexpression of wild-type, but not catalytically dead, ATGL increases FAHFA biosynthesis. Chemical inhibition of ATGL or genetic deletion of Atgl inhibits FAHFA biosynthesis and reduces the levels of FAHFA and FAHFA-TG. Levels of endogenous and nascent FAHFAs and FAHFA-TGs are 80-90 per cent lower in adipose tissue of mice in which Atgl is knocked out specifically in the adipose tissue. Increasing TG levels by upregulating diacylglycerol acyltransferase (DGAT) activity promotes FAHFA biosynthesis, and decreasing DGAT activity inhibits it, reinforcing TGs as FAHFA precursors. ATGL biosynthetic transacylase activity is present in human adipose tissue underscoring its potential clinical relevance. In summary, we discovered the first, to our knowledge, biosynthetic enzyme that catalyses the formation of the FAHFA ester bond in mammals. Whereas ATGL lipase activity is well known, our data establish a paradigm shift demonstrating that ATGL transacylase activity is biologically important.
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Affiliation(s)
- Rucha Patel
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Anna Santoro
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Peter Hofer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Dan Tan
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Andrew T Nelson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, La Jolla, CA, USA
| | - Srihari Konduri
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, La Jolla, CA, USA
| | - Dionicio Siegel
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, La Jolla, CA, USA
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Barbara B Kahn
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
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7
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Grabner GF, Guttenberger N, Mayer N, Migglautsch-Sulzer AK, Lembacher-Fadum C, Fawzy N, Bulfon D, Hofer P, Züllig T, Hartig L, Kulminskaya N, Chalhoub G, Schratter M, Radner FPW, Preiss-Landl K, Masser S, Lass A, Zechner R, Gruber K, Oberer M, Breinbauer R, Zimmermann R. Small-Molecule Inhibitors Targeting Lipolysis in Human Adipocytes. J Am Chem Soc 2022; 144:6237-6250. [PMID: 35362954 PMCID: PMC9011347 DOI: 10.1021/jacs.1c10836] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
![]()
Chronically elevated
circulating fatty acid levels promote lipid
accumulation in nonadipose tissues and cause lipotoxicity. Adipose
triglyceride lipase (ATGL) critically determines the release of fatty
acids from white adipose tissue, and accumulating evidence suggests
that inactivation of ATGL has beneficial effects on lipotoxicity-driven
disorders including insulin resistance, steatohepatitis, and heart
disease, classifying ATGL as a promising drug target. Here, we report
on the development and biological characterization of the first small-molecule
inhibitor of human ATGL. This inhibitor, designated NG-497, selectively
inactivates human and nonhuman primate ATGL but not structurally and
functionally related lipid hydrolases. We demonstrate that NG-497
abolishes lipolysis in human adipocytes in a dose-dependent and reversible
manner. The combined analysis of mouse- and human-selective inhibitors,
chimeric ATGL proteins, and homology models revealed detailed insights
into enzyme–inhibitor interactions. NG-497 binds ATGL within
a hydrophobic cavity near the active site. Therein, three amino acid
residues determine inhibitor efficacy and species selectivity and
thus provide the molecular scaffold for selective inhibition.
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Affiliation(s)
- Gernot F Grabner
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Nikolaus Guttenberger
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Nicole Mayer
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | | | | | - Nermeen Fawzy
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Dominik Bulfon
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Peter Hofer
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Thomas Züllig
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Lennart Hartig
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Natalia Kulminskaya
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Gabriel Chalhoub
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Margarita Schratter
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Franz P W Radner
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Karina Preiss-Landl
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Sarah Masser
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria.,BioTechMed-Graz, Mozartgasse 12/2, 8010 Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria.,BioTechMed-Graz, Mozartgasse 12/2, 8010 Graz, Austria.,BioHealth Field of Excellence, University of Graz, Universitätsplatz 3, 8010 Graz, Austria
| | - Karl Gruber
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria.,BioTechMed-Graz, Mozartgasse 12/2, 8010 Graz, Austria.,BioHealth Field of Excellence, University of Graz, Universitätsplatz 3, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria.,BioTechMed-Graz, Mozartgasse 12/2, 8010 Graz, Austria.,BioHealth Field of Excellence, University of Graz, Universitätsplatz 3, 8010 Graz, Austria
| | - Rolf Breinbauer
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria.,BioTechMed-Graz, Mozartgasse 12/2, 8010 Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010 Graz, Austria.,BioTechMed-Graz, Mozartgasse 12/2, 8010 Graz, Austria.,BioHealth Field of Excellence, University of Graz, Universitätsplatz 3, 8010 Graz, Austria
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8
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Riegler-Berket L, Wechselberger L, Cerk IK, Padmanabha Das KM, Viertlmayr R, Kulminskaya N, Rodriguez Gamez CF, Schweiger M, Zechner R, Zimmermann R, Oberer M. Residues of the minimal sequence of G0S2 collectively contribute to ATGL inhibition while C-and N-terminal extensions promote binding to ATGL. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159105. [PMID: 35026402 DOI: 10.1016/j.bbalip.2021.159105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/29/2021] [Accepted: 12/17/2021] [Indexed: 11/25/2022]
Abstract
The protein encoded by the G0/G1 switch gene 2 (G0S2) is a potent inhibitor of adipose triglyceride lipase (ATGL) and thus an important regulator of intracellular lipolysis. Since dysfunction of lipolysis is associated with metabolic diseases including diabetes and obesity, inhibition of ATGL is considered a therapeutic strategy. G0S2 interacts with ATGL's patatin-domain to mediate non-competitive inhibition, however atomic details of the inhibition mechanism are incompletely understood. Sequences of G0S2 from higher organisms show a highly conserved N-terminal part, including a hydrophobic region covering amino acids 27 to 42. We show that predicted G0S2 orthologs from platypus, chicken and Japanese rice-fish are able to inhibit human and mouse ATGL, emphasizing the contribution of conserved amino acid to ATGL inhibition. Our site directed mutagenesis and truncation studies give insights in the protein-protein interaction on a per-residue level. We determine that the minimal sequence required for ATGL inhibition ranges from amino acids 20 to 44. Residues Y27, V28, G30, A34 G37, V39 or L42 within this sequence play a substantial role in ATGL inhibition. Furthermore, we show that unspecific interactions of the N-terminal part (amino acids 20-27) of the minimal sequence facilitate the interaction to ATGL. Our studies also demonstrate that full-length G0S2 shows higher tolerance to specific single amino acid exchanges in the hydrophobic region due to the stronger contributions of unspecific interactions. However, exchanges of more than one amino-acid in the hydrophobic region also result in the loss of function as ATGL inhibitor even in the full-length protein.
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Affiliation(s)
- L Riegler-Berket
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - L Wechselberger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - I K Cerk
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - K M Padmanabha Das
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - R Viertlmayr
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - N Kulminskaya
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | | | - M Schweiger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria
| | - R Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria; BioHealth Field of Excellence, University of Graz, 8010 Graz, Austria
| | - R Zimmermann
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria; BioHealth Field of Excellence, University of Graz, 8010 Graz, Austria
| | - M Oberer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria; BioHealth Field of Excellence, University of Graz, 8010 Graz, Austria.
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9
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Kulminskaya N, Radler C, Viertlmayr R, Heier C, Hofer P, Colaço-Gaspar M, Owens RJ, Zimmermann R, Schreiber R, Zechner R, Oberer M. Optimized expression and purification of adipose triglyceride lipase improved hydrolytic and transacylation activities in vitro. J Biol Chem 2021; 297:101206. [PMID: 34543623 PMCID: PMC8506970 DOI: 10.1016/j.jbc.2021.101206] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 09/06/2021] [Accepted: 09/15/2021] [Indexed: 11/21/2022] Open
Abstract
Adipose triglyceride lipase (ATGL) plays a key role in intracellular lipolysis, the mobilization of stored triacylglycerol. This work provides an important basis for generating reproducible and detailed data on the hydrolytic and transacylation activities of ATGL. We generated full-length and C-terminally truncated ATGL variants fused with various affinity tags and analyzed their expression in different hosts, namely E.coli, the insect cell line Sf9, and the mammalian cell line human embryonic kidney 293T. Based on this screen, we expressed a fusion protein of ATGL covering residues M1-D288 flanked with N-terminal and C-terminal purification tags. Using these fusions, we identified key steps in expression and purification protocols, including production in the E. coli strain ArcticExpress (DE3) and removal of copurified chaperones. The resulting purified ATGL variant demonstrated improved lipolytic activity compared with previously published data, and it could be stimulated by the coactivator protein comparative gene identification-58 and inhibited by the protein G0/G1 switch protein 2. Shock freezing and storage did not affect the basal activity but reduced coactivation of ATGL by comparative gene identification 58. In vitro, the truncated ATGL variant demonstrated acyl-CoA-independent transacylation activity when diacylglycerol was offered as substrate, resulting in the formation of fatty acid as well as triacylglycerol and monoacylglycerol. However, the ATGL variant showed neither hydrolytic activity nor transacylation activity upon offering of monoacylglycerol as substrate. To understand the role of ATGL in different physiological contexts, it is critical for future studies to identify all its different functions and to determine under what conditions these activities occur.
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Affiliation(s)
| | - Claudia Radler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Roland Viertlmayr
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Christoph Heier
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Peter Hofer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Raymond J Owens
- Division of Structural Biology, The Welcome Centre for Human Genetics, University of Oxford, Oxford, UK; Protein Production UK, Research Complex at Harwell, Didcot, UK
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioTechMed, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioTechMed, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioTechMed, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria.
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10
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Grininger C, Leypold M, Aschauer P, Pavkov-Keller T, Riegler-Berket L, Breinbauer R, Oberer M. Structural Changes in the Cap of Rv0183/mtbMGL Modulate the Shape of the Binding Pocket. Biomolecules 2021; 11:1299. [PMID: 34572512 PMCID: PMC8472722 DOI: 10.3390/biom11091299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 11/23/2022] Open
Abstract
Tuberculosis continues to be a major threat to the human population. Global efforts to eradicate the disease are ongoing but are hampered by the increasing occurrence of multidrug-resistant strains of Mycobacterium tuberculosis. Therefore, the development of new treatment, and the exploration of new druggable targets and treatment strategies, are of high importance. Rv0183/mtbMGL, is a monoacylglycerol lipase of M. tuberculosis and it is involved in providing fatty acids and glycerol as building blocks and as an energy source. Since the lipase is expressed during the dormant and active phase of an infection, Rv0183/mtbMGL is an interesting target for inhibition. In this work, we determined the crystal structures of a surface-entropy reduced variant K74A Rv0183/mtbMGL in its free form and in complex with a substrate mimicking inhibitor. The two structures reveal conformational changes in the cap region that forms a major part of the substrate/inhibitor binding region. We present a completely closed conformation in the free form and semi-closed conformation in the ligand-bound form. These conformations differ from the previously published, completely open conformation of Rv0183/mtbMGL. Thus, this work demonstrates the high conformational plasticity of the cap from open to closed conformations and provides useful insights into changes in the substrate-binding pocket, the target of potential small-molecule inhibitors.
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Affiliation(s)
- Christoph Grininger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; (C.G.); (P.A.); (T.P.-K.); (L.R.-B.)
| | - Mario Leypold
- Institute of Organic Chemistry, Graz University of Technology, 8010 Graz, Austria; (M.L.); (R.B.)
| | - Philipp Aschauer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; (C.G.); (P.A.); (T.P.-K.); (L.R.-B.)
| | - Tea Pavkov-Keller
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; (C.G.); (P.A.); (T.P.-K.); (L.R.-B.)
- BioHealth Graz, 8010 Graz, Austria
- BioTechMed Graz, 8010 Graz, Austria
| | - Lina Riegler-Berket
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; (C.G.); (P.A.); (T.P.-K.); (L.R.-B.)
| | - Rolf Breinbauer
- Institute of Organic Chemistry, Graz University of Technology, 8010 Graz, Austria; (M.L.); (R.B.)
- BioTechMed Graz, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; (C.G.); (P.A.); (T.P.-K.); (L.R.-B.)
- BioHealth Graz, 8010 Graz, Austria
- BioTechMed Graz, 8010 Graz, Austria
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11
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Chalhoub G, Kolleritsch S, Maresch LK, Taschler U, Pajed L, Tilp A, Eisner H, Rosina P, Kien B, Radner FPW, Schicho R, Oberer M, Schoiswohl G, Haemmerle G. Carboxylesterase 2 proteins are efficient diglyceride and monoglyceride lipases possibly implicated in metabolic disease. J Lipid Res 2021; 62:100075. [PMID: 33872605 PMCID: PMC8131317 DOI: 10.1016/j.jlr.2021.100075] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 12/31/2022] Open
Abstract
Carboxylesterase 2 (CES2/Ces2) proteins exert established roles in (pro)drug metabolism. Recently, human and murine CES2/Ces2c have been discovered as triglyceride (TG) hydrolases implicated in the development of obesity and fatty liver disease. The murine Ces2 family consists of seven homologous genes as opposed to a single CES2 gene in humans. However, the mechanistic role of Ces2 protein family members is not completely understood. In this study, we examined activities of all Ces2 members toward TGs, diglycerides (DGs), and monoglycerides (MGs) as the substrate. Besides CES2/Ces2c, we measured significant TG hydrolytic activities for Ces2a, Ces2b, and Ces2e. Notably, these Ces2 members and CES2 efficiently hydrolyzed DGs and MGs, and their activities even surpassed those measured for TG hydrolysis. The localization of CES2/Ces2c proteins at the ER may implicate a role of these lipases in lipid signaling pathways. We found divergent expression of Ces2 genes in the liver and intestine of mice on a high-fat diet, which could relate to changes in lipid signaling. Finally, we demonstrate reduced CES2 expression in the colon of patients with inflammatory bowel disease and a similar decline in Ces2 expression in the colon of a murine colitis model. Together, these results demonstrate that CES2/Ces2 members are highly efficient DG and MG hydrolases that may play an important role in liver and gut lipid signaling.
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Affiliation(s)
- Gabriel Chalhoub
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Lisa K Maresch
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Ulrike Taschler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Laura Pajed
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Anna Tilp
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Helgit Eisner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Philipp Rosina
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Benedikt Kien
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Franz P W Radner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Rudolf Schicho
- Division of Pharmacology, Otto Loewi Research Center, Medical University of Graz, Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
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12
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Kulminskaya N, Oberer M. Protein-protein interactions regulate the activity of Adipose Triglyceride Lipase in intracellular lipolysis. Biochimie 2020; 169:62-68. [DOI: 10.1016/j.biochi.2019.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/06/2019] [Indexed: 12/31/2022]
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13
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Jebessa ZH, Shanmukha KD, Dewenter M, Lehmann LH, Xu C, Schreiter F, Siede D, Gong XM, Worst BC, Federico G, Sauer SW, Fischer T, Wechselberger L, Müller OJ, Sossalla S, Dieterich C, Most P, Gröne HJ, Moro C, Oberer M, Haemmerle G, Katus HA, Tyedmers J, Backs J. The lipid droplet-associated protein ABHD5 protects the heart through proteolysis of HDAC4. Nat Metab 2019; 1:1157-1167. [PMID: 31742248 PMCID: PMC6861130 DOI: 10.1038/s42255-019-0138-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Catecholamines stimulate the first step of lipolysis by PKA-dependent release of the lipid droplet-associated protein ABHD5 from perilipin to co-activate the lipase ATGL. Here, we unmask a yet unrecognized proteolytic and cardioprotective function of ABHD5. ABHD5 acts in vivo and in vitro as a serine protease cleaving HDAC4. Through the production of an N-terminal polypeptide of HDAC4 (HDAC4-NT), ABHD5 inhibits MEF2-dependent gene expression and thereby controls glucose handling. ABHD5-deficiency leads to neutral lipid storage disease in mice. Cardiac-specific gene therapy of HDAC4-NT does not protect from intra-cardiomyocyte lipid accumulation but strikingly from heart failure, thereby challenging the concept of lipotoxicity-induced heart failure. ABHD5 levels are reduced in failing human hearts and murine transgenic ABHD5 expression protects from pressure-overload induced heart failure. These findings represent a conceptual advance by connecting lipid with glucose metabolism through HDAC4 proteolysis and enable new translational approaches to treat cardiometabolic disease.
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Affiliation(s)
- Zegeye H Jebessa
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Kumar D Shanmukha
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Matthias Dewenter
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Lorenz H Lehmann
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Chang Xu
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Friederike Schreiter
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Dominik Siede
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Xue-Min Gong
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Barbara C Worst
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
- Pediatric Glioma Research Group, Hopp Children's Cancer Center Heidelberg (KiTZ) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Giuseppina Federico
- Department of Cellular and Molecular Pathology, German Cancer Research Center, Heidelberg, Germany
| | - Sven W Sauer
- Department of General Pediatrics, Division of Inborn Metabolic Diseases, University Children's Hospital, Heidelberg, Germany
| | - Tamas Fischer
- John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Lisa Wechselberger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Oliver J Müller
- Department of Internal Medicine III, University of Kiel, Kiel, Germany
| | - Samuel Sossalla
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - Christoph Dieterich
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Patrick Most
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Herrmann-Josef Gröne
- Department of Cellular and Molecular Pathology, German Cancer Research Center, Heidelberg, Germany
- Institute for Pathology and Nephropathology, University Hospital Marburg, Marburg, Germany
| | - Cedric Moro
- INSERM, UMR1048, Obesity Research Laboratory, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Hugo A Katus
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Jens Tyedmers
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Johannes Backs
- Institute of Experimental Cardiology, University of Heidelberg, Heidelberg, Germany.
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany.
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14
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Pressler K, Mitterer F, Vorkapic D, Reidl J, Oberer M, Schild S. Characterization of Vibrio cholerae's Extracellular Nuclease Xds. Front Microbiol 2019; 10:2057. [PMID: 31551990 PMCID: PMC6746945 DOI: 10.3389/fmicb.2019.02057] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/20/2019] [Indexed: 12/22/2022] Open
Abstract
The Gram-negative bacterium Vibrio cholerae encodes two nucleases, Dns and Xds, which play a major role during the human pathogen’s lifecycle. Dns and Xds control three-dimensional biofilm formation and bacterial detachment from biofilms via degradation of extracellular DNA and thus contribute to the environmental, inter-epidemic persistence of the pathogen. During intestinal colonization the enzymes help evade the innate immune response, and therefore promote survival by mediating escape from neutrophil extracellular traps. Xds has the additional function of degrading extracellular DNA down to nucleotides, which are an important nutrient source for V. cholerae. Thus, Xds is a key enzyme for survival fitness during distinct stages of the V. cholerae lifecycle and could be a potential therapeutic target. This study provides detailed information about the enzymatic properties of Xds using purified protein in combination with a real time nuclease activity assay. The data define an optimal buffer composition for Xds activity as 50 mM Tris/HCl pH 7, 100 mM NaCl, 10 mM MgCl2, and 20 mM CaCl2. Moreover, maximal activity was observed using substrate DNA with low GC content and ambient temperatures of 20–25°C. In silico analysis and homology modeling predicted an exonuclease domain in the C-terminal part of the protein. Biochemical analyses with truncated variants and point mutants of Xds confirm that the C-terminal region is sufficient for nuclease activity. We also find that residues D787 and H837 within the predicted exonuclease domain are key to formation of the catalytic center.
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Affiliation(s)
| | - Fabian Mitterer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Dina Vorkapic
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Joachim Reidl
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
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15
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Eder M, Dordic A, Sagmeister T, Damisch E, Vejzovic D, Berni F, Codee J, Palva A, Vonck J, Oberer M, Pavkov-Keller T. Surface layer proteins of lactobacilli – determining the cell wall binding and their antibacterial effect. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s2053273319093604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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16
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Aschauer P, Riegler-Berket L, Grinninger C, Natmessnig H, Pavkov-Keller T, Breinbauer R, Birner-Grünberger R, Zimmermann R, Oberer M. The drug target monoacylglycerol lipase: structure and dynamics, conservation and divergence. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s205327331908940x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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17
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Hehlert P, Hofferek V, Heier C, Eichmann TO, Riedel D, Rosenberg J, Takaćs A, Nagy HM, Oberer M, Zimmermann R, Kühnlein RP. The α/β-hydrolase domain-containing 4- and 5-related phospholipase Pummelig controls energy storage in Drosophila. J Lipid Res 2019; 60:1365-1378. [PMID: 31164391 DOI: 10.1194/jlr.m092817] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 06/03/2019] [Indexed: 01/05/2023] Open
Abstract
Triglycerides (TGs) are the main energy storage form that accommodates changing organismal energy demands. In Drosophila melanogaster, the TG lipase Brummer is centrally important for body fat mobilization. Its gene brummer (bmm) encodes the ortholog of mammalian adipose TG lipase, which becomes activated by α/β-hydrolase domain-containing 5 (ABHD5/CGI-58), one member of the paralogous gene pair, α/β-hydrolase domain-containing 4 (ABHD4) and ABHD5 In Drosophila, the pummelig (puml) gene encodes the single sequence-related protein to mammalian ABHD4/ABHD5 with unknown function. We generated puml deletion mutant flies, that were short-lived as a result of lipid metabolism changes, stored excess body fat at the expense of glycogen, and exhibited ectopic fat storage with altered TG FA profile in the fly kidneys, called Malpighian tubules. TG accumulation in puml mutants was not associated with increased food intake but with elevated lipogenesis; starvation-induced lipid mobilization remained functional. Despite its structural similarity to mammalian ABHD5, Puml did not stimulate TG lipase activity of Bmm in vitro. Rather, Puml acted as a phospholipase that localized on lipid droplets, mitochondria, and peroxisomes. Together, these results show that the ABHD4/5 family member Puml is a versatile phospholipase that regulates Drosophila body fat storage and energy metabolism.
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Affiliation(s)
- Philip Hehlert
- Research Group Molecular Physiology Max-Planck-Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Vinzenz Hofferek
- Max-Planck-Institut für Molekulare Pflanzenphysiologie Potsdam, Germany
| | - Christoph Heier
- Institute of Molecular Biosciences University of Graz, Graz, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences University of Graz, Graz, Austria
| | - Dietmar Riedel
- Department of Structural Dynamics, Electron Microscopy, Max-Planck-Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Jonathan Rosenberg
- Research Group Molecular Physiology Max-Planck-Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Anna Takaćs
- Research Group Molecular Physiology Max-Planck-Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Harald M Nagy
- Institute of Molecular Biosciences University of Graz, Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences University of Graz, Graz, Austria.,BioTechMed-Graz Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences University of Graz, Graz, Austria.,BioTechMed-Graz Graz, Austria
| | - Ronald P Kühnlein
- Research Group Molecular Physiology Max-Planck-Institut für Biophysikalische Chemie, Göttingen, Germany .,Institute of Molecular Biosciences University of Graz, Graz, Austria.,BioTechMed-Graz Graz, Austria
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18
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Cerk IK, Wechselberger L, Oberer M. Adipose Triglyceride Lipase Regulation: An Overview. Curr Protein Pept Sci 2018; 19:221-233. [PMID: 28925902 DOI: 10.2174/1389203718666170918160110] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 11/22/2022]
Abstract
Adipose triglyceride lipase (ATGL) is the key-enzyme for the release of fatty acids (FAs) from triacylglycerol (TG) stores during intracellular lipolysis producing FAs used for energy production. There is growing evidence that the products and intermediates from lipolytic breakdown during the FA mobilization process also have fundamental regulatory functions affecting cell signaling, gene expression, metabolism, cell growth, cell death, and lipotoxicity. Regulation of ATGL is therefore vital for maintaining a defined balance between lipid storage and mobilization. This review addresses the regulation of ATGL activity at the post-translational level with special emphasis on protein-mediated interaction at the site of hydrolytic action, namely to the lipid droplet.
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Affiliation(s)
- Ines Katrin Cerk
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, A-8010 Graz, Austria
| | - Lisa Wechselberger
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, A-8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, A-8010 Graz, Austria
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19
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Damisch E, Eder M, Dordic A, Mohan K, Das P, Hynönen U, Palva A, Vonck J, Oberer M, Pavkov-Keller T. The attachment of the Lactobacillus surface-layer array to the bacterial cell. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s2053273318094913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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20
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Aschauer P, Zimmermann R, Breinbauer R, Pavkov-Keller T, Oberer M. The crystal structure of monoacylglycerol lipase from M. tuberculosis reveals the basis for specific inhibition. Sci Rep 2018; 8:8948. [PMID: 29895832 PMCID: PMC5997763 DOI: 10.1038/s41598-018-27051-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 05/25/2018] [Indexed: 01/20/2023] Open
Abstract
Monoacylglycerol lipases (MGLs) are enzymes that hydrolyze monoacylglycerol into a free fatty acid and glycerol. Fatty acids can be used for triacylglycerol synthesis, as energy source, as building blocks for energy storage, and as precursor for membrane phospholipids. In Mycobacterium tuberculosis, fatty acids also serve as precursor for polyketide lipids like mycolic acids, major components of the cellular envelope associated to resistance for drug. We present the crystal structure of the MGL Rv0183 from Mycobacterium tuberculosis (mtbMGL) in open conformation. The structure reveals remarkable similarities with MGL from humans (hMGL) in both, the cap region and the α/β core. Nevertheless, mtbMGL could not be inhibited with JZL-184, a known inhibitor of hMGL. Docking studies provide an explanation why the activity of mtbMGL was not affected by the inhibitor. Our findings suggest that specific inhibition of mtbMGL from Mycobacterium tuberculosis, one of the oldest recognized pathogens, is possible without influencing hMGL.
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Affiliation(s)
- Philipp Aschauer
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010, Graz, Austria.,BioTechMed-Graz, Mozartgasse 12/II, 8010, Graz, Austria
| | - Rolf Breinbauer
- BioTechMed-Graz, Mozartgasse 12/II, 8010, Graz, Austria.,Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010, Graz, Austria
| | - Tea Pavkov-Keller
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010, Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010, Graz, Austria. .,BioTechMed-Graz, Mozartgasse 12/II, 8010, Graz, Austria.
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21
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Riegler-Berket L, Leitmeier A, Aschauer P, Dreveny I, Oberer M. Identification of lipases with activity towards monoacylglycerol by criterion of conserved cap architectures. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:679-687. [PMID: 29627382 DOI: 10.1016/j.bbalip.2018.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 03/09/2018] [Accepted: 03/27/2018] [Indexed: 11/26/2022]
Abstract
Monoacylglycerol lipases (MGL) are a subclass of lipases that predominantly hydrolyze monoacylglycerol (MG) into glycerol and fatty acid. MGLs are ubiquitous enzymes across species and play a role in lipid metabolism, affecting energy homeostasis and signaling processes. Structurally, MGLs belong to the α/β hydrolase fold family with a cap covering the substrate binding pocket. Analysis of the known 3D structures of human, yeast and bacterial MGLs revealed striking similarity of the cap architecture. Since MGLs from different organisms share very low sequence similarity, it is difficult to identify MGLs based on the amino acid sequence alone. Here, we investigated whether the cap architecture could be a characteristic feature of this subclass of lipases with activity towards MG and whether it is possible to identify MGLs based on the cap shape. Through database searches, we identified the structures of five different candidate α/β hydrolase fold proteins with unknown or reported esterase activity. These proteins exhibit cap architecture similarities to known human, yeast and bacterial MGL structures. Out of these candidates we confirmed MGL activity for the protein LipS, which displayed the highest structural similarity to known MGLs. Two further enzymes, Avi_0199 and VC1974, displayed low level MGL activities. These findings corroborate our hypothesis that this conserved cap architecture can be used as criterion to identify lipases with activity towards MGs.
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Affiliation(s)
- Lina Riegler-Berket
- Institute of Molecular Biosciences, University of Graz, Austria; BioTechMed-Graz, Austria
| | - Andrea Leitmeier
- Institute of Molecular Biosciences, University of Graz, Austria; BioTechMed-Graz, Austria
| | - Philipp Aschauer
- Institute of Molecular Biosciences, University of Graz, Austria; BioTechMed-Graz, Austria
| | - Ingrid Dreveny
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Austria; BioTechMed-Graz, Austria.
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22
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Padmanabha Das KM, Wechselberger L, Liziczai M, De la Rosa Rodriguez M, Grabner GF, Heier C, Viertlmayr R, Radler C, Lichtenegger J, Zimmermann R, Borst JW, Zechner R, Kersten S, Oberer M. Hypoxia-inducible lipid droplet-associated protein inhibits adipose triglyceride lipase. J Lipid Res 2018; 59:531-541. [PMID: 29326160 PMCID: PMC5832925 DOI: 10.1194/jlr.m082388] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/10/2018] [Indexed: 11/29/2022] Open
Abstract
Elaborate control mechanisms of intracellular triacylglycerol (TAG) breakdown are critically involved in the maintenance of energy homeostasis. Hypoxia-inducible lipid droplet-associated protein (HILPDA)/hypoxia-inducible gene-2 (Hig-2) has been shown to affect intracellular TAG levels, yet, the underlying molecular mechanisms are unclear. Here, we show that HILPDA inhibits adipose triglyceride lipase (ATGL), the enzyme catalyzing the first step of intracellular TAG hydrolysis. HILPDA shares structural similarity with G0/G1 switch gene 2 (G0S2), an established inhibitor of ATGL. HILPDA inhibits ATGL activity in a dose-dependent manner with an IC50 value of ∼2 μM. ATGL inhibition depends on the direct physical interaction of both proteins and involves the N-terminal hydrophobic region of HILPDA and the N-terminal patatin domain-containing segment of ATGL. Finally, confocal microscopy combined with Förster resonance energy transfer-fluorescence lifetime imaging microscopy analysis indicated that HILPDA and ATGL colocalize and physically interact intracellularly. These findings provide a rational biochemical explanation for the tissue-specific increased TAG accumulation in HILPDA-overexpressing transgenic mouse models.
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Affiliation(s)
| | - Lisa Wechselberger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Márton Liziczai
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | | | - Gernot F Grabner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Christoph Heier
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Roland Viertlmayr
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Claudia Radler
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Jörg Lichtenegger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria.,BioTechMed-Graz, 8010 Graz, Austria
| | - Jan Willem Borst
- Laboratory of Biochemistry and Microspectroscopy Research Facility, Wageningen University, Wageningen, The Netherlands
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria.,BioTechMed-Graz, 8010 Graz, Austria
| | - Sander Kersten
- Division of Human Nutrition University of Graz, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria .,BioTechMed-Graz, 8010 Graz, Austria
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23
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Thul PJ, Tschapalda K, Kolkhof P, Thiam AR, Oberer M, Beller M. Lipid droplet subset targeting of the Drosophila protein CG2254/dmLdsdh1. J Cell Sci 2017; 130:3141-3157. [DOI: 10.1242/jcs.199661] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 07/26/2017] [Indexed: 01/02/2023] Open
Abstract
Lipid droplets (LDs) are the principal organelles of lipid storage. They consist of a hydrophobic core of storage lipids, surrounded by a phospholipid monolayer with proteins attached. While some of these proteins are essential to regulate cellular and organismic lipid metabolism, key questions concerning LD protein function, such as their targeting to LDs, are still unanswered. Intriguingly, some proteins are restricted to LD subsets by an as yet unknown mechanism. This finding makes LD targeting even more complex.
Here, we characterize the Drosophila protein CG2254 which targets LD subsets in cultured cells and different larval Drosophila tissues, where the prevalence of LD subsets appears highly dynamic. We find that an amphipathic amino acid stretch mediates CG2254 LD localization. Additionally, we identified a juxtaposed sequence stretch limiting CG2254 localization to LD subsets. This sequence is sufficient to restrict a chimeric protein - consisting of the subset targeting sequence introduced to an otherwise pan LD localized protein sequence - to LD subsets. Based on its subcellular localization and annotated function, we suggest to rename CG2254 to Lipid droplet subset dehydrogenase 1 (Ldsdh1).
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Affiliation(s)
- Peter J. Thul
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Department of Molecular Developmental Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Kirsten Tschapalda
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Department of Molecular Developmental Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
- Systems Biology of Lipid Metabolism, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Department of Chemical Biology, Max Planck Institute for Molecular Physiology, Dortmund, Germany
| | - Petra Kolkhof
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Abdou Rachid Thiam
- Laboratoire de Physique Statistique, Ecole Normale Superieure, PSL Research University, Universite de Paris Diderot Sorbonne Paris-Cite, Paris, France
| | - Monika Oberer
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, Austria
| | - Mathias Beller
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Systems Biology of Lipid Metabolism, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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24
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Fong LG, Young SG, Beigneux AP, Bensadoun A, Oberer M, Jiang H, Ploug M. GPIHBP1 and Plasma Triglyceride Metabolism. Trends Endocrinol Metab 2016; 27:455-469. [PMID: 27185325 PMCID: PMC4927088 DOI: 10.1016/j.tem.2016.04.013] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 10/21/2022]
Abstract
GPIHBP1, a GPI-anchored protein in capillary endothelial cells, is crucial for the lipolytic processing of triglyceride-rich lipoproteins (TRLs). GPIHBP1 shuttles lipoprotein lipase (LPL) to its site of action in the capillary lumen and is essential for the margination of TRLs along capillaries - such that lipolytic processing can proceed. GPIHBP1 also reduces the unfolding of the LPL catalytic domain, thereby stabilizing LPL catalytic activity. Many different GPIHBP1 mutations have been identified in patients with severe hypertriglyceridemia (chylomicronemia), the majority of which interfere with folding of the protein and abolish its capacity to bind and transport LPL. The discovery of GPIHBP1 has substantially revised our understanding of intravascular triglyceride metabolism but has also raised many new questions for future research.
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Affiliation(s)
- Loren G Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
| | - Stephen G Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
| | - Anne P Beigneux
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - André Bensadoun
- Division of Nutritional Science, Cornell University, Ithaca, NY 14853, USA
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz and BioTechMed, Graz, Austria
| | - Haibo Jiang
- Centre for Microscopy, Characterisation, and Analysis, The University of Western Australia
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, 2200 Copenhagen N, Denmark; Biotech Research and Innovation Centre (BRIC), University of Copenhagen, 220 Copenhagen N, Denmark.
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25
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Heier C, Taschler U, Radulovic M, Aschauer P, Eichmann TO, Grond S, Wolinski H, Oberer M, Zechner R, Kohlwein SD, Zimmermann R. Monoacylglycerol Lipases Act as Evolutionarily Conserved Regulators of Non-oxidative Ethanol Metabolism. J Biol Chem 2016; 291:11865-75. [PMID: 27036938 PMCID: PMC4882453 DOI: 10.1074/jbc.m115.705541] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Indexed: 12/27/2022] Open
Abstract
Fatty acid ethyl esters (FAEEs) are non-oxidative metabolites of ethanol that accumulate in human tissues upon ethanol intake. Although FAEEs are considered as toxic metabolites causing cellular dysfunction and tissue damage, the enzymology of FAEE metabolism remains poorly understood. In this study, we used a biochemical screen in Saccharomyces cerevisiae to identify and characterize putative hydrolases involved in FAEE catabolism. We found that Yju3p, the functional orthologue of mammalian monoacylglycerol lipase (MGL), contributes >90% of cellular FAEE hydrolase activity, and its loss leads to the accumulation of FAEE. Heterologous expression of mammalian MGL in yju3Δ mutants restored cellular FAEE hydrolase activity and FAEE catabolism. Moreover, overexpression or pharmacological inhibition of MGL in mouse AML-12 hepatocytes decreased or increased FAEE levels, respectively. FAEEs were transiently incorporated into lipid droplets (LDs) and both Yju3p and MGL co-localized with these organelles. We conclude that the storage of FAEE in inert LDs and their mobilization by LD-resident FAEE hydrolases facilitate a controlled metabolism of these potentially toxic lipid metabolites.
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Affiliation(s)
- Christoph Heier
- From the Institute of Molecular Biosciences, University of Graz and
| | - Ulrike Taschler
- From the Institute of Molecular Biosciences, University of Graz and
| | - Maja Radulovic
- From the Institute of Molecular Biosciences, University of Graz and
| | - Philip Aschauer
- From the Institute of Molecular Biosciences, University of Graz and
| | | | - Susanne Grond
- From the Institute of Molecular Biosciences, University of Graz and
| | - Heimo Wolinski
- From the Institute of Molecular Biosciences, University of Graz and BioTechMed-Graz, 8010 Graz, Austria
| | - Monika Oberer
- From the Institute of Molecular Biosciences, University of Graz and
| | - Rudolf Zechner
- From the Institute of Molecular Biosciences, University of Graz and
| | - Sepp D Kohlwein
- From the Institute of Molecular Biosciences, University of Graz and BioTechMed-Graz, 8010 Graz, Austria
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26
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Aschauer P, Rengachari S, Lichtenegger J, Schittmayer M, Das KMP, Mayer N, Breinbauer R, Birner-Gruenberger R, Gruber CC, Zimmermann R, Gruber K, Oberer M. Crystal structure of the Saccharomyces cerevisiae monoglyceride lipase Yju3p. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:462-70. [PMID: 26869448 DOI: 10.1016/j.bbalip.2016.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 01/25/2016] [Accepted: 02/06/2016] [Indexed: 10/22/2022]
Abstract
Monoglyceride lipases (MGLs) are a group of α/β-hydrolases that catalyze the hydrolysis of monoglycerides (MGs) into free fatty acids and glycerol. This reaction serves different physiological functions, namely in the last step of phospholipid and triglyceride degradation, in mammalian endocannabinoid and arachidonic acid metabolism, and in detoxification processes in microbes. Previous crystal structures of MGLs from humans and bacteria revealed conformational plasticity in the cap region of this protein and gave insight into substrate binding. In this study, we present the structure of a MGL from Saccharomyces cerevisiae called Yju3p in its free form and in complex with a covalently bound substrate analog mimicking the tetrahedral intermediate of MG hydrolysis. These structures reveal a high conservation of the overall shape of the MGL cap region and also provide evidence for conformational changes in the cap of Yju3p. The complex structure reveals that, despite the high structural similarity, Yju3p seems to have an additional opening to the substrate binding pocket at a different position compared to human and bacterial MGL. Substrate specificities towards MGs with saturated and unsaturated alkyl chains of different lengths were tested and revealed highest activity towards MG containing a C18:1 fatty acid.
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Affiliation(s)
- Philipp Aschauer
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010 Graz, Austria
| | - Srinivasan Rengachari
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010 Graz, Austria
| | - Joerg Lichtenegger
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010 Graz, Austria
| | - Matthias Schittmayer
- Research Unit Functional Proteomics and Metabolic Pathways, Institute of Pathology, Medical University of Graz, Stiftingtalstrasse 24, 8010 Graz, Austria; Omics Center Graz, BioTechMed-Graz, Stiftingtalstrasse 24, 8010 Graz, Austria
| | | | - Nicole Mayer
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Rolf Breinbauer
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Ruth Birner-Gruenberger
- Research Unit Functional Proteomics and Metabolic Pathways, Institute of Pathology, Medical University of Graz, Stiftingtalstrasse 24, 8010 Graz, Austria; Omics Center Graz, BioTechMed-Graz, Stiftingtalstrasse 24, 8010 Graz, Austria
| | - Christian C Gruber
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010 Graz, Austria; ACIB - Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010 Graz, Austria
| | - Karl Gruber
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/3, 8010 Graz, Austria.
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27
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Boeszoermenyi A, Nagy HM, Arthanari H, Pillip CJ, Lindermuth H, Luna RE, Wagner G, Zechner R, Zangger K, Oberer M. Structure of a CGI-58 motif provides the molecular basis of lipid droplet anchoring. J Biol Chem 2015; 290:26361-72. [PMID: 26350461 PMCID: PMC4646293 DOI: 10.1074/jbc.m115.682203] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Indexed: 11/29/2022] Open
Abstract
Triacylglycerols (TGs) stored in lipid droplets (LDs) are hydrolyzed in a highly regulated metabolic process called lipolysis to free fatty acids that serve as energy substrates for β-oxidation, precursors for membrane lipids and signaling molecules. Comparative gene identification-58 (CGI-58) stimulates the enzymatic activity of adipose triglyceride lipase (ATGL), which catalyzes the hydrolysis of TGs to diacylglycerols and free fatty acids. In adipose tissue, protein-protein interactions between CGI-58 and the LD coating protein perilipin 1 restrain the ability of CGI-58 to activate ATGL under basal conditions. Phosphorylation of perilipin 1 disrupts these interactions and mobilizes CGI-58 for the activation of ATGL. We have previously demonstrated that the removal of a peptide at the N terminus (residues 10–31) of CGI-58 abrogates CGI-58 localization to LDs and CGI-58-mediated activation of ATGL. Here, we show that this tryptophan-rich N-terminal peptide serves as an independent LD anchor, with its three tryptophans serving as focal points of the left (harboring Trp21 and Trp25) and right (harboring Trp29) anchor arms. The solution state NMR structure of a peptide comprising the LD anchor bound to dodecylphosphocholine micelles as LD mimic reveals that the left arm forms a concise hydrophobic core comprising tryptophans Trp21 and Trp25 and two adjacent leucines. Trp29 serves as the core of a functionally independent anchor arm. Consequently, simultaneous tryptophan alanine permutations in both arms abolish localization and activity of CGI-58 as opposed to tryptophan substitutions that occur in only one arm.
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Affiliation(s)
- Andras Boeszoermenyi
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria, the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Harald Manuel Nagy
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Haribabu Arthanari
- the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | | | - Hanna Lindermuth
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria, the Institute of Biophysics, Medical University of Graz, 8010 Graz, Austria
| | - Rafael Eulogio Luna
- the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Gerhard Wagner
- the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Rudolf Zechner
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Klaus Zangger
- the Institute of Chemistry, University of Graz, 8010 Graz, Austria, and
| | - Monika Oberer
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria,
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28
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Heier C, Radner FPW, Moustafa T, Schreiber R, Grond S, Eichmann TO, Schweiger M, Schmidt A, Cerk IK, Oberer M, Theussl HC, Wojciechowski J, Penninger JM, Zimmermann R, Zechner R. G0/G1 Switch Gene 2 Regulates Cardiac Lipolysis. J Biol Chem 2015; 290:26141-50. [PMID: 26350455 DOI: 10.1074/jbc.m115.671842] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Indexed: 12/13/2022] Open
Abstract
The anabolism and catabolism of myocardial triacylglycerol (TAG) stores are important processes for normal cardiac function. TAG synthesis detoxifies and stockpiles fatty acids to prevent lipotoxicity, whereas TAG hydrolysis (lipolysis) remobilizes fatty acids from endogenous storage pools as energy substrates, signaling molecules, or precursors for complex lipids. This study focused on the role of G0/G1 switch 2 (G0S2) protein, which was previously shown to inhibit the principal TAG hydrolase adipose triglyceride lipase (ATGL), in the regulation of cardiac lipolysis. Using wild-type and mutant mice, we show the following: (i) G0S2 is expressed in the heart and regulated by the nutritional status with highest expression levels after re-feeding. (ii) Cardiac-specific overexpression of G0S2 inhibits cardiac lipolysis by direct protein-protein interaction with ATGL. This leads to severe cardiac steatosis. The steatotic hearts caused by G0S2 overexpression are less prone to fibrotic remodeling or cardiac dysfunction than hearts with a lipolytic defect due to ATGL deficiency. (iii) Conversely to the phenotype of transgenic mice, G0S2 deficiency results in a de-repression of cardiac lipolysis and decreased cardiac TAG content. We conclude that G0S2 acts as a potent ATGL inhibitor in the heart modulating cardiac substrate utilization by regulating cardiac lipolysis.
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Affiliation(s)
- Christoph Heier
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
| | - Franz P W Radner
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
| | - Tarek Moustafa
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria, the Laboratory of Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine and
| | - Renate Schreiber
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
| | - Susanne Grond
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
| | - Thomas O Eichmann
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
| | - Martina Schweiger
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
| | - Albrecht Schmidt
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, A-8036 Graz, Austria, and
| | - Ines K Cerk
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
| | - Monika Oberer
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
| | - H-Christian Theussl
- the Transgenic Service, Research Institute of Molecular Pathology (IMP), 1030 Vienna, Austria, and the IMBA Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Jacek Wojciechowski
- the Transgenic Service, Research Institute of Molecular Pathology (IMP), 1030 Vienna, Austria, and the IMBA Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Josef M Penninger
- the Transgenic Service, Research Institute of Molecular Pathology (IMP), 1030 Vienna, Austria, and the IMBA Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Robert Zimmermann
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
| | - Rudolf Zechner
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria,
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29
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Adeyo O, Oberer M, Ploug M, Fong LG, Young SG, Beigneux AP. Heterogeneity in the properties of mutant secreted lymphocyte antigen 6/urokinase receptor-related protein 1 (SLURP1) in Mal de Meleda. Br J Dermatol 2015; 173:1066-9. [PMID: 25919322 DOI: 10.1111/bjd.13868] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- O Adeyo
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, 90095, CA, U.S.A
| | - M Oberer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/3, A-8010, Graz, Austria
| | - M Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark
| | - L G Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, 90095, CA, U.S.A
| | - S G Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, 90095, CA, U.S.A.,Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, 90095, CA, U.S.A
| | - A P Beigneux
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, 90095, CA, U.S.A
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30
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Hofer P, Boeszoermenyi A, Jaeger D, Feiler U, Arthanari H, Mayer N, Zehender F, Rechberger G, Oberer M, Zimmermann R, Lass A, Haemmerle G, Breinbauer R, Zechner R, Preiss-Landl K. Fatty Acid-binding Proteins Interact with Comparative Gene Identification-58 Linking Lipolysis with Lipid Ligand Shuttling. J Biol Chem 2015; 290:18438-53. [PMID: 25953897 PMCID: PMC4513104 DOI: 10.1074/jbc.m114.628958] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Indexed: 12/18/2022] Open
Abstract
The coordinated breakdown of intracellular triglyceride (TG) stores requires the exquisitely regulated interaction of lipolytic enzymes with regulatory, accessory, and scaffolding proteins. Together they form a dynamic multiprotein network designated as the “lipolysome.” Adipose triglyceride lipase (Atgl) catalyzes the initiating step of TG hydrolysis and requires comparative gene identification-58 (Cgi-58) as a potent activator of enzyme activity. Here, we identify adipocyte-type fatty acid-binding protein (A-Fabp) and other members of the fatty acid-binding protein (Fabp) family as interaction partners of Cgi-58. Co-immunoprecipitation, microscale thermophoresis, and solid phase assays proved direct protein/protein interaction between A-Fabp and Cgi-58. Using nuclear magnetic resonance titration experiments and site-directed mutagenesis, we located a potential contact region on A-Fabp. In functional terms, A-Fabp stimulates Atgl-catalyzed TG hydrolysis in a Cgi-58-dependent manner. Additionally, transcriptional transactivation assays with a luciferase reporter system revealed that Fabps enhance the ability of Atgl/Cgi-58-mediated lipolysis to induce the activity of peroxisome proliferator-activated receptors. Our studies identify Fabps as crucial structural and functional components of the lipolysome.
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Affiliation(s)
- Peter Hofer
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Andras Boeszoermenyi
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Doris Jaeger
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Ursula Feiler
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Haribabu Arthanari
- the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Nicole Mayer
- the Institute of Organic Chemistry, Graz University of Technology, 8010 Graz, Austria, and
| | | | - Gerald Rechberger
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Monika Oberer
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Robert Zimmermann
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Achim Lass
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Guenter Haemmerle
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Rolf Breinbauer
- the Institute of Organic Chemistry, Graz University of Technology, 8010 Graz, Austria, and
| | - Rudolf Zechner
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria,
| | - Karina Preiss-Landl
- From the Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria,
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31
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Rengachari S, Aschauer P, Sturm C, Oberer M. Purification, crystallization and preliminary X-ray diffraction analysis of a soluble variant of the monoglyceride lipase Yju3p from the yeast Saccharomyces cerevisiae. Acta Crystallogr F Struct Biol Commun 2015; 71:243-6. [PMID: 25664804 PMCID: PMC4321484 DOI: 10.1107/s2053230x15001557] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 01/23/2015] [Indexed: 11/10/2022]
Abstract
The protein Yju3p is the orthologue of monoglyceride lipases in the yeast Saccharomyces cerevisiae. A soluble variant of this lipase termed s-Yju3p (38.3 kDa) was generated and purified to homogeneity by affinity and size-exclusion chromatography. s-Yju3p was crystallized in a vapour-diffusion setup at 293 K and a complete data set was collected to 2.4 Å resolution. The crystal form was orthorhombic (space group P212121), with unit-cell parameters a = 77.2, b = 108.6, c = 167.7 Å. The asymmetric unit contained four molecules with a solvent content of 46.4%.
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Affiliation(s)
- Srinivasan Rengachari
- Institute of Molecular Biology, University of Graz, Humboldtstrasse 50/3, 8010 Graz, Austria
| | - Philipp Aschauer
- Institute of Molecular Biology, University of Graz, Humboldtstrasse 50/3, 8010 Graz, Austria
| | - Christian Sturm
- Institute of Molecular Biology, University of Graz, Humboldtstrasse 50/3, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biology, University of Graz, Humboldtstrasse 50/3, 8010 Graz, Austria
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Sahu-Osen A, Montero-Moran G, Schittmayer M, Fritz K, Dinh A, Chang YF, McMahon D, Boeszoermenyi A, Cornaciu I, Russell D, Oberer M, Carman GM, Birner-Gruenberger R, Brasaemle DL. CGI-58/ABHD5 is phosphorylated on Ser239 by protein kinase A: control of subcellular localization. J Lipid Res 2014; 56:109-21. [PMID: 25421061 PMCID: PMC4274058 DOI: 10.1194/jlr.m055004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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 RKYS239S240, 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 immunoblotting 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.
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Affiliation(s)
- Anita Sahu-Osen
- 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
| | - Gabriela Montero-Moran
- 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
| | - Matthias Schittmayer
- 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
| | - Katarina Fritz
- 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
| | - Anna Dinh
- 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
| | - Yu-Fang Chang
- 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
| | - Derek McMahon
- 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
| | | | - Irina Cornaciu
- Institute of Molecular Biosciences, University of Graz, Graz, Austria A-8010
| | - Deanna Russell
- 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
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria A-8010
| | - George M Carman
- 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
| | - Ruth Birner-Gruenberger
- 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
| | - Dawn L Brasaemle
- 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
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Beigneux AP, Fong LG, Bensadoun A, Davies BSJ, Oberer M, Gårdsvoll H, Ploug M, Young SG. GPIHBP1 missense mutations often cause multimerization of GPIHBP1 and thereby prevent lipoprotein lipase binding. Circ Res 2014; 116:624-32. [PMID: 25387803 DOI: 10.1161/circresaha.116.305085] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
RATIONALE GPIHBP1, a GPI-anchored protein of capillary endothelial cells, binds lipoprotein lipase (LPL) in the subendothelial spaces and shuttles it to the capillary lumen. GPIHBP1 missense mutations that interfere with LPL binding cause familial chylomicronemia. OBJECTIVE We sought to understand mechanisms by which GPIHBP1 mutations prevent LPL binding and lead to chylomicronemia. METHODS AND RESULTS We expressed mutant forms of GPIHBP1 in Chinese hamster ovary cells, rat and human endothelial cells, and Drosophila S2 cells. In each expression system, mutation of cysteines in GPIHBP1's Ly6 domain (including mutants identified in patients with chylomicronemia) led to the formation of disulfide-linked dimers and multimers. GPIHBP1 dimerization/multimerization was not unique to cysteine mutations; mutations in other amino acid residues, including several associated with chylomicronemia, also led to protein dimerization/multimerization. The loss of GPIHBP1 monomers is relevant to the pathogenesis of chylomicronemia because only GPIHBP1 monomers-and not dimers or multimers-are capable of binding LPL. One GPIHBP1 mutant, GPIHBP1-W109S, had distinctive properties. GPIHBP1-W109S lacked the ability to bind LPL but had a reduced propensity for forming dimers or multimers, suggesting that W109 might play a more direct role in binding LPL. In support of that idea, replacing W109 with any of 8 other amino acids abolished LPL binding-and often did so without promoting the formation of dimers and multimers. CONCLUSIONS Many amino acid substitutions in GPIHBP1's Ly6 domain that abolish LPL binding lead to protein dimerization/multimerization. Dimerization/multimerization is relevant to disease pathogenesis, given that only GPIHBP1 monomers are capable of binding LPL.
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Affiliation(s)
- Anne P Beigneux
- From the Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles (A.P.B., L.G.F., S.G.Y.); Division of Nutritional Science, Cornell University, Ithaca, NY (A.B.); Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City (B.S.J.D.); Institute of Molecular Biosciences, University of Graz, Graz, Austria (M.O.); Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark (H.G., M.P.); and Molecular Biology Institute (S.G.Y.), Department of Human Genetics, David Geffen School of Medicine (S.G.Y.), University of California at Los Angeles.
| | - Loren G Fong
- From the Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles (A.P.B., L.G.F., S.G.Y.); Division of Nutritional Science, Cornell University, Ithaca, NY (A.B.); Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City (B.S.J.D.); Institute of Molecular Biosciences, University of Graz, Graz, Austria (M.O.); Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark (H.G., M.P.); and Molecular Biology Institute (S.G.Y.), Department of Human Genetics, David Geffen School of Medicine (S.G.Y.), University of California at Los Angeles
| | - André Bensadoun
- From the Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles (A.P.B., L.G.F., S.G.Y.); Division of Nutritional Science, Cornell University, Ithaca, NY (A.B.); Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City (B.S.J.D.); Institute of Molecular Biosciences, University of Graz, Graz, Austria (M.O.); Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark (H.G., M.P.); and Molecular Biology Institute (S.G.Y.), Department of Human Genetics, David Geffen School of Medicine (S.G.Y.), University of California at Los Angeles
| | - Brandon S J Davies
- From the Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles (A.P.B., L.G.F., S.G.Y.); Division of Nutritional Science, Cornell University, Ithaca, NY (A.B.); Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City (B.S.J.D.); Institute of Molecular Biosciences, University of Graz, Graz, Austria (M.O.); Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark (H.G., M.P.); and Molecular Biology Institute (S.G.Y.), Department of Human Genetics, David Geffen School of Medicine (S.G.Y.), University of California at Los Angeles
| | - Monika Oberer
- From the Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles (A.P.B., L.G.F., S.G.Y.); Division of Nutritional Science, Cornell University, Ithaca, NY (A.B.); Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City (B.S.J.D.); Institute of Molecular Biosciences, University of Graz, Graz, Austria (M.O.); Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark (H.G., M.P.); and Molecular Biology Institute (S.G.Y.), Department of Human Genetics, David Geffen School of Medicine (S.G.Y.), University of California at Los Angeles
| | - Henrik Gårdsvoll
- From the Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles (A.P.B., L.G.F., S.G.Y.); Division of Nutritional Science, Cornell University, Ithaca, NY (A.B.); Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City (B.S.J.D.); Institute of Molecular Biosciences, University of Graz, Graz, Austria (M.O.); Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark (H.G., M.P.); and Molecular Biology Institute (S.G.Y.), Department of Human Genetics, David Geffen School of Medicine (S.G.Y.), University of California at Los Angeles
| | - Michael Ploug
- From the Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles (A.P.B., L.G.F., S.G.Y.); Division of Nutritional Science, Cornell University, Ithaca, NY (A.B.); Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City (B.S.J.D.); Institute of Molecular Biosciences, University of Graz, Graz, Austria (M.O.); Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark (H.G., M.P.); and Molecular Biology Institute (S.G.Y.), Department of Human Genetics, David Geffen School of Medicine (S.G.Y.), University of California at Los Angeles
| | - Stephen G Young
- From the Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles (A.P.B., L.G.F., S.G.Y.); Division of Nutritional Science, Cornell University, Ithaca, NY (A.B.); Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City (B.S.J.D.); Institute of Molecular Biosciences, University of Graz, Graz, Austria (M.O.); Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark (H.G., M.P.); and Molecular Biology Institute (S.G.Y.), Department of Human Genetics, David Geffen School of Medicine (S.G.Y.), University of California at Los Angeles
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Boeszoermenyi A, Schmidt J, Cheeseman IM, Oberer M, Wagner G, Arthanari H. Resonance assignments of the microtubule-binding domain of the C. elegans spindle and kinetochore-associated protein 1. Biomol NMR Assign 2014; 8:275-278. [PMID: 23765286 PMCID: PMC3823668 DOI: 10.1007/s12104-013-9499-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 06/03/2013] [Indexed: 06/02/2023]
Abstract
During mitosis, kinetochores coordinate the attachment of centromeric DNA to the dynamic plus ends of microtubules, which is hypothesized to pull sister chromatids toward opposing poles of the mitotic spindle. The outer kinetochore Ndc80 complex acts synergistically with the Ska (spindle and kinetochore-associated) complex to harness the energy of depolymerizing microtubules and power chromosome movement. The Ska complex is a hexamer consisting of two copies of the proteins Ska1, Ska2 and Ska3, respectively. The C-terminal domain of the spindle and kinetochore-associated protein 1 (Ska1) is the microtubule-binding domain of the Ska complex. We solved the solution structure of the C. elegans microtubule-binding domain (MTBD) of the protein Ska1 using NMR spectroscopy. Here, we report the resonance assignments of the MTBD of C. elegans Ska1.
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Affiliation(s)
- Andras Boeszoermenyi
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Jens Schmidt
- Whitehead Institute for Biomedical Research, and Department of Biology, MIT, Cambridge, MA 02142, USA
| | - Iain M. Cheeseman
- Whitehead Institute for Biomedical Research, and Department of Biology, MIT, Cambridge, MA 02142, USA
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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35
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Cerk IK, Salzburger B, Boeszoermenyi A, Heier C, Pillip C, Romauch M, Schweiger M, Cornaciu I, Lass A, Zimmermann R, Zechner R, Oberer M. A peptide derived from G0/G1 switch gene 2 acts as noncompetitive inhibitor of adipose triglyceride lipase. J Biol Chem 2014; 289:32559-70. [PMID: 25258314 PMCID: PMC4239610 DOI: 10.1074/jbc.m114.602599] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The protein G0/G1 switch gene 2 (G0S2) is a small basic protein that functions as an endogenous inhibitor of adipose triglyceride lipase (ATGL), a key enzyme in intracellular lipolysis. In this study, we identified a short sequence covering residues Lys-20 to Ala-52 in G0S2 that is still fully capable of inhibiting mouse and human ATGL. We found that a synthetic peptide corresponding to this region inhibits ATGL in a noncompetitive manner in the nanomolar range. This peptide is highly selective for ATGL and does not inhibit other lipases, including hormone-sensitive lipase, monoacylglycerol lipase, lipoprotein lipase, and patatin domain-containing phospholipases 6 and 7. Because increased lipolysis is linked to the development of metabolic disorders, the inhibition of ATGL by G0S2-derived peptides may represent a novel therapeutic tool to modulate lipolysis.
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Affiliation(s)
- Ines K Cerk
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Barbara Salzburger
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Andras Boeszoermenyi
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Christoph Heier
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Christoph Pillip
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Matthias Romauch
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Martina Schweiger
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Irina Cornaciu
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Achim Lass
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Robert Zimmermann
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Rudolf Zechner
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Monika Oberer
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
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Steinkellner G, Gruber CC, Pavkov-Keller T, Binter A, Steiner K, Winkler C, Łyskowski A, Schwamberger O, Oberer M, Schwab H, Faber K, Macheroux P, Gruber K. Identification of promiscuous ene-reductase activity by mining structural databases using active site constellations. Nat Commun 2014; 5:4150. [PMID: 24954722 PMCID: PMC4083419 DOI: 10.1038/ncomms5150] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 05/15/2014] [Indexed: 12/03/2022] Open
Abstract
The exploitation of catalytic promiscuity and the application of de novo design have recently opened the access to novel, non-natural enzymatic activities. Here we describe a structural bioinformatic method for predicting catalytic activities of enzymes based on three-dimensional constellations of functional groups in active sites ('catalophores'). As a proof-of-concept we identify two enzymes with predicted promiscuous ene-reductase activity (reduction of activated C-C double bonds) and compare them with known ene-reductases, that is, members of the Old Yellow Enzyme family. Despite completely different amino acid sequences, overall structures and protein folds, high-resolution crystal structures reveal equivalent binding modes of typical Old Yellow Enzyme substrates and ligands. Biochemical and biocatalytic data show that the two enzymes indeed possess ene-reductase activity and reveal an inverted stereopreference compared with Old Yellow Enzymes for some substrates. This method could thus be a tool for the identification of viable starting points for the development and engineering of novel biocatalysts.
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Affiliation(s)
- Georg Steinkellner
- ACIB GmbH, Petersgasse 14, 8010 Graz, Austria
- These authors contributed equally to this work
| | - Christian C. Gruber
- ACIB GmbH, Petersgasse 14, 8010 Graz, Austria
- These authors contributed equally to this work
| | | | | | | | - Christoph Winkler
- Department of Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | | | - Orsolya Schwamberger
- ACIB GmbH, Petersgasse 14, 8010 Graz, Austria
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Helmut Schwab
- ACIB GmbH, Petersgasse 14, 8010 Graz, Austria
- Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria
| | - Kurt Faber
- ACIB GmbH, Petersgasse 14, 8010 Graz, Austria
- Department of Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - Peter Macheroux
- ACIB GmbH, Petersgasse 14, 8010 Graz, Austria
- Institute of Biochemistry, Graz University of Technology, Petersgasse 12, 8010 Graz, Austria
| | - Karl Gruber
- ACIB GmbH, Petersgasse 14, 8010 Graz, Austria
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
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37
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Harper S, Gratton HE, Cornaciu I, Oberer M, Scott D, Emsley J, Dreveny I. Structure and catalytic regulatory function of ubiquitin specific protease 11 N-terminal and ubiquitin-like domains. Biochemistry 2014; 53:2966-78. [PMID: 24724799 PMCID: PMC4020902 DOI: 10.1021/bi500116x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/31/2014] [Indexed: 12/17/2022]
Abstract
The ubiquitin specific protease 11 (USP11) is implicated in DNA repair, viral RNA replication, and TGFβ signaling. We report the first characterization of the USP11 domain architecture and its role in regulating the enzymatic activity. USP11 consists of an N-terminal "domain present in USPs" (DUSP) and "ubiquitin-like" (UBL) domain, together referred to as DU domains, and the catalytic domain harboring a second UBL domain. Crystal structures of the DU domains show a tandem arrangement with a shortened β-hairpin at the two-domain interface and altered surface characteristics compared to the homologues USP4 and USP15. A conserved VEVY motif is a signature feature at the two-domain interface that shapes a potential protein interaction site. Small angle X-ray scattering and gel filtration experiments are consistent with the USP11DU domains and full-length USP11 being monomeric. Unexpectedly, we reveal, through kinetic assays of a series of deletion mutants, that the catalytic activity of USP11 is not regulated through intramolecular autoinhibition or activation by the N-terminal DU or UBL domains. Moreover, ubiquitin chain cleavage assays with all eight linkages reveal a preference for Lys(63)-, Lys(6)-, Lys(33)-, and Lys(11)-linked chains over Lys(27)-, Lys(29)-, and Lys(48)-linked and linear chains consistent with USP11's function in DNA repair pathways that is mediated by the protease domain. Our data support a model whereby USP11 domains outside the catalytic core domain serve as protein interaction or trafficking modules rather than a direct regulatory function of the proteolytic activity. This highlights the diversity of USPs in substrate recognition and regulation of ubiquitin deconjugation.
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Affiliation(s)
- Stephen Harper
- Centre for Biomolecular Sciences, University of Nottingham, University
Park Campus, Nottingham, NG7 2RD, United Kingdom
| | - Hayley E. Gratton
- Centre for Biomolecular Sciences, University of Nottingham, University
Park Campus, Nottingham, NG7 2RD, United Kingdom
| | - Irina Cornaciu
- Institute
of Molecular Biosciences, University of
Graz, Humboldtstraße
50/3, A-8010 Graz, Austria
| | - Monika Oberer
- Institute
of Molecular Biosciences, University of
Graz, Humboldtstraße
50/3, A-8010 Graz, Austria
| | - David
J. Scott
- School
of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, LE12 5RD, United Kingdom
| | - Jonas Emsley
- Centre for Biomolecular Sciences, University of Nottingham, University
Park Campus, Nottingham, NG7 2RD, United Kingdom
| | - Ingrid Dreveny
- Centre for Biomolecular Sciences, University of Nottingham, University
Park Campus, Nottingham, NG7 2RD, United Kingdom
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Nagy HM, Paar M, Heier C, Moustafa T, Hofer P, Haemmerle G, Lass A, Zechner R, Oberer M, Zimmermann R. Adipose triglyceride lipase activity is inhibited by long-chain acyl-coenzyme A. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:588-94. [PMID: 24440819 PMCID: PMC3988850 DOI: 10.1016/j.bbalip.2014.01.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 12/20/2013] [Accepted: 01/06/2014] [Indexed: 12/28/2022]
Abstract
Adipose triglyceride lipase (ATGL) is required for efficient mobilization of triglyceride (TG) stores in adipose tissue and non-adipose tissues. Therefore, ATGL strongly determines the availability of fatty acids for metabolic reactions. ATGL activity is regulated by a complex network of lipolytic and anti-lipolytic hormones. These signals control enzyme expression and the interaction of ATGL with the regulatory proteins CGI-58 and G0S2. Up to date, it was unknown whether ATGL activity is also controlled by lipid intermediates generated during lipolysis. Here we show that ATGL activity is inhibited by long-chain acyl-CoAs in a non-competitive manner, similar as previously shown for hormone-sensitive lipase (HSL), the rate-limiting enzyme for diglyceride breakdown in adipose tissue. ATGL activity is only marginally inhibited by medium-chain acyl-CoAs, diglycerides, monoglycerides, and free fatty acids. Immunoprecipitation assays revealed that acyl-CoAs do not disrupt the protein–protein interaction of ATGL and its co-activator CGI-58. Furthermore, inhibition of ATGL is independent of the presence of CGI-58 and occurs directly at the N-terminal patatin-like phospholipase domain of the enzyme. In conclusion, our results suggest that inhibition of the major lipolytic enzymes ATGL and HSL by long-chain acyl-CoAs could represent an effective feedback mechanism controlling lipolysis and protecting cells from lipotoxic concentrations of fatty acids and fatty acid-derived lipid metabolites. Long-chain acyl-CoAs inhibit ATGL in a non-competitive manner. Inhibition occurs at the N-terminal region of ATGL and independent of CGI-58, the co-activator of ATGL. Acyl-CoA mediated inhibition of lipolysis could represent a general feedback mechanism protecting cells from fatty acid overload.
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Affiliation(s)
- Harald M Nagy
- Institute of Molecular Biosciences, University of Graz, Austria
| | - Margret Paar
- Institute of Molecular Biosciences, University of Graz, Austria
| | - Christoph Heier
- Institute of Molecular Biosciences, University of Graz, Austria
| | - Tarek Moustafa
- Institute of Molecular Biosciences, University of Graz, Austria
| | - Peter Hofer
- Institute of Molecular Biosciences, University of Graz, Austria
| | | | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Austria
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Rengachari S, Aschauer P, Schittmayer M, Mayer N, Gruber K, Breinbauer R, Birner-Gruenberger R, Dreveny I, Oberer M. Conformational plasticity and ligand binding of bacterial monoacylglycerol lipase. J Biol Chem 2013; 288:31093-104. [PMID: 24014019 PMCID: PMC3829422 DOI: 10.1074/jbc.m113.491415] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Monoacylglycerol lipases (MGLs) play an important role in lipid catabolism across all kingdoms of life by catalyzing the release of free fatty acids from monoacylglycerols. The three-dimensional structures of human and a bacterial MGL were determined only recently as the first members of this lipase family. In addition to the α/β-hydrolase core, they showed unexpected structural similarities even in the cap region. Nevertheless, the structural basis for substrate binding and conformational changes of MGLs is poorly understood. Here, we present a comprehensive study of five crystal structures of MGL from Bacillus sp. H257 in its free form and in complex with different substrate analogs and the natural substrate 1-lauroylglycerol. The occurrence of different conformations reveals a high degree of conformational plasticity of the cap region. We identify a specific residue, Ile-145, that might act as a gatekeeper restricting access to the binding site. Site-directed mutagenesis of Ile-145 leads to significantly reduced hydrolase activity. Bacterial MGLs in complex with 1-lauroylglycerol, myristoyl, palmitoyl, and stearoyl substrate analogs enable identification of the binding sites for the alkyl chain and the glycerol moiety of the natural ligand. They also provide snapshots of the hydrolytic reaction of a bacterial MGL at different stages. The alkyl chains are buried in a hydrophobic tunnel in an extended conformation. Binding of the glycerol moiety is mediated via Glu-156 and water molecules. Analysis of the structural features responsible for cap plasticity and the binding modes of the ligands suggests conservation of these features also in human MGL.
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Affiliation(s)
- Srinivasan Rengachari
- From the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/3, A-8010 Graz, Austria
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40
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Thiel K, Heier C, Haberl V, Thul PJ, Oberer M, Lass A, Jäckle H, Beller M. The evolutionarily conserved protein CG9186 is associated with lipid droplets, required for their positioning and for fat storage. J Cell Sci 2013; 126:2198-212. [PMID: 23525007 DOI: 10.1242/jcs.120493] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Lipid droplets (LDs) are specialized cell organelles for the storage of energy-rich lipids. Although lipid storage is a conserved feature of all cells and organisms, little is known about fundamental aspects of the cell biology of LDs, including their biogenesis, structural assembly and subcellular positioning, and the regulation of organismic energy homeostasis. We identified a novel LD-associated protein family, represented by the Drosophila protein CG9186 and its murine homolog MGI:1916082. In the absence of LDs, both proteins localize at the endoplasmic reticulum (ER). Upon lipid storage induction, they translocate to LDs using an evolutionarily conserved targeting mechanism that acts through a 60-amino-acid targeting motif in the center of the CG9186 protein. Overexpression of CG9186, and MGI:1916082, causes clustering of LDs in both tissue culture and salivary gland cells, whereas RNAi knockdown of CG9186 results in a reduction of LDs. Organismal RNAi knockdown of CG9186 results in a reduction in lipid storage levels of the fly. The results indicate that we identified the first members of a novel and evolutionarily conserved family of lipid storage regulators, which are also required to properly position LDs within cells.
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Affiliation(s)
- Katharina Thiel
- Department of Molecular Developmental Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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41
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Schmidt J, Arthanari H, Boeszoermenyi A, Dashkevich N, Wilson-Kubalek E, Monnier N, Markus M, Oberer M, Milligan R, Bathe M, Wagner G, Grishchuk E, Cheeseman I. The Kinetochore-Bound Ska1 Complex Tracks Depolymerizing Microtubules and Binds to Curved Protofilaments. Dev Cell 2012. [DOI: 10.1016/j.devcel.2012.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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42
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Schmidt JC, Arthanari H, Boeszoermenyi A, Dashkevich NM, Wilson-Kubalek EM, Monnier N, Markus M, Oberer M, Milligan RA, Bathe M, Wagner G, Grishchuk EL, Cheeseman IM. The kinetochore-bound Ska1 complex tracks depolymerizing microtubules and binds to curved protofilaments. Dev Cell 2012; 23:968-80. [PMID: 23085020 DOI: 10.1016/j.devcel.2012.09.012] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 08/16/2012] [Accepted: 09/18/2012] [Indexed: 12/25/2022]
Abstract
To ensure equal chromosome segregation during mitosis, the macromolecular kinetochore must remain attached to depolymerizing microtubules, which drive chromosome movements. How kinetochores associate with depolymerizing microtubules, which undergo dramatic structural changes forming curved protofilaments, has yet to be defined in vertebrates. Here, we demonstrate that the conserved kinetochore-localized Ska1 complex tracks with depolymerizing microtubule ends and associates with both the microtubule lattice and curved protofilaments. In contrast, the Ndc80 complex, a central player in the kinetochore-microtubule interface, binds only to the straight microtubule lattice and lacks tracking activity. We demonstrate that the Ska1 complex imparts its tracking capability to the Ndc80 complex. Finally, we present a structure of the Ska1 microtubule-binding domain that reveals its interaction with microtubules and its regulation by Aurora B. This work defines an integrated kinetochore-microtubule interface formed by the Ska1 and Ndc80 complexes that associates with depolymerizing microtubules, potentially by interacting with curved microtubule protofilaments.
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Affiliation(s)
- Jens C Schmidt
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
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43
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Schweiger M, Paar M, Eder C, Brandis J, Moser E, Gorkiewicz G, Grond S, Radner FPW, Cerk I, Cornaciu I, Oberer M, Kersten S, Zechner R, Zimmermann R, Lass A. G0/G1 switch gene-2 regulates human adipocyte lipolysis by affecting activity and localization of adipose triglyceride lipase. J Lipid Res 2012; 53:2307-17. [PMID: 22891293 DOI: 10.1194/jlr.m027409] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The hydrolysis of triglycerides in adipocytes, termed lipolysis, provides free fatty acids as energy fuel. Murine lipolysis largely depends on the activity of adipose triglyceride lipase (ATGL), which is regulated by two proteins annotated as comparative gene identification-58 (CGI-58) and G0/G1 switch gene-2 (G0S2). CGI-58 activates and G0S2 inhibits ATGL activity. In contrast to mice, the functional role of G0S2 in human adipocyte lipolysis is poorly characterized. Here we show that overexpression or silencing of G0S2 in human SGBS adipocytes decreases and increases lipolysis, respectively. Human G0S2 is upregulated during adipocyte differentiation and inhibits ATGL activity in a dose-dependent manner. Interestingly, C-terminally truncated ATGL mutants, which fail to localize to lipid droplets, translocate to the lipid droplet upon coexpression with G0S2, suggesting that G0S2 anchors ATGL to lipid droplets independent of ATGL's C-terminal lipid binding domain. Taken together, our results indicate that G0S2 also regulates human lipolysis by affecting enzyme activity and intracellular localization of ATGL. Increased lipolysis is known to contribute to the pathogenesis of insulin resistance, and G0S2 expression has been shown to be reduced in poorly controlled type 2 diabetic patients. Our data indicate that downregulation of G0S2 in adipose tissue could represent one of the underlying causes leading to increased lipolysis in the insulin-resistant state.
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Affiliation(s)
- Martina Schweiger
- Institute of Molecular Biosciences University of Graz, 8010 Graz, Austria
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44
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Rengachari S, Bezerra GA, Riegler-Berket L, Gruber CC, Sturm C, Taschler U, Boeszoermenyi A, Dreveny I, Zimmermann R, Gruber K, Oberer M. The structure of monoacylglycerol lipase from Bacillus sp. H257 reveals unexpected conservation of the cap architecture between bacterial and human enzymes. Biochim Biophys Acta 2012; 1821:1012-21. [PMID: 22561231 PMCID: PMC3790968 DOI: 10.1016/j.bbalip.2012.04.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 04/18/2012] [Accepted: 04/20/2012] [Indexed: 11/20/2022]
Abstract
Monoacylglycerol lipases (MGLs) catalyse the hydrolysis of monoacylglycerol into free fatty acid and glycerol. MGLs have been identified throughout all genera of life and have adopted different substrate specificities depending on their physiological role. In humans, MGL plays an integral part in lipid metabolism affecting energy homeostasis, signalling processes and cancer cell progression. In bacteria, MGLs degrade short-chain monoacylglycerols which are otherwise toxic to the organism. We report the crystal structures of MGL from the bacterium Bacillus sp. H257 (bMGL) in its free form at 1.2Å and in complex with phenylmethylsulfonyl fluoride at 1.8Å resolution. In both structures, bMGL adopts an α/β hydrolase fold with a cap in an open conformation. Access to the active site residues, which were unambiguously identified from the protein structure, is facilitated by two different channels. The larger channel constitutes the highly hydrophobic substrate binding pocket with enough room to accommodate monoacylglycerol. The other channel is rather small and resembles the proposed glycerol exit hole in human MGL. Molecular dynamics simulation of bMGL yielded open and closed states of the entrance channel and the glycerol exit hole. Despite differences in the number of residues, secondary structure elements, and low sequence identity in the cap region, this first structure of a bacterial MGL reveals striking structural conservation of the overall cap architecture in comparison with human MGL. Thus it provides insight into the structural conservation of the cap amongst MGLs throughout evolution and provides a framework for rationalising substrate specificities in each organism.
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Affiliation(s)
| | - Gustavo A. Bezerra
- Institute of Molecular Biosciences, University of Graz, A‐8010 Graz, Austria
| | - Lina Riegler-Berket
- Institute of Molecular Biosciences, University of Graz, A‐8010 Graz, Austria
| | | | - Christian Sturm
- Institute of Molecular Biosciences, University of Graz, A‐8010 Graz, Austria
| | - Ulrike Taschler
- Institute of Molecular Biosciences, University of Graz, A‐8010 Graz, Austria
| | | | - Ingrid Dreveny
- School of Pharmacy, University of Nottingham, NG7 2RD, UK
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, A‐8010 Graz, Austria
| | - Karl Gruber
- Institute of Molecular Biosciences, University of Graz, A‐8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, A‐8010 Graz, Austria
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45
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Kumari M, Schoiswohl G, Chitraju C, Paar M, Cornaciu I, Rangrez AY, Wongsiriroj N, Nagy HM, Ivanova PT, Scott SA, Knittelfelder O, Rechberger GN, Birner-Gruenberger R, Eder S, Brown HA, Haemmerle G, Oberer M, Lass A, Kershaw EE, Zimmermann R, Zechner R. Adiponutrin functions as a nutritionally regulated lysophosphatidic acid acyltransferase. Cell Metab 2012; 15:691-702. [PMID: 22560221 PMCID: PMC3361708 DOI: 10.1016/j.cmet.2012.04.008] [Citation(s) in RCA: 219] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 02/17/2012] [Accepted: 04/10/2012] [Indexed: 12/12/2022]
Abstract
Numerous studies in humans link a nonsynonymous genetic polymorphism (I148M) in adiponutrin (ADPN) to various forms of fatty liver disease and liver cirrhosis. Despite its high clinical relevance, the molecular function of ADPN and the mechanism by which I148M variant affects hepatic metabolism are unclear. Here we show that ADPN promotes cellular lipid synthesis by converting lysophosphatidic acid (LPA) into phosphatidic acid. The ADPN-catalyzed LPA acyltransferase (LPAAT) reaction is specific for LPA and long-chain acyl-CoAs. Wild-type mice receiving a high-sucrose diet exhibit substantial upregulation of Adpn in the liver and a concomitant increase in LPAAT activity. In Adpn-deficient mice, this diet-induced increase in hepatic LPAAT activity is reduced. Notably, the I148M variant of human ADPN exhibits increased LPAAT activity leading to increased cellular lipid accumulation. This gain of function provides a plausible biochemical mechanism for the development of liver steatosis in subjects carrying the I148M variant.
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Affiliation(s)
- Manju Kumari
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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46
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Cornaciu I, Boeszoermenyi A, Lindermuth H, Nagy HM, Cerk IK, Ebner C, Salzburger B, Gruber A, Schweiger M, Zechner R, Lass A, Zimmermann R, Oberer M. The minimal domain of adipose triglyceride lipase (ATGL) ranges until leucine 254 and can be activated and inhibited by CGI-58 and G0S2, respectively. PLoS One 2011; 6:e26349. [PMID: 22039468 PMCID: PMC3198459 DOI: 10.1371/journal.pone.0026349] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 09/25/2011] [Indexed: 12/25/2022] Open
Abstract
Adipose triglyceride lipase (ATGL) is the rate-limiting enzyme of lipolysis. ATGL specifically hydrolyzes triacylglycerols (TGs), thereby generating diacylglycerols and free fatty acids. ATGL's enzymatic activity is co-activated by the protein comparative gene identification-58 (CGI-58) and inhibited by the protein G0/G1 switch gene 2 (G0S2). The enzyme is predicted to act through a catalytic dyad (Ser47, Asp166) located within the conserved patatin domain (Ile10-Leu178). Yet, neither an experimentally determined 3D structure nor a model of ATGL is currently available, which would help to understand how CGI-58 and G0S2 modulate ATGL's activity. In this study we determined the minimal active domain of ATGL. This minimal fragment of ATGL could still be activated and inhibited by CGI-58 and G0S2, respectively. Furthermore, we show that this minimal domain is sufficient for protein-protein interaction of ATGL with its regulatory proteins. Based on these data, we generated a 3D homology model for the minimal domain. It strengthens our experimental finding that amino acids between Leu178 and Leu254 are essential for the formation of a stable protein domain related to the patatin fold. Our data provide insights into the structure-function relationship of ATGL and indicate higher structural similarities in the N-terminal halves of mammalian patatin-like phospholipase domain containing proteins, (PNPLA1, -2,- 3 and -5) than originally anticipated.
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Affiliation(s)
- Irina Cornaciu
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Hanna Lindermuth
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Harald M. Nagy
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Ines K. Cerk
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Catharina Ebner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Astrid Gruber
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Martina Schweiger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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47
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Sturm C, Rengachari S, Bezerra GA, Riegler L, Gruber CC, Taschler U, Boeszoermenyi A, Zimmermann R, Gruber K, Oberer M. Cap architecture conservation in monoglyceride lipases from bacteria to humans. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311080172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
PURPOSE OF REVIEW Comparative gene identification-58 (CGI-58) is an important player in lipid metabolism. It acts as activator of triglyceride hydrolases and as acyl-CoA-dependent lysophosphatidic acid acyltransferase. This review aims at establishing a structure-function relationship of this still rather enigmatic protein based on recent studies characterizing different functions of CGI-58. RECENT FINDINGS Novel studies confirm the important regulatory role of CGI-58 as activator of the triglyceride hydrolase adipose triglyceride lipase. New evidence, corroborated by the characterization of a CGI-58 knockout mouse model, also suggests the existence of yet unknown lipases that are activated by CGI-58. Additionally, CGI-58 was identified to exert acyl-CoA-dependent lysophosphatidic acid acyltransferase activity, which implies possible roles in triglyceride or phospholipid synthesis or signaling processes. Unlike mammalian CGI-58 proteins, orthologs from plants and yeast additionally act as weak triglyceride and phospholipid hydrolases. A first three-dimensional model was calculated and allows preliminary structural considerations for the functions of CGI-58. SUMMARY Despite important progress concerning the different biochemical functions of CGI-58, the physiological importance of these activities requires better characterization. Furthermore, three-dimensional structural data for CGI-58 are required to unveil the molecular mechanism of how CGI-58 acts as activator of lipases and exerts its enzymatic functions.
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Affiliation(s)
- Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/3, 8010 Graz, Austria
| | - Andras Boeszoermenyi
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/3, 8010 Graz, Austria
| | - Harald Manuel Nagy
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/3, 8010 Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
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Lass A, Zimmermann R, Oberer M, Zechner R. Lipolysis - a highly regulated multi-enzyme complex mediates the catabolism of cellular fat stores. Prog Lipid Res 2010; 50:14-27. [PMID: 21087632 PMCID: PMC3031774 DOI: 10.1016/j.plipres.2010.10.004] [Citation(s) in RCA: 436] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 10/12/2010] [Accepted: 10/13/2010] [Indexed: 12/17/2022]
Abstract
Lipolysis is the biochemical pathway responsible for the catabolism of triacylglycerol (TAG) stored in cellular lipid droplets. The hydrolytic cleavage of TAG generates non-esterified fatty acids, which are subsequently used as energy substrates, essential precursors for lipid and membrane synthesis, or mediators in cell signaling processes. Consistent with its central importance in lipid and energy homeostasis, lipolysis occurs in essentially all tissues and cell types, it is most abundant, however, in white and brown adipose tissue. Over the last 5years, important enzymes and regulatory protein factors involved in lipolysis have been identified. These include an essential TAG hydrolase named adipose triglyceride lipase (ATGL) [annotated as patatin-like phospholipase domain-containing protein A2], the ATGL activator comparative gene identification-58 [annotated as α/β hydrolase containing protein 5], and the ATGL inhibitor G0/G1 switch gene 2. Together with the established hormone-sensitive lipase [annotated as lipase E] and monoglyceride lipase, these proteins constitute the basic "lipolytic machinery". Additionally, a large number of hormonal signaling pathways and lipid droplet-associated protein factors regulate substrate access and the activity of the "lipolysome". This review summarizes the current knowledge concerning the enzymes and regulatory processes governing lipolysis of fat stores in adipose and non-adipose tissues. Special emphasis will be given to ATGL, its regulation, and physiological function.
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Affiliation(s)
- Achim Lass
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
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50
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Heier C, Taschler U, Rengachari S, Oberer M, Wolinski H, Natter K, Kohlwein SD, Leber R, Zimmermann R. Identification of Yju3p as functional orthologue of mammalian monoglyceride lipase in the yeast Saccharomycescerevisiae. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:1063-71. [PMID: 20554061 PMCID: PMC2911655 DOI: 10.1016/j.bbalip.2010.06.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 05/19/2010] [Accepted: 06/01/2010] [Indexed: 01/16/2023]
Abstract
Monoacylglycerols (MAGs) are short-lived intermediates of glycerolipid metabolism. Specific molecular species, such as 2-arachidonoylglycerol, which is a potent activator of cannabinoid receptors, may also function as lipid signaling molecules. In mammals, enzymes hydrolyzing MAG to glycerol and fatty acids, resembling the final step in lipolysis, or esterifying MAG to diacylglycerol, are well known; however, despite the high level of conservation of lipolysis, the corresponding activities in yeast have not been characterized yet. Here we provide evidence that the protein Yju3p functions as a potent MAG hydrolase in yeast. Cellular MAG hydrolase activity was decreased by more than 90% in extracts of Yju3p-deficient cells, indicating that Yju3p accounts for the vast majority of this activity in yeast. Loss of this activity was restored by heterologous expression of murine monoglyceride lipase (MGL). Since yju3Δ mutants accumulated MAG in vivo only at very low concentrations, we considered the possibility that MAGs are re-esterified into DAG by acyltransferases. Indeed, cellular MAG levels were further increased in mutant cells lacking Yju3p and Dga1p or Lro1p acyltransferase activities. In conclusion, our studies suggest that catabolic and anabolic reactions affect cellular MAG levels. Yju3p is the functional orthologue of mammalian MGL and is required for efficient degradation of MAG in yeast.
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Affiliation(s)
| | | | | | | | | | | | | | - Regina Leber
- Corresponding author. Applied Biocatalysis Research Center, Petersgasse 14, A-8010 Graz, Austria. Tel.: +43 316 873 9342; fax: +43 316 873 9343.
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