1
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Bhutada P, Favre S, Jaafar M, Hafner J, Liesinger L, Unterweger S, Bischof K, Darnhofer B, Siva Sankar D, Rechberger G, Abou Merhi R, Lebaron S, Birner-Gruenberger R, Kressler D, Henras AK, Pertschy B. Rbp95 binds to 25S rRNA helix H95 and cooperates with the Npa1 complex during early pre-60S particle maturation. Nucleic Acids Res 2022; 50:10053-10077. [PMID: 36018804 PMCID: PMC9508819 DOI: 10.1093/nar/gkac724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 12/02/2021] [Revised: 08/05/2022] [Accepted: 08/12/2022] [Indexed: 11/21/2022] Open
Abstract
Eukaryotic ribosome synthesis involves more than 200 assembly factors, which promote ribosomal RNA (rRNA) processing, modification and folding, and assembly of ribosomal proteins. The formation and maturation of the earliest pre-60S particles requires structural remodeling by the Npa1 complex, but is otherwise still poorly understood. Here, we introduce Rbp95 (Ycr016w), a constituent of early pre-60S particles, as a novel ribosome assembly factor. We show that Rbp95 is both genetically and physically linked to most Npa1 complex members and to ribosomal protein Rpl3. We demonstrate that Rbp95 is an RNA-binding protein containing two independent RNA-interacting domains. In vivo, Rbp95 associates with helix H95 in the 3′ region of the 25S rRNA, in close proximity to the binding sites of Npa1 and Rpl3. Additionally, Rbp95 interacts with several snoRNAs. The absence of Rbp95 results in alterations in the protein composition of early pre-60S particles. Moreover, combined mutation of Rbp95 and Npa1 complex members leads to a delay in the maturation of early pre-60S particles. We propose that Rbp95 acts together with the Npa1 complex during early pre-60S maturation, potentially by promoting pre-rRNA folding events within pre-60S particles.
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Affiliation(s)
- Priya Bhutada
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Sébastien Favre
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Mariam Jaafar
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France.,Genomic Stability and Biotherapy (GSBT) Laboratory, Faculty of Sciences, Rafik Hariri Campus, Lebanese University, Beirut, Lebanon
| | - Jutta Hafner
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Laura Liesinger
- BioTechMed-Graz, Graz, Austria.,Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria
| | - Stefan Unterweger
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Karin Bischof
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Barbara Darnhofer
- BioTechMed-Graz, Graz, Austria.,Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria
| | - Devanarayanan Siva Sankar
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Gerald Rechberger
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Raghida Abou Merhi
- Genomic Stability and Biotherapy (GSBT) Laboratory, Faculty of Sciences, Rafik Hariri Campus, Lebanese University, Beirut, Lebanon
| | - Simon Lebaron
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Ruth Birner-Gruenberger
- BioTechMed-Graz, Graz, Austria.,Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria.,Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/E164, 1060 Vienna, Austria
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Anthony K Henras
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
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2
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Tehlivets O, Brunner M, Almer G, Schoiswohl G, Wolinski H, Kolb D, Kravets V, Ortner M, Schwarz A, Opriessnig P, Hörl G, Groselj‐Strele A, Höfler G, Kratky D, Mangge H, Rechberger G. Elevation of homocysteine levels in the plasma leads to deregulation of lipid metabolism in a rabbit model of atherosclerosis. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.05203] [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: 11/11/2022]
Affiliation(s)
| | | | - Gunter Almer
- Clinical Institute for Medical and Chemical Laboratory DiagnosticMedical University of GrazGraz
| | | | | | - Dagmar Kolb
- Core Facility Ultrastructure Analysis, Division of Cell Biology, Histology and EmbryologyMedical University of GrazGraz
| | | | | | | | - Peter Opriessnig
- Clinical Division of Neurology, Clinical Division of RadiologyMedical University of GrazGraz
| | - Gerd Hörl
- Otto Loewi Research Center, Physiological Chemistry, Medical University of GrazGraz
| | | | - Gerald Höfler
- Clinical Institute for Medical and Chemical Laboratory DiagnosticMedical University of GrazGraz
| | - Dagmar Kratky
- Schatz Research CenterMolecular Biology and Biochemistry, Medical University of GrazGraz
| | - Harald Mangge
- Clinical Institute for Medical and Chemical Laboratory DiagnosticMedical University of GrazGraz
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3
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Sunjic SB, Gasparovic AC, Jaganjac M, Rechberger G, Meinitzer A, Grune T, Kohlwein SD, Mihaljevic B, Zarkovic N. Sensitivity of Osteosarcoma Cells to Concentration-Dependent Bioactivities of Lipid Peroxidation Product 4-Hydroxynonenal Depend on Their Level of Differentiation. Cells 2021; 10:cells10020269. [PMID: 33572933 PMCID: PMC7912392 DOI: 10.3390/cells10020269] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/21/2021] [Accepted: 01/26/2021] [Indexed: 12/24/2022] Open
Abstract
4-Hydroxynonenal (HNE) is a major aldehydic product of lipid peroxidation known to exert several biological effects. Normal and malignant cells of the same origin express different sensitivity to HNE. We used human osteosarcoma cells (HOS) in different stages of differentiation in vitro, showing differences in mitosis, DNA synthesis, and alkaline phosphatase (ALP) staining. Differentiated HOS cells showed decreased proliferation (3H-thymidine incorporation), decreased viability (thiazolyl blue tetrazolium bromide-MTT), and increased apoptosis and necrosis (nuclear morphology by staining with 4′,6-diamidino-2-phenylindole-DAPI). Differentiated HOS also had less expressed c-MYC, but the same amount of c-FOS (immunocytochemistry). When exposed to HNE, differentiated HOS produced more reactive oxygen species (ROS) in comparison with undifferentiated HOS. To clarify this, we measured HNE metabolism by an HPLC method, total glutathione (GSH), oxidized GSH (ox GSH), glutathione transferase activity (GST), proteasomal activity by enzymatic methods, HNE-protein adducts by genuine ELISA and fatty acid composition by GC-MS in these cell cultures. Differentiated HOS cells had less GSH, lower HNE metabolism, increased formation of HNE-protein adducts, and lower proteasomal activity, in comparison to undifferentiated counterpart cells, while GST and oxGSH were the same. Fatty acids analyzed by GC-MS showed that there is an increase in C20:3 in differentiated HOS while the amount of C20:4 remained the same. The results showed that the cellular machinery responsible for protection against toxicity of HNE was less efficient in differentiated HOS cells. Moreover, differentiated HOS cells contained more C20:3 fatty acid, which might make them more sensitive to free radical-initiated oxidative chain reactions and more vulnerable to the effects of reactive aldehydes such as HNE. We propose that HNE might act as natural promotor of decay of malignant (osteosarcoma) cells in case of their differentiation associated with alteration of the lipid metabolism.
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Affiliation(s)
- Suzana Borovic Sunjic
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
| | - Ana Cipak Gasparovic
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
| | - Morana Jaganjac
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
| | - Gerald Rechberger
- Institute of Molecular Biosciences, Bio TechMed-Graz, University of Graz, 8010 Graz, Austria; (G.R.); (S.D.K.)
| | - Andreas Meinitzer
- University Clinic of Traumatology, University of Graz, 8010 Graz, Austria;
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke, 14558 Nuthetal, Germany;
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, A-1090 Vienna, Austria
| | - Sepp D. Kohlwein
- Institute of Molecular Biosciences, Bio TechMed-Graz, University of Graz, 8010 Graz, Austria; (G.R.); (S.D.K.)
| | - Branka Mihaljevic
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
| | - Neven Zarkovic
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
- Correspondence:
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4
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Bischof K, Schiffer D, Trunk S, Höfler T, Hopfer A, Rechberger G, Koraimann G. Regulation of R1 Plasmid Transfer by H-NS, ArcA, TraJ, and DNA Sequence Elements. Front Microbiol 2020; 11:1254. [PMID: 32595626 PMCID: PMC7303359 DOI: 10.3389/fmicb.2020.01254] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 05/18/2020] [Indexed: 11/17/2022] Open
Abstract
In conjugative elements such as integrating conjugative elements (ICEs) or conjugative plasmids (CPs) transcription of DNA transfer genes is a prerequisite for cells to become transfer competent, i.e., capable of delivering plasmid DNA via bacterial conjugation into new host bacteria. In the large family of F-like plasmids belonging to the MobF12A group, transcription of DNA transfer genes is tightly controlled and dependent on the activation of a single promoter, designated PY. Plasmid encoded TraJ and chromosomally encoded ArcA proteins are known activators, whereas the nucleoid associated protein heat-stable nucleoid structuring (H-NS) silences the PY promoter. To better understand the role of these proteins in PY promoter activation, we performed in vitro DNA binding studies using purified H-NS, ArcA, and TraJR1 (TraJ encoded by the conjugative resistance plasmid R1). All proteins could bind to R1PY DNA with high affinities; however, only ArcA was found to be highly sequence specific. DNase I footprinting studies revealed three H-NS binding sites, confirmed the binding site for ArcA, and suggested that TraJ contacts a dyad symmetry DNA sequence located between −51 and −38 in the R1PY promoter region. Moreover, TraJR1 and ArcA supplied together changed the H-NS specific protection pattern suggesting that these proteins are able to replace H-NS from R1PY regions proximal to the transcription start site. Our findings were corroborated by PY-lacZ reporter fusions with a series of site specific R1PY promoter mutations. Sequential changes of some critical DNA bases in the TraJ binding site (jbs) from plasmid R1 to plasmid F led to a remarkable specificity switch: The PY promoter became activatable by F encoded TraJ whereas TraJR1 lost its activation function. The R1PY mutagenesis approach also confirmed the requirement for the host-encoded response-regulator ArcA and indicated that the sequence context, especially in the −35 region is critical for PY regulation and function.
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Affiliation(s)
- Karin Bischof
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Doris Schiffer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Sarah Trunk
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Thomas Höfler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Anja Hopfer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Gerald Rechberger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Günther Koraimann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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5
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Goeritzer M, Bernhart E, Plastira I, Reicher H, Leopold C, Eichmann TO, Rechberger G, Madreiter-Sokolowski CT, Prasch J, Eller P, Graier WF, Kratky D, Malle E, Sattler W. Myeloperoxidase and Septic Conditions Disrupt Sphingolipid Homeostasis in Murine Brain Capillaries In Vivo and Immortalized Human Brain Endothelial Cells In Vitro. Int J Mol Sci 2020; 21:E1143. [PMID: 32050431 PMCID: PMC7037060 DOI: 10.3390/ijms21031143] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [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: 12/12/2019] [Revised: 01/27/2020] [Accepted: 02/06/2020] [Indexed: 02/07/2023] Open
Abstract
During inflammation, activated leukocytes release cytotoxic mediators that compromise blood-brain barrier (BBB) function. Under inflammatory conditions, myeloperoxidase (MPO) is critically involved in inflicting BBB damage. We used genetic and pharmacological approaches to investigate whether MPO induces aberrant lipid homeostasis at the BBB in a murine endotoxemia model. To corroborate findings in a human system we studied the impact of sera from sepsis and non-sepsis patients on brain endothelial cells (hCMEC/D3). In response to endotoxin, the fatty acid, ceramide, and sphingomyelin content of isolated mouse brain capillaries dropped and barrier dysfunction occurred. In mice, genetic deficiency or pharmacological inhibition of MPO abolished these alterations. Studies in metabolic cages revealed increased physical activity and less pronounced sickness behavior of MPO-/- compared to wild-type mice in response to sepsis. In hCMEC/D3 cells, exogenous tumor necrosis factor α (TNFα) potently regulated gene expression of pro-inflammatory cytokines and a set of genes involved in sphingolipid (SL) homeostasis. Notably, treatment of hCMEC/D3 cells with sera from septic patients reduced cellular ceramide concentrations and induced barrier and mitochondrial dysfunction. In summary, our in vivo and in vitro data revealed that inflammatory mediators including MPO, TNFα induce dysfunctional SL homeostasis in brain endothelial cells. Genetic and pharmacological inhibition of MPO attenuated endotoxin-induced alterations in SL homeostasis in vivo, highlighting the potential role of MPO as drug target to treat inflammation-induced brain dysfunction.
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Affiliation(s)
- Madeleine Goeritzer
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
- BioTechMed-Graz, Graz 8010, Austria; (T.O.E.); (G.R.)
| | - Eva Bernhart
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
| | - Ioanna Plastira
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
| | - Helga Reicher
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
| | - Christina Leopold
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
| | - Thomas O. Eichmann
- BioTechMed-Graz, Graz 8010, Austria; (T.O.E.); (G.R.)
- Institute of Molecular Biosciences, University of Graz, Graz 8010, Austria
- Center for Explorative Lipidomics, BioTechMed-Graz, Graz 8010, Austria
| | - Gerald Rechberger
- BioTechMed-Graz, Graz 8010, Austria; (T.O.E.); (G.R.)
- Institute of Molecular Biosciences, University of Graz, Graz 8010, Austria
- Center for Explorative Lipidomics, BioTechMed-Graz, Graz 8010, Austria
| | - Corina T. Madreiter-Sokolowski
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
- Department of Health Sciences and Technology, ETH Zurich, Schwerzenbach 8603, Switzerland
| | - Jürgen Prasch
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
| | - Philipp Eller
- Department of Internal Medicine, Intensive Care Unit, Medical University of Graz, Graz 8036, Austria;
| | - Wolfgang F. Graier
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
| | - Dagmar Kratky
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
- BioTechMed-Graz, Graz 8010, Austria; (T.O.E.); (G.R.)
| | - Ernst Malle
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
| | - Wolfgang Sattler
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz 8010, Austria; (M.G.); (E.B.); (I.P.); (H.R.); (C.L.); (C.T.M.-S.); (J.P.); (W.F.G.); (D.K.); (E.M.)
- BioTechMed-Graz, Graz 8010, Austria; (T.O.E.); (G.R.)
- Center for Explorative Lipidomics, BioTechMed-Graz, Graz 8010, Austria
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Bhat Kumble V, Bernhart E, Fan K, Wadsack C, Rechberger G, Becker J, Sattler W. 608 Interference with sphingosine 1-phosphate synthesis affects Merkel cell carcinoma proliferation in vitro. J Invest Dermatol 2017. [DOI: 10.1016/j.jid.2017.07.805] [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: 11/16/2022]
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7
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Bhat Kumble V, Bernhart E, Plastira I, Kogelnik N, Göritzer M, Fan K, Wadsack C, Rechberger G, Becker J, Sattler W. 484 Merkel cell carcinoma proliferation is regulated by sphingosine-1-phosphate-mediated pathways in vitro. J Invest Dermatol 2016. [DOI: 10.1016/j.jid.2016.06.506] [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: 10/21/2022]
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Riessberger-Gallé U, Hernández-López J, Rechberger G, Crailsheim K, Schuehly W. Lysophosphatidylcholine acts in the constitutive immune defence against American foulbrood in adult honeybees. Sci Rep 2016; 6:30699. [PMID: 27480379 PMCID: PMC4969740 DOI: 10.1038/srep30699] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [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: 04/19/2016] [Accepted: 07/06/2016] [Indexed: 12/17/2022] Open
Abstract
Honeybee (Apis mellifera) imagines are resistant to the Gram-positive bacterium Paenibacillus larvae (P. larvae), causative agent of American foulbrood (AFB), whereas honeybee larvae show susceptibility against this pathogen only during the first 48 h of their life. It is known that midgut homogenate of adult honeybees as well as a homogenate of aged larvae exhibit strong anti-P. larvae activity. A bioactivity-guided LC-HRMS analysis of midgut homogenate resulted in the identification of 1-oleoyl-sn-glycero-3-phosphocholine (LPC) pointing to a yet unknown immune defence in adult honeybees against P. larvae. Antimicrobial activity of LPC was also demonstrated against Melissococcus plutonius, causative agent of European Foulbrood. To demonstrate an AFB-preventive effect of LPC in larvae, artificially reared larvae were supplemented with LPC to evaluate its toxicity and to assess whether, after infection with P. larvae spores, LPC supplementation prevents AFB infection. 10 μg LPC per larva applied for 3 d significantly lowered mortality due to AFB in comparison to controls. A potential delivery route of LPC to the larvae in a colony via nurse bees was assessed through a tracking experiment using fluorescent-labelled LPC. This yet undescribed and non-proteinous defense of honeybees against P. larvae may offer new perspectives for a treatment of AFB without the utilization of classic antibiotics.
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Affiliation(s)
| | | | - Gerald Rechberger
- Institute of Molecular Biosciences, University of Graz, NAWI Graz, Humboldtstraße 50/II, 8010 Graz, Austria
- OMICS Centre Graz, BioTechMed-Graz, 8010 Graz, Austria
| | - Karl Crailsheim
- Institute of Zoology, Universitätsplatz 2, University of Graz, 8010 Graz, Austria
| | - Wolfgang Schuehly
- Institute of Zoology, Universitätsplatz 2, University of Graz, 8010 Graz, Austria
- Institute of Pharmaceutical Sciences, Pharmacognosy, Universitätsplatz 4, University of Graz, 8010 Graz, Austria
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9
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Kollau A, Russwurm M, Neubauer A, Rechberger G, Schmidt K, Koesling D, Fassett J, Schrammel A, Mayer B. Scavenging of nitric oxide by hemoglobin in the tunica media of porcine coronary arteries. Nitric Oxide 2016; 54:8-14. [PMID: 26805578 PMCID: PMC5933522 DOI: 10.1016/j.niox.2016.01.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [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: 10/21/2015] [Revised: 01/19/2016] [Accepted: 01/20/2016] [Indexed: 11/23/2022]
Abstract
Scavenging of nitric oxide (NO) often interferes with studies on NO signaling in cell-free preparations. We observed that formation of cGMP by NO-stimulated purified soluble guanylate cyclase (sGC) was virtually abolished in the presence of cytosolic preparations of porcine coronary arteries, with the scavenging activity localized in the tunica media (smooth muscle layer). Electrochemical measurement of NO release from a donor compound and light absorbance spectroscopy showed that cytosolic preparations contained a reduced heme protein that scavenged NO. This protein, which reacted with anti-human hemoglobin antibodies, was efficiently removed from the preparations by haptoglobin affinity chromatography. The cleared cytosols showed only minor scavenging of NO according to electrochemical measurements and did not decrease cGMP formation by NO-stimulated sGC. In contrast, the column flow-through caused a nearly 2-fold increase of maximal sGC activity (from 33.1 ± 1.6 to 54.9 ± 2.2 μmol × min(-1) × mg(-1)). The proteins retained on the affinity column were identified as hemoglobin α and β subunits. The results indicate that hemoglobin, presumably derived from vasa vasorum erythrocytes, is present and scavenges NO in preparations of porcine coronary artery smooth muscle. Selective removal of hemoglobin-mediated scavenging unmasked stimulation of maximal NO-stimulated sGC activity by a soluble factor expressed in vascular tissue.
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Affiliation(s)
- Alexander Kollau
- Institute of Pharmaceutical Sciences, Department of Pharmacology and Toxicology, University of Graz, Austria
| | - Michael Russwurm
- Department of Pharmacology and Toxicology, Ruhr University Bochum, Germany
| | - Andrea Neubauer
- Institute of Pharmaceutical Sciences, Department of Pharmacology and Toxicology, University of Graz, Austria
| | - Gerald Rechberger
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Austria; Omics-Center, BioTechMed-Graz, Austria
| | - Kurt Schmidt
- Institute of Pharmaceutical Sciences, Department of Pharmacology and Toxicology, University of Graz, Austria
| | - Doris Koesling
- Department of Pharmacology and Toxicology, Ruhr University Bochum, Germany
| | - John Fassett
- Institute of Pharmaceutical Sciences, Department of Pharmacology and Toxicology, University of Graz, Austria
| | - Astrid Schrammel
- Institute of Pharmaceutical Sciences, Department of Pharmacology and Toxicology, University of Graz, Austria
| | - Bernd Mayer
- Institute of Pharmaceutical Sciences, Department of Pharmacology and Toxicology, University of Graz, Austria.
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10
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Nusshold C, Üllen A, Kogelnik N, Bernhart E, Reicher H, Plastira I, Glasnov T, Zangger K, Rechberger G, Kollroser M, Fauler G, Wolinski H, Weksler BB, Romero IA, Kohlwein SD, Couraud PO, Malle E, Sattler W. Assessment of electrophile damage in a human brain endothelial cell line utilizing a clickable alkyne analog of 2-chlorohexadecanal. Free Radic Biol Med 2016; 90:59-74. [PMID: 26577177 PMCID: PMC6392177 DOI: 10.1016/j.freeradbiomed.2015.11.010] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 11/05/2015] [Accepted: 11/07/2015] [Indexed: 11/19/2022]
Abstract
Peripheral leukocytes aggravate brain damage by releasing cytotoxic mediators that compromise blood-brain barrier function. One of the oxidants released by activated leukocytes is hypochlorous acid (HOCl) that is formed via the myeloperoxidase-H2O2-chloride system. The reaction of HOCl with the endogenous plasmalogen pool of brain endothelial cells results in the generation of 2-chlorohexadecanal (2-ClHDA), a toxic, lipid-derived electrophile that induces blood-brain barrier dysfunction in vivo. Here, we synthesized an alkynyl-analog of 2-ClHDA, 2-chlorohexadec-15-yn-1-al (2-ClHDyA) to identify potential protein targets in the human brain endothelial cell line hCMEC/D3. Similar to 2-ClHDA, 2-ClHDyA administration reduced cell viability/metabolic activity, induced processing of pro-caspase-3 and PARP, and led to endothelial barrier dysfunction at low micromolar concentrations. Protein-2-ClHDyA adducts were fluorescently labeled with tetramethylrhodamine azide (N3-TAMRA) by 1,3-dipolar cycloaddition in situ, which unveiled a preferential accumulation of 2-ClHDyA adducts in mitochondria, the Golgi, endoplasmic reticulum, and endosomes. Thirty-three proteins that are subject to 2-ClHDyA-modification in hCMEC/D3 cells were identified by mass spectrometry. Identified proteins include cytoskeletal components that are central to tight junction patterning, metabolic enzymes, induction of the oxidative stress response, and electrophile damage to the caveolar/endosomal Rab machinery. A subset of the targets was validated by a combination of N3-TAMRA click chemistry and specific antibodies by fluorescence microscopy. This novel alkyne analog is a valuable chemical tool to identify cellular organelles and protein targets of 2-ClHDA-mediated damage in settings where myeloperoxidase-derived oxidants may play a disease-propagating role.
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Affiliation(s)
- Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria
| | - Andreas Üllen
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Nora Kogelnik
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Ioanna Plastira
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Toma Glasnov
- Christian Doppler Laboratory for Flow Chemistry, Institute of Chemistry, University of Graz, Austria
| | | | - Gerald Rechberger
- BioTechMed Graz, Austria; Institute of Molecular Biosciences, NAWI-Graz, University of Graz, Austria; OMICS-Center Graz, BioTechMed Graz, Austria
| | | | - Günter Fauler
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Austria
| | - Heimo Wolinski
- BioTechMed Graz, Austria; Institute of Molecular Biosciences, NAWI-Graz, University of Graz, Austria
| | - Babette B Weksler
- Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Ignacio A Romero
- Department of Biological Sciences, The Open University, Walton Hall, Milton Keynes MK7 6BJ, UK
| | - Sepp D Kohlwein
- BioTechMed Graz, Austria; Institute of Molecular Biosciences, NAWI-Graz, University of Graz, Austria
| | - Pierre-Olivier Couraud
- Institut Cochin, Inserm, U1016, CNRS UMR 8104, Paris Descartes University, Sorbonne Paris Cité, Paris, France
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria.
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11
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Eichmann TO, Grumet L, Taschler U, Hartler J, Heier C, Woblistin A, Pajed L, Kollroser M, Rechberger G, Thallinger GG, Zechner R, Haemmerle G, Zimmermann R, Lass A. ATGL and CGI-58 are lipid droplet proteins of the hepatic stellate cell line HSC-T6. J Lipid Res 2015; 56:1972-84. [PMID: 26330055 PMCID: PMC4583087 DOI: 10.1194/jlr.m062372] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [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: 07/30/2015] [Indexed: 12/31/2022] Open
Abstract
Lipid droplets (LDs) of hepatic stellate cells (HSCs) contain large amounts of vitamin A [in the form of retinyl esters (REs)] as well as other neutral lipids such as TGs. During times of insufficient vitamin A availability, RE stores are mobilized to ensure a constant supply to the body. To date, little is known about the enzymes responsible for the hydrolysis of neutral lipid esters, in particular of REs, in HSCs. In this study, we aimed to identify LD-associated neutral lipid hydrolases by a proteomic approach using the rat stellate cell line HSC-T6. First, we loaded cells with retinol and FAs to promote lipid synthesis and deposition within LDs. Then, LDs were isolated and lipid composition and the LD proteome were analyzed. Among other proteins, we found perilipin 2, adipose TG lipase (ATGL), and comparative gene identification-58 (CGI-58), known and established LD proteins. Bioinformatic search of the LD proteome for α/β-hydrolase fold-containing proteins revealed no yet uncharacterized neutral lipid hydrolases. In in vitro activity assays, we show that rat (r)ATGL, coactivated by rat (r)CGI-58, efficiently hydrolyzes TGs and REs. These findings suggest that rATGL and rCGI-58 are LD-resident proteins in HSCs and participate in the mobilization of both REs and TGs.
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Affiliation(s)
- Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Lukas Grumet
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Ulrike Taschler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Jürgen Hartler
- Bioinformatics, Institute for Knowledge Discovery, Graz University of Technology, Graz, Austria
| | - Christoph Heier
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Aaron Woblistin
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Laura Pajed
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Manfred Kollroser
- Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Gerald Rechberger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria BioTechMed-Graz, Graz, Austria OMICS Center, Graz, Austria
| | - Gerhard G Thallinger
- Bioinformatics, Institute for Knowledge Discovery, Graz University of Technology, Graz, Austria BioTechMed-Graz, Graz, Austria OMICS Center, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Günter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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12
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Bernhart E, Damm S, Wintersperger A, Nusshold C, Brunner AM, Plastira I, Rechberger G, Reicher H, Wadsack C, Zimmer A, Malle E, Sattler W. Interference with distinct steps of sphingolipid synthesis and signaling attenuates proliferation of U87MG glioma cells. Biochem Pharmacol 2015; 96:119-30. [PMID: 26002572 PMCID: PMC4490581 DOI: 10.1016/j.bcp.2015.05.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 05/12/2015] [Indexed: 12/22/2022]
Abstract
Glioblastoma is the most common malignant brain tumor, which, despite combined radio- and chemotherapy, recurs and is invariably fatal for affected patients. Members of the sphingolipid (SL) family are potent effectors of glioma cell proliferation. In particular sphingosine-1-phosphate (S1P) and the corresponding G protein-coupled S1P receptors transmit proliferative signals to glioma cells. To investigate the contribution to glioma cell proliferation we inhibited the first step of de novo SL synthesis in p53wt and p53mut glioma cells, and interfered with S1P signaling specifically in p53wt U87MG cells. Subunit silencing (RNAi) or pharmacological antagonism (using myriocin) of serine palmitoyltransferase (SPT; catalyzing the first committed step of SL biosynthesis) reduced proliferation of p53wt but not p53mut GBM cells. In U87MG cells these observations were accompanied by decreased ceramide, sphingomyelin, and S1P content. Inhibition of SPT upregulated p53 and p21 expression and induced an increase in early and late apoptotic U87MG cells. Exogenously added S1P (complexed to physiological carriers) increased U87MG proliferation. In line, silencing of individual members of the S1P receptor family decreased U87MG proliferation. Silencing and pharmacological inhibition of the ATP-dependent cassette transporter A1 (ABCA1) that facilitates S1P efflux in astrocytes attenuated U87MG growth. Glyburide-mediated inhibition of ABCA1 resulted in intracellular accumulation of S1P raising the possibility that ABCA1 promotes S1P efflux in U87MG glioma cells thereby contributing to inside-out signaling. Our findings indicate that de novo SL synthesis, S1P receptor-mediated signaling, and ABCA1-mediated S1P efflux could provide pharmacological targets to interfere with glioma cell proliferation.
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Affiliation(s)
- Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Sabine Damm
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Andrea Wintersperger
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria
| | - Anna Martina Brunner
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Ioanna Plastira
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | | | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Christian Wadsack
- Department of Obstetrics and Gynecology, Medical University of Graz, Austria
| | - Andreas Zimmer
- BioTechMed Graz, Austria; Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology, University of Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria.
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13
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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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14
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Rockenfeller P, Ring J, Muschett V, Beranek A, Büttner S, Carmona-Gutierrez D, Eisenberg T, Khoury C, Rechberger G, Kohlwein SD, Kroemer G, Madeo F. Fatty acids trigger mitochondrion-dependent necrosis. Cell Cycle 2014; 9:2908-10. [DOI: 10.4161/cc.9.14.12346] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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15
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Riedl S, Rinner B, Rechberger G, Schaider H, Lohner K, Zweytick D. Interaction of an Antitumor Peptide with Lipids of the Cancer Plasma Membrane - Formation of Membrane Domains and Influence of Cholesterol. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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16
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Ploier B, Scharwey M, Koch B, Schmidt C, Schatte J, Rechberger G, Kollroser M, Hermetter A, Daum G. Screening for hydrolytic enzymes reveals Ayr1p as a novel triacylglycerol lipase in Saccharomyces cerevisiae. J Biol Chem 2013; 288:36061-72. [PMID: 24187129 DOI: 10.1074/jbc.m113.509927] [Citation(s) in RCA: 35] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Saccharomyces cerevisiae, as well as other eukaryotes, preserves fatty acids and sterols in a biologically inert form, as triacylglycerols and steryl esters. The major triacylglycerol lipases of the yeast S. cerevisiae identified so far are Tgl3p, Tgl4p, and Tgl5p (Athenstaedt, K., and Daum, G. (2003) YMR313c/TGL3 encodes a novel triacylglycerol lipase located in lipid particles of Saccharomyces cerevisiae. J. Biol. Chem. 278, 23317-23323; Athenstaedt, K., and Daum, G. (2005) Tgl4p and Tgl5p, two triacylglycerol lipases of the yeast Saccharomyces cerevisiae, are localized to lipid particles. J. Biol. Chem. 280, 37301-37309). We observed that upon cultivation on oleic acid, triacylglycerol mobilization did not come to a halt in a yeast strain deficient in all currently known triacylglycerol lipases, indicating the presence of additional not yet characterized lipases/esterases. Functional proteome analysis using lipase and esterase inhibitors revealed a subset of candidate genes for yet unknown hydrolytic enzymes on peroxisomes and lipid droplets. Based on the conserved GXSXG lipase motif, putative functions, and subcellular localizations, a selected number of candidates were characterized by enzyme assays in vitro, gene expression analysis, non-polar lipid analysis, and in vivo triacylglycerol mobilization assays. These investigations led to the identification of Ayr1p as a novel triacylglycerol lipase of yeast lipid droplets and confirmed the hydrolytic potential of the peroxisomal Lpx1p in vivo. Based on these results, we discuss a possible link between lipid storage, lipid mobilization, and peroxisomal utilization of fatty acids as a carbon source.
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Affiliation(s)
- Birgit Ploier
- From the Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, A-8010 Graz, Austria
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17
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Kappel L, Loibl M, Zisser G, Klein I, Fruhmann G, Gruber C, Unterweger S, Rechberger G, Pertschy B, Bergler H. Rlp24 activates the AAA-ATPase Drg1 to initiate cytoplasmic pre-60S maturation. ACTA ACUST UNITED AC 2013. [PMID: 23185031 PMCID: PMC3514788 DOI: 10.1083/jcb.201205021] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [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: 11/22/2022]
Abstract
Formation of eukaryotic ribosomes is driven by energy-consuming enzymes. The AAA-ATPase Drg1 is essential for the release of several shuttling proteins from cytoplasmic pre-60S particles and the loading of late joining proteins. However, its exact role in ribosome biogenesis has been unknown. Here we show that the shuttling protein Rlp24 recruited Drg1 to pre-60S particles and stimulated its ATPase activity. ATP hydrolysis in the second AAA domain of Drg1 was required to release shuttling proteins. In vitro, Drg1 specifically and exclusively extracted Rlp24 from purified pre-60S particles. Rlp24 release required ATP and was promoted by the interaction of Drg1 with the nucleoporin Nup116. Subsequent ATP hydrolysis in the first AAA domain dissociated Drg1 from Rlp24, liberating both proteins for consecutive cycles of activity. Our results show that release of Rlp24 by Drg1 defines a key event in large subunit formation that is a prerequisite for progression of cytoplasmic pre-60S maturation.
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Affiliation(s)
- Lisa Kappel
- Institut für Molekulare Biowissenschaften, Karl-Franzens Universität Graz, A-8010 Graz, Austria
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18
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Baßler J, Klein I, Schmidt C, Kallas M, Thomson E, Wagner MA, Bradatsch B, Rechberger G, Strohmaier H, Hurt E, Bergler H. The conserved Bud20 zinc finger protein is a new component of the ribosomal 60S subunit export machinery. Mol Cell Biol 2012; 32:4898-912. [PMID: 23045392 PMCID: PMC3510546 DOI: 10.1128/mcb.00910-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 09/17/2012] [Indexed: 01/03/2023] Open
Abstract
The nuclear export of the preribosomal 60S (pre-60S) subunit is coordinated with late steps in ribosome assembly. Here, we show that Bud20, a conserved C(2)H(2)-type zinc finger protein, is an unrecognized shuttling factor required for the efficient export of pre-60S subunits. Bud20 associates with late pre-60S particles in the nucleoplasm and accompanies them into the cytoplasm, where it is released through the action of the Drg1 AAA-ATPase. Cytoplasmic Bud20 is then reimported via a Kap123-dependent pathway. The deletion of Bud20 induces a strong pre-60S export defect and causes synthetic lethality when combined with mutant alleles of known pre-60S subunit export factors. The function of Bud20 in ribosome export depends on a short conserved N-terminal sequence, as we observed that mutations or the deletion of this motif impaired 60S subunit export and generated the genetic link to other pre-60S export factors. We suggest that the shuttling Bud20 is recruited to the nascent 60S subunit via its central zinc finger rRNA binding domain to facilitate the subsequent nuclear export of the preribosome employing its N-terminal extension.
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MESH Headings
- Active Transport, Cell Nucleus
- Amino Acid Sequence
- Gene Deletion
- Genes, Fungal
- Models, Biological
- Models, Molecular
- Molecular Sequence Data
- Mutant Proteins/genetics
- Mutant Proteins/metabolism
- Mutation
- Protein Conformation
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Ribosomal Proteins/chemistry
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosome Subunits, Large, Eukaryotic/chemistry
- Ribosome Subunits, Large, Eukaryotic/genetics
- Ribosome Subunits, Large, Eukaryotic/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Saccharomyces cerevisiae Proteins/chemistry
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Sequence Homology, Amino Acid
- Zinc Fingers
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Affiliation(s)
- Jochen Baßler
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Isabella Klein
- Institut für Molekulare Biowissenschaften, Karl-Franzens Universität Graz, Graz, Austria
| | - Claudia Schmidt
- Institut für Molekulare Biowissenschaften, Karl-Franzens Universität Graz, Graz, Austria
| | - Martina Kallas
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Emma Thomson
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Maria Anna Wagner
- Institut für Molekulare Biowissenschaften, Karl-Franzens Universität Graz, Graz, Austria
| | | | - Gerald Rechberger
- Institut für Molekulare Biowissenschaften, Karl-Franzens Universität Graz, Graz, Austria
| | - Heimo Strohmaier
- Zentrum für Medizinische Grundlagenforschung, Medizinische Universität Graz, Graz, Austria
| | - Ed Hurt
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Helmut Bergler
- Institut für Molekulare Biowissenschaften, Karl-Franzens Universität Graz, Graz, Austria
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19
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Koch B, Mitterer V, Niederhauser J, Stanborough T, Murat G, Rechberger G, Bergler H, Kressler D, Pertschy B. Yar1 protects the ribosomal protein Rps3 from aggregation. J Biol Chem 2012; 287:21806-15. [PMID: 22570489 DOI: 10.1074/jbc.m112.365791] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
2000 ribosomes have to be synthesized in yeast every minute. Therefore the fast production of ribosomal proteins, their efficient delivery to the nucleus and correct incorporation into ribosomal subunits are prerequisites for optimal growth rates. Here, we report that the ankyrin repeat protein Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus where Rps3 is assembled into pre-ribosomal subunits. A yar1 deletion strain displays a similar phenotype as an rps3 mutant strain, showing an accumulation of 20S pre-rRNA and a 40S export defect. The combination of an rps3 mutation with a yar1 deletion leads to an enhancement of these phenotypes, while increased expression of RPS3 suppresses the defects of a yar1 deletion strain. We further show that Yar1 protects Rps3 from aggregation in vitro and increases its solubility in vivo. Our data suggest that Yar1 is a specific chaperone for Rps3, which serves to keep Rps3 soluble until its incorporation into the pre-ribosome.
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Affiliation(s)
- Barbara Koch
- Institut für Molekulare Biowissenschaften, Universität Graz, Humboldtstrasse 50, A-8010 Graz, Austria
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20
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Rohde E, Schallmoser K, Reinisch A, Hofmann NA, Pfeifer T, Fröhlich E, Rechberger G, Lanzer G, Kratky D, Strunk D. Pro-angiogenic induction of myeloid cells for therapeutic angiogenesis can induce mitogen-activated protein kinase p38-dependent foam cell formation. Cytotherapy 2010; 13:503-12. [PMID: 21128706 DOI: 10.3109/14653249.2010.536214] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND AIMS Clinical trials for therapeutic angiogenesis use blood- or bone marrow-derived hematopoietic cells, endothelial progenitor cells (EPC) and mesenchymal stromal cells (MSC) for vascular regeneration. Recently concerns have emerged that all three cell types could also contribute to atherosclerosis by foam cell formation. Therefore, we asked whether human myelomonocytic cells, EPC or MSC can accumulate lipid droplets (LD) and develop into foam cells. METHODS LD accumulation was quantified by flow cytometry, confocal microscopy and cholesterol measurement in each of the cell types. The impact of an initial pro-angiogenic induction on subsequent foam cell formation was studied to mimic relevant settings already used in clinical trials. The phosphorylation state of intracellular signaling molecules in response to the pro-angiogenic stimulation was determined to delineate the operative mechanisms and establish a basis for interventional strategies. RESULTS Foam cells were formed by monocytes but not by EPC or MSC after pro-angiogenic induction. Mitogen-activated protein kinase (MAPK) p38 phosphorylation was enhanced and kinase inhibition almost abrogated intracellular LD accumulation in monocytes. CONCLUSIONS These data suggest that hematopoietic cell preparations containing monocytes bear the risk of foam cell formation after pro-angiogenic induction. Instead, EPC and MSC may drive vascular regeneration without atherogenesis aggravation. A thorough understanding of cell biology is necessary to develop new strategies combining pro-angiogenic and anti-atherogenic effects during cell therapy.
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Affiliation(s)
- Eva Rohde
- Stem Cell Research Unit, University of Graz, Graz, Austria
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21
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Schicher M, Morak M, Birner-Gruenberger R, Kayer H, Stojcic B, Rechberger G, Kollroser M, Hermetter A. Functional Proteomic Analysis of Lipases and Esterases in Cultured Human Adipocytes. J Proteome Res 2010; 9:6334-44. [DOI: 10.1021/pr1005795] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Maximilian Schicher
- Institute of Biochemistry, Graz University of Technology, Graz, Austria, Institute of Molecular Biosciences, University of Graz, Graz, Austria, and Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Maria Morak
- Institute of Biochemistry, Graz University of Technology, Graz, Austria, Institute of Molecular Biosciences, University of Graz, Graz, Austria, and Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Ruth Birner-Gruenberger
- Institute of Biochemistry, Graz University of Technology, Graz, Austria, Institute of Molecular Biosciences, University of Graz, Graz, Austria, and Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Heidemarie Kayer
- Institute of Biochemistry, Graz University of Technology, Graz, Austria, Institute of Molecular Biosciences, University of Graz, Graz, Austria, and Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Bojana Stojcic
- Institute of Biochemistry, Graz University of Technology, Graz, Austria, Institute of Molecular Biosciences, University of Graz, Graz, Austria, and Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Gerald Rechberger
- Institute of Biochemistry, Graz University of Technology, Graz, Austria, Institute of Molecular Biosciences, University of Graz, Graz, Austria, and Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Manfred Kollroser
- Institute of Biochemistry, Graz University of Technology, Graz, Austria, Institute of Molecular Biosciences, University of Graz, Graz, Austria, and Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Albin Hermetter
- Institute of Biochemistry, Graz University of Technology, Graz, Austria, Institute of Molecular Biosciences, University of Graz, Graz, Austria, and Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
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22
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Stemmer U, Zenzmaier E, Stojcic B, Rechberger G, Kollroser M, Hermetter A. Oxidized phospholipids: uptake and targeting in RAW 264.7 macrophages. Chem Phys Lipids 2010. [DOI: 10.1016/j.chemphyslip.2010.05.034] [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: 11/25/2022]
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23
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Rockenfeller P, Ring J, Muschett V, Beranek A, Buettner S, Carmona-Gutierrez D, Eisenberg T, Khoury C, Rechberger G, Kohlwein SD, Kroemer G, Madeo F. Fatty acids trigger mitochondrion-dependent necrosis. Cell Cycle 2010; 9:2836-42. [PMID: 20647757 DOI: 10.4161/cc.9.14.12267] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Obesity is characterised by lipid accumulation in non-adipose tissues, leading to organ degeneration and a wide range of diseases, including diabetes, heart attack and liver cirrhosis. Free fatty acids (FFA) are believed to be the principal toxic triggers mediating the adverse cellular effects of lipids. Here, we show that various cooking oils used in human nutrition cause cell death in yeast in the presence of a triacylglycerol lipase, mimicking the physiological microenvironment of the small intestine. Combining genetic and cell death assays, we demonstrate that elevated FFA concentrations lead to necrotic cell death, as evidenced by loss of membrane integrity and release of nuclear HMGB1. FFA-mediated necrosis depends on functional mitochondria and leads to the accumulation of reactive oxygen species. We conclude that lipotoxicity is executed via a mitochondrial necrotic pathway, challenging the dogma that the adverse effects of lipid stress are exclusively apoptotic.
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24
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Nusshold C, Kollroser M, Köfeler H, Rechberger G, Reicher H, Üllen A, Bernhart E, Waltl S, Kratzer I, Hermetter A, Hackl H, Trajanoski Z, Hrzenjak A, Malle E, Sattler W. Hypochlorite modification of sphingomyelin generates chlorinated lipid species that induce apoptosis and proteome alterations in dopaminergic PC12 neurons in vitro. Free Radic Biol Med 2010; 48:1588-600. [PMID: 20226853 PMCID: PMC4061462 DOI: 10.1016/j.freeradbiomed.2010.02.037] [Citation(s) in RCA: 43] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 01/12/2010] [Accepted: 02/27/2010] [Indexed: 11/15/2022]
Abstract
Recent observations link myeloperoxidase (MPO) activation to neurodegeneration. In multiple sclerosis MPO is present in areas of active demyelination where the potent oxidant hypochlorous acid (HOCl), formed by MPO from H(2)O(2) and chloride ions, could oxidatively damage myelin-associated lipids. The purpose of this study was (i) to characterize reaction products of sphingomyelin (SM) formed in response to modification by HOCl, (ii) to define the impact of exogenously added SM and HOCl-modified SM (HOCl-SM) on viability parameters of a neuronal cell line (PC12), and (iii) to study alterations in the PC12 cell proteome in response to SM and HOCl-SM. MALDI-TOF-MS analyses revealed that HOCl, added as reagent or generated enzymatically, transforms SM into chlorinated species. On the cellular level HOCl-SM but not SM induced the formation of reactive oxygen species. HOCl-SM induced severely impaired cell viability, dissipation of the mitochondrial membrane potential, and activation of caspase-3 and DNA damage. Proteome analyses identified differential expression of specific subsets of proteins in response to SM and HOCl-SM. Our results demonstrate that HOCl modification of SM results in the generation of chlorinated lipid species with potent neurotoxic properties. Given the emerging connections between the MPO-H(2)O(2)-chloride axis and neurodegeneration, this chlorinating pathway might be implicated in neuropathogenesis.
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Affiliation(s)
- Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Manfred Kollroser
- Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Harald Köfeler
- Center of Medical Research, Medical University of Graz, Graz, Austria
| | - Gerald Rechberger
- Institute of Molecular Biosciences, Karl-Franzens University, Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Andreas Üllen
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Sabine Waltl
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Ingrid Kratzer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Albin Hermetter
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Hubert Hackl
- Institute for Genomics and Bioinformatics, Graz University of Technology, Graz, Austria
| | - Zlatko Trajanoski
- Institute for Genomics and Bioinformatics, Graz University of Technology, Graz, Austria
| | - Andelko Hrzenjak
- Department of Pulmonology, Medical University of Graz, Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
- Corresponding author. Fax: +43 316 380 9615.
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25
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Radner FPW, Streith IE, Schoiswohl G, Schweiger M, Kumari M, Eichmann TO, Rechberger G, Koefeler HC, Eder S, Schauer S, Theussl HC, Preiss-Landl K, Lass A, Zimmermann R, Hoefler G, Zechner R, Haemmerle G. Growth retardation, impaired triacylglycerol catabolism, hepatic steatosis, and lethal skin barrier defect in mice lacking comparative gene identification-58 (CGI-58). J Biol Chem 2010; 285:7300-11. [PMID: 20023287 PMCID: PMC2844178 DOI: 10.1074/jbc.m109.081877] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [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: 11/03/2009] [Revised: 12/14/2009] [Indexed: 11/06/2022] Open
Abstract
Comparative gene identification-58 (CGI-58), also designated as alpha/beta-hydrolase domain containing-5 (ABHD-5), is a lipid droplet-associated protein that activates adipose triglyceride lipase (ATGL) and acylates lysophosphatidic acid. Activation of ATGL initiates the hydrolytic catabolism of cellular triacylglycerol (TG) stores to glycerol and nonesterified fatty acids. Mutations in both ATGL and CGI-58 cause "neutral lipid storage disease" characterized by massive accumulation of TG in various tissues. The analysis of CGI-58-deficient (Cgi-58(-/-)) mice, presented in this study, reveals a dual function of CGI-58 in lipid metabolism. First, systemic TG accumulation and severe hepatic steatosis in newborn Cgi-58(-/-) mice establish a limiting role for CGI-58 in ATGL-mediated TG hydrolysis and supply of nonesterified fatty acids as energy substrate. Second, a severe skin permeability barrier defect uncovers an essential ATGL-independent role of CGI-58 in skin lipid metabolism. The neonatal lethal skin barrier defect is linked to an impaired hydrolysis of epidermal TG. As a consequence, sequestration of fatty acids in TG prevents the synthesis of acylceramides, which are essential lipid precursors for the formation of a functional skin permeability barrier. This mechanism may also underlie the pathogenesis of ichthyosis in neutral lipid storage disease patients lacking functional CGI-58.
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Affiliation(s)
- Franz P. W. Radner
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Ingo E. Streith
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Gabriele Schoiswohl
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Martina Schweiger
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Manju Kumari
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Thomas O. Eichmann
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Gerald Rechberger
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | | | - Sandra Eder
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Silvia Schauer
- the Institute of Pathology, Medical University of Graz, A-8010 Graz, and
| | | | - Karina Preiss-Landl
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Achim Lass
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Robert Zimmermann
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Gerald Hoefler
- the Institute of Pathology, Medical University of Graz, A-8010 Graz, and
| | - Rudolf Zechner
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
| | - Guenter Haemmerle
- From the Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, A-8010 Graz
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26
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Bernhart E, Kollroser M, Rechberger G, Reicher H, Heinemann A, Schratl P, Hallström S, Wintersperger A, Nusshold C, DeVaney T, Zorn-Pauly K, Malli R, Graier W, Malle E, Sattler W. Lysophosphatidic acid receptor activation affects the C13NJ microglia cell line proteome leading to alterations in glycolysis, motility, and cytoskeletal architecture. Proteomics 2010; 10:141-58. [PMID: 19899077 DOI: 10.1002/pmic.200900195] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Microglia, the immunocompetent cells of the CNS, are rapidly activated in response to injury and microglia migration towards and homing at damaged tissue plays a key role in CNS regeneration. Lysophosphatidic acid (LPA) is involved in signaling events evoking microglia responses through cognate G protein-coupled receptors. Here we show that human immortalized C13NJ microglia express LPA receptor subtypes LPA(1), LPA(2), and LPA(3) on mRNA and protein level. LPA activation of C13NJ cells induced Rho and extracellular signal-regulated kinase activation and enhanced cellular ATP production. In addition, LPA induced process retraction, cell spreading, led to pronounced changes of the actin cytoskeleton and reduced cell motility, which could be reversed by inhibition of Rho activity. To get an indication about LPA-induced global alterations in protein expression patterns a 2-D DIGE/LC-ESI-MS proteomic approach was applied. On the proteome level the most prominent changes in response to LPA were observed for glycolytic enzymes and proteins regulating cell motility and/or cytoskeletal dynamics. The present findings suggest that naturally occurring LPA is a potent regulator of microglia biology. This might be of particular relevance in the pathophysiological context of neurodegenerative disorders where LPA concentrations can be significantly elevated in the CNS.
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Affiliation(s)
- Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
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27
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Damm M, Rechberger G, Kollroser M, Kappe CO. Microwave-assisted high-throughput derivatization techniques utilizing silicon carbide microtiter platforms. J Chromatogr A 2010; 1217:167-70. [DOI: 10.1016/j.chroma.2009.11.071] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 11/18/2009] [Accepted: 11/23/2009] [Indexed: 11/26/2022]
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28
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Stemmer U, Koller D, Rechberger G, Kollroser M, Hermetter A. Cellular uptake and primary molecular targets of fluorescent oxidized phospholipids in RAW 264.7 macrophages. Chem Phys Lipids 2009. [DOI: 10.1016/j.chemphyslip.2009.06.073] [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: 10/20/2022]
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29
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Morak M, Schmidinger H, Krempl P, Rechberger G, Kollroser M, Birner-Gruenberger R, Hermetter A. Differential activity-based gel electrophoresis for comparative analysis of lipolytic and esterolytic activities. J Lipid Res 2009; 50:1281-92. [PMID: 19282273 DOI: 10.1194/jlr.m800566-jlr200] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We established a novel technique for differential activity-based gel electrophoresis (DABGE) of lipolytic enzymes from two different biological samples. For this purpose, a set of three fluorescent suicide inhibitors was developed. These probes possess the same substrate analogous structures but carry different cyanine dyes (Cy2b, Cy3, and Cy5) as reporter fluorophores. For comparison of enzyme profiles, two samples are individually labeled with a different probe followed by mixing, gel electrophoresis, fluorescence imaging, and identification of the tagged proteins by MS/MS. Protocols for quantitative determination of active enzymes were developed on the basis of lipolytic proteomes that had been admixed with defined amounts of known lipases and esterases. A detailed analysis of the fluorescence intensities showed that the found enzyme ratios very closely reflected the relative amounts of the labeled enzymes that were used for spiking. The DABGE method was used to compare the lipolytic proteomes of brown and white adipose tissue showing specific enzyme patterns of both samples. This study represents the first application of this technology for comparative analysis of lipases and esterases. Further applications of this technique can be expected to provide entirely new information on lipid enzymology in health and disease with high precision.
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Affiliation(s)
- Maria Morak
- Institute of Biochemistry, Graz University of Technology, Austria
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30
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Beranek A, Rechberger G, Knauer H, Wolinski H, Kohlwein SD, Leber R. Identification of a cardiolipin-specific phospholipase encoded by the gene CLD1 (YGR110W) in yeast. J Biol Chem 2009; 284:11572-8. [PMID: 19244244 PMCID: PMC2670162 DOI: 10.1074/jbc.m805511200] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial dimeric phospholipid cardiolipin is characterized by a high degree of unsaturation of its acyl chains, which is important for its functional interaction with mitochondrial enzymes. The unusual fatty acid composition of cardiolipin molecular species emerges from a de novo synthesized "premature" species by extensive acyl chain remodeling that involves as yet only partially identified acyltransferases and phospholipases. Recently, the yeast protein Taz1p was shown to function as a transacylase, which catalyzes the reacylation of monolysocardiolipin to mature cardiolipin. A defect in the orthologous human TAZ gene is associated with Barth syndrome, a severe genetic disorder, which may lead to cardiac failure and death in childhood. We now identified the protein encoded by reading frame YGR110W as a mitochondrial phospholipase, which deacylates de novo synthesized cardiolipin. Ygr110wp has a strong substrate preference for palmitic acid residues and functions upstream of Taz1p, to generate monolysocardiolipin for Taz1p-dependent reacylation with unsaturated fatty acids. We therefore rename the Ygr110wp as Cld1p (cardiolipin-specific deacylase 1).
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Affiliation(s)
- Andreas Beranek
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, Graz A-8010, Austria
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31
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Raspotnig G, Stabentheiner E, Föttinger P, Schaider M, Krisper G, Rechberger G, Leis HJ. Opisthonotal glands in the Camisiidae (Acari, Oribatida): evidence for a regressive evolutionary trend. J ZOOL SYST EVOL RES 2009. [DOI: 10.1111/j.1439-0469.2008.00486.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Schatte J, Susani-Etzerodt H, Birner-Gruenberger R, Rechberger G, Kollroser M, Hermetter A. The lipolytic and esterolytic proteome of liver. Chem Phys Lipids 2008. [DOI: 10.1016/j.chemphyslip.2008.05.139] [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: 11/26/2022]
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33
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Malanovic N, Streith I, Wolinski H, Rechberger G, Kohlwein SD, Tehlivets O. S-adenosyl-L-homocysteine hydrolase, key enzyme of methylation metabolism, regulates phosphatidylcholine synthesis and triacylglycerol homeostasis in yeast: implications for homocysteine as a risk factor of atherosclerosis. J Biol Chem 2008; 283:23989-99. [PMID: 18591246 DOI: 10.1074/jbc.m800830200] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In eukaryotes, S-adenosyl-L-homocysteine hydrolase (Sah1) offers a single way for degradation of S-adenosyl-L-homocysteine, a product and potent competitive inhibitor of S-adenosyl-L-methionine (AdoMet)-dependent methyltransferases. De novo phosphatidylcholine (PC) synthesis requires three AdoMet-dependent methylation steps. Here we show that down-regulation of SAH1 expression in yeast leads to accumulation of S-adenosyl-L-homocysteine and decreased de novo PC synthesis in vivo. This decrease is accompanied by an increase in triacylglycerol (TG) levels, demonstrating that Sah1-regulated methylation has a major impact on cellular lipid homeostasis. TG accumulation is also observed in cho2 and opi3 mutants defective in methylation of phosphatidylethanolamine to PC, confirming that PC de novo synthesis and TG synthesis are metabolically coupled through the efficiency of the phospholipid methylation reaction. Indeed, because both types of lipids share phosphatidic acid as a precursor, we find in cells with down-regulated Sah1 activity major alterations in the expression of the INO1 gene as well as in the localization of Opi1, a negative regulatory factor of phospholipid synthesis, which binds and is retained in the endoplasmic reticulum membrane by phosphatidic acid in conjunction with VAMP/synaptobrevin-associated protein, Scs2. The addition of homocysteine, by the reversal of the Sah1-catalyzed reaction, also leads to TG accumulation in yeast, providing an attractive model for the role of homocysteine as a risk factor of atherosclerosis in humans.
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Affiliation(s)
- Nermina Malanovic
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, Graz, Austria
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34
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Schmeisser E, Rumpler A, Kollroser M, Rechberger G, Goessler W, Francesconi KA. Arsenic Fatty Acids Are Human Urinary Metabolites of Arsenolipids Present in Cod Liver. Angew Chem Int Ed Engl 2006; 45:150-4. [PMID: 16307462 DOI: 10.1002/anie.200502706] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ernst Schmeisser
- Institute of Chemistry--Analytical Chemistry, Karl-Franzens University Graz, Universitätsplatz 1, 8010 Graz, Austria
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35
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Schmeisser E, Rumpler A, Kollroser M, Rechberger G, Goessler W, Francesconi KA. Arsenhaltige Fettsäuren im menschlichen Urin als Abbauprodukte von Arsenlipiden nach Verzehr von Dorschleberprodukten. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200502706] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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36
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Birner-Gruenberger R, Susani-Etzerodt H, Waldhuber M, Riesenhuber G, Schmidinger H, Rechberger G, Kollroser M, Strauss JG, Lass A, Zimmermann R, Haemmerle G, Zechner R, Hermetter A. The lipolytic proteome of mouse adipose tissue. Mol Cell Proteomics 2005; 4:1710-7. [PMID: 16048907 DOI: 10.1074/mcp.m500062-mcp200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hydrolysis of triacylglycerols and cholesteryl esters is a key event in energy homeostasis of animals. However, many lipolytic activities still await their molecular identification. Here we report on a novel tool for concomitant analysis of lipases in complex proteomes. Fluorescent activity tags mimicking lipid substrates were used to label the proteome of mouse adipose tissue. Analysis by two-dimensional gel electrophoresis and LC-MS/MS led to the identification of all known intracellular lipases as well as a number of novel candidates. One of them was recently shown to be involved in triacylglycerol mobilization in adipocytes and therefore named adipose triglyceride lipase. Functional characterization of expressed enzymes demonstrated that lipolytic and esterolytic activities could be well discriminated. Thus our results show the first map of the lipolytic proteome of mouse adipose tissue and demonstrate the general applicability of our method for rapid profiling and identification of lipolytic activities in complex biological samples.
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37
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Gauster M, Rechberger G, Sovic A, Hörl G, Steyrer E, Sattler W, Frank S. Endothelial lipase releases saturated and unsaturated fatty acids of high density lipoprotein phosphatidylcholine. J Lipid Res 2005; 46:1517-25. [PMID: 15834125 DOI: 10.1194/jlr.m500054-jlr200] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We assessed the ability of endothelial lipase (EL) to hydrolyze the sn-1 and sn-2 fatty acids (FAs) from HDL phosphatidylcholine. For this purpose, reconstituted discoidal HDLs (rHDLs) that contained free cholesterol, apolipoprotein A-I, and either 1-palmitoyl-2-oleoylphosphatidylcholine, 1-palmitoyl-2-linoleoylphosphatidylcholine, or 1-palmitoyl-2-arachidonylphosphatidylcholine were incubated with EL- and control (LacZ)-conditioned media. Gas chromatography analysis of the reaction mixtures revealed that both the sn-1 (16:0) and sn-2 (18:1, 18:2, and 20:4) FAs were liberated by EL. The higher rate of sn-1 FA cleavage compared with sn-2 FA release generated corresponding sn-2 acyl lyso-species as determined by MS analysis. EL failed to release sn-2 FA from rHDLs containing 1-O-1'-hexadecenyl-2-arachidonoylphosphatidylcholine, whose sn-1 position contained a nonhydrolyzable alkyl ether linkage. The lack of phospholipase A(2) activity of EL and its ability to liberate [(14)C]FA from [(14)C]lysophosphatidylcholine (lyso-PC) led us to conclude that EL-mediated deacylation of phosphatidylcholine (PC) is initiated at the sn-1 position, followed by the release of the remaining FA from the lyso-PC intermediate. Thin-layer chromatography analysis of cellular lipids obtained from EL-overexpressing cells revealed a pronounced accumulation of [(14)C]phospholipid and [(14)C]triglyceride upon incubation with 1-palmitoyl-2-[1-(14)C]linoleoyl-PC-labeled HDL(3), indicating the ability of EL to supply cells with unsaturated FAs.
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Affiliation(s)
- M Gauster
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University Graz, Harrachgasse 21/III, Graz A-8010, Austria
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