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Traczyk G, Hromada-Judycka A, Świątkowska A, Wiśniewska J, Ciesielska A, Kwiatkowska K. Diacylglycerol kinase-ε is S-palmitoylated on cysteine in the cytoplasmic end of its N-terminal transmembrane fragment. J Lipid Res 2024; 65:100480. [PMID: 38008259 PMCID: PMC10759177 DOI: 10.1016/j.jlr.2023.100480] [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: 03/30/2023] [Revised: 11/17/2023] [Accepted: 11/18/2023] [Indexed: 11/28/2023] Open
Abstract
Diacylglycerol kinase-ε (DGKε) catalyzes phosphorylation of diacylglycerol to phosphatidic acid with a unique specificity toward 1-stearoyl-2-arachidonoyl-sn-glycerol, which is a backbone of phosphatidylinositol (PI). Owing to this specificity, DGKε is involved in the PI cycle maintaining the cellular level of phosphorylated PI derivatives of signaling activity and was also found crucial for lipid metabolism. DGKε dysfunction is linked with the development of atypical hemolytic uremic syndrome (aHUS) and possibly other human diseases. Despite the DGKε significance, data on its regulation by cotranslational and/or post-translational modifications are scarce. Here, we report that DGKε is S-palmitoylated at Cys38/40 (mouse/human DGKε) located in the cytoplasmic end of its N-terminal putative transmembrane fragment. The S-palmitoylation of DGKε was revealed by metabolic labeling of cells with a palmitic acid analogue followed by click chemistry and with acyl-biotin and acyl-polyethylene glycol exchange assays. The S-acyltransferases zDHHC7 (zinc finger DHHC domain containing) and zDHHC17 and the zDHHC6/16 tandem were found to catalyze DGKε S-palmitoylation, which also increased the DGKε abundance. Mouse DGKε-Myc ectopically expressed in human embryonic kidney 293 cells localized to the endoplasmic reticulum where zDHHC6/16 reside and in small amounts also to the Golgi apparatus where zDHHC7 and zDHHC17 are present. The Cys38Ala substitution upregulated, whereas hyperpalmitoylation of wild-type DGKε reduced the kinase activity, indicating an inhibitory effect of the Cys38 S-palmitoylation. In addition, the substitution of neighboring Pro31 with Ala also diminished the activity of DGKε. Taken together, our data indicate that S-palmitoylation can fine-tune DGKε activity in distinct cellular compartments, possibly by affecting the distance between the kinase and its substrate in a membrane.
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Affiliation(s)
- Gabriela Traczyk
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | - Aneta Hromada-Judycka
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | - Anna Świątkowska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | - Julia Wiśniewska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | - Anna Ciesielska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | - Katarzyna Kwiatkowska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland.
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Ruisanchez É, Janovicz A, Panta RC, Kiss L, Párkányi A, Straky Z, Korda D, Liliom K, Tigyi G, Benyó Z. Enhancement of Sphingomyelinase-Induced Endothelial Nitric Oxide Synthase-Mediated Vasorelaxation in a Murine Model of Type 2 Diabetes. Int J Mol Sci 2023; 24:ijms24098375. [PMID: 37176081 PMCID: PMC10179569 DOI: 10.3390/ijms24098375] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/30/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
Sphingolipids are important biological mediators both in health and disease. We investigated the vascular effects of enhanced sphingomyelinase (SMase) activity in a mouse model of type 2 diabetes mellitus (T2DM) to gain an understanding of the signaling pathways involved. Myography was used to measure changes in the tone of the thoracic aorta after administration of 0.2 U/mL neutral SMase in the presence or absence of the thromboxane prostanoid (TP) receptor antagonist SQ 29,548 and the nitric oxide synthase (NOS) inhibitor L-NAME. In precontracted aortic segments of non-diabetic mice, SMase induced transient contraction and subsequent weak relaxation, whereas vessels of diabetic (Leprdb/Leprdb, referred to as db/db) mice showed marked relaxation. In the presence of the TP receptor antagonist, SMase induced enhanced relaxation in both groups, which was 3-fold stronger in the vessels of db/db mice as compared to controls and could not be abolished by ceramidase or sphingosine-kinase inhibitors. Co-administration of the NOS inhibitor L-NAME abolished vasorelaxation in both groups. Our results indicate dual vasoactive effects of SMase: TP-mediated vasoconstriction and NO-mediated vasorelaxation. Surprisingly, in spite of the general endothelial dysfunction in T2DM, the endothelial NOS-mediated vasorelaxant effect of SMase was markedly enhanced.
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Affiliation(s)
- Éva Ruisanchez
- Institute of Translational Medicine, Semmelweis University, H-1094 Budapest, Hungary
- Eötvös Loránd Research Network and Semmelweis University (ELKH-SE) Cerebrovascular and Neurocognitive Disorders Research Group, H-1052 Budapest, Hungary
| | - Anna Janovicz
- Institute of Translational Medicine, Semmelweis University, H-1094 Budapest, Hungary
- Eötvös Loránd Research Network and Semmelweis University (ELKH-SE) Cerebrovascular and Neurocognitive Disorders Research Group, H-1052 Budapest, Hungary
| | - Rita Cecília Panta
- Institute of Translational Medicine, Semmelweis University, H-1094 Budapest, Hungary
| | - Levente Kiss
- Department of Physiology, Semmelweis University, H-1094 Budapest, Hungary
| | - Adrienn Párkányi
- Institute of Translational Medicine, Semmelweis University, H-1094 Budapest, Hungary
| | - Zsuzsa Straky
- Institute of Translational Medicine, Semmelweis University, H-1094 Budapest, Hungary
| | - Dávid Korda
- Institute of Translational Medicine, Semmelweis University, H-1094 Budapest, Hungary
| | - Károly Liliom
- Institute of Biophysics and Radiation Biology, Semmelweis University, H-1094 Budapest, Hungary
| | - Gábor Tigyi
- Institute of Translational Medicine, Semmelweis University, H-1094 Budapest, Hungary
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Zoltán Benyó
- Institute of Translational Medicine, Semmelweis University, H-1094 Budapest, Hungary
- Eötvös Loránd Research Network and Semmelweis University (ELKH-SE) Cerebrovascular and Neurocognitive Disorders Research Group, H-1052 Budapest, Hungary
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Abstract
Diacylglycerol (DAG) and phosphatidic acid (PtdOH) play important roles in a variety of signaling cascades (Carrasco and Merida, 2007; Stace and Ktistakis, 2006). Therefore, the physiological roles and regulatory mechanisms controlling the levels of these lipids are important. One class of enzymes capable of coordinating the levels of these two lipids are the diacylglycerol kinases (DGKs). DGKs catalyze the transfer of the γ-phosphate of ATP to the hydroxyl group of DAG which generates PtdOH(Merida et al., 2008; Sakane et al., 2007). As DGKs reciprocally modulate the relative levels of these two signaling lipids, it is not surprising that there is increasing interest in understanding the mechanism underlying the catalysis and regulation of these kinases. While post-translational modifications (PTMs) are often involved in enzyme regulation, there is surprisingly little information regarding the PTMs on these enzymes and their roles in modulating their activity and function. In this review, we will summarize what is known about one PTM on DGKs, phosphorylation, and the possible functions of this modification.
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Affiliation(s)
- Xin Barbernitz
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Daniel M Raben
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Traczyk G, Świątkowska A, Hromada-Judycka A, Janikiewicz J, Kwiatkowska K. An intact zinc finger motif of the C1B domain is critical for stability and activity of diacylglycerol kinase-ε. Int J Biochem Cell Biol 2022; 152:106295. [PMID: 36113832 DOI: 10.1016/j.biocel.2022.106295] [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: 04/11/2022] [Revised: 08/08/2022] [Accepted: 09/08/2022] [Indexed: 10/31/2022]
Abstract
Diacylglycerol kinase-ε (DGKε) phosphorylates DAG to phosphatidic acid with unique specificity toward 18:0/20:4 DAG (SAG). SAG is a typical backbone of phosphatidylinositol and its derivatives, therefore DGKε activity is crucial for the turnover of these signaling lipids. Malfunction of DGKε contributes to several pathophysiological conditions, including atypical hemolytic uremic syndrome (aHUS) linked with DGKE mutations. In the present study we analyzed the role of a zinc finger motif of the C1B domain of DGKε, as some aHUS-linked mutations affect this ill-defined part of the kinase. For this, we introduce a novel fluorescent assay for determination of DGKε activity which relies on the use of NBD-SAG in mixed micelles as a substrate, followed by TLC separation of NBD-phosphatidic acid formed. The assay reliably determines the activity of purified human GST-DGKε, also endogenous DGKε or overexpressed mouse DGKε-Myc in cell lysates, homogenates, and kinase immunoprecipitates. Using the above assay we found that four amino acids, Cys135, Cys138, His161 and Cys164, forming the zinc finger motif in the C1B domain are required for the DGKε-Myc activity and stability. Substitution of any of these amino acids with Ala or Trp in DGKε-Myc abolished its activity and led to its proteasomal degradation, possibly assisted by Hsp70/90/40 chaperones. Inhibition of the 26S proteasome prevented the degradation but the mutated proteins were inactive. The present data on the deleterious effect of the zinc finger motif disruption contribute to the understanding of the DGKε-linked aHUS, as the Cys164Trp substitution in mouse DGKε corresponds to the Cys167Trp one in human DGKε found in some aHUS patients.
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Affiliation(s)
- Gabriela Traczyk
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, 3 Pasteur St., 02-093 Warsaw, Poland.
| | - Anna Świątkowska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, 3 Pasteur St., 02-093 Warsaw, Poland.
| | - Aneta Hromada-Judycka
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, 3 Pasteur St., 02-093 Warsaw, Poland.
| | - Justyna Janikiewicz
- Laboratory of Cell Signaling and Metabolic Disorders, Nencki Institute of Experimental Biology PAS, 3 Pasteur St., 02-093 Warsaw, Poland.
| | - Katarzyna Kwiatkowska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology PAS, 3 Pasteur St., 02-093 Warsaw, Poland.
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Bozelli JC, Yune J, Aulakh SS, Cao Z, Fernandes A, Seitova A, Tong Y, Schreier S, Epand RM. Human Diacylglycerol Kinase ε N-Terminal Segment Regulates the Phosphatidylinositol Cycle, Controlling the Rate but Not the Acyl Chain Composition of Its Lipid Intermediates. ACS Chem Biol 2022; 17:2495-2506. [PMID: 35767833 DOI: 10.1021/acschembio.2c00387] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Diacylglycerol kinase ε (DGKε), an enzyme of the phosphatidylinositol (PI) cycle, bears a highly conserved hydrophobic N-terminal segment, which was proposed to anchor the enzyme into the membrane. However, the importance of this segment to the DGKε function remains to be determined. To address this question, it is here reported an in silico and in vitro combined research strategy. Capitalizing on the AlphaFold 2.0 predicted structure of human DGKε, it is shown that its hydrophobic N-terminal segment anchors it into the membrane via a transmembrane α-helix. Coarse-grained based elastic network model studies showed that a conformational change in the hydrophobic N-terminal segment determines the proximity between the active site of DGKε and the membrane-water interface, likely regulating its kinase activity. In vitro studies with a purified DGKε construct lacking the hydrophobic N-terminal segment (His-SUMO*-Δ50-DGKε) corroborated the role of the N-terminus in regulating DGKε enzymatic properties. The comparison between the enzymatic properties of DGKε and His-SUMO*-Δ50-DGKε showed that the conserved N-terminal segment markedly inhibits the enzyme activity and its sensitivity to membrane intrinsic negative curvature, while also playing a role in the modulation of the enzyme by phosphatidylserine. On the other hand, this segment did not strongly affect its diacylglycerol acyl chain specificity, the modulation of the enzyme by membrane morphological changes, or the activation by phosphatidic acid-rich lipid domains. Hence, these results suggest that the conservation of the hydrophobic N-terminal segment of DGKε throughout evolution guaranteed not only membrane anchorage but also an efficient and elegant manner to regulate the rate of the PI cycle.
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Affiliation(s)
- José Carlos Bozelli
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 3L8, Canada
| | - Jenny Yune
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 3L8, Canada
| | - Sukhvershjit S Aulakh
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 3L8, Canada
| | - Zihao Cao
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 3L8, Canada
| | - Alexia Fernandes
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 3L8, Canada
| | - Alma Seitova
- Structural Genomics Consortium, University of Toronto, Toronto, ON N5G 1L7, Canada
| | - Yufeng Tong
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Shirley Schreier
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo 05508-000, Brazil
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 3L8, Canada
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Abstract
Diacylglycerol kinases (DGKs) are important enzymes in molecular membrane biology, as they can lower the concentration of diacylglycerol through phosphorylation while at the same time producing phosphatidic acid. Dysfunction of DGK is linked with multiple diseases including cancer and autoimmune disorders. Currently, the high-resolution structures have not been determined for any of the 10 human DGK paralogs, which has made it difficult to gain a more complete understanding of the enzyme's mechanism of action and regulation. In the present study, we have taken advantage of the significant developments in protein structural prediction technology by artificial intelligence (i.e., Alphafold 2.0), to conduct a comprehensive investigation on the properties of all 10 human DGK paralogs. Structural alignment of the predictions reveals that the C1, catalytic, and accessory domains are conserved in their spatial arrangement relative to each other, across all paralogs. This suggests a critical role played by this domain architecture in DGK function. Moreover, docking studies corroborate the existence of a conserved ATP-binding site between the catalytic and accessory domains. Interestingly, the ATP bound to the interdomain cleft was also found to be in proximity of the conserved glycine-rich motif, which in protein kinases has been suggested to function in ATP binding. Lastly, the spatial arrangement of DGK, with respect to the membrane, reveals that most paralogs possess a more energetically favorable interaction with curved membranes. In conclusion, AlphaFold predictions of human DGKs provide novel insights into the enzyme's structural and functional properties while also paving the way for future experimentation.
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Affiliation(s)
- Sukhvershjit S Aulakh
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - José Carlos Bozelli
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, ON L8S 4K1, Canada
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Flores J, Brea RJ, Lamas A, Fracassi A, Salvador-Castell M, Xu C, Baiz CR, Sinha SK, Devaraj NK. Rapid and Sequential Dual Oxime Ligation Enables De Novo Formation of Functional Synthetic Membranes from Water-Soluble Precursors. Angew Chem Int Ed Engl 2022; 61:e202200549. [PMID: 35546783 DOI: 10.1002/anie.202200549] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Indexed: 01/28/2023]
Abstract
Cell membranes define the boundaries of life and primarily consist of phospholipids. Living organisms assemble phospholipids by enzymatically coupling two hydrophobic tails to a soluble polar head group. Previous studies have taken advantage of micellar assembly to couple single-chain precursors, forming non-canonical phospholipids. However, biomimetic nonenzymatic coupling of two alkyl tails to a polar head-group remains challenging, likely due to the sluggish reaction kinetics of the initial coupling step. Here we demonstrate rapid de novo formation of biomimetic liposomes in water using dual oxime bond formation between two alkyl chains and a phosphocholine head group. Membranes can be generated from non-amphiphilic, water-soluble precursors at physiological conditions using micromolar concentrations of precursors. We demonstrate that functional membrane proteins can be reconstituted into synthetic oxime liposomes from bacterial extracts in the absence of detergent-like molecules.
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Affiliation(s)
- Judith Flores
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Natural Sciences Building 3328, La Jolla, CA 92093, USA
| | - Roberto J Brea
- Biomimetic Membrane Chemistry (BioMemChem) Group, Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, Rúa As Carballeiras, 15701, A Coruña, Spain
| | - Alejandro Lamas
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Natural Sciences Building 3328, La Jolla, CA 92093, USA
| | - Alessandro Fracassi
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Natural Sciences Building 3328, La Jolla, CA 92093, USA
| | - Marta Salvador-Castell
- Department of Physics, University of California, San Diego, 9500 Gilman Drive, Building: Mayer Hall Addition 4561, La Jolla, CA 92093, USA
| | - Cong Xu
- Department of Chemistry, The University of Texas at Austin, 105 E. 24th St. Stop A5300, Austin, TX 78712-1224, USA
| | - Carlos R Baiz
- Department of Chemistry, The University of Texas at Austin, 105 E. 24th St. Stop A5300, Austin, TX 78712-1224, USA
| | - Sunil K Sinha
- Department of Physics, University of California, San Diego, 9500 Gilman Drive, Building: Mayer Hall Addition 4561, La Jolla, CA 92093, USA
| | - Neal K Devaraj
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Natural Sciences Building 3328, La Jolla, CA 92093, USA
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Flores J, Brea RJ, Lamas A, Fracassi A, Salvador‐Castell M, Xu C, Baiz CR, Sinha SK, Devaraj NK. Rapid and Sequential Dual Oxime Ligation Enables De Novo Formation of Functional Synthetic Membranes from Water‐Soluble Precursors. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200549] [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: 11/07/2022]
Affiliation(s)
- Judith Flores
- Department of Chemistry and Biochemistry University of California, San Diego 9500 Gilman Drive, Natural Sciences Building 3328 La Jolla CA 92093 USA
| | - Roberto J. Brea
- Biomimetic Membrane Chemistry (BioMemChem) Group Centro de Investigacións Científicas Avanzadas (CICA) Universidade da Coruña Rúa As Carballeiras 15701 A Coruña Spain
| | - Alejandro Lamas
- Department of Chemistry and Biochemistry University of California, San Diego 9500 Gilman Drive, Natural Sciences Building 3328 La Jolla CA 92093 USA
| | - Alessandro Fracassi
- Department of Chemistry and Biochemistry University of California, San Diego 9500 Gilman Drive, Natural Sciences Building 3328 La Jolla CA 92093 USA
| | - Marta Salvador‐Castell
- Department of Physics University of California, San Diego 9500 Gilman Drive, Building: Mayer Hall Addition 4561 La Jolla CA 92093 USA
| | - Cong Xu
- Department of Chemistry The University of Texas at Austin 105 E. 24th St. Stop A5300 Austin TX 78712-1224 USA
| | - Carlos R. Baiz
- Department of Chemistry The University of Texas at Austin 105 E. 24th St. Stop A5300 Austin TX 78712-1224 USA
| | - Sunil K. Sinha
- Department of Physics University of California, San Diego 9500 Gilman Drive, Building: Mayer Hall Addition 4561 La Jolla CA 92093 USA
| | - Neal K. Devaraj
- Department of Chemistry and Biochemistry University of California, San Diego 9500 Gilman Drive, Natural Sciences Building 3328 La Jolla CA 92093 USA
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Gupta RS, Khadka B. Conserved Molecular Signatures in the Spike, Nucleocapsid, and Polymerase Proteins Specific for the Genus Betacoronavirus and Its Different Subgenera. Genes (Basel) 2022; 13:genes13030423. [PMID: 35327976 PMCID: PMC8949385 DOI: 10.3390/genes13030423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 02/04/2023] Open
Abstract
The genus Betacoronavirus, consisting of four main subgenera (Embecovirus, Merbecovirus, Nobecovirus, and Sarbecovirus), encompasses all clinically significant coronaviruses (CoVs), including SARS, MERS, and the SARS-CoV-2 virus responsible for current COVID-19 pandemic. Very few molecular characteristics are known that are specific for the genus Betacoronavirus or its different subgenera. In this study, our analyses of the sequences of four essential proteins of CoVs, viz., spike, nucleocapsid, envelope, and RNA-dependent RNA polymerase (RdRp), identified ten novel molecular signatures consisting of conserved signature indels (CSIs) in these proteins which are specific for the genus Betacoronavirus or its subgenera. Of these CSIs, two 14-aa-conserved deletions found within the heptad repeat motifs 1 and 2 of the spike protein are specific for all betacoronaviruses, except for their shared presence in the highly infectious avian coronavirus. Six additional CSIs present in the nucleocapsid protein and one CSI in the RdRp protein are distinctive characteristics of either the Merbecovirus, Nobecovirus, or Sarbecovirus subgenera. In addition, a 4-aa insert is present in the spike protein, which is uniquely shared by all viruses from the subgenera Merbecovirus, Nobecovirus, and Sarbecovirus, but absent in Embecovirus and all other genera of CoVs. This molecular signature provides evidence that viruses from the three subgenera sharing this CSI are more closely related to each other, and they evolved after the divergence of embecoviruses and other CoVs. As all CSIs specific for different groups of CoVs are flanked by conserved regions, their sequences provide novel means for identifying the above groups of CoVs and for developing novel diagnostic tests. Furthermore, our analyses of the structures of the spike and nucleocapsid proteins show that all identified CSIs are localized in the surface-exposed loops of these protein. It is postulated that these surface loops, through their interactions with other cellular proteins/ligands, play important roles in the biology/pathology of these viruses.
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Affiliation(s)
- Radhey S. Gupta
- Department of Biochemistry and Biomedical Sciences McMaster University, Hamilton, ON L8N 3Z5, Canada
- Correspondence:
| | - Bijendra Khadka
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada;
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Günay N, Pınarbaşı AS, Doğan ME, Yel S, Balaban AG, Dursun İ, Eken A, Akgün H, Dündar M, Poyrazoğlu MH. A rare cause of membranoproliferative patterns of injury in siblings with steroid-resistant nephrotic syndrome: Answers. Pediatr Nephrol 2021; 36:4029-4032. [PMID: 34185135 DOI: 10.1007/s00467-021-05154-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/13/2021] [Indexed: 11/30/2022]
Affiliation(s)
- Neslihan Günay
- Department of Pediatric Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Ayşe Seda Pınarbaşı
- Department of Pediatric Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Muhammet Ensar Doğan
- Department of Medical Genetics, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Sibel Yel
- Department of Pediatric Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Aynur Gencer Balaban
- Department of Pediatric Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - İsmail Dursun
- Department of Pediatric Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey.
| | - Ahmet Eken
- Department of Medical Biology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Hülya Akgün
- Department of Pathology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Munis Dündar
- Department of Medical Genetics, Erciyes University Medical Faculty, Kayseri, Turkey
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11
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Bozelli JC, Yune J, Takahashi D, Sakane F, Epand RM. Membrane morphology determines diacylglycerol kinase α substrate acyl chain specificity. FASEB J 2021; 35:e21602. [PMID: 33977628 DOI: 10.1096/fj.202100264r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 02/10/2021] [Revised: 03/22/2021] [Accepted: 04/01/2021] [Indexed: 01/06/2023]
Abstract
Diacylglycerol kinases catalyze the ATP-dependent phosphorylation of diacylglycerol (DAG) to produce phosphatidic acid (PA). In humans, the alpha isoform (DGKα) has emerged as a potential target in the treatment of cancer due to its anti-tumor and pro-immune responses. However, its mechanism of action at a molecular level is not fully understood. In this work, a systematic investigation of the role played by the membrane in the regulation of the enzymatic properties of human DGKα is presented. By using a cell-free system with purified DGKα and model membranes of variable physical and chemical properties, it is shown that membrane physical properties determine human DGKα substrate acyl chain specificity. In model membranes with a flat morphology; DGKα presents high enzymatic activity, but it is not able to differentiate DAG molecular species. Furthermore, DGKα enzymatic properties are insensitive to membrane intrinsic curvature. However, in the presence of model membranes with altered morphology, specifically the presence of physically curved membrane structures, DGKα bears substrate acyl chain specificity for palmitic acid-containing DAG. The present results identify changes in membrane morphology as one possible mechanism for the depletion of specific pools of DAG as well as the production of specific pools of PA by DGKα, adding an extra layer of regulation on the interconversion of these two potent lipid-signaling molecules. It is proposed that the interplay between membrane physical (shape) and chemical (lipid composition) properties guarantee a fine-tuned signal transduction system dependent on the levels and molecular species of DAG and PA.
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Affiliation(s)
- José Carlos Bozelli
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON, Canada
| | - Jenny Yune
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON, Canada
| | - Daisuke Takahashi
- Department of Pharmaceutical Health Care and Sciences, Kyushu University, Fukuoka, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba, Japan
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON, Canada
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12
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Bozelli JC, Aulakh SS, Epand RM. Membrane shape as determinant of protein properties. Biophys Chem 2021; 273:106587. [PMID: 33865153 DOI: 10.1016/j.bpc.2021.106587] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/26/2021] [Accepted: 03/26/2021] [Indexed: 11/30/2022]
Abstract
Membrane lipids play a role in the modulation of a variety of biological processes. This is often achieved through fine-tuned changes in membrane physical and chemical properties. While some membrane physical properties (e.g., curvature, lipid domains, fluidity) have received increased scientific attention over the years, only recently has membrane shape emerged as an active modulator of protein properties. Biological membranes are mostly found organized into a lipid bilayer arrangement, in which the spontaneous shape is an intrinsically flat, planar morphology (in relation to the size of proteins). However, it is known that many cells and organelles have non-planar morphologies. In addition, perturbations in membrane morphology occur in a variety of biological processes. Recent studies have shown that membrane shape can modulate a variety of biological processes by determining protein properties. While membrane shape generation modulates proteins via changes in membrane mechanical properties, membrane shape recognition regulates proteins by providing the optimal surface for interaction. Hence, membranes have evolved an elegant mechanism to couple mesoscopic perturbations to molecular properties and vice-versa. In this review, the regulation of the enzymatic properties of two isoforms of mammalian diacylglycerol kinase, which play important roles in cellular signal transductions, will be used to exemplify the recent advancements in the field of membrane shape recognition, as well as future challenges and perspectives.
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Affiliation(s)
- José Carlos Bozelli
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, Ontario, Canada.
| | - Sukhvershjit S Aulakh
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, Ontario, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, Ontario, Canada.
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13
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Bozelli JC, Epand RM. Determinants of lipids acyl chain specificity: A tale of two enzymes. Biophys Chem 2020; 265:106431. [DOI: 10.1016/j.bpc.2020.106431] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 07/10/2020] [Indexed: 12/12/2022]
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14
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Gholizad-Kolveiri S, Hooman N, Alizadeh R, Hoseini R, Otukesh H, Talebi S, Akouchekian M. Whole exome sequencing revealed a novel homozygous variant in the DGKE catalytic domain: a case report of familial hemolytic uremic syndrome. BMC Med Genet 2020; 21:169. [PMID: 32838746 PMCID: PMC7446132 DOI: 10.1186/s12881-020-01097-9] [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] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 07/28/2020] [Indexed: 11/13/2022]
Abstract
Background Atypical hemolytic uremic syndrome (aHUS) is a rare disease characterized by microangiopathic hemolytic anemia caused by small vessel thrombosis, thrombocytopenia, and renal failure. The common cause of aHUS is a dysregulation in the alternative complement pathway. Mutations in none complement genes such as diacylglycerol kinase epsilon (DGKE) can also result in this syndrome. Case presentation Here, we report on a 19-year-old female with the clinical diagnosis of aHUS, who has unaffected consanguineous parents and an older sibling who was deceased from aHUS when she was seven months old. We performed whole exome sequencing (WES) followed by evaluation of detected variants for functional significance, using several online prediction tools. Next, in order to confirm the detected pathogenic variant in proband and segregation analysis in her family, Sanger sequencing was done. The novel variant was analyzed in terms of its impact on the protein 3-dimensional structure by computational structural modeling. The results revealed that the proband carried a novel homozygous missense variant in DGKE located in exon 6 of the gene (NM_003647.3, c.942C > G [p.Asn314Lys]), and in silico analysis anticipated it as damaging. Protein computational study confirmed the influence of potential pathogenic variant on structural stability and protein function. Conclusion We suggest that some variations in the catalytic domain of DGKE like p.Asn314Lys which can cause alterations in secondary and 3-D structure of protein, might lead to aHUS.
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Affiliation(s)
- Soraya Gholizad-Kolveiri
- Department of Medical Genetics and Molecular Biology, school of medicine, Iran University of Medical Sciences, P.O.Box: 1449614525, Tehran, Iran
| | - Nakysa Hooman
- Department of Pediatric Nephrology, Ali-Asghar Children Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Rasoul Alizadeh
- Department of Medical Genetics and Molecular Biology, school of medicine, Iran University of Medical Sciences, P.O.Box: 1449614525, Tehran, Iran
| | - Rozita Hoseini
- Department of Pediatric Nephrology, Ali-Asghar Children Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Hasan Otukesh
- Department of Pediatric Nephrology, Ali-Asghar Children Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Saeed Talebi
- Department of Medical Genetics and Molecular Biology, school of medicine, Iran University of Medical Sciences, P.O.Box: 1449614525, Tehran, Iran.
| | - Mansoureh Akouchekian
- Department of Medical Genetics and Molecular Biology, school of medicine, Iran University of Medical Sciences, P.O.Box: 1449614525, Tehran, Iran.
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15
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Thornhill D, Murakami T, Ono A. Rendezvous at Plasma Membrane: Cellular Lipids and tRNA Set up Sites of HIV-1 Particle Assembly and Incorporation of Host Transmembrane Proteins. Viruses 2020; 12:E842. [PMID: 32752131 DOI: 10.3390/v12080842] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 07/20/2020] [Accepted: 07/24/2020] [Indexed: 12/28/2022] Open
Abstract
The HIV-1 structural polyprotein Gag drives the virus particle assembly specifically at the plasma membrane (PM). During this process, the nascent virion incorporates specific subsets of cellular lipids and host membrane proteins, in addition to viral glycoproteins and viral genomic RNA. Gag binding to the PM is regulated by cellular factors, including PM-specific phospholipid PI(4,5)P2 and tRNAs, both of which bind the highly basic region in the matrix domain of Gag. In this article, we review our current understanding of the roles played by cellular lipids and tRNAs in specific localization of HIV-1 Gag to the PM. Furthermore, we examine the effects of PM-bound Gag on the organization of the PM bilayer and discuss how the reorganization of the PM at the virus assembly site potentially contributes to the enrichment of host transmembrane proteins in the HIV-1 particle. Since some of these host transmembrane proteins alter release, attachment, or infectivity of the nascent virions, the mechanism of Gag targeting to the PM and the nature of virus assembly sites have major implications in virus spread.
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16
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Abstract
Phosphatidylinositol (PI) lipids have a predominance of a single molecular species present through the organism. In healthy mammals this molecular species is 1-stearoyl-2-arachidonoyl (18:0/20:4) PI. Although the importance of PI lipids for cell physiology has long been appreciated, less is known about the biological role of enriching PI lipids with 18:0/20:4 acyl chains. In conditions with dysfunctional lipid metabolism, the predominance of 18:0/20:4 acyl chains is lost. Recently, molecular mechanisms underpinning the enrichment or alteration of these acyl chains in PI lipids have begun to emerge. In the majority of the cases a common feature is the presence of enzymes bearing substrate acyl chain specificity. However, in cancer cells, it has been shown that one (not the only) of the mechanisms responsible for the loss in this acyl chain enrichment is mutation on the transcription factor p53 gene, which is one of the most highly mutated genes in cancers. There is a compelling need for a global picture of the specificity of the acyl chain composition of PIs. This can be possible once high-resolution spatio-temporal information is gathered in a cellular context; which can ultimately lead to potential novel targets to combat conditions with altered PI acyl chain profiles.
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Affiliation(s)
- José Carlos Bozelli
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre, Hamilton, Ontario, L8S 4K1, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre, Hamilton, Ontario, L8S 4K1, Canada
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17
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Abstract
The transient receptor potential vanilloid 1 (TRPV1) channel is activated by heat and by capsaicin, the pungent compound in chili peppers. Calcium influx through TRPV1 has been shown to activate a calcium-sensitive phospholipase C (PLC) enzyme and to lead to a robust decrease in phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] levels, which is a major contributor to channel desensitization. Diacylglycerol (DAG), the product of the PLC-catalyzed PI(4,5)P2 hydrolysis, activates protein kinase C (PKC). PKC is known to potentiate TRPV1 activity during activation of G protein-coupled receptors, but it is not known whether DAG modulates TRPV1 during desensitization. We found here that inhibition of diacylglycerol kinase (DAGK) enzymes reduces desensitization of native TRPV1 in dorsal root ganglion neurons as well as of recombinant TRPV1 expressed in HEK293 cells. The effect of DAGK inhibition was eliminated by mutating two PKC-targeted phosphorylation sites, Ser-502 and Ser-800, indicating involvement of PKC. TRPV1 activation induced only a small and transient increase in DAG levels, unlike the robust and more sustained increase induced by muscarinic receptor activation. DAGK inhibition substantially increased the DAG signal evoked by TRPV1 activation but not that evoked by M1 muscarinic receptor activation. Our results show that Ca2+ influx through TRPV1 activates PLC and DAGK enzymes and that the latter limits formation of DAG and negatively regulates TRPV1 channel activity. Our findings uncover a role of DAGK in ion channel regulation.
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Affiliation(s)
- Luyu Liu
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Yevgen Yudin
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Tibor Rohacs
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey, USA
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18
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Blunsom NJ, Cockcroft S. CDP-Diacylglycerol Synthases (CDS): Gateway to Phosphatidylinositol and Cardiolipin Synthesis. Front Cell Dev Biol 2020; 8:63. [PMID: 32117988 PMCID: PMC7018664 DOI: 10.3389/fcell.2020.00063] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [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: 11/24/2019] [Accepted: 01/22/2020] [Indexed: 12/15/2022] Open
Abstract
Cytidine diphosphate diacylglycerol (CDP-DAG) is a key intermediate in the synthesis of phosphatidylinositol (PI) and cardiolipin (CL). Both PI and CL have highly specialized roles in cells. PI can be phosphorylated and these phosphorylated derivatives play major roles in signal transduction, membrane traffic, and maintenance of the actin cytoskeletal network. CL is the signature lipid of mitochondria and has a plethora of functions including maintenance of cristae morphology, mitochondrial fission, and fusion and for electron transport chain super complex formation. Both lipids are synthesized in different organelles although they share the common intermediate, CDP-DAG. CDP-DAG is synthesized from phosphatidic acid (PA) and CTP by enzymes that display CDP-DAG synthase activities. Two families of enzymes, CDS and TAMM41, which bear no sequence or structural relationship, have now been identified. TAMM41 is a peripheral membrane protein localized in the inner mitochondrial membrane required for CL synthesis. CDS enzymes are ancient integral membrane proteins found in all three domains of life. In mammals, they provide CDP-DAG for PI synthesis and for phosphatidylglycerol (PG) and CL synthesis in prokaryotes. CDS enzymes are critical for maintaining phosphoinositide levels during phospholipase C (PLC) signaling. Hydrolysis of PI (4,5) bisphosphate by PLC requires the resynthesis of PI and CDS enzymes catalyze the rate-limiting step in the process. In mammals, the protein products of two CDS genes (CDS1 and CDS2) localize to the ER and it is suggested that CDS2 is the major CDS for this process. Expression of CDS enzymes are regulated by transcription factors and CDS enzymes may also contribute to CL synthesis in mitochondria. Studies of CDS enzymes in protozoa reveal spatial segregation of CDS enzymes from the rest of the machinery required for both PI and CL synthesis identifying a key gap in our understanding of how CDP-DAG can cross the different membrane compartments in protozoa and in mammals.
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Affiliation(s)
| | - Shamshad Cockcroft
- Division of Biosciences, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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19
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Reinhardt R, Truebestein L, Schmidt HA, Leonard TA. It Takes Two to Tango: Activation of Protein Kinase D by Dimerization. Bioessays 2020; 42:e1900222. [PMID: 31997382 DOI: 10.1002/bies.201900222] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/10/2020] [Indexed: 12/23/2022]
Abstract
The recent discovery and structure determination of a novel ubiquitin-like dimerization domain in protein kinase D (PKD) has significant implications for its activation. PKD is a serine/threonine kinase activated by the lipid second messenger diacylglycerol (DAG). It is an essential and highly conserved protein that is implicated in plasma membrane directed trafficking processes from the trans-Golgi network. However, many open questions surround its mechanism of activation, its localization, and its role in the biogenesis of cargo transport carriers. In reviewing this field, the focus is primarily on the mechanisms that control the activation of PKD at precise locations in the cell. In light of the new structural findings, the understanding of the mechanisms underlying PKD activation is critically evaluated, with particular emphasis on the role of dimerization in PKD autophosphorylation, and the provenance and recognition of the DAG that activates PKD.
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Affiliation(s)
- Ronja Reinhardt
- Department of Structural and Computational Biology, Max Perutz Labs, Vienna Biocenter, 1030, Vienna, Austria.,Department of Medical Biochemistry, Medical University of Vienna, 1030, Vienna, Austria
| | - Linda Truebestein
- Department of Structural and Computational Biology, Max Perutz Labs, Vienna Biocenter, 1030, Vienna, Austria.,Department of Medical Biochemistry, Medical University of Vienna, 1030, Vienna, Austria
| | - Heiko A Schmidt
- Center for Integrative Bioinformatics Vienna, Max Perutz Labs, University of Vienna and Medical University of Vienna, Vienna Biocenter, 1030, Vienna, Austria
| | - Thomas A Leonard
- Department of Structural and Computational Biology, Max Perutz Labs, Vienna Biocenter, 1030, Vienna, Austria.,Department of Medical Biochemistry, Medical University of Vienna, 1030, Vienna, Austria
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20
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Bozelli JC, Yune J, Hou YH, Chatha P, Fernandes A, Cao Z, Tong Y, Epand RM. Regulation of DGKε Activity and Substrate Acyl Chain Specificity by Negatively Charged Phospholipids. Biophys J 2019; 118:957-966. [PMID: 31587830 DOI: 10.1016/j.bpj.2019.09.008] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 01/09/2023] Open
Abstract
Diacylglycerol kinase ε (DGKε) is a membrane-bound enzyme that catalyzes the ATP-dependent phosphorylation of diacylglycerol to form phosphatidic acid (PA) in the phosphatidylinositol cycle. DGKε lacks a putative regulatory domain and has recently been reported to be regulated by highly curved membranes. To further study the effect of other membrane properties as a regulatory mechanism of DGKε, our work reports the effect of negatively charged phospholipids on DGKε activity and substrate acyl chain specificity. These studies were conducted using purified DGKε and detergent-free phospholipid aggregates, which present a more suitable model system to access the impact of membrane physical properties on membrane-active enzymes. The structural properties of the different model membranes were studied by means of differential scanning calorimetry and 31P-NMR. It is shown that the enzyme is inhibited by a variety of negatively charged phospholipids. However, PA, which is a negatively charged phospholipid and the product of DGKε catalyzed reaction, showed a varied regulatory effect on the enzyme from being an activator to an inhibitor. The type of feedback regulation of DGKε by PA depends on the particular PA molecular species as well as the physical properties of the membrane that the enzyme binds to. In the presence of highly packed PA-rich domains, the enzyme is activated. However, its acyl chain specificity is only observed in liposomes containing 1,2-dioleoyl PA in the presence of Ca2+. It is proposed that to endow the enzyme with its substrate acyl chain specificity, a highly dehydrated (hydrophobic) membrane interface is needed. The presence of an overlap of mechanisms to regulate DGKε ensures proper phosphatidylinositol cycle function regardless of the trigged stimulus and represents a sophisticated and specialized manner of membrane-enzyme regulation.
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Affiliation(s)
- José Carlos Bozelli
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario, Canada
| | - Jenny Yune
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario, Canada
| | - You H Hou
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario, Canada
| | - Preet Chatha
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario, Canada
| | - Alexia Fernandes
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario, Canada
| | - Zihao Cao
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario, Canada
| | - Yufeng Tong
- Structural Genomics Consortium, Toronto, Ontario, Canada; Department of Chemistry and Biochemistry, University of Windsor, Ontario, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario, Canada.
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21
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Bozelli JC, Epand RM. Role of membrane shape in regulating the phosphatidylinositol cycle at contact sites. Chem Phys Lipids 2019; 221:24-29. [DOI: 10.1016/j.chemphyslip.2019.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/25/2019] [Accepted: 03/01/2019] [Indexed: 01/09/2023]
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22
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Mérida I, Arranz-nicolás J, Rodríguez-rodríguez C, Ávila-flores A. Diacylglycerol kinase control of protein kinase C. Biochem J 2019; 476:1205-19. [DOI: 10.1042/bcj20180620] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/29/2019] [Accepted: 04/01/2019] [Indexed: 12/27/2022]
Abstract
Abstract
The diacylglycerol kinases (DGK) are lipid kinases that transform diacylglycerol (DAG) into phosphatidic acid (PA) in a reaction that terminates DAG-based signals. DGK provide negative regulation to conventional and novel protein kinase C (PKC) enzymes, limiting local DAG availability in a tissue- and subcellular-restricted manner. Defects in the expression/activity of certain DGK isoforms contribute substantially to cognitive impairment and mental disorders. Abnormal DGK overexpression in tumors facilitates invasion and resistance to chemotherapy preventing tumor immune destruction by tumor-infiltrating lymphocytes. Effective translation of these findings into therapeutic approaches demands a better knowledge of the physical and functional interactions between the DGK and PKC families. DGKζ is abundantly expressed in the nervous and immune system, where physically and functionally interacts with PKCα. The latest discoveries suggest that PDZ-mediated interaction facilitates spatial restriction of PKCα by DGKζ at the cell–cell contact sites in a mechanism where the two enzymes regulate each other. In T lymphocytes, DGKζ interaction with Sorting Nexin 27 (SNX27) guarantees the basal control of PKCα activation. SNX27 is a trafficking component required for normal brain function whose deficit has been linked to Alzheimer's disease (AD) pathogenesis. The enhanced PKCα activation as the result of SNX27 silencing in T lymphocytes aligns with the recent correlation found between gain-of-function PKCα mutations and AD and suggests that disruption of the mechanisms that provides a correct spatial organization of DGKζ and PKCα may lie at the basis of immune and neuronal synapse impairment.
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23
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Merida I, Arranz-Nicolás J, Torres-Ayuso P, Ávila-Flores A. Diacylglycerol Kinase Malfunction in Human Disease and the Search for Specific Inhibitors. Handb Exp Pharmacol 2019; 259:133-162. [PMID: 31227890 DOI: 10.1007/164_2019_221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [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: 12/17/2022]
Abstract
The diacylglycerol kinases (DGKs) are master regulator kinases that control the switch from diacylglycerol (DAG) to phosphatidic acid (PA), two lipids with important structural and signaling properties. Mammalian DGKs distribute into five subfamilies that regulate local availability of DAG and PA pools in a tissue- and subcellular-restricted manner. Pharmacological manipulation of DGK activity holds great promise, given the critical contribution of specific DGK subtypes to the control of membrane structure, signaling complexes, and cell-cell communication. The latest advances in the DGK field have unveiled the differential contribution of selected isoforms to human disease. Defects in the expression/activity of individual DGK isoforms contribute substantially to cognitive impairment, mental disorders, insulin resistance, and vascular pathologies. Abnormal DGK overexpression, on the other hand, confers the acquisition of malignant traits including invasion, chemotherapy resistance, and inhibition of immune attack on tumors. Translation of these findings into therapeutic approaches will require development of methods to pharmacologically modulate DGK functions. In particular, inhibitors that target the DGKα isoform hold particular promise in the fight against cancer, on their own or in combination with immune-targeting therapies.
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Affiliation(s)
- Isabel Merida
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain.
| | - Javier Arranz-Nicolás
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain
| | - Pedro Torres-Ayuso
- Laboratory of Cell and Developmental Signaling, National Cancer Institute (NCI-NIH), Frederick, MD, USA
| | - Antonia Ávila-Flores
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain
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24
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Fanning S, Haque A, Imberdis T, Baru V, Barrasa MI, Nuber S, Termine D, Ramalingam N, Ho GPH, Noble T, Sandoe J, Lou Y, Landgraf D, Freyzon Y, Newby G, Soldner F, Terry-Kantor E, Kim TE, Hofbauer HF, Becuwe M, Jaenisch R, Pincus D, Clish CB, Walther TC, Farese RV, Srinivasan S, Welte MA, Kohlwein SD, Dettmer U, Lindquist S, Selkoe D. Lipidomic Analysis of α-Synuclein Neurotoxicity Identifies Stearoyl CoA Desaturase as a Target for Parkinson Treatment. Mol Cell 2018; 73:1001-1014.e8. [PMID: 30527540 DOI: 10.1016/j.molcel.2018.11.028] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [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: 01/24/2018] [Revised: 09/05/2018] [Accepted: 11/19/2018] [Indexed: 01/08/2023]
Abstract
In Parkinson's disease (PD), α-synuclein (αS) pathologically impacts the brain, a highly lipid-rich organ. We investigated how alterations in αS or lipid/fatty acid homeostasis affect each other. Lipidomic profiling of human αS-expressing yeast revealed increases in oleic acid (OA, 18:1), diglycerides, and triglycerides. These findings were recapitulated in rodent and human neuronal models of αS dyshomeostasis (overexpression; patient-derived triplication or E46K mutation; E46K mice). Preventing lipid droplet formation or augmenting OA increased αS yeast toxicity; suppressing the OA-generating enzyme stearoyl-CoA-desaturase (SCD) was protective. Genetic or pharmacological SCD inhibition ameliorated toxicity in αS-overexpressing rat neurons. In a C. elegans model, SCD knockout prevented αS-induced dopaminergic degeneration. Conversely, we observed detrimental effects of OA on αS homeostasis: in human neural cells, excess OA caused αS inclusion formation, which was reversed by SCD inhibition. Thus, monounsaturated fatty acid metabolism is pivotal for αS-induced neurotoxicity, and inhibiting SCD represents a novel PD therapeutic approach.
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Affiliation(s)
- Saranna Fanning
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Aftabul Haque
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Thibaut Imberdis
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Valeriya Baru
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | | | - Silke Nuber
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Daniel Termine
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Nagendran Ramalingam
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Gary P H Ho
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Tallie Noble
- Mira Costa College, 1 Barnard Drive, Oceanside, CA 92056, USA
| | - Jackson Sandoe
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Yali Lou
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Dirk Landgraf
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Yelena Freyzon
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Gregory Newby
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, MIT, Cambridge, MA 02139, USA
| | - Frank Soldner
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Elizabeth Terry-Kantor
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Tae-Eun Kim
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Harald F Hofbauer
- Institute of Molecular Biosciences, BioTechMed-Graz, University of Graz, 8010 Graz, Austria
| | - Michel Becuwe
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, 655 Huntington Avenue, Boston, MA 02115, USA
| | - Rudolf Jaenisch
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, MIT, Cambridge, MA 02139, USA
| | - David Pincus
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Clary B Clish
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Tobias C Walther
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, 655 Huntington Avenue, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA; HHMI, Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, 655 Huntington Avenue, Boston, MA 02115, USA
| | - Robert V Farese
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, 655 Huntington Avenue, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Supriya Srinivasan
- Department of Chemical Physiology and The Dorris Neuroscience Center, 1 Barnard Drive, Oceanside, CA 92056, USA; The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Michael A Welte
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Sepp D Kohlwein
- Institute of Molecular Biosciences, BioTechMed-Graz, University of Graz, 8010 Graz, Austria
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| | - Susan Lindquist
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, MIT, Cambridge, MA 02139, USA; HHMI, Department of Biology, MIT, Cambridge, MA 02139, USA
| | - Dennis Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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25
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Abbas F, El Kossi M, Kim JJ, Sharma A, Halawa A. Thrombotic microangiopathy after renal transplantation: Current insights in de novo and recurrent disease. World J Transplant 2018; 8:122-141. [PMID: 30211021 PMCID: PMC6134269 DOI: 10.5500/wjt.v8.i5.122] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 06/26/2018] [Accepted: 07/10/2018] [Indexed: 02/05/2023] Open
Abstract
Thrombotic microangiopathy (TMA) is one of the most devastating sequalae of kidney transplantation. A number of published articles have covered either de novo or recurrent TMA in an isolated manner. We have, hereby, in this article endeavored to address both types of TMA in a comparative mode. We appreciate that de novo TMA is more common and its prognosis is poorer than recurrent TMA; the latter has a genetic background, with mutations that impact disease behavior and, consequently, allograft and patient survival. Post-transplant TMA can occur as a recurrence of the disease involving the native kidney or as de novo disease with no evidence of previous involvement before transplant. While atypical hemolytic uremic syndrome is a rare disease that results from complement dysregulation with alternative pathway overactivity, de novo TMA is a heterogenous set of various etiologies and constitutes the vast majority of post-transplant TMA cases. Management of both diseases varies from simple maneuvers, e.g., plasmapheresis, drug withdrawal or dose modification, to lifelong complement blockade, which is rather costly. Careful donor selection and proper recipient preparation, including complete genetic screening, would be a pragmatic approach. Novel therapies, e.g., purified products of the deficient genes, though promising in theory, are not yet of proven value.
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Affiliation(s)
- Fedaey Abbas
- Nephrology Department, Jaber El Ahmed Military Hospital, Safat 13005, Kuwait
- Faculty of Health and Science, University of Liverpool, Institute of Learning and Teaching, School of Medicine, Liverpool L69 3GB, United Kingdom
| | - Mohsen El Kossi
- Faculty of Health and Science, University of Liverpool, Institute of Learning and Teaching, School of Medicine, Liverpool L69 3GB, United Kingdom
- Doncaster Renal Unit, Doncaster Royal Infirmary, Doncaster DN2 5LT, United Kingdom
| | - Jon Jin Kim
- Faculty of Health and Science, University of Liverpool, Institute of Learning and Teaching, School of Medicine, Liverpool L69 3GB, United Kingdom
- Nottingham Children Hospital, Nottingham NG7 2UH, United Kingdom
| | - Ajay Sharma
- Faculty of Health and Science, University of Liverpool, Institute of Learning and Teaching, School of Medicine, Liverpool L69 3GB, United Kingdom
- Transplant Surgery, Royal Liverpool University Hospitals, Liverpool UK L7 8XP, United Kingdom
| | - Ahmed Halawa
- Faculty of Health and Science, University of Liverpool, Institute of Learning and Teaching, School of Medicine, Liverpool L69 3GB, United Kingdom
- Department of Transplantation Surgery, Sheffield Teaching Hospitals, Sheffield S57AU, United Kingdom
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26
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Entova S, Billod JM, Swiecicki JM, Martín-Santamaría S, Imperiali B. Insights into the key determinants of membrane protein topology enable the identification of new monotopic folds. eLife 2018; 7:40889. [PMID: 30168796 PMCID: PMC6133551 DOI: 10.7554/elife.40889] [Citation(s) in RCA: 14] [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: 08/08/2018] [Accepted: 08/27/2018] [Indexed: 01/31/2023] Open
Abstract
Monotopic membrane proteins integrate into the lipid bilayer via reentrant hydrophobic domains that enter and exit on a single face of the membrane. Whereas many membrane-spanning proteins have been structurally characterized and transmembrane topologies can be predicted computationally, relatively little is known about the determinants of membrane topology in monotopic proteins. Recently, we reported the X-ray structure determination of PglC, a full-length monotopic membrane protein with phosphoglycosyl transferase (PGT) activity. The definition of this unique structure has prompted in vivo, biochemical, and computational analyses to understand and define key motifs that contribute to the membrane topology and to provide insight into the dynamics of the enzyme in a lipid bilayer environment. Using the new information gained from studies on the PGT superfamily we demonstrate that two motifs exemplify principles of topology determination that can be applied to the identification of reentrant domains among diverse monotopic proteins of interest.
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Affiliation(s)
- Sonya Entova
- Department of BiologyMassachusetts Institute of TechnologyCambridgeUnited States
| | - Jean-Marc Billod
- Department of Structural & Chemical BiologyCentro de Investigaciones BiológicasMadridSpain
| | - Jean-Marie Swiecicki
- Department of BiologyMassachusetts Institute of TechnologyCambridgeUnited States
| | | | - Barbara Imperiali
- Department of BiologyMassachusetts Institute of TechnologyCambridgeUnited States
- Department of ChemistryMassachusetts Institute of TechnologyCambridgeUnited States
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27
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Abstract
Thrombotic microangiopathy (TMA) refers to phenotypically similar disorders, including hemolytic uremic syndromes (HUS) and thrombotic thrombocytopenic purpura (TTP). This review explores the role of the influenza virus as trigger of HUS or TTP. We conducted a literature survey in PubMed and Google Scholar using HUS, TTP, TMA, and influenza as keywords, and extracted and analyzed reported epidemiological and clinical data. We identified 25 cases of influenza-associated TMA. Five additional cases were linked to influenza vaccination and analyzed separately. Influenza A was found in 83%, 10 out of 25 during the 2009 A(H1N1) pandemic. Two patients had bona fide TTP with ADAMTS13 activity <10%. Median age was 15 years (range 0.5-68 years), two thirds were male. Oligoanuria was documented in 81% and neurological involvement in 40% of patients. Serum C3 was reduced in 5 out of 14 patients (36%); Coombs test was negative in 7 out of 7 and elevated fibrin/fibrinogen degradation products were documented in 6 out of 8 patients. Pathogenic complement gene mutations were found in 7 out of 8 patients tested (C3, MCP, or MCP combined with CFB or clusterin). Twenty out of 24 patients recovered completely, but 3 died (12%). Ten of the surviving patients underwent plasma exchange (PLEX) therapy, 5 plasma infusions. Influenza-mediated HUS or TTP is rare. A sizable proportion of tested patients demonstrated mutations associated with alternative pathway of complement dysregulation that was uncovered by this infection. Further research is warranted targeting the roles of viral neuraminidase, enhanced virus-induced complement activation and/or ADAMTS13 antibodies, and rational treatment approaches.
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Affiliation(s)
- Martin Bitzan
- Division of Nephrology, The Montreal Children's Hospital, McGill University Health Centre, 1001, boul. Décarie-Room B RC.6651, Montréal, QC, H4A 3J1, Canada.
| | - Jakub Zieg
- 0000 0004 1937 116Xgrid.4491.8Department of Pediatric Nephrology, 2nd Faculty of Medicine, University Hospital Motol, Charles University, Prague, Czech Republic
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28
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Sobocińska J, Roszczenko-Jasińska P, Zaręba-Kozioł M, Hromada-Judycka A, Matveichuk OV, Traczyk G, Łukasiuk K, Kwiatkowska K. Lipopolysaccharide Upregulates Palmitoylated Enzymes of the Phosphatidylinositol Cycle: An Insight from Proteomic Studies. Mol Cell Proteomics 2017; 17:233-254. [PMID: 29217618 DOI: 10.1074/mcp.ra117.000050] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Indexed: 12/28/2022] Open
Abstract
Lipopolysaccharide (LPS) is a component of the outer membrane of Gram-negative bacteria that induces strong proinflammatory reactions of mammals. These processes are triggered upon sequential binding of LPS to CD14, a GPI-linked plasma membrane raft protein, and to the TLR4/MD2 receptor complex. We have found earlier that upon LPS binding, CD14 triggers generation of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], a lipid controlling subsequent proinflammatory cytokine production. Here we show that stimulation of RAW264 macrophage-like cells with LPS induces global changes of the level of fatty-acylated, most likely palmitoylated, proteins. Among the acylated proteins that were up-regulated in those conditions were several enzymes of the phosphatidylinositol cycle. Global profiling of acylated proteins was performed by metabolic labeling of RAW264 cells with 17ODYA, an analogue of palmitic acid functionalized with an alkyne group, followed by detection and enrichment of labeled proteins using biotin-azide/streptavidin and their identification with mass spectrometry. This proteomic approach revealed that 154 fatty-acylated proteins were up-regulated, 186 downregulated, and 306 not affected in cells stimulated with 100 ng/ml LPS for 60 min. The acylated proteins affected by LPS were involved in diverse biological functions, as found by Ingenuity Pathway Analysis. Detailed studies of 17ODYA-labeled and immunoprecipitated proteins revealed that LPS induces S-palmitoylation, hence activation, of type II phosphatidylinositol 4-kinase (PI4KII) β, which phosphorylates phosphatidylinositol to phosphatidylinositol 4-monophosphate, a PI(4,5)P2 precursor. Silencing of PI4KIIβ and PI4KIIα inhibited LPS-induced expression and production of proinflammatory cytokines, especially in the TRIF-dependent signaling pathway of TLR4. Reciprocally, this LPS-induced signaling pathway was significantly enhanced after overexpression of PI4KIIβ or PI4KIIα; this was dependent on palmitoylation of the kinases. However, the S-palmitoylation of PI4KIIα, hence its activity, was constitutive in RAW264 cells. Taken together the data indicate that LPS triggers S-palmitoylation and activation of PI4KIIβ, which generates PI(4)P involved in signaling pathways controlling production of proinflammatory cytokines.
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Affiliation(s)
- Justyna Sobocińska
- From the ‡Laboratory of Molecular Membrane Biology, Department of Cell Biology
| | | | - Monika Zaręba-Kozioł
- §Laboratory of Cell Biophysics, Department of Molecular and Cellular Neurobiology
| | | | - Orest V Matveichuk
- From the ‡Laboratory of Molecular Membrane Biology, Department of Cell Biology
| | - Gabriela Traczyk
- From the ‡Laboratory of Molecular Membrane Biology, Department of Cell Biology
| | - Katarzyna Łukasiuk
- ¶Laboratory of Epileptogenesis, Department of Neurophysiology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
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29
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Gupta RS, Epand RM. Phylogenetic analysis of the diacylglycerol kinase family of proteins and identification of multiple highly-specific conserved inserts and deletions within the catalytic domain that are distinctive characteristics of different classes of DGK homologs. PLoS One 2017; 12:e0182758. [PMID: 28829789 PMCID: PMC5567653 DOI: 10.1371/journal.pone.0182758] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 04/27/2017] [Accepted: 07/24/2017] [Indexed: 01/01/2023] Open
Abstract
Diacylglycerol kinase (DGK) family of proteins, which phosphorylates diacylglycerol into phosphatidic acid, play important role in controlling diverse cellular processes in eukaryotic organisms. Most vertebrate species contain 10 different DGK isozymes, which are grouped into 5 different classes based on the presence or absence of specific functional domains. However, the relationships among different DGK isozymes or how they have evolved from a common ancestor is unclear. The catalytic domain constitutes the single largest sequence element within the DGK proteins that is commonly and uniquely shared by all family members, but there is limited understanding of the overall function of this domain. In this work, we have used the catalytic domain sequences to construct a phylogenetic tree for the DGK family members from representatives of the main vertebrate classes and have also examined the distributions of various DGK isozymes in eukaryotic phyla. In a tree based on catalytic domain sequences, the DGK homologs belonging to different classes formed strongly supported clusters which were separated by long branches, and the different isozymes within each class also generally formed monophyletic groupings. Further, our analysis of the sequence alignments of catalytic domains has identified >10 novel sequence signatures consisting of conserved signature indels (inserts or deletions, CSIs) that are distinctive characteristics of either particular classes of DGK isozymes, or are commonly shared by members of two or more classes of DGK isozymes. The conserved indels in protein sequences are known to play important functional roles in the proteins/organisms where they are found. Thus, our identification of multiple highly specific CSIs that are distinguishing characteristics of different classes of DGK homologs points to the existence of important differences in the catalytic domain function among the DGK isozymes. The identified CSIs in conjunction with the results of blast searches on species distribution of DGK isozymes also provide useful insights into the evolutionary relationships among the DGK family of proteins.
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Affiliation(s)
- Radhey S. Gupta
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
| | - Richard M. Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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30
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Mannerås-Holm L, Schönke M, Brozinick JT, Vetterli L, Bui HH, Sanders P, Nascimento EBM, Björnholm M, Chibalin AV, Zierath JR. Diacylglycerol kinase ε deficiency preserves glucose tolerance and modulates lipid metabolism in obese mice. J Lipid Res 2017; 58:907-915. [PMID: 28246337 DOI: 10.1194/jlr.m074443] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 12/21/2016] [Revised: 02/13/2017] [Indexed: 12/19/2022] Open
Abstract
Diacylglycerol kinases (DGKs) catalyze the phosphorylation and conversion of diacylglycerol (DAG) into phosphatidic acid. DGK isozymes have unique primary structures, expression patterns, subcellular localizations, regulatory mechanisms, and DAG preferences. DGKε has a hydrophobic segment that promotes its attachment to membranes and shows substrate specificity for DAG with an arachidonoyl acyl chain in the sn-2 position of the substrate. We determined the role of DGKε in the regulation of energy and glucose homeostasis in relation to diet-induced insulin resistance and obesity using DGKε-KO and wild-type mice. Lipidomic analysis revealed elevated unsaturated and saturated DAG species in skeletal muscle of DGKε KO mice, which was paradoxically associated with increased glucose tolerance. Although skeletal muscle insulin sensitivity was unaltered, whole-body respiratory exchange ratio was reduced, and abundance of mitochondrial markers was increased, indicating a greater reliance on fat oxidation and intracellular lipid metabolism in DGKε KO mice. Thus, the increased intracellular lipids in skeletal muscle from DGKε KO mice may undergo rapid turnover because of increased mitochondrial function and lipid oxidation, rather than storage, which in turn may preserve insulin sensitivity. In conclusion, DGKε plays a role in glucose and energy homeostasis by modulating lipid metabolism in skeletal muscle.
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Affiliation(s)
- Louise Mannerås-Holm
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Milena Schönke
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | - Laurène Vetterli
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Hai-Hoang Bui
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Philip Sanders
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Emmani B M Nascimento
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Marie Björnholm
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Alexander V Chibalin
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Juleen R Zierath
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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31
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Jennings W, Doshi S, Hota PK, Prodeus A, Black S, Epand RM. Expression, Purification, and Properties of a Human Arachidonoyl-Specific Isoform of Diacylglycerol Kinase. Biochemistry 2017; 56:1337-1347. [PMID: 28199087 DOI: 10.1021/acs.biochem.6b01193] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Diacylglycerol kinase ε (DGKε) catalyzes the phosphorylation of diacylglycerol, producing phosphatidic acid. DGKε demonstrates exquisite specificity for the acyl chains of diacylglycerol. This contributes to the enrichment of particular acyl chains within the lipids of the phosphatidylinositol cycle. Phosphatidylinositol is highly enriched with 1-stearoyl-2-arachidonoyl, which is important for maintaining cellular health. Dysregulation of DGKε perturbs lipid signaling and biosynthesis, which has been linked to epilepsy, Huntington's disease, and heart disease. Recessive loss-of-function mutations in the DGKε gene cause atypical hemolytic uremic syndrome. Because DGKε has never been purified, little is known about its molecular properties. We expressed human DGKε and a truncated version lacking the first 40 residues (DGKεΔ40) and purified both proteins to near homogeneity using nickel affinity chromatography. Kinase activity measurements showed that both purified constructs retained their acyl chain specificity for diacylglycerol with an activity level comparable to that of N-terminally FLAG epitope-tagged forms of these proteins expressed in COS7 cells. Both constructs lost activity upon being stored, particularly upon freezing and thawing, which was minimized by the addition of glycerol. Circular dichroism revealed that DGKε and DGKεΔ40 both contain significant amounts of α-helical and β structure and exhibit biphasic thermal denaturations. The loss of secondary structure upon heating was irreversible for both constructs, with relatively little effect of added dioleoylphosphatidylcholine. The addition of 50% glycerol stabilized both constructs and facilitated refolding of their secondary structures after heating. This is the first successful purification and characterization of DGKε's enzymatic and conformational properties. The purification of DGKε permits detailed analyses of this unique enzyme and will improve our understanding of DGKε-related diseases.
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Affiliation(s)
- William Jennings
- Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Sejal Doshi
- Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Prasanta Kumar Hota
- Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Aaron Prodeus
- Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Stephanie Black
- Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
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