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Ralph-Epps T, Onu CJ, Vo L, Schmidtke MW, Le A, Greenberg ML. Studying Lipid-Related Pathophysiology Using the Yeast Model. Front Physiol 2021; 12:768411. [PMID: 34777024 PMCID: PMC8581491 DOI: 10.3389/fphys.2021.768411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/04/2021] [Indexed: 01/01/2023] Open
Abstract
Saccharomyces cerevisiae, commonly known as baker's yeast, is one of the most comprehensively studied model organisms in science. Yeast has been used to study a wide variety of human diseases, and the yeast model system has proved to be an especially amenable tool for the study of lipids and lipid-related pathophysiologies, a topic that has gained considerable attention in recent years. This review focuses on how yeast has contributed to our understanding of the mitochondrial phospholipid cardiolipin (CL) and its role in Barth syndrome (BTHS), a genetic disorder characterized by partial or complete loss of function of the CL remodeling enzyme tafazzin. Defective tafazzin causes perturbation of CL metabolism, resulting in many downstream cellular consequences and clinical pathologies that are discussed herein. The influence of yeast research in the lipid-related pathophysiologies of Alzheimer's and Parkinson's diseases is also summarized.
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Affiliation(s)
- Tyler Ralph-Epps
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Chisom J Onu
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Linh Vo
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Michael W Schmidtke
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Anh Le
- Muskegon Catholic Central High School, Muskegon, MI, United States
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
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2
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Liposomes modified with cardiolipin can act as a platform to regulate the potential flux of NADP +-dependent isocitrate dehydrogenase. Metab Eng Commun 2015; 3:8-14. [PMID: 29142819 PMCID: PMC5678819 DOI: 10.1016/j.meteno.2015.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 11/05/2015] [Accepted: 11/10/2015] [Indexed: 11/22/2022] Open
Abstract
Cardiolipin (CL) is a phospholipid found in the outer mitochondrial membrane (OMM) and inner mitochondrial membrane (IMM) in animal cells. Isocitrate dehydrogenase (ICDH) is an important catalytic enzyme that is localized at the cytosol and mitochondria; the metabolic pathway catalyzed by ICDH differs between the OMM and IMM. To estimate the possible role of lipid membrane in the enzymatic activity of NADP+-dependent ICDH, CL-modified liposomes were prepared using CL/1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/cholesterol (Ch), and their characteristics were analyzed based on the fluorescent probe method. The relative enzymatic activity of ICDH decreased in the presence of CL/DPPC/Ch=(30/50/20) liposome, whereas activity increased in the presence of CL/DPPC/Ch=(5/75/20) liposome. NADP+ had the greatest substrate affinity and was dominant in the regulation of ICDH activity. Analysis of membrane properties indicated that membranes in CL-modified liposomes were dehydrated by ICDH binding. Using circular dichroism analysis, CL/DPPC/Ch=(30/50/20) liposome induced a conformational change in ICDH, indicating that CL-rich membrane domains could inhibit ICDH activity. These results suggest that lipid membranes, including CL molecules, could act as a platform to regulate ICDH-related metabolic pathways such as the tricarboxylic acid cycle and lipid synthesis. Phosphatidylcholine liposomes were modified with cardiolipin and characterized. DPPC liposomes did not affect the activity of ICDH. ICDH activity was enhanced with liposomes at 5 mol% cardiolipin. ICDH activity was lowered with liposomes at 30 mol% cardiolipin. Liposomes with high content of cardiolipin led to conformational changes of ICDH.
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Key Words
- CL, cardiolipin
- Cardiolipin
- Ch, cholesterol
- DPPC, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine
- ICDH, isocitrate dehydrogenase
- IMM, inner mitochondrial membrane
- Isocitrate dehydrogenase
- LUV, large unilamellar vesicles
- Liposome
- MLV, multilamellar vesicles
- Membranome
- NADP+, β-nicotinamide-adenine dinucleotide phosphate oxidized form
- NADPH, β-nicotinamide-adenine dinucleotide phosphate reduced form
- OMM, outer mitochondrial membrane
- PDB, protein data bank
- System biology
- TCA, tricarboxylic acid
- ld, liquid-disordered
- lo, liquid-ordered
- so, solid-ordered
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3
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Gsell M, Fankl A, Klug L, Mascher G, Schmidt C, Hrastnik C, Zellnig G, Daum G. A Yeast Mutant Deleted of GPH1 Bears Defects in Lipid Metabolism. PLoS One 2015; 10:e0136957. [PMID: 26327557 PMCID: PMC4556709 DOI: 10.1371/journal.pone.0136957] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 08/10/2015] [Indexed: 11/18/2022] Open
Abstract
In a previous study we demonstrated up-regulation of the yeast GPH1 gene under conditions of phosphatidylethanolamine (PE) depletion caused by deletion of the mitochondrial (M) phosphatidylserine decarboxylase 1 (PSD1) (Gsell et al., 2013, PLoS One. 8(10):e77380. doi: 10.1371/journal.pone.0077380). Gph1p has originally been identified as a glycogen phosphorylase catalyzing degradation of glycogen to glucose in the stationary growth phase of the yeast. Here we show that deletion of this gene also causes decreased levels of phosphatidylcholine (PC), triacylglycerols and steryl esters. Depletion of the two non-polar lipids in a Δgph1 strain leads to lack of lipid droplets, and decrease of the PC level results in instability of the plasma membrane. In vivo labeling experiments revealed that formation of PC via both pathways of biosynthesis, the cytidine diphosphate (CDP)-choline and the methylation route, is negatively affected by a Δgph1 mutation, although expression of genes involved is not down regulated. Altogether, Gph1p besides its function as a glycogen mobilizing enzyme appears to play a regulatory role in yeast lipid metabolism.
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Affiliation(s)
- Martina Gsell
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Ariane Fankl
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Lisa Klug
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Gerald Mascher
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Claudia Schmidt
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Claudia Hrastnik
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Günther Zellnig
- Institute of Plant Sciences, Karl Franzens University Graz, NaWi Graz, Austria
| | - Günther Daum
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
- * E-mail:
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4
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Kagan VE, Tyurina YY, Tyurin VA, Mohammadyani D, Angeli JPF, Baranov SV, Klein-Seetharaman J, Friedlander RM, Mallampalli RK, Conrad M, Bayir H. Cardiolipin signaling mechanisms: collapse of asymmetry and oxidation. Antioxid Redox Signal 2015; 22:1667-80. [PMID: 25566681 PMCID: PMC4486147 DOI: 10.1089/ars.2014.6219] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
SIGNIFICANCE An ancient anionic phospholipid, cardiolipin (CL), ubiquitously present in prokaryotic and eukaryotic membranes, is essential for several structural and functional purposes. RECENT ADVANCES The emerging role of CLs in signaling has become the focus of many studies. CRITICAL ISSUES In this work, we describe two major pathways through which mitochondrial CLs may fulfill the signaling functions via utilization of their (i) asymmetric distribution across membranes and translocations, leading to the surface externalization and (ii) ability to undergo oxidation reactions to yield the signature products recognizable by the executionary machinery of cells. FUTURE DIRECTIONS We present a concept that CLs and their oxidation/hydrolysis products constitute a rich communication language utilized by mitochondria of eukaryotic cells for diversified regulation of cell physiology and metabolism as well as for inter-cellular interactions.
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Affiliation(s)
- Valerian E Kagan
- 1Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania.,2Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania.,3Department of Radiation Oncology, University of Pittsburgh, Pittsburgh, Pennsylvania.,4Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Yulia Y Tyurina
- 1Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Vladimir A Tyurin
- 1Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Dariush Mohammadyani
- 5Department of Bioengineering, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jose Pedro Friedmann Angeli
- 6Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Developmental Genetics, Neuherberg, Germany
| | - Sergei V Baranov
- 7Department of Neurosurgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Judith Klein-Seetharaman
- 8Division of Metabolic and Vascular Health, Medical School, University of Warwick, Coventry, United Kingdom
| | | | - Rama K Mallampalli
- 9Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, and VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania
| | - Marcus Conrad
- 6Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Developmental Genetics, Neuherberg, Germany
| | - Hülya Bayir
- 10Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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5
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Luévano-Martínez LA, Forni MF, dos Santos VT, Souza-Pinto NC, Kowaltowski AJ. Cardiolipin is a key determinant for mtDNA stability and segregation during mitochondrial stress. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:587-98. [PMID: 25843549 DOI: 10.1016/j.bbabio.2015.03.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 03/16/2015] [Accepted: 03/29/2015] [Indexed: 01/05/2023]
Abstract
Mitochondria play a key role in adaptation during stressing situations. Cardiolipin, the main anionic phospholipid in mitochondrial membranes, is expected to be a determinant in this adaptive mechanism since it modulates the activity of most membrane proteins. Here, we used Saccharomyces cerevisiae subjected to conditions that affect mitochondrial metabolism as a model to determine the possible role of cardiolipin in stress adaptation. Interestingly, we found that thermal stress promotes a 30% increase in the cardiolipin content and modifies the physical state of mitochondrial membranes. These changes have effects on mtDNA stability, adapting cells to thermal stress. Conversely, this effect is cardiolipin-dependent since a cardiolipin synthase-null mutant strain is unable to adapt to thermal stress as observed by a 60% increase of cells lacking mtDNA (ρ0). Interestingly, we found that the loss of cardiolipin specifically affects the segregation of mtDNA to daughter cells, leading to a respiratory deficient phenotype after replication. We also provide evidence that mtDNA physically interacts with cardiolipin both in S. cerevisiae and in mammalian mitochondria. Overall, our results demonstrate that the mitochondrial lipid cardiolipin is a key determinant in the maintenance of mtDNA stability and segregation.
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Affiliation(s)
- Luis Alberto Luévano-Martínez
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Cidade Universitária, Av. Prof. Lineu Prestes, 748, São Paulo, SP 05508-000, Brazil.
| | - Maria Fernanda Forni
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Cidade Universitária, Av. Prof. Lineu Prestes, 748, São Paulo, SP 05508-000, Brazil
| | - Valquiria Tiago dos Santos
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Cidade Universitária, Av. Prof. Lineu Prestes, 748, São Paulo, SP 05508-000, Brazil
| | - Nadja C Souza-Pinto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Cidade Universitária, Av. Prof. Lineu Prestes, 748, São Paulo, SP 05508-000, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Cidade Universitária, Av. Prof. Lineu Prestes, 748, São Paulo, SP 05508-000, Brazil
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Bowron A, Honeychurch J, Williams M, Tsai-Goodman B, Clayton N, Jones L, Shortland GJ, Qureshi SA, Heales SJR, Steward CG. Barth syndrome without tetralinoleoyl cardiolipin deficiency: a possible ameliorated phenotype. J Inherit Metab Dis 2015; 38:279-86. [PMID: 25112388 PMCID: PMC4341014 DOI: 10.1007/s10545-014-9747-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/08/2014] [Accepted: 07/15/2014] [Indexed: 12/01/2022]
Abstract
Barth syndrome (BTHS) is an X-linked disorder characterised by cardiac and skeletal myopathy, growth delay, neutropenia and 3-methylglutaconic aciduria (3-MGCA). Patients have TAZ gene mutations which affect metabolism of cardiolipin, resulting in low tetralinoleoyl cardiolipin (CL(4)), an increase in its precursor, monolysocardiolipin (MLCL), and an increased MLCL/CL(4) ratio. During development of a diagnostic service for BTHS, leukocyte CL(4) was measured in 156 controls and 34 patients with genetically confirmed BTHS. A sub-group of seven subjects from three unrelated families was identified with leukocyte CL(4) concentrations within the control range. This had led to initial false negative disease detection in two of these patients. MLCL/CL(4) in this subgroup was lower than in other BTHS patients but higher than controls, with no overlap between the groups. TAZ gene mutations in these families are all predicted to be pathological. This report describes the clinical histories of these seven individuals with an atypical phenotype: some features were typical of BTHS (five have had cardiomyopathy, one family has a history of male infant deaths, three have growth delay and five have 3-MGCA) but none has persistent neutropenia, five have excellent exercise tolerance and two adults are asymptomatic. This report also emphasises the importance of measurement of MLCL/CL(4) ratio rather than CL(4) alone in the biochemical diagnosis of the BTHS.
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Affiliation(s)
- Ann Bowron
- Department of Clinical Biochemistry, University Hospitals Bristol NHS Trust, Bristol, BS2 8HW, UK,
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7
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Faber C, Zhu ZJ, Castellino S, Wagner DS, Brown RH, Peterson RA, Gates L, Barton J, Bickett M, Hagerty L, Kimbrough C, Sola M, Bailey D, Jordan H, Elangbam CS. Cardiolipin profiles as a potential biomarker of mitochondrial health in diet-induced obese mice subjected to exercise, diet-restriction and ephedrine treatment. J Appl Toxicol 2014; 34:1122-9. [PMID: 25132005 DOI: 10.1002/jat.3030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 04/17/2014] [Accepted: 04/23/2014] [Indexed: 11/08/2022]
Abstract
Cardiolipin (CL) is crucial for mitochondrial energy metabolism and structural integrity. Alterations in CL quantity or CL species have been associated with mitochondrial dysfunction in several pathological conditions and diseases, including mitochondrial dysfunction-related compound attrition and post-market withdrawal of promising drugs. Here we report alterations in the CL profiles in conjunction with morphology of soleus muscle (SM) and brown adipose tissue (BAT) in diet-induced obese (DIO) mice, subjected to ephedrine treatment (EPH: 200 mg kg(-1) day(-1) orally), treadmill exercise (EX: 10 meters per min, 1 h per day), or dietary restriction (DR: 25% less of mean food consumed by the EX group) for 7 days. Mice from the DR and EPH groups had a significant decrease in percent body weight and reduced fat mass compared with DIO controls. Morphologic alterations in the BAT included brown adipocytes with reduced cytoplasmic lipid droplets and increased cytoplasmic eosinophilia in the EX, DR and EPH groups. Increased cytoplasmic eosinophilia in the BAT was ultrastructurally manifested by increased mitochondrial cristae, fenestration of mitochondrial cristae, increased electron density of mitochondrial matrix, and increased complexity of shape and elongation of mitochondria. Mitochondrial ultrastructural alterations in the SM of the EX and DR groups included increased mitochondrial cristae, cup-shaped mitochondria and mitochondrial degeneration. All four CL species (tri-linoleoyl-mono-docosahexaenoyl, tetralinoleoyl, tri-linoleoyl-mono-oleoyl, and di-linoleoyl-di-oleoyl) were increased in the BAT of the DR and EPH groups and in the SM of the EPH and EX groups. In conclusion, cardiolipin profiling supported standard methods for assessing mitochondrial biogenesis and health, and may serve as a potential marker of mitochondrial dysfunction in preclinical toxicity studies.
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Affiliation(s)
- Catherine Faber
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, 47907, USA
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8
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Cardiolipin-dependent formation of mitochondrial respiratory supercomplexes. Chem Phys Lipids 2013; 179:42-8. [PMID: 24220496 DOI: 10.1016/j.chemphyslip.2013.10.012] [Citation(s) in RCA: 180] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 10/21/2013] [Accepted: 10/30/2013] [Indexed: 11/20/2022]
Abstract
The organization of individual respiratory Complexes I, III, and IV (mammalian cells) or III and IV (yeast) of the mitochondria into higher order supercomplexes (SCs) is generally accepted. However, the factors that regulate SC formation and the functional significance of SCs are not well understood. The mitochondrial signature phospholipid cardiolipin (CL) plays a central role in formation and stability of respiratory SCs from yeast to man. Studies in yeast mutants in which the CL level can be regulated displayed a direct correlation between CL levels and SC formation. Disease states in which CL levels are reduced also show defects in SC formation. Three-dimensional density maps of yeast and bovine SCs by electron cryo-microscopy show gaps between the transmembrane-localized interfaces of individual complexes consistent with the large excess of CL in SCs over that integrated into the structure of individual respiratory complexes. Finally, the yeast SC composed of Complex III and two Complexes IV was reconstituted in liposomes from purified individual complexes containing integrated CLs. Reconstitution was wholly dependent on inclusion of additional CL in the liposomes. Therefore, non-integral CL molecules play an important role in SC formation and may be involved in regulation of SC stability under metabolic conditions where CL levels fluctuate.
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9
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The Taz1p transacylase is imported and sorted into the outer mitochondrial membrane via a membrane anchor domain. EUKARYOTIC CELL 2013; 12:1600-8. [PMID: 24078306 DOI: 10.1128/ec.00237-13] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mutations in the mitochondrial transacylase tafazzin, Taz1p, in Saccharomyces cerevisiae cause Barth syndrome, a disease of defective cardiolipin remodeling. Taz1p is an interfacial membrane protein that localizes to both the outer and inner membranes, lining the intermembrane space. Pathogenic point mutations in Taz1p that alter import and membrane insertion result in accumulation of monolysocardiolipin. In this study, we used yeast as a model to investigate the biogenesis of Taz1p. We show that to achieve this unique topology in mitochondria, Taz1p follows a novel import pathway in which it crosses the outer membrane via the translocase of the outer membrane and then uses the Tim9p-Tim10p complex of the intermembrane space to insert into the mitochondrial outer membrane. Taz1p is then transported to membranes of an intermediate density to reach a location in the inner membrane. Moreover, a pathogenic mutation within the membrane anchor (V224R) alters Taz1p import so that it bypasses the Tim9p-Tim10p complex and interacts with the translocase of the inner membrane, TIM23, to reach the matrix. Critical targeting information for Taz1p resides in the membrane anchor and flanking sequences, which are often mutated in Barth syndrome patients. These studies suggest that altering the mitochondrial import pathway of Taz1p may be important in understanding the molecular basis of Barth syndrome.
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10
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Clarke SLN, Bowron A, Gonzalez IL, Groves SJ, Newbury-Ecob R, Clayton N, Martin RP, Tsai-Goodman B, Garratt V, Ashworth M, Bowen VM, McCurdy KR, Damin MK, Spencer CT, Toth MJ, Kelley RI, Steward CG. Barth syndrome. Orphanet J Rare Dis 2013; 8:23. [PMID: 23398819 PMCID: PMC3583704 DOI: 10.1186/1750-1172-8-23] [Citation(s) in RCA: 218] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 02/05/2013] [Indexed: 02/07/2023] Open
Abstract
First described in 1983, Barth syndrome (BTHS) is widely regarded as a rare X-linked genetic disease characterised by cardiomyopathy (CM), skeletal myopathy, growth delay, neutropenia and increased urinary excretion of 3-methylglutaconic acid (3-MGCA). Fewer than 200 living males are known worldwide, but evidence is accumulating that the disorder is substantially under-diagnosed. Clinical features include variable combinations of the following wide spectrum: dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), endocardial fibroelastosis (EFE), left ventricular non-compaction (LVNC), ventricular arrhythmia, sudden cardiac death, prolonged QTc interval, delayed motor milestones, proximal myopathy, lethargy and fatigue, neutropenia (absent to severe; persistent, intermittent or perfectly cyclical), compensatory monocytosis, recurrent bacterial infection, hypoglycaemia, lactic acidosis, growth and pubertal delay, feeding problems, failure to thrive, episodic diarrhoea, characteristic facies, and X-linked family history. Historically regarded as a cardiac disease, BTHS is now considered a multi-system disorder which may be first seen by many different specialists or generalists. Phenotypic breadth and variability present a major challenge to the diagnostician: some children with BTHS have never been neutropenic, whereas others lack increased 3-MGCA and a minority has occult or absent CM. Furthermore, BTHS was first described in 2010 as an unrecognised cause of fetal death. Disabling mutations or deletions of the tafazzin (TAZ) gene, located at Xq28, cause the disorder by reducing remodeling of cardiolipin, a principal phospholipid of the inner mitochondrial membrane. A definitive biochemical test, based on detecting abnormal ratios of different cardiolipin species, was first described in 2008. Key areas of differential diagnosis include metabolic and viral cardiomyopathies, mitochondrial diseases, and many causes of neutropenia and recurrent male miscarriage and stillbirth. Cardiolipin testing and TAZ sequencing now provide relatively rapid diagnostic testing, both prospectively and retrospectively, from a range of fresh or stored tissues, blood or neonatal bloodspots. TAZ sequencing also allows female carrier detection and antenatal screening. Management of BTHS includes medical therapy of CM, cardiac transplantation (in 14% of patients), antibiotic prophylaxis and granulocyte colony-stimulating factor (G-CSF) therapy. Multidisciplinary teams/clinics are essential for minimising hospital attendances and allowing many more individuals with BTHS to live into adulthood.
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Affiliation(s)
- Sarah L N Clarke
- NHS Specialised Services Barth Syndrome Service, Royal Hospital for Children, Upper Maudlin St, Bristol, BS2 8BJ, UK.
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11
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Gsell M, Daum G. Analysis of membrane lipid biogenesis pathways using yeast genetics. Methods Mol Biol 2013; 1033:29-44. [PMID: 23996169 DOI: 10.1007/978-1-62703-487-6_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The yeast Saccharomyces cerevisiae has become a valuable eukaryotic model organism to study biochemical and cellular processes at a molecular basis. A common strategy for such studies is the use of single and multiple mutants constructed by genetic manipulation which are compromised in individual enzymatic steps or certain metabolic pathways. Here, we describe selected examples of yeast research on phospholipid metabolism with emphasis on our own work dealing with investigations of phosphatidylethanolamine synthesis. Such studies start with the selection and construction of appropriate mutants and lead to phenotype analysis, lipid profiling, enzymatic analysis, and in vivo experiments. Comparing results obtained with wild-type and mutant strains allows us to understand the role of gene products and metabolic processes in more detail. Such studies are valuable not only for contributing to our knowledge of the complex network of lipid metabolism, but also of effects of lipids on structure and function of cellular membranes.
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Affiliation(s)
- Martina Gsell
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
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12
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Tamura Y, Onguka O, Itoh K, Endo T, Iijima M, Claypool SM, Sesaki H. Phosphatidylethanolamine biosynthesis in mitochondria: phosphatidylserine (PS) trafficking is independent of a PS decarboxylase and intermembrane space proteins UPS1P and UPS2P. J Biol Chem 2012; 287:43961-71. [PMID: 23124206 DOI: 10.1074/jbc.m112.390997] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphatidylethanolamine (PE) plays important roles for the structure and function of mitochondria and other intracellular organelles. In yeast, the majority of PE is produced from phosphatidylserine (PS) by a mitochondrion-located PS decarboxylase, Psd1p. Because PS is synthesized in the endoplasmic reticulum (ER), PS is transported from the ER to mitochondria and converted to PE. After its synthesis, a portion of PE moves back to the ER. Two mitochondrial proteins located in the intermembrane space, Ups1p and Ups2p, have been shown to regulate PE metabolism by controlling the export of PE. It remains to be determined where PS is decarboxylated in mitochondria and whether decarboxylation is coupled to trafficking of PS. Here, using fluorescent PS as a substrate in an in vitro assay for Psd1p-dependent PE production in isolated mitochondria, we show that PS is transferred from the mitochondrial outer membrane to the inner membrane independently of Psd1p, Ups1p, and Ups2p and decarboxylated to PE by Psd1p in the inner membrane. Interestingly, Ups1p is required for the maintenance of Psd1p and therefore PE production. Restoration of Psd1p levels rescued PE production defects in ups1Δ mitochondria. Our data provide novel mechanistic insight into PE biogenesis in mitochondria.
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Affiliation(s)
- Yasushi Tamura
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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13
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Singh A, Yadav V, Prasad R. Comparative lipidomics in clinical isolates of Candida albicans reveal crosstalk between mitochondria, cell wall integrity and azole resistance. PLoS One 2012; 7:e39812. [PMID: 22761908 PMCID: PMC3384591 DOI: 10.1371/journal.pone.0039812] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 05/26/2012] [Indexed: 11/19/2022] Open
Abstract
Prolonged usage of antifungal azoles which target enzymes involved in lipid biosynthesis invariably leads to the development of multi-drug resistance (MDR) in Candida albicans. We had earlier shown that membrane lipids and their fluidity are closely linked to the MDR phenomenon. In one of our recent studies involving comparative lipidomics between azole susceptible (AS) and azole resistant (AR) matched pair clinical isolates of C. albicans, we could not see consistent differences in the lipid profiles of AS and AR strains because they came from different patients and so in this study, we have used genetically related variant recovered from the same patient collected over a period of 2-years. During this time, the levels of fluconazole (FLC) resistance of the strain increased by over 200-fold. By comparing the lipid profiles of select isolates, we were able to observe gradual and statistically significant changes in several lipid classes, particularly in plasma membrane microdomain specific lipids such as mannosylinositolphosphorylceramides and ergosterol, and in a mitochondrial specific phosphoglyceride, phosphatidyl glycerol. Superimposed with these quantitative and qualitative changes in the lipid profiles, were simultaneous changes at the molecular lipid species levels which again coincided with the development of resistance to FLC. Reverse transcriptase-PCR of the key genes of the lipid metabolism validated lipidomic picture. Taken together, this study illustrates how the gradual corrective changes in Candida lipidome correspond to the development of FLC tolerance. Our study also shows a first instance of the mitochondrial membrane dysfunction and defective cell wall (CW) in clinical AR isolates of C. albicans, and provides evidence of a cross-talk between mitochondrial lipid homeostasis, CW integrity and azole tolerance.
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Affiliation(s)
- Ashutosh Singh
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Vipin Yadav
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Rajendra Prasad
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
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14
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Abstract
Due to its genetic tractability and increasing wealth of accessible data, the yeast Saccharomyces cerevisiae is a model system of choice for the study of the genetics, biochemistry, and cell biology of eukaryotic lipid metabolism. Glycerolipids (e.g., phospholipids and triacylglycerol) and their precursors are synthesized and metabolized by enzymes associated with the cytosol and membranous organelles, including endoplasmic reticulum, mitochondria, and lipid droplets. Genetic and biochemical analyses have revealed that glycerolipids play important roles in cell signaling, membrane trafficking, and anchoring of membrane proteins in addition to membrane structure. The expression of glycerolipid enzymes is controlled by a variety of conditions including growth stage and nutrient availability. Much of this regulation occurs at the transcriptional level and involves the Ino2–Ino4 activation complex and the Opi1 repressor, which interacts with Ino2 to attenuate transcriptional activation of UASINO-containing glycerolipid biosynthetic genes. Cellular levels of phosphatidic acid, precursor to all membrane phospholipids and the storage lipid triacylglycerol, regulates transcription of UASINO-containing genes by tethering Opi1 to the nuclear/endoplasmic reticulum membrane and controlling its translocation into the nucleus, a mechanism largely controlled by inositol availability. The transcriptional activator Zap1 controls the expression of some phospholipid synthesis genes in response to zinc availability. Regulatory mechanisms also include control of catalytic activity of glycerolipid enzymes by water-soluble precursors, products and lipids, and covalent modification of phosphorylation, while in vivo function of some enzymes is governed by their subcellular location. Genome-wide genetic analysis indicates coordinate regulation between glycerolipid metabolism and a broad spectrum of metabolic pathways.
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15
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Mulligan CM, Sparagna GC, Le CH, De Mooy AB, Routh MA, Holmes MG, Hickson-Bick DL, Zarini S, Murphy RC, Xu FY, Hatch GM, McCune SA, Moore RL, Chicco AJ. Dietary linoleate preserves cardiolipin and attenuates mitochondrial dysfunction in the failing rat heart. Cardiovasc Res 2012; 94:460-8. [PMID: 22411972 DOI: 10.1093/cvr/cvs118] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIMS Cardiolipin (CL) is a tetra-acyl phospholipid that provides structural and functional support to several proteins in the inner mitochondrial membrane. The majority of CL in the healthy mammalian heart contains four linoleic acid acyl chains (L(4)CL). A selective loss of L(4)CL is associated with mitochondrial dysfunction and heart failure in humans and animal models. We examined whether supplementing the diet with linoleic acid would preserve cardiac L(4)CL and attenuate mitochondrial dysfunction and contractile failure in rats with hypertensive heart failure. METHODS AND RESULTS Male spontaneously hypertensive heart failure rats (21 months of age) were administered diets supplemented with high-linoleate safflower oil (HLSO) or lard (10% w/w; 28% kilocalorie fat) or without supplemental fat (control) for 4 weeks. HLSO preserved L(4)CL and total CL to 90% of non-failing levels (vs. 61-75% in control and lard groups), and attenuated 17-22% decreases in state 3 mitochondrial respiration observed in the control and lard groups (P < 0.05). Left ventricular fractional shortening was significantly higher in HLSO vs. control (33 ± 2 vs. 29 ± 2%, P < 0.05), while plasma insulin levels were lower (5.4 ± 1.1 vs. 9.1 ± 2.3 ng/mL; P < 0.05), with no significant effect of lard supplementation. HLSO also increased serum concentrations of several eicosanoid species compared with control and lard diets, but had no effect on plasma glucose or blood pressure. CONCLUSION Moderate consumption of HLSO preserves CL and mitochondrial function in the failing heart and may be a useful adjuvant therapy for this condition.
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Affiliation(s)
- Christopher M Mulligan
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO 80523-1582, USA
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16
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Fernández-Cid A, Riera A, Herrero P, Moreno F. Glucose levels regulate the nucleo-mitochondrial distribution of Mig2. Mitochondrion 2012; 12:370-80. [PMID: 22353369 DOI: 10.1016/j.mito.2012.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 01/16/2012] [Accepted: 02/03/2012] [Indexed: 12/24/2022]
Abstract
Mig2 has been described as a transcriptional factor that in the absence of Mig1 protein is required for glucose repression of the SUC2 gene. Thus, until now, the main role assigned to Mig2 has been the functional redundancy to Mig1. In this study, we report that Mig2 has a double subcellular localization. As expected, in high-glucose conditions it is accumulated in the nucleus but in low-glucose conditions Mig2 has an unexpected mitochondrial localization and role in mitochondrial morphology. We describe that Mig2 physically interacts with the mitochondrial protein Ups1 in a glucose-dependent manner. We also show that Δmig2 mutant cells exhibit a fragmented network of mitochondrial tubules, a phenotype similarly observed in cells lacking Fzo1 and Ups1. Furthermore, Mig2 acts antagonistically with respect to the fission-promoting components, because mitochondrial aggregation induced by DNM1 deletion was rescued in the Δdnm1Δmig2 double mutant. Thus, our studies have revealed an additional role for Mig2 as a novel factor required for the maintenance of fusion-competent mitochondria in Saccharomyces cerevisiae and strongly suggest that Mig2 could be involved in the cross talk between the nucleus and the mitochondria through Ups1 to regulate mitochondrial morphology in a glucose dependent manner.
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17
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Abstract
The yeast Saccharomyces cerevisiae, with its full complement of organelles, synthesizes membrane phospholipids by pathways that are generally common to those found in higher eukaryotes. Phospholipid synthesis in yeast is regulated in response to a variety of growth conditions (e.g., inositol supplementation, zinc depletion, and growth stage) by a coordination of genetic (e.g., transcriptional activation and repression) and biochemical (e.g., activity modulation and localization) mechanisms. Phosphatidate (PA), whose cellular levels are controlled by the activities of key phospholipid synthesis enzymes, plays a central role in the transcriptional regulation of phospholipid synthesis genes. In addition to the regulation of gene expression, phosphorylation of key phospholipid synthesis catalytic and regulatory proteins controls the metabolism of phospholipid precursors and products.
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Affiliation(s)
- George M Carman
- Department of Food Science and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey 08901, USA.
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18
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Yoda E, Hachisu K, Taketomi Y, Yoshida K, Nakamura M, Ikeda K, Taguchi R, Nakatani Y, Kuwata H, Murakami M, Kudo I, Hara S. Mitochondrial dysfunction and reduced prostaglandin synthesis in skeletal muscle of Group VIB Ca2+-independent phospholipase A2gamma-deficient mice. J Lipid Res 2010; 51:3003-15. [PMID: 20625036 DOI: 10.1194/jlr.m008060] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Group VIB Ca(2+)-independent phospholipase A(2)γ (iPLA(2)γ) is a membrane-bound iPLA(2) enzyme with unique features, such as the utilization of distinct translation initiation sites and the presence of mitochondrial and peroxisomal localization signals. Here we investigated the physiological functions of iPLA(2)γ by disrupting its gene in mice. iPLA(2)γ-knockout (KO) mice were born with an expected Mendelian ratio and appeared normal and healthy at the age of one month but began to show growth retardation from the age of two months as well as kyphosis and significant muscle weakness at the age of four months. Electron microscopy revealed swelling and reduced numbers of mitochondria and atrophy of myofilaments in iPLA(2)γ-KO skeletal muscles. Increased lipid peroxidation and the induction of several oxidative stress-related genes were also found in the iPLA(2)γ-KO muscles. These results provide evidence that impairment of iPLA(2)γ causes mitochondrial dysfunction and increased oxidative stress, leading to the loss of skeletal muscle structure and function. We further found that the compositions of cardiolipin and other phospholipid subclasses were altered and that the levels of myoprotective prostanoids were reduced in iPLA(2)γ-KO skeletal muscle. Thus, in addition to maintenance of homeostasis of the mitochondrial membrane, iPLA(2)γ may contribute to modulation of lipid mediator production in vivo.
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Affiliation(s)
- Emiko Yoda
- Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan
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19
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Kiebish MA, Bell R, Yang K, Phan T, Zhao Z, Ames W, Seyfried TN, Gross RW, Chuang JH, Han X. Dynamic simulation of cardiolipin remodeling: greasing the wheels for an interpretative approach to lipidomics. J Lipid Res 2010; 51:2153-70. [PMID: 20410019 DOI: 10.1194/jlr.m004796] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Cardiolipin is a class of mitochondrial specific phospholipid, which is intricately involved in mitochondrial functionality. Differences in cardiolipin species exist in a variety of tissues and diseases. It has been demonstrated that the cardiolipin profile is a key modulator of the functions of many mitochondrial proteins. However, the chemical mechanism(s) leading to normal and/or pathological distribution of cardiolipin species remain elusive. Herein, we describe a novel approach for investigating the molecular mechanism of cardiolipin remodeling through a dynamic simulation. This approach applied data from shotgun lipidomic analyses of the heart, liver, brain, and lung mitochondrial lipidomes to model cardiolipin remodeling, including relative content, regiospecificity, and isomeric composition of cardiolipin species. Generated cardiolipin profiles were nearly identical to those determined by shotgun lipidomics. Importantly, the simulated isomeric compositions of cardiolipin species were further substantiated through product ion analysis. Finally, unique enzymatic activities involved in cardiolipin remodeling were assessed from the parameters used in the dynamic simulation of cardiolipin profiles. Collectively, we described, verified, and demonstrated a novel approach by integrating both lipidomic analysis and dynamic simulation to study cardiolipin biology. We believe this study provides a foundation to investigate cardiolipin metabolism and bioenergetic homeostasis in normal and disease states.
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Affiliation(s)
- Michael A Kiebish
- Division of Bioorganic Chemistry and Molecular Pharmacology, Washington University School of Medicine, St Louis, MO 63110, USA
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20
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Nie J, Hao X, Chen D, Han X, Chang Z, Shi Y. A novel function of the human CLS1 in phosphatidylglycerol synthesis and remodeling. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1801:438-45. [PMID: 20025994 DOI: 10.1016/j.bbalip.2009.12.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2009] [Revised: 11/30/2009] [Accepted: 12/07/2009] [Indexed: 10/20/2022]
Abstract
Phosphatidylglycerol (PG) is a precursor for the biosynthesis of cardiolipin and a signaling molecule required for various cellular functions. PG is subjected to remodeling subsequent to its de novo biosynthesis in mitochondria to incorporate appropriate acyl content for its biological functions and to prevent the harmful effect of lysophosphatidylglycerol (LPG) accumulation. Yet, a gene encoding a mitochondrial LPG acyltransferase has not been identified. In this report, we identified a novel function of the human cardiolipin synthase (hCLS1) in regulating PG remodeling. In addition to the reported cardiolipin synthase activity, the recombinant hCLS1 protein expressed in COS-7 cells and Sf-9 insect cells exhibited a strong acyl-CoA-dependent LPG acyltransferase activity, which was further confirmed by purified hCLS1 protein overexpressed in Sf-9 cells. The recombinant hCLS1 displayed an acyl selectivity profile in the order of in the order of C18:1>C18:2>C18:0>C16:0, which is similar to that of hCLS1 toward PGs in cardiolipin synthesis, suggesting that the PG remodeling by hCLS1 is an intrinsic property of the enzyme. In contrast, no significant acyltransferase activity was detected from the recombinant hCLS1 enzyme toward lysocardiolipin which shares a similar structure with LPG. In support of a key function of hCLS1 in PG remodeling, overexpression of hCLS1 in COS-7 cells significantly increased PG biosynthesis concurrent with elevated levels of cardiolipin without any significant effects on the biosynthesis of other phospholipids. These results demonstrate for the first time that hCLS1 catalyzes two consecutive steps in cardiolipin biosynthesis by acylating LPG to PG and then converting PG to cardiolipin.
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Affiliation(s)
- Jia Nie
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, 500 University Drive, H166, Hershey, PA 17033, USA
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21
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Mitchell RW, Hatch GM. Regulation of cardiolipin biosynthesis by fatty acid transport protein-1 IN HEK 293 cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:2015-21. [PMID: 19523918 DOI: 10.1016/j.bbamem.2009.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 06/02/2009] [Accepted: 06/04/2009] [Indexed: 11/26/2022]
Abstract
Cardiolipin (CL) is a major phospholipid involved in energy metabolism mammalian mitochondria and fatty acid transport protein-1 (FATP-1) is a fatty acid transport protein that may regulate the intracellular level of fatty acyl-Coenzyme A's. Since fatty acids are required for oxidative phosphorylation via mitochondrial oxidation, we examined the effect of altering FATP-1 levels on CL biosynthesis. HEK-293 mock- and FATP-1 siRNA transfected cells or mock and FATP-1 expressing cells were incubated for 24 h with 0.1 mM oleic acid bound to albumin (1:1 molar ratio) then incubated for 24 h with 0.1 mM [1,3-(3)H]glycerol and radioactivity incorporated into CL determined. FATP-1 siRNA transfected cells exhibited reduced FATP-1 mRNA and increased incorporation of [1,3-(3)H]glycerol into CL (2-fold, p<0.05) compared to controls indicating elevation in de novo CL biosynthesis. The reason for this was an increase in [1,3-(3)H]glycerol uptake and increase in activity and mRNA expression of the CL biosynthetic enzymes. In contrast, expression of FATP-1 resulted a reduction in incorporation of [1,3-(3)H]glycerol into CL (65%, p<0.05) indicating reduced CL synthesis. [1,3-(3)H]Glycerol uptake was unaltered whereas activity of cytidine-5'-diphosphate-1,2-diacyl-sn-glycerol synthetase (CDS) and CDS-2 mRNA expression were reduced in FATP-1 expressing cells compared to control. In addition, in vitro CDS activity was reduced by exogenous addition of oleoyl-Coenzyme A. The data indicate that CL de novo biosynthesis may be regulated by FATP-1 through CDS-2 expression in HEK 293 cells.
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Affiliation(s)
- Ryan W Mitchell
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Manitoba, Canada R3E 0T6
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22
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Tamura Y, Endo T, Iijima M, Sesaki H. Ups1p and Ups2p antagonistically regulate cardiolipin metabolism in mitochondria. ACTA ACUST UNITED AC 2009; 185:1029-45. [PMID: 19506038 PMCID: PMC2711612 DOI: 10.1083/jcb.200812018] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiolipin, a unique phospholipid composed of four fatty acid chains, is located mainly in the mitochondrial inner membrane (IM). Cardiolipin is required for the integrity of several protein complexes in the IM, including the TIM23 translocase, a dynamic complex which mediates protein import into the mitochondria through interactions with the import motor presequence translocase–associated motor (PAM). In this study, we report that two homologous intermembrane space proteins, Ups1p and Ups2p, control cardiolipin metabolism and affect the assembly state of TIM23 and its association with PAM in an opposing manner. In ups1Δ mitochondria, cardiolipin levels were decreased, and the TIM23 translocase showed altered conformation and decreased association with PAM, leading to defects in mitochondrial protein import. Strikingly, loss of Ups2p restored normal cardiolipin levels and rescued TIM23 defects in ups1Δ mitochondria. Furthermore, we observed synthetic growth defects in ups mutants in combination with loss of Pam17p, which controls the integrity of PAM. Our findings provide a novel molecular mechanism for the regulation of cardiolipin metabolism.
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Affiliation(s)
- Yasushi Tamura
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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23
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Mileykovskaya E, Dowhan W. Cardiolipin membrane domains in prokaryotes and eukaryotes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:2084-91. [PMID: 19371718 DOI: 10.1016/j.bbamem.2009.04.003] [Citation(s) in RCA: 275] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 04/01/2009] [Accepted: 04/06/2009] [Indexed: 11/18/2022]
Abstract
Cardiolipin (CL) plays a key role in dynamic organization of bacterial and mitochondrial membranes. CL forms membrane domains in bacterial cells, and these domains appear to participate in binding and functional regulation of multi-protein complexes involved in diverse cellular functions including cell division, energy metabolism, and membrane transport. Visualization of CL domains in bacterial cells by the fluorescent dye 10-N-nonyl acridine orange is critically reviewed. Possible mechanisms proposed for CL dynamic localization in bacterial cells are discussed. In the mitochondrial membrane CL is involved in organization of multi-subunit oxidative phosphorylation complexes and in their association into higher order supercomplexes. Evidence suggesting a possible role for CL in concert with ATP synthase oligomers in establishing mitochondrial cristae morphology is presented. Hypotheses on CL-dependent dynamic re-organization of the respiratory chain in response to changes in metabolic states and CL dynamic re-localization in mitochondria during the apoptotic response are briefly addressed.
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Affiliation(s)
- Eugenia Mileykovskaya
- Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston, TX 77030, USA.
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24
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Gohil VM, Greenberg ML. Mitochondrial membrane biogenesis: phospholipids and proteins go hand in hand. ACTA ACUST UNITED AC 2009; 184:469-72. [PMID: 19237595 PMCID: PMC2654137 DOI: 10.1083/jcb.200901127] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondrial membrane biogenesis requires the import and synthesis of proteins as well as phospholipids. How the mitochondrion regulates phospholipid levels and maintains a tight protein-to-phospholipid ratio is not well understood. Two recent papers (Kutik, S., M. Rissler, X.L. Guan, B. Guiard, G. Shui, N. Gebert, P.N. Heacock, P. Rehling, W. Dowhan, M.R. Wenk, et al. 2008. J. Cell Biol. 183:1213–1221; Osman, C., M. Haag, C. Potting, J. Rodenfels, P.V. Dip, F.T. Wieland, B. Brügger, B. Westermann, and T. Langer. 2009. J. Cell Biol. 184:583–596) identify novel regulators of mitochondrial phospholipid biosynthesis. The biochemical approach of Kutik et al. (2008) uncovered an unexpected role of the mitochondrial translocator assembly and maintenance protein, Tam41, in the biosynthesis of cardiolipin (CL), the signature phospholipid of mitochondria. The genetic analyses of Osman et al. (2009) led to the discovery of a new class of mitochondrial proteins that coordinately regulate CL and phosphatidylethanolamine, another key mitochondrial phospholipid. These elegant studies highlight overlapping functions and interdependent roles of mitochondrial phospholipid biosynthesis and protein import and assembly.
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Affiliation(s)
- Vishal M Gohil
- Massachusetts General Hospital Center for Human Genetic Research, Boston, MA 02114, USA
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25
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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] [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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26
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Kutik S, Rissler M, Guan XL, Guiard B, Shui G, Gebert N, Heacock PN, Rehling P, Dowhan W, Wenk MR, Pfanner N, Wiedemann N. The translocator maintenance protein Tam41 is required for mitochondrial cardiolipin biosynthesis. ACTA ACUST UNITED AC 2009; 183:1213-21. [PMID: 19114592 PMCID: PMC2606970 DOI: 10.1083/jcb.200806048] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mitochondrial inner membrane contains different translocator systems for the import of presequence-carrying proteins and carrier proteins. The translocator assembly and maintenance protein 41 (Tam41/mitochondrial matrix protein 37) was identified as a new member of the mitochondrial protein translocator systems by its role in maintaining the integrity and activity of the presequence translocase of the inner membrane (TIM23 complex). Here we demonstrate that the assembly of proteins imported by the carrier translocase, TIM22 complex, is even more strongly affected by the lack of Tam41. Moreover, respiratory chain supercomplexes and the inner membrane potential are impaired by lack of Tam41. The phenotype of Tam41-deficient mitochondria thus resembles that of mitochondria lacking cardiolipin. Indeed, we found that Tam41 is required for the biosynthesis of the dimeric phospholipid cardiolipin. The pleiotropic effects of the translocator maintenance protein on preprotein import and respiratory chain can be attributed to its role in biosynthesis of mitochondrial cardiolipin.
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Affiliation(s)
- Stephan Kutik
- Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung, Universität Freiburg, 79104 Freiburg, Germany
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27
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Role of calcium-independent phospholipase A2 in the pathogenesis of Barth syndrome. Proc Natl Acad Sci U S A 2009; 106:2337-41. [PMID: 19164547 DOI: 10.1073/pnas.0811224106] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Quantitative and qualitative alterations of mitochondrial cardiolipin have been implicated in the pathogenesis of Barth syndrome, an X-linked cardioskeletal myopathy caused by a deficiency in tafazzin, an enzyme in the cardiolipin remodeling pathway. We have generated and previously reported a tafazzin-deficient Drosophila model of Barth syndrome that is characterized by low cardiolipin concentration, abnormal cardiolipin fatty acyl composition, abnormal mitochondria, and poor motor function. Here, we first show that tafazzin deficiency in Drosophila disrupts the final stage of spermatogenesis, spermatid individualization, and causes male sterility. This phenotype can be genetically suppressed by inactivation of the gene encoding a calcium-independent phospholipase A(2), iPLA2-VIA, which also prevents cardiolipin depletion/monolysocardiolipin accumulation, although in wild-type flies inactivation of the iPLA2-VIA does not affect the molecular composition of cardiolipin. Furthermore, we show that treatment of Barth syndrome patients' lymphoblasts in tissue culture with the iPLA(2) inhibitor, bromoenol lactone, partially restores their cardiolipin homeostasis. Taken together, these findings establish a causal role of cardiolipin deficiency in the pathogenesis of Barth syndrome and identify iPLA2-VIA as an important enzyme in cardiolipin deacylation, and as a potential target for therapeutic intervention.
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Formation of molecular species of mitochondrial cardiolipin. 1. A novel transacylation mechanism to shuttle fatty acids between sn-1 and sn-2 positions of multiple phospholipid species. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:314-20. [PMID: 19416660 DOI: 10.1016/j.bbalip.2009.01.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 01/06/2009] [Accepted: 01/08/2009] [Indexed: 12/21/2022]
Abstract
Mitochondrial cardiolipin undergoes extensive remodeling of its acyl groups to generate uniformly substituted species, such as tetralinoleoyl-cardiolipin, but the mechanism of this remodeling has not been elucidated, except for the fact that it requires tafazzin. Here we show that purified recombinant Drosophila tafazzin exchanges acyl groups between cardiolipin and phosphatidylcholine by a combination of forward and reverse transacylations. The acyl exchange is possible in the absence of phospholipase A(2) because it requires only trace amounts of lysophospholipids. We show that purified tafazzin reacts with various phospholipid classes and with various acyl groups both in sn-1 and sn-2 position. Expression studies in Sf9 insect cells suggest that the effect of tafazzin on cardiolipin species is dependent on the cellular environment and not on enzymatic substrate specificity. Our data demonstrate that tafazzin catalyzes general acyl exchange between phospholipids, which raises the question whether pattern formation in cardiolipin is the result of the equilibrium distribution of acyl groups between multiple phospholipid species.
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Abstract
Phospholipid synthesis in the yeast Saccharomyces cerevisiae is a complex process that involves regulation by both genetic and biochemical mechanisms. The activity levels of phospholipid synthesis enzymes are controlled by gene expression (e.g., transcription) and by factors (lipids, water-soluble phospholipid precursors and products, and covalent modification of phosphorylation) that modulate catalysis. Phosphatidic acid, whose levels are controlled by the biochemical regulation of key phospholipid synthesis enzymes, plays a central role in the regulation of phospholipid synthesis gene expression.
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Affiliation(s)
- George M Carman
- Department of Food Science and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ 08901, USA.
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Chen S, Tarsio M, Kane PM, Greenberg ML. Cardiolipin mediates cross-talk between mitochondria and the vacuole. Mol Biol Cell 2008; 19:5047-58. [PMID: 18799619 DOI: 10.1091/mbc.e08-05-0486] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Cardiolipin (CL) is an anionic phospholipid with a dimeric structure predominantly localized in the mitochondrial inner membrane, where it is closely associated with mitochondrial function, biogenesis, and genome stability (Daum, 1985; Janitor and Subik, 1993; Jiang et al., 2000; Schlame et al., 2000; Zhong et al., 2004). Previous studies have shown that yeast mutant cells lacking CL due to a disruption in CRD1, the structural gene encoding CL synthase, exhibit defective colony formation at elevated temperature even on glucose medium (Jiang et al., 1999; Zhong et al., 2004), suggesting a role for CL in cellular processes apart from mitochondrial bioenergetics. In the current study, we present evidence that the crd1Delta mutant exhibits severe vacuolar defects, including swollen vacuole morphology and loss of vacuolar acidification, at 37 degrees C. Moreover, vacuoles from crd1Delta show decreased vacuolar H(+)-ATPase activity and proton pumping, which may contribute to loss of vacuolar acidification. Deletion mutants in RTG2 and NHX1, which mediate vacuolar pH and ion homeostasis, rescue the defective colony formation phenotype of crd1Delta, strongly suggesting that the temperature sensitivity of crd1Delta is a consequence of the vacuolar defects. Our results demonstrate the existence of a novel mitochondria-vacuole signaling pathway mediated by CL synthesis.
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Affiliation(s)
- Shuliang Chen
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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31
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Current world literature. Curr Opin Neurol 2008; 21:615-24. [PMID: 18769258 DOI: 10.1097/wco.0b013e32830fb782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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32
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Joshi AS, Zhou J, Gohil VM, Chen S, Greenberg ML. Cellular functions of cardiolipin in yeast. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:212-8. [PMID: 18725250 DOI: 10.1016/j.bbamcr.2008.07.024] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Revised: 07/23/2008] [Accepted: 07/26/2008] [Indexed: 11/17/2022]
Abstract
Cardiolipin (CL), the signature lipid of mitochondria, plays a critical role in mitochondrial function and biogenesis. The availability of yeast mutants blocked in CL synthesis has facilitated studies of the biological role of this lipid. Perturbation of CL synthesis leads to growth defects not only during respiratory growth but also under conditions in which respiration is not essential. CL was shown to play a role in mitochondrial protein import, cell wall biogenesis, aging and apoptosis, ceramide synthesis, and translation of electron transport chain components. The genetic disorder Barth syndrome (BTHS) is caused by mutations in the tafazzin gene resulting in decreased total CL levels, accumulation of monolysocardiolipin (MLCL), and decreased unsaturated fatty acyl species of CL. The variation in clinical presentation of BTHS indicates that other physiological factors play a significant role in modifying the phenotype resulting from tafazzin deficiency. Elucidating the functions of CL is expected to shed light on the role of this important lipid in BTHS and other disorders of mitochondrial dysfunction.
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Affiliation(s)
- Amit S Joshi
- Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA
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Lundbäck AK, van den Berg S, Hebert H, Berglund H, Eshaghi S. Exploring the activity of tobacco etch virus protease in detergent solutions. Anal Biochem 2008; 382:69-71. [PMID: 18682245 DOI: 10.1016/j.ab.2008.07.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 07/15/2008] [Accepted: 07/19/2008] [Indexed: 11/30/2022]
Abstract
Tobacco etch virus (TEV) protease is generally used to remove affinity tags from target proteins. It has been reported that some detergents inhibit the activity of this protease, and therefore should be avoided when removing affinity tags from membrane proteins. The aim of this study was to explore and evaluate this further. Hence, affinity tag removal with TEV protease was tested from three membrane proteins (a Pgp synthase and two CorA homologs) in the presence of 16 different detergents commonly used in membrane protein purification and crystallization. We observed that in the presence of the same detergent (Triton X-100), TEV protease could remove the affinity tag completely from one protein (CorA) but not from another protein (Pgp synthase). There was also a large variation in yield of cleaved membrane protein in different detergents, which probably depends on features of the protein-detergent complex. These observations show that, contrary to an earlier report, detergents do not inhibit the enzymatic activity of the TEV protease.
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Affiliation(s)
- Anna-Karin Lundbäck
- Division of Biophysics, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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34
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Han GS, O'Hara L, Siniossoglou S, Carman GM. Characterization of the yeast DGK1-encoded CTP-dependent diacylglycerol kinase. J Biol Chem 2008; 283:20443-53. [PMID: 18458076 DOI: 10.1074/jbc.m802866200] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Saccharomyces cerevisiae DGK1 gene encodes a diacylglycerol kinase enzyme that catalyzes the formation of phosphatidate from diacylglycerol. Unlike the diacylglycerol kinases from bacteria, plants, and animals, the yeast enzyme utilizes CTP, instead of ATP, as the phosphate donor in the reaction. Dgk1p contains a CTP transferase domain that is present in the SEC59-encoded dolichol kinase and CDS1-encoded CDP-diacylglycerol synthase enzymes. Deletion analysis showed that the CTP transferase domain was sufficient for diacylglycerol kinase activity. Point mutations (R76A, K77A, D177A, and G184A) of conserved residues within the CTP transferase domain caused a loss of diacylglycerol kinase activity. Analysis of DGK1 alleles showed that the in vivo functions of Dgk1p were specifically due to its diacylglycerol kinase activity. The DGK1-encoded enzyme had a pH optimum at 7.0-7.5, required Ca(2+) or Mg(2+) ions for activity, was potently inhibited by N-ethylmaleimide, and was labile at temperatures above 40 degrees C. The enzyme exhibited positive cooperative (Hill number = 2.5) kinetics with respect to diacylglycerol (apparent K(m) = 6.5 mol %) and saturation kinetics with respect to CTP (apparent K(m) = 0.3 mm). dCTP was both a substrate (apparent K(m) = 0.4 mm) and competitive inhibitor (apparent K(i) = 0.4 mm) of the enzyme. Diacylglycerol kinase activity was stimulated by major membrane phospholipids and was inhibited by CDP-diacylglycerol and sphingoid bases.
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Affiliation(s)
- Gil-Soo Han
- Department of Food Science and the Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ 08901, USA
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35
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Cheng H, Mancuso DJ, Jiang X, Guan S, Yang J, Yang K, Sun G, Gross RW, Han X. Shotgun lipidomics reveals the temporally dependent, highly diversified cardiolipin profile in the mammalian brain: temporally coordinated postnatal diversification of cardiolipin molecular species with neuronal remodeling. Biochemistry 2008; 47:5869-80. [PMID: 18454555 DOI: 10.1021/bi7023282] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Large-scale neuronal remodeling through apoptosis occurs shortly after birth in all known mammalian species. Apoptosis, in large part, depends upon critical interactions between mitochondrial membranes and cytochrome c. Herein, we examined the hypothesis that the large-scale reorganization of neuronal circuitry after birth is accompanied by profound alterations in cardiolipin (CL) content and molecular species distribution. During embryonic development, over 100 CL molecular species were identified and quantitated in murine neuronal tissues. The embryonic CL profile was notable for the presence of abundant amounts of relatively short aliphatic chains (e.g., palmitoleic and oleic acids). In sharp contrast, after birth, the CL profile contained a remarkably complex repertoire of CL molecular species, in which the signaling fatty acids (i.e., arachidonic and docosahexaenoic acids) were markedly increased. These results identify the rapid remodeling of CL in the perinatal period with resultant alterations in the physical properties of the mitochondrial membrane. The complex distribution of aliphatic chains in the neuronal CL pool is separate and distinct from that in other organs (e.g., heart, liver, etc.), where CL molecular species contain predominantly only one major type of aliphatic chain (e.g., linoleic acid). Analyses of mRNA levels by real-time quantitative polymerase chain reactions suggested that the alterations in CL content were due to the combined effects of both attenuation of de novo CL biosynthesis and decreased remodeling of CL. Collectively, these results provide a new perspective on the complexity of CL in neuronal signaling, mitochondrial bioenergetics, and apoptosis.
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Affiliation(s)
- Hua Cheng
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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36
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Simocková M, Holic R, Tahotná D, Patton-Vogt J, Griac P. Yeast Pgc1p (YPL206c) controls the amount of phosphatidylglycerol via a phospholipase C-type degradation mechanism. J Biol Chem 2008; 283:17107-15. [PMID: 18434318 DOI: 10.1074/jbc.m800868200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The product of the open reading frame YPL206c, Pgc1p, of the yeast Saccharomyces cerevisiae displays homology to bacterial and mammalian glycerophosphodiester phosphodiesterases. Deletion of PGC1 causes an accumulation of the anionic phospholipid, phosphatidylglycerol (PG), especially under conditions of inositol limitation. This PG accumulation was not caused by increased production of phosphatidyl-glycerol phosphate or by decreased consumption of PG in the formation of cardiolipin, the end product of the pathway. PG accumulation in the pgc1Delta strain was caused rather by inactivation of the PG degradation pathway. Our data demonstrate an existence of a novel regulatory mechanism in the cardiolipin biosynthetic pathway in which Pgc1p is required for the removal of excess PG via a phospholipase C-type degradation mechanism.
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Affiliation(s)
- Mária Simocková
- Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Moyzesova 61, Ivanka pri Dunaji, 900 28, Slovakia
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37
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Batova M, Borecka-Melkusova S, Simockova M, Dzugasova V, Goffa E, Subik J. Functional characterization of the CgPGS1 gene reveals a link between mitochondrial phospholipid homeostasis and drug resistance in Candida glabrata. Curr Genet 2008; 53:313-22. [PMID: 18343926 DOI: 10.1007/s00294-008-0187-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 03/04/2008] [Accepted: 03/05/2008] [Indexed: 10/22/2022]
Abstract
Cardiolipin and its precursor phosphatidylglycerol are two anionic phospholipids that are essential for the biogenesis of functional mitochondria. To assess their role in mitochondrial and cellular functions in the pathogenic yeast Candida glabrata, a functional characterization of the CgPGS1 gene encoding the phosphatidylglycerolphosphate synthase has been carried out. Transposon insertion mutation in CgPGS1 resulted in the loss of phosphatidylglycerolphosphate synthase activity and in deficiency of both phosphatidylglycerol and cardiolipin. The Cgpgs1 Delta mutant cells displayed reduced amounts of cytochrome b and cytochrome a, and had impaired growth on minimal media containing non-fermentable carbon and energy sources. They did not grow at elevated temperatures and failed to form colonies after induction of mitochondrial DNA deletions. The mutant cells also displayed a decreased susceptibility to fluconazole, ketoconazole, clotrimazole, voriconazole and posaconazole. In the Cgpgs1 Delta mutant, a quantitative real time PCR revealed enhanced mRNA levels for multidrug resistance associated genes such as CgPDR1 encoding transcriptional activator and CgCDR1, CgPDH1 and CgSNQ2 coding for drug efflux transporters. These results indicate that CgPGS1 and anionic phospholipids are required for optimal mitochondrial functions and maintenance of yeast susceptibility to azole antifungals.
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Affiliation(s)
- Monika Batova
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina B-2, 842 15 Bratislava 4, Slovak Republic
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38
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Guler JL, Kriegova E, Smith TK, Lukeš J, Englund PT. Mitochondrial fatty acid synthesis is required for normal mitochondrial morphology and function in Trypanosoma brucei. Mol Microbiol 2008; 67:1125-42. [PMID: 18221265 PMCID: PMC3776142 DOI: 10.1111/j.1365-2958.2008.06112.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Trypanosoma brucei use microsomal elongases for de novo synthesis of most of its fatty acids. In addition, this parasite utilizes an essential mitochondrial type II synthase for production of octanoate (a lipoic acid precursor) as well as longer fatty acids such as palmitate. Evidence from other organisms suggests that mitochondrially synthesized fatty acids are required for efficient respiration but the exact relationship remains unclear. In procyclic form trypanosomes, we also found that RNAi depletion of the mitochondrial acyl carrier protein, an important component of the fatty acid synthesis machinery, significantly reduces cytochrome-mediated respiration. This reduction was explained by RNAi-mediated inhibition of respiratory complexes II, III and IV, but not complex I. Other effects of RNAi, such as changes in mitochondrial morphology and alterations in membrane potential, raised the possibility of a change in mitochondrial membrane composition. Using mass spectrometry, we observed a decrease in total and mitochondrial phosphatidylinositol and mitochondrial phosphatidylethanolamine. Thus, we conclude that the mitochondrial synthase produces fatty acids needed for maintaining local phospholipid levels that are required for activity of respiratory complexes and preservation of mitochondrial morphology and function.
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Affiliation(s)
- Jennifer L. Guler
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Eva Kriegova
- Institute of Parasitology, Czech Academy of Sciences, and Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Terry K. Smith
- Division of Biological Chemistry and Drug Discovery, Wellcome Trust Biocentre, College of Life Sciences, University of Dundee, Dundee, Scotland
| | - Julius Lukeš
- Institute of Parasitology, Czech Academy of Sciences, and Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Paul T. Englund
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Lipids in the assembly of membrane proteins and organization of protein supercomplexes: implications for lipid-linked disorders. Subcell Biochem 2008; 49:197-239. [PMID: 18751913 DOI: 10.1007/978-1-4020-8831-5_8] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Lipids play important roles in cellular dysfunction leading to disease. Although a major role for phospholipids is in defining the membrane permeability barrier, phospholipids play a central role in a diverse range of cellular processes and therefore are important factors in cellular dysfunction and disease. This review is focused on the role of phospholipids in normal assembly and organization of the membrane proteins, multimeric protein complexes, and higher order supercomplexes. Since lipids have no catalytic activity, it is difficult to determine their function at the molecular level. Lipid function has generally been defined by affects on protein function or cellular processes. Molecular details derived from genetic, biochemical, and structural approaches are presented for involvement of phosphatidylethanolamine and cardiolipin in protein organization. Experimental evidence is presented that changes in phosphatidylethanolamine levels results in misfolding and topological misorientation of membrane proteins leading to dysfunctional proteins. Examples are presented for diseases in which proper protein folding or topological organization is not attained due to either demonstrated or proposed involvement of a lipid. Similar changes in cardiolipin levels affects the structure and function of individual components of the mitochondrial electron transport chain and their organization into supercomplexes resulting in reduced mitochondrial oxidative phosphorylation efficiency and apoptosis. Diseases in which mitochondrial dysfunction has been linked to reduced cardiolipin levels are described. Therefore, understanding the principles governing lipid-dependent assembly and organization of membrane proteins and protein complexes will be useful in developing novel therapeutic approaches for disorders in which lipids play an important role.
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40
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Schlame M. Cardiolipin synthesis for the assembly of bacterial and mitochondrial membranes. J Lipid Res 2007; 49:1607-20. [PMID: 18077827 DOI: 10.1194/jlr.r700018-jlr200] [Citation(s) in RCA: 292] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In this article, the formation of prokaryotic and eukaryotic cardiolipin is reviewed in light of its biological function. I begin with a detailed account of the structure of cardiolipin, its stereochemistry, and the resulting physical properties, and I present structural analogs of cardiolipin that occur in some organisms. Then I continue to discuss i) the de novo formation of cardiolipin, ii) its acyl remodeling, iii) the assembly of cardiolipin into biological membranes, and iv) the degradation of cardiolipin, which may be involved in apoptosis and mitochondrial fusion. Thus, this article covers the entire metabolic cycle of this unique phospholipid. It is shown that mitochondria produce cardiolipin species with a high degree of structural uniformity and molecular symmetry, among which there is often a dominant form with four identical acyl chains. The subsequent assembly of cardiolipin into functional membranes is largely unknown, but the analysis of crystal structures of membrane proteins has revealed a first glimpse into the underlying principles of cardiolipin-protein interactions. Disturbances of cardiolipin metabolism are crucial in the pathophysiology of human Barth syndrome and perhaps also play a role in diabetes and ischemic heart disease.
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Affiliation(s)
- Michael Schlame
- Department of Anesthesiology and Cell Biology, New York University School of Medicine, New York, NY 10016, USA.
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41
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Regulation of mitochondrial oxidative phosphorylation through cell signaling. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1773:1701-20. [DOI: 10.1016/j.bbamcr.2007.10.001] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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42
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Han GS, Siniossoglou S, Carman GM. The cellular functions of the yeast lipin homolog PAH1p are dependent on its phosphatidate phosphatase activity. J Biol Chem 2007; 282:37026-35. [PMID: 17971454 DOI: 10.1074/jbc.m705777200] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Saccharomyces cerevisiae PAH1-encoded Mg2+-dependent phosphatidate phosphatase (PAP1, 3-sn-phosphatidate phosphohydrolase, EC 3.1.3.4) catalyzes the dephosphorylation of phosphatidate to yield diacylglycerol and Pi. This enzyme plays a major role in the synthesis of triacylglycerols and phospholipids in S. cerevisiae. PAP1 contains the DXDX(T/V) catalytic motif (DIDGT at residues 398-402) that is shared by the mammalian fat-regulating protein lipin 1 and the superfamily of haloacid dehalogenase-like proteins. The yeast enzyme also contains a conserved glycine residue (Gly80) that is essential for the fat-regulating function of lipin 1 in a mouse model. In this study, we examined the roles of the putative catalytic motif and the conserved glycine for PAP1 activity by a mutational analysis. The PAP1 activities of the D398E and D400E mutant enzymes were reduced by >99.9%, and the activity of the G80R mutant enzyme was reduced by 98%. The mutant PAH1 alleles whose products lacked PAP1 activity were nonfunctional in vivo and failed to complement the pah1Delta mutant phenotypes of temperature sensitivity, respiratory deficiency, nuclear/endoplasmic reticulum membrane expansion, derepression of INO1 expression, and alterations in lipid composition. These results demonstrated that the PAP1 activity of the PAH1 gene product is essential for its roles in lipid metabolism and cell physiology.
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Affiliation(s)
- Gil-Soo Han
- Department of Food Science and the Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey 08901, USA
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43
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Tamaki H, Shimada A, Ito Y, Ohya M, Takase J, Miyashita M, Miyagawa H, Nozaki H, Nakayama R, Kumagai H. LPT1 encodes a membrane-bound O-acyltransferase involved in the acylation of lysophospholipids in the yeast Saccharomyces cerevisiae. J Biol Chem 2007; 282:34288-98. [PMID: 17890783 DOI: 10.1074/jbc.m704509200] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phospholipids are major components of cellular membranes that participate in a range of cellular processes. Phosphatidic acid (PA) is a key molecule in the phospholipid biosynthetic pathway. In Saccharomyces cerevisiae, SLC1 has been identified as the gene encoding lysophosphatidic acid acyltransferase, which catalyzes PA synthesis. However, despite the importance of PA, disruption of SLC1 does not affect cell viability (Nagiec, M. M., Wells, G. B., Lester, R. L., and Dickson, R. C. (1993) J. Biol. Chem. 268, 22156-22163). We originally aimed to identify the acetyl-CoA:lyso platelet-activating factor acetyltransferase (lysoPAF AT) gene in yeast. Screening of a complete set of yeast deletion clones (4741 homozygous diploid clones) revealed a single mutant strain, YOR175c, with a defect in lysoPAF AT activity. YOR175c has been predicted to be a member of the membrane-bound O-acyltransferase superfamily, and we designated the gene LPT1. An Lpt1-green fluorescent protein fusion protein localized at the endoplasmic reticulum. Other than lysoPAF AT activity, Lpt1 catalyzed acyltransferase activity with a wide variety of lysophospholipids as acceptors, including lysophosphatidic acid, lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylglycerol, lysophosphatidylinositol, and lysophosphatidylserine. A liquid chromatography-mass spectrometry analysis indicated that lysophosphatidylcholine and lysophosphatidylethanolamine accumulated in the Deltalpt1 mutant strain. Although the Deltalpt1 mutant strain did not show other detectable defects, the Deltalpt1 Deltaslc1 double mutant strain had a synthetic lethal phenotype. These results indicate that, in concert with Slc1, Lpt1 plays a central role in PA biosynthesis, which is essential for cell viability.
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Affiliation(s)
- Hisanori Tamaki
- Department of Biochemical Science and Technology, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima, Japan.
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44
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Choi HS, Carman GM. Respiratory deficiency mediates the regulation of CHO1-encoded phosphatidylserine synthase by mRNA stability in Saccharomyces cerevisiae. J Biol Chem 2007; 282:31217-27. [PMID: 17761681 PMCID: PMC2150996 DOI: 10.1074/jbc.m705098200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The CHO1-encoded phosphatidylserine synthase (CDP-diacylglycerol:l-serine O-phosphatidyltransferase, EC 2.7.8.8) is one of the most highly regulated phospholipid biosynthetic enzymes in the yeast Saccharomyces cerevisiae. CHO1 expression is regulated by nutrient availability through a regulatory circuit involving a UAS(INO) cis-acting element in the CHO1 promoter, the positive transcription factors Ino2p and Ino4p, and the transcriptional repressor Opi1p. In this work, we examined the post-transcriptional regulation of CHO1 by mRNA stability. CHO1 mRNA was stabilized in mutants defective in deadenylation (ccr4Delta), mRNA decapping (dcp1), and the 5'-3'-exonuclease (xrn1), indicating that the CHO1 transcript is primarily degraded through the general 5'-3' mRNA decay pathway. In respiratory-sufficient cells, the CHO1 transcript was moderately stable with a half-life of 12 min. However, the CHO1 transcript was stabilized to a half-life of >45 min in respiratory-deficient (rho(-) and rho(o)) cells, the cox4Delta mutant defective in the cytochrome c oxidase, and wild type cells treated with KCN (a cytochrome c oxidase inhibitor). The increased CHO1 mRNA stability in response to respiratory deficiency caused increases in CHO1 mRNA abundance, phosphatidylserine synthase protein and activity, and the synthesis of phosphatidylserine in vivo. Respiratory deficiency also caused increases in the activities of CDP-diacylglycerol synthase, phosphatidylserine decarboxylase, and the phospholipid methyltransferases. Phosphatidylinositol synthase and choline kinase activities were not affected by respiratory deficiency. This work advances our understanding of phosphatidylserine synthase regulation and underscores the importance of mitochondrial respiration to the regulation of phospholipid synthesis in S. cerevisiae.
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Affiliation(s)
| | - George M. Carman
- To whom correspondence should be addressed. Dept of Food Science, Rutgers University, 65 Dudley Rd., New Brunswick, NJ 08901. Tel: 732-932-9611 (ext. 217); E-mail:
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45
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Gulmezian M, Hyman KR, Marbois BN, Clarke CF, Javor GT. The role of UbiX in Escherichia coli coenzyme Q biosynthesis. Arch Biochem Biophys 2007; 467:144-53. [PMID: 17889824 PMCID: PMC2475804 DOI: 10.1016/j.abb.2007.08.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2007] [Revised: 08/06/2007] [Accepted: 08/07/2007] [Indexed: 11/17/2022]
Abstract
The reversible redox chemistry of coenzyme Q serves a crucial function in respiratory electron transport. Biosynthesis of Q in Escherichia coli depends on the ubi genes. However, very little is known about UbiX, an enzyme thought to be involved in the decarboxylation step in Q biosynthesis in E. coli and Salmonella enterica. Here we characterize an E. coli ubiX gene deletion strain, LL1, to further elucidate E. coli ubiX function in Q biosynthesis. LLI produces very low levels of Q, grows slowly on succinate as the sole carbon source, accumulates 4-hydroxy-3-octaprenyl-benzoate, and has reduced UbiG O-methyltransferase activity. Expression of either E. coli ubiX or the Saccharomyces cerevisiae ortholog PAD1, rescues the deficient phenotypes of LL1, identifying PAD1 as an ortholog of ubiX. Our results suggest that both UbiX and UbiD are required for the decarboxylation of 4-hydroxy-3-octaprenyl-benzoate in E. coli coenzyme Q biosynthesis, especially during logarithmic growth.
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Affiliation(s)
- Melissa Gulmezian
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, 90095
| | - Kyle R. Hyman
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, 90095
| | - Beth N. Marbois
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, 90095
| | - Catherine F. Clarke
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, 90095
- Joint corresponding author: Department of Chemistry and Biochemistry, 607 Charles E. Young Dr., Los Angeles CA 90095-1569. Tel. (310) 825-0771; Fax (310) 206-7286; ; *Joint corresponding author: Department of Biochemistry, Loma Linda University School of Medicine, Loma Linda CA. 92354.
| | - George T. Javor
- Department of Biochemistry, Loma Linda University School of Medicine, Loma Linda, California 92354
- Joint corresponding author: Department of Chemistry and Biochemistry, 607 Charles E. Young Dr., Los Angeles CA 90095-1569. Tel. (310) 825-0771; Fax (310) 206-7286; ; *Joint corresponding author: Department of Biochemistry, Loma Linda University School of Medicine, Loma Linda CA. 92354.
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46
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Han X, Yang J, Yang K, Zhao Z, Abendschein DR, Gross RW. Alterations in myocardial cardiolipin content and composition occur at the very earliest stages of diabetes: a shotgun lipidomics study. Biochemistry 2007; 46:6417-28. [PMID: 17487985 PMCID: PMC2139909 DOI: 10.1021/bi7004015] [Citation(s) in RCA: 225] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recently, we have identified the dramatic depletion of cardiolipin (CL) in diabetic myocardium 6 weeks after streptozotocin (STZ) injection that was accompanied by increases in triacylglycerol content and multiple changes in polar lipid molecular species. However, after 6 weeks in the diabetic state, the predominant lipid hallmarks of diabetic cardiomyopathy were each present concomitantly, and thus, it was impossible to identify the temporal course of lipid alterations in diabetic myocardium. Using the newly developed enhanced shotgun lipidomics approach, we demonstrated the dramatic loss of abundant CL molecular species in STZ-treated hearts at the very earliest stages of diabetes accompanied by a profound remodeling of the remaining CL molecular species including a 16-fold increase in the content of 18:2-22:6-22:6-22:6 CL. These alterations in CL metabolism occur within days after the induction of the diabetic state and precede the triacylglycerol accumulation manifest in diabetic myocardium. Similarly, in ob/ob mice, a dramatic and progressive redistribution from 18:2 FA-containing CL molecular species to 22:6 FA-containing CL molecular species was also identified. Collectively, these results demonstrate alterations in CL hydrolysis and remodeling at the earliest stages of diabetes and are consistent with a role for alterations in CL content in precipitating mitochondrial dysfunction in diabetic cardiomyopathy.
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Affiliation(s)
- Xianlin Han
- Division of Bioorganic Chemistry and Molecular Pharmacology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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