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Venkatraman K, Budin I. Cardiolipin remodeling maintains the inner mitochondrial membrane in cells with saturated lipidomes. J Lipid Res 2024:100601. [PMID: 39038656 DOI: 10.1016/j.jlr.2024.100601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/14/2024] [Accepted: 07/16/2024] [Indexed: 07/24/2024] Open
Abstract
Cardiolipin (CL) is a unique, four-chain phospholipid synthesized in the inner mitochondrial membrane (IMM). The acyl chain composition of CL is regulated through a remodeling pathway, whose loss causes mitochondrial dysfunction in Barth syndrome (BTHS). Yeast has been used extensively as a model system to characterize CL metabolism, but mutants lacking its two remodeling enzymes, Cld1p and Taz1p, exhibit mild structural and respiratory phenotypes compared to mammalian cells. Here we show the essential role of CL remodeling in the structure and function of the IMM in yeast grown under reduced oxygenation. Microaerobic fermentation, which mimics natural yeast environments, caused the accumulation of saturated fatty acids and, under these conditions, remodeling mutants showed a loss of IMM ultrastructure. We extended this observation to HEK293 cells, where iPLA2 inhibition by Bromoenol lactone resulted in respiratory dysfunction and cristae loss upon mild treatment with exogenous saturated fatty acids. In microaerobic yeast, remodeling mutants accumulated unremodeled, saturated CL, but also displayed reduced total CL levels, highlighting the interplay between saturation and CL biosynthesis and breakdown. We identified the mitochondrial phospholipase A1 Ddl1p as a regulator of CL levels, and those of its precursors phosphatidylglycerol and phosphatidic acid, under these conditions. Loss of DDL1 partially rescued IMM structure in cells unable to initiate CL remodeling and had differing lipidomic effects depending on oxygenation. These results introduce a revised yeast model for investigating CL remodeling and suggest that its structural functions are dependent on the overall lipid environment in the mitochondrion.
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Affiliation(s)
- Kailash Venkatraman
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Itay Budin
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA.
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2
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Eldeeb MH, Camacho Lopez LJ, Fontanesi F. Mitochondrial respiratory supercomplexes of the yeast Saccharomyces cerevisiae. IUBMB Life 2024. [PMID: 38529880 DOI: 10.1002/iub.2817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 02/28/2024] [Indexed: 03/27/2024]
Abstract
The functional and structural relationship among the individual components of the mitochondrial respiratory chain constitutes a central aspect of our understanding of aerobic catabolism. This interplay has been a subject of intense debate for over 50 years. It is well established that individual respiratory enzymes associate into higher-order structures known as respiratory supercomplexes, which represent the evolutionarily conserved organizing principle of the mitochondrial respiratory chain. In the yeast Saccharomyces cerevisiae, supercomplexes are formed by a complex III homodimer flanked by one or two complex IV monomers, and their high-resolution structures have been recently elucidated. Despite the wealth of structural information, several proposed supercomplex functions remain speculative and our understanding of their physiological relevance is still limited. Recent advances in the field were made possible by the construction of yeast strains where the association of complex III and IV into supercomplexes is impeded, leading to diminished respiratory capacity and compromised cellular competitive fitness. Here, we discuss the experimental evidence and hypotheses relative to the functional roles of yeast respiratory supercomplexes. Moreover, we review the current models of yeast complex III and IV assembly in the context of supercomplex formation and highlight the data scattered throughout the literature suggesting the existence of cross talk between their biogenetic processes.
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Affiliation(s)
- Mazzen H Eldeeb
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Lizeth J Camacho Lopez
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Flavia Fontanesi
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA
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3
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Joshi A, Gohil VM. Cardiolipin deficiency leads to the destabilization of mitochondrial magnesium channel MRS2 in Barth syndrome. Hum Mol Genet 2023; 32:3353-3360. [PMID: 37721533 DOI: 10.1093/hmg/ddad153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/10/2023] [Accepted: 09/11/2023] [Indexed: 09/19/2023] Open
Abstract
Barth syndrome (BTHS) is a debilitating X-linked cardio-skeletal myopathy caused by loss-of-function mutations in TAFAZZIN, a cardiolipin (CL)-remodeling enzyme required for the maintenance of normal levels of CL species in mitochondrial membranes. At present, how perturbations in CL abundance and composition lead to many debilitating clinical presentations in BTHS patients have not been fully elucidated. Inspired by our recent findings that CL is essential for optimal mitochondrial calcium uptake, we measured the levels of other biologically important metal ions in BTHS mitochondria and found that in addition to calcium, magnesium levels are significantly reduced. Consistent with this observation, we report a decreased abundance of the mitochondrial magnesium influx channel MRS2 in multiple models of BTHS including yeast, murine myoblast, and BTHS patient cells and cardiac tissue. Mechanistically, we attribute reduced steady-state levels of MRS2 to its increased turnover in CL-deficient BTHS models. By expressing Mrs2 in well-characterized yeast mutants of the phospholipid biosynthetic pathways, we demonstrate a specific requirement of CL for Mrs2 abundance and assembly. Finally, we provide in vitro evidence for the direct binding of CL with human MRS2. Together, our study has identified a critical requirement of CL for MRS2 stability and suggests perturbation of mitochondrial magnesium homeostasis as a novel contributing factor to BTHS pathology.
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Affiliation(s)
- Alaumy Joshi
- Department of Biochemistry and Biophysics, Texas A&M University, 301 Old Main Drive, TAMU 3474, College Station, TX 77843, United States
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, 301 Old Main Drive, TAMU 3474, College Station, TX 77843, United States
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Magistrati M, Gilea AI, Gerra MC, Baruffini E, Dallabona C. Drug Drop Test: How to Quickly Identify Potential Therapeutic Compounds for Mitochondrial Diseases Using Yeast Saccharomyces cerevisiae. Int J Mol Sci 2023; 24:10696. [PMID: 37445873 DOI: 10.3390/ijms241310696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/22/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023] Open
Abstract
Mitochondrial diseases (MDs) refer to a group of clinically and genetically heterogeneous pathologies characterized by defective mitochondrial function and energy production. Unfortunately, there is no effective treatment for most MDs, and current therapeutic management is limited to relieving symptoms. The yeast Saccharomyces cerevisiae has been efficiently used as a model organism to study mitochondria-related disorders thanks to its easy manipulation and well-known mitochondrial biogenesis and metabolism. It has been successfully exploited both to validate alleged pathogenic variants identified in patients and to discover potential beneficial molecules for their treatment. The so-called "drug drop test", a phenotype-based high-throughput screening, especially if coupled with a drug repurposing approach, allows the identification of molecules with high translational potential in a cost-effective and time-saving manner. In addition to drug identification, S. cerevisiae can be used to point out the drug's target or pathway. To date, drug drop tests have been successfully carried out for a variety of disease models, leading to very promising results. The most relevant aspect is that studies on more complex model organisms confirmed the effectiveness of the drugs, strengthening the results obtained in yeast and demonstrating the usefulness of this screening as a novel approach to revealing new therapeutic molecules for MDs.
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Affiliation(s)
- Martina Magistrati
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Alexandru Ionut Gilea
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Maria Carla Gerra
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
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Płatek T, Sordyl M, Polus A, Olszanecka A, Kroczka S, Solnica B. Analysis of tafazzin and deoxyribonuclease 1 like 1 transcripts and X chromosome sequencing in the evaluation of the effect of mosaicism in the TAZ gene on phenotypes in a family affected by Barth syndrome. Mutat Res 2022; 826:111812. [PMID: 36628843 DOI: 10.1016/j.mrfmmm.2022.111812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 11/11/2022] [Accepted: 12/23/2022] [Indexed: 12/31/2022]
Abstract
Barth syndrome is a rare disease affecting mitochondria structure and function in males. In our previous study, we have shown a new mutation (c.83T>A, p.Val28Glu) in the TAZ gene in two affected patients with congenital cardiomyopathy. Furthermore, women in this family had no mutations in their blood cells, whereas they only had mutations in the oral epithelial cells. The objective of the project was to evaluate the effect of intertissue mosaicisms on the Barth syndrome phenotypes, searching for another disease-related loci on chromosome X and finally to assess the consequences of the mutation. We conducted the advanced genetic study including cytogenetic research (constitutional karyotyping in blood and fibroblasts), NGS sequencing (with custom chromosome X sequencing together with the evaluation of loss of heterozygosity (LOH) and aberrations (CNV) in the whole genome) in four different tissues and sequencing of tafazzin and deoxyribonuclease 1 like 1 transcripts. The presence of deletions within the 5'untranslated region of the TAZ gene and/or the noncoding regions of the DNASE1L1 gene were detected in several tissues. Whereas, there is no intertissue mosaicism regarding point mutation in TAZ gene in all investigated tissues in female carriers. Only the male patient presented biochemical markers and neurological symptoms of Barth syndrome. All the female carriers are healthy and have normal tafazzin and deoxyribonuclease 1 like 1 transcripts in 2 analyzed tissues. The conclusion of this study is that we cannot rule out or confirm mosaicism in the noncoding regions of TAZ or DNASE1L1 genes, but this is not clinically relevant in female carriers because they are healthy. Finally, it has been proven that mutation (c.83T>A, p.Val28Glu) is responsible for disease in males in this family.
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Affiliation(s)
- Teresa Płatek
- Department of Clinical Biochemistry, Jagiellonian University Medical College, Kraków, Poland.
| | - Maria Sordyl
- Department of Clinical Biochemistry, Jagiellonian University Medical College, Kraków, Poland
| | - Anna Polus
- Department of Clinical Biochemistry, Jagiellonian University Medical College, Kraków, Poland
| | - Agnieszka Olszanecka
- 1st Department of Cardiology, Interventional Electrocardiology and Hypertension, Faculty of Medicine, Jagiellonian University Medical College, Krakow, Poland
| | - Sławomir Kroczka
- Department of Child and Adolescent Neurology, Jagiellonian University Medical College, Krakow, Poland; Department of Child Neurology, University Children's Hospital, Krakow, Poland
| | - Bogdan Solnica
- Department of Clinical Biochemistry, Jagiellonian University Medical College, Kraków, Poland
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Hornby B, Thompson WR, Almuqbil M, Manuel R, Abbruscato A, Carr J, Vernon HJ. Natural history comparison study to assess the efficacy of elamipretide in patients with Barth syndrome. Orphanet J Rare Dis 2022; 17:336. [PMID: 36056411 PMCID: PMC9438322 DOI: 10.1186/s13023-022-02469-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 08/13/2022] [Indexed: 11/23/2022] Open
Abstract
Background Natural history studies are increasingly recognized as having an important role in drug development for rare diseases. A phase 3, observational, retrospective, and non-interventional study was designed to establish a natural history control (NHC) cohort of patients with Barth syndrome (BTHS) to provide further analysis of the efficacy of elamipretide observed in an open-label extension (OLE) phase of the TAZPOWER trial, a clinical trial that tested the efficacy of 40 mg daily of elamipretide in patients with BTHS. Methods This was a retrospective, non-interventional study. A propensity score model was used to compare elamipretide-treated patients and NHCs. The analysis included 8 patients from the TAZPOWER OLE and 19 untreated NHCs (including 12 with serial echocardiographic assessments). Results For the 6-min walk test (6MWT, primary endpoint), the least squares (LS) mean difference between groups was 79.7 m (P = 0.0004) at week 64 and 91.0 m (P = 0.0005) at week 76 in favor of elamipretide. Significant improvements in muscle strength (secondary endpoint), as assessed by handheld dynamometry (HHD) were also observed with elamipretide, with LS mean differences of 40.8 Newtons at 64 weeks (P = 0.0002) and 56.7 Newtons at 76 weeks (P = 0.0005). Patients continuously treated with elamipretide also experienced statistically significant improvements in other secondary endpoints (i.e., 5 times sit-to-stand [5XSST], multi-domain responder index [MDRI]). The functional improvements were robust to sensitivity analyses. Left ventricular stroke volume increased from baseline in patients with elamipretide but decreased in NHCs.
Conclusions Overall, the study established a NHC for use in assessing the efficacy of therapeutic interventions in patients with BTHS and the results suggest that elamipretide may improve natural history of BTHS at least in part by attenuating the natural decline in heart function and provide meaningful improvements in heart function and functional capacity in patients with BTHS compared to NHCs. Highlights A matched Natural History Control (NHC) was used to evaluate elamipretide in BTHS Elamipretide may improve natural history of BTHS by attenuating natural decline in heart function Elamipretide was associated with meaningful clinical improvements in skeletal muscle and cardiovascular parameters that were not observed in NHCs The study established a NHC for use in assessing the efficacy of therapeutic interventions in BTHS
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Affiliation(s)
- Brittany Hornby
- Department of Physical Therapy, Kennedy Krieger, Baltimore, MD, USA
| | - William Reid Thompson
- Department of Pediatric Cardiology, Taussig Heart Center, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Mohammed Almuqbil
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS); King Abdullah Specialized Children's Hospital (KASCH), Riyadh, Saudi Arabia
| | - Ryan Manuel
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, 733 N Broadway, MRB 512, Baltimore, Maryland, 21205, USA
| | | | - Jim Carr
- Stealth BioTherapeutics, Inc, Needham, MA, USA
| | - Hilary J Vernon
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, 733 N Broadway, MRB 512, Baltimore, Maryland, 21205, USA.
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Pang J, Bao Y, Mitchell-Silbaugh K, Veevers J, Fang X. Barth Syndrome Cardiomyopathy: An Update. Genes (Basel) 2022; 13:genes13040656. [PMID: 35456462 PMCID: PMC9030331 DOI: 10.3390/genes13040656] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/23/2022] [Accepted: 04/02/2022] [Indexed: 12/28/2022] Open
Abstract
Barth syndrome (BTHS) is an X-linked mitochondrial lipid disorder caused by mutations in the TAFAZZIN (TAZ) gene, which encodes a mitochondrial acyltransferase/transacylase required for cardiolipin (CL) biosynthesis. Cardiomyopathy is a major clinical feature of BTHS. During the past four decades, we have witnessed many landmark discoveries that have led to a greater understanding of clinical features of BTHS cardiomyopathy and their molecular basis, as well as the therapeutic targets for this disease. Recently published Taz knockout mouse models provide useful experimental models for studying BTHS cardiomyopathy and testing potential therapeutic approaches. This review aims to summarize key findings of the clinical features, molecular mechanisms, and potential therapeutic approaches for BTHS cardiomyopathy, with particular emphasis on the most recent studies.
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Affiliation(s)
- Jing Pang
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
- Department of Biological Science, University of California San Diego, La Jolla, CA 92093, USA
| | - Yutong Bao
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
- Department of Biological Science, University of California San Diego, La Jolla, CA 92093, USA
| | - Kalia Mitchell-Silbaugh
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
| | - Jennifer Veevers
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
| | - Xi Fang
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
- Correspondence: ; Tel.: +1-858-246-4637
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Chu I, Chen YC, Lai RY, Chan JF, Lee YH, Balazova M, Hsu YHH. Phosphatidylglycerol Supplementation Alters Mitochondrial Morphology and Cardiolipin Composition. MEMBRANES 2022; 12:membranes12040383. [PMID: 35448353 PMCID: PMC9028734 DOI: 10.3390/membranes12040383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 02/01/2023]
Abstract
The pathogenic variant of the TAZ gene is directly associated with Barth syndrome. Because tafazzin in the mitochondria is responsible for cardiolipin (CL) remodeling, all molecules related to the metabolism of CL can affect or be affected by TAZ mutation. In this study, we intend to recover the distortion of the mitochondrial lipid composition, especially CL, for Barth syndrome treatment. The genetically edited TAZ knockout HAP1 cells were demonstrated to be a suitable cellular model, where CL desaturation occurred and monolyso-CL (MLCL) was accumulated. From the species analysis by mass spectrometry, phosphatidylethanolamine showed changed species content after TAZ knockout. TAZ knockout also caused genetic down-regulation of PGS gene and up-regulation of PNPLA8 gene, which may decrease the biosynthesis of CLs and increase the hydrolysis product MLCL. Supplemented phosphatidylglycerol(18:1)2 (PG(18:1)2) was successfully biosynthesized to mature symmetrical CL and drastically decrease the concentration of MLCL to recover the morphology of mitochondria and the cristae shape of inner mitochondria. Newly synthesized mature CL may induce the down-regulation of PLA2G6 and PNPLA8 genes to potentially decrease MLCL production. The excess supplemented PG was further metabolized into phosphatidylcholine and phosphatidylethanolamine.
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Affiliation(s)
- I Chu
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan; (I.C.); (Y.-C.C.); (R.-Y.L.); (J.-F.C.); (Y.-H.L.)
| | - Ying-Chih Chen
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan; (I.C.); (Y.-C.C.); (R.-Y.L.); (J.-F.C.); (Y.-H.L.)
| | - Ruo-Yun Lai
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan; (I.C.); (Y.-C.C.); (R.-Y.L.); (J.-F.C.); (Y.-H.L.)
| | - Jui-Fen Chan
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan; (I.C.); (Y.-C.C.); (R.-Y.L.); (J.-F.C.); (Y.-H.L.)
| | - Ya-Hui Lee
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan; (I.C.); (Y.-C.C.); (R.-Y.L.); (J.-F.C.); (Y.-H.L.)
| | - Maria Balazova
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, 840 05 Bratislava, Slovakia;
| | - Yuan-Hao Howard Hsu
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan; (I.C.); (Y.-C.C.); (R.-Y.L.); (J.-F.C.); (Y.-H.L.)
- Correspondence: ; Tel.: +886-4-23590121 (ext. 32230); Fax: +886-4-23590426
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Murakami A, Nagao K, Sakaguchi R, Kida K, Hara Y, Mori Y, Okabe K, Harada Y, Umeda M. Cell-autonomous control of intracellular temperature by unsaturation of phospholipid acyl chains. Cell Rep 2022; 38:110487. [PMID: 35294880 DOI: 10.1016/j.celrep.2022.110487] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 12/03/2021] [Accepted: 02/14/2022] [Indexed: 11/25/2022] Open
Abstract
Intracellular temperature affects a wide range of cellular functions in living organisms. However, it remains unclear whether temperature in individual animal cells is controlled autonomously as a response to fluctuations in environmental temperature. Using two distinct intracellular thermometers, we find that the intracellular temperature of steady-state Drosophila S2 cells is maintained in a manner dependent on Δ9-fatty acid desaturase DESAT1, which introduces a double bond at the Δ9 position of the acyl moiety of acyl-CoA. The DESAT1-mediated increase of intracellular temperature is caused by the enhancement of F1Fo-ATPase-dependent mitochondrial respiration, which is coupled with thermogenesis. We also reveal that F1Fo-ATPase-dependent mitochondrial respiration is potentiated by cold exposure through the remodeling of mitochondrial cristae structures via DESAT1-dependent unsaturation of mitochondrial phospholipid acyl chains. Based on these findings, we propose a cell-autonomous mechanism for intracellular temperature control during environmental temperature changes.
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Affiliation(s)
- Akira Murakami
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan; Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Kohjiro Nagao
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
| | - Reiko Sakaguchi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Keisuke Kida
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Yuji Hara
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Yasuo Mori
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Kohki Okabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yoshie Harada
- Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Masato Umeda
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
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Zhao Q, Luo T, Gao F, Fu Y, Li B, Shao X, Chen H, Zhou Z, Guo S, Shen L, Jin L, Cen D, Zhou H, Lyu J, Fang H. GRP75 Regulates Mitochondrial-Supercomplex Turnover to Modulate Insulin Sensitivity. Diabetes 2022; 71:233-248. [PMID: 34810178 DOI: 10.2337/db21-0173] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 11/16/2021] [Indexed: 11/13/2022]
Abstract
GRP75 (75-kDA glucose-regulated protein), defined as a major component of both the mitochondrial quality control system and mitochondria-associated membrane, plays a key role in mitochondrial homeostasis. In this study, we assessed the roles of GRP75, other than as a component, in insulin action in both in vitro and in vivo models with insulin resistance. We found that GRP75 was downregulated in mice fed a high-fat diet (HFD) and that induction of Grp75 in mice could prevent HFD-induced obesity and insulin resistance. Mechanistically, GRP75 influenced insulin sensitivity by regulating mitochondrial function through its modulation of mitochondrial-supercomplex turnover rather than mitochondria-associated membrane communication: GRP75 was negatively associated with respiratory chain complex activity and was essential for mitochondrial-supercomplex assembly and stabilization. Moreover, mitochondrial dysfunction in Grp75-knockdown cells might further increase mitochondrial fragmentation, thus triggering cytosolic mtDNA release and activating the cGAS/STING-dependent proinflammatory response. Therefore, GRP75 can serve as a potential therapeutic target of insulin resistant-related diabetes or other metabolic diseases.
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Affiliation(s)
- Qiongya Zhao
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
- Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Ting Luo
- Ningbo Yinzhou No. 2 Hospital, Ningbo, Zhejiang, China
| | - Feng Gao
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Yinxu Fu
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Bin Li
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaoli Shao
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Haifeng Chen
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zhuohua Zhou
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Sihan Guo
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Lijun Shen
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Liqin Jin
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Dong Cen
- Ningbo Yinzhou No. 2 Hospital, Ningbo, Zhejiang, China
| | - Huaibin Zhou
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jianxin Lyu
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
- Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Hezhi Fang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
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11
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Dudek J, Maack C. Mechano-energetic aspects of Barth syndrome. J Inherit Metab Dis 2022; 45:82-98. [PMID: 34423473 DOI: 10.1002/jimd.12427] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/28/2021] [Accepted: 08/19/2021] [Indexed: 12/22/2022]
Abstract
Energy-demanding organs like the heart are strongly dependent on oxidative phosphorylation in mitochondria. Oxidative phosphorylation is governed by the respiratory chain located in the inner mitochondrial membrane. The inner mitochondrial membrane is the only cellular membrane with significant amounts of the phospholipid cardiolipin, and cardiolipin was found to directly interact with a number of essential protein complexes, including respiratory chain complexes I to V. An inherited defect in the biogenesis of cardiolipin causes Barth syndrome, which is associated with cardiomyopathy, skeletal myopathy, neutropenia and growth retardation. Energy conversion is dependent on reducing equivalents, which are replenished by oxidative metabolism in the Krebs cycle. Cardiolipin deficiency in Barth syndrome also affects Krebs cycle activity, metabolite transport and mitochondrial morphology. During excitation-contraction coupling, calcium (Ca2+ ) released from the sarcoplasmic reticulum drives sarcomeric contraction. At the same time, Ca2+ influx into mitochondria drives the activation of Krebs cycle dehydrogenases and the regeneration of reducing equivalents. Reducing equivalents are essential not only for energy conversion, but also for maintaining a redox buffer, which is required to detoxify reactive oxygen species (ROS). Defects in CL may also affect Ca2+ uptake into mitochondria and thereby hamper energy supply and demand matching, but also detoxification of ROS. Here, we review the impact of cardiolipin deficiency on mitochondrial function in Barth syndrome and discuss potential therapeutic strategies.
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Affiliation(s)
- Jan Dudek
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
| | - Christoph Maack
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
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12
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Ji J, Greenberg ML. Cardiolipin function in the yeast S. cerevisiae and the lessons learned for Barth syndrome. J Inherit Metab Dis 2022; 45:60-71. [PMID: 34626131 PMCID: PMC8755574 DOI: 10.1002/jimd.12447] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/21/2021] [Accepted: 10/06/2021] [Indexed: 01/03/2023]
Abstract
Cardiolipin (CL) is the signature phospholipid (PL) of mitochondria and plays a pivotal role in mitochondrial and cellular function. Disruption of the CL remodeling gene tafazzin (TAZ) causes the severe genetic disorder Barth syndrome (BTHS). Our current understanding of the function of CL and the mechanism underlying the disease has greatly benefited from studies utilizing the powerful yeast model Saccharomyces cerevisiae. In this review, we discuss important findings on the function of CL and its remodeling from yeast studies and the implications of these findings for BTHS, highlighting the potential physiological modifiers that may contribute to the disparities in clinical presentation among BTHS patients.
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Affiliation(s)
- Jiajia Ji
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
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13
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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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14
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Zegallai HM, Abu-El-Rub E, Cole LK, Field J, Mejia EM, Gordon JW, Marshall AJ, Hatch GM. Tafazzin deficiency impairs mitochondrial metabolism and function of lipopolysaccharide activated B lymphocytes in mice. FASEB J 2021; 35:e22023. [PMID: 34767647 DOI: 10.1096/fj.202100811rr] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/05/2021] [Accepted: 10/19/2021] [Indexed: 01/21/2023]
Abstract
B lymphocytes are responsible for humoral immunity and play a key role in the immune response. Optimal mitochondrial function is required to support B cell activity during activation. We examined how deficiency of tafazzin, a cardiolipin remodeling enzyme required for mitochondrial function, alters the metabolic activity of B cells and their response to activation by lipopolysaccharide in mice. B cells were isolated from 3-month-old wild type or tafazzin knockdown mice and incubated for up to 72 h with lipopolysaccharide and cell proliferation, expression of cell surface markers, secretion of antibodies and chemokines, proteasome and immunoproteasome activities, and metabolic function determined. In addition, proteomic analysis was performed to identify altered levels of proteins involved in survival, immunogenic, proteasomal and mitochondrial processes. Compared to wild type lipopolysaccharide activated B cells, lipopolysaccharide activated tafazzin knockdown B cells exhibited significantly reduced proliferation, lowered expression of cluster of differentiation 86 and cluster of differentiation 69 surface markers, reduced secretion of immunoglobulin M antibody, reduced secretion of keratinocytes-derived chemokine and macrophage-inflammatory protein-2, reduced proteasome and immunoproteasome activities, and reduced mitochondrial respiration and glycolysis. Proteomic analysis revealed significant alterations in key protein targets that regulate cell survival, immunogenicity, proteasomal processing and mitochondrial function consistent with the findings of the above functional studies. The results indicate that the cardiolipin transacylase enzyme tafazzin plays a key role in regulating mouse B cell function and metabolic activity during activation through modulation of mitochondrial function.
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Affiliation(s)
- Hana M Zegallai
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ejlal Abu-El-Rub
- Department of Physiology and Pathophysiology, Yarmouk University, Irbid, Jordan.,Department of Basic Medical Sciences, Faculty of Medicine, Yarmouk University, Irbid, Jordan.,Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Regenerative Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Laura K Cole
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jared Field
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Edgard M Mejia
- Department of Immunology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Joseph W Gordon
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada.,College of Nursing, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Aaron J Marshall
- Department of Immunology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Grant M Hatch
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
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15
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Zhao F, Zou MH. Role of the Mitochondrial Protein Import Machinery and Protein Processing in Heart Disease. Front Cardiovasc Med 2021; 8:749756. [PMID: 34651031 PMCID: PMC8505727 DOI: 10.3389/fcvm.2021.749756] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 08/26/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondria are essential organelles for cellular energy production, metabolic homeostasis, calcium homeostasis, cell proliferation, and apoptosis. About 99% of mammalian mitochondrial proteins are encoded by the nuclear genome, synthesized as precursors in the cytosol, and imported into mitochondria by mitochondrial protein import machinery. Mitochondrial protein import systems function not only as independent units for protein translocation, but also are deeply integrated into a functional network of mitochondrial bioenergetics, protein quality control, mitochondrial dynamics and morphology, and interaction with other organelles. Mitochondrial protein import deficiency is linked to various diseases, including cardiovascular disease. In this review, we describe an emerging class of protein or genetic variations of components of the mitochondrial import machinery involved in heart disease. The major protein import pathways, including the presequence pathway (TIM23 pathway), the carrier pathway (TIM22 pathway), and the mitochondrial intermembrane space import and assembly machinery, related translocases, proteinases, and chaperones, are discussed here. This review highlights the importance of mitochondrial import machinery in heart disease, which deserves considerable attention, and further studies are urgently needed. Ultimately, this knowledge may be critical for the development of therapeutic strategies in heart disease.
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Affiliation(s)
- Fujie Zhao
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
| | - Ming-Hui Zou
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
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16
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Nirody JA, Budin I, Rangamani P. ATP synthase: Evolution, energetics, and membrane interactions. J Gen Physiol 2021; 152:152111. [PMID: 32966553 PMCID: PMC7594442 DOI: 10.1085/jgp.201912475] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 08/24/2020] [Indexed: 12/24/2022] Open
Abstract
The synthesis of ATP, life’s “universal energy currency,” is the most prevalent chemical reaction in biological systems and is responsible for fueling nearly all cellular processes, from nerve impulse propagation to DNA synthesis. ATP synthases, the family of enzymes that carry out this endless task, are nearly as ubiquitous as the energy-laden molecule they are responsible for making. The F-type ATP synthase (F-ATPase) is found in every domain of life and has facilitated the survival of organisms in a wide range of habitats, ranging from the deep-sea thermal vents to the human intestine. Accordingly, there has been a large amount of work dedicated toward understanding the structural and functional details of ATP synthases in a wide range of species. Less attention, however, has been paid toward integrating these advances in ATP synthase molecular biology within the context of its evolutionary history. In this review, we present an overview of several structural and functional features of the F-type ATPases that vary across taxa and are purported to be adaptive or otherwise evolutionarily significant: ion channel selectivity, rotor ring size and stoichiometry, ATPase dimeric structure and localization in the mitochondrial inner membrane, and interactions with membrane lipids. We emphasize the importance of studying these features within the context of the enzyme’s particular lipid environment. Just as the interactions between an organism and its physical environment shape its evolutionary trajectory, ATPases are impacted by the membranes within which they reside. We argue that a comprehensive understanding of the structure, function, and evolution of membrane proteins—including ATP synthase—requires such an integrative approach.
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Affiliation(s)
- Jasmine A Nirody
- Center for Studies in Physics and Biology, The Rockefeller University, New York, NY.,All Souls College, University of Oxford, Oxford, UK
| | - Itay Budin
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA
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17
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Rivett ED, Heo L, Feig M, Hegg EL. Biosynthesis and trafficking of heme o and heme a: new structural insights and their implications for reaction mechanisms and prenylated heme transfer. Crit Rev Biochem Mol Biol 2021; 56:640-668. [PMID: 34428995 DOI: 10.1080/10409238.2021.1957668] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Aerobic respiration is a key energy-producing pathway in many prokaryotes and virtually all eukaryotes. The final step of aerobic respiration is most commonly catalyzed by heme-copper oxidases embedded in the cytoplasmic or mitochondrial membrane. The majority of these terminal oxidases contain a prenylated heme (typically heme a or occasionally heme o) in the active site. In addition, many heme-copper oxidases, including mitochondrial cytochrome c oxidases, possess a second heme a cofactor. Despite the critical role of heme a in the electron transport chain, the details of the mechanism by which heme b, the prototypical cellular heme, is converted to heme o and then to heme a remain poorly understood. Recent structural investigations, however, have helped clarify some elements of heme a biosynthesis. In this review, we discuss the insight gained from these advances. In particular, we present a new structural model of heme o synthase (HOS) based on distance restraints from inferred coevolutionary relationships and refined by molecular dynamics simulations that are in good agreement with the experimentally determined structures of HOS homologs. We also analyze the two structures of heme a synthase (HAS) that have recently been solved by other groups. For both HOS and HAS, we discuss the proposed catalytic mechanisms and highlight how new insights into the heme-binding site locations shed light on previously obtained biochemical data. Finally, we explore the implications of the new structural data in the broader context of heme trafficking in the heme a biosynthetic pathway and heme-copper oxidase assembly.
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Affiliation(s)
- Elise D Rivett
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Lim Heo
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Eric L Hegg
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
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18
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Mukherjee I, Ghosh M, Meinecke M. MICOS and the mitochondrial inner membrane morphology - when things get out of shape. FEBS Lett 2021; 595:1159-1183. [PMID: 33837538 DOI: 10.1002/1873-3468.14089] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 12/21/2022]
Abstract
Mitochondria play a key role in cellular signalling, metabolism and energetics. Proper architecture and remodelling of the inner mitochondrial membrane are essential for efficient respiration, apoptosis and quality control in the cell. Several protein complexes including mitochondrial contact site and cristae organizing system (MICOS), F1 FO -ATP synthase, and Optic Atrophy 1 (OPA1), facilitate formation, maintenance and stability of cristae membranes. MICOS, the F1 FO -ATP synthase, OPA1 and inner membrane phospholipids such as cardiolipin and phosphatidylethanolamine interact with each other to organize the inner membrane ultra-structure and remodel cristae in response to the cell's demands. Functional alterations in these proteins or in the biosynthesis pathway of cardiolipin and phosphatidylethanolamine result in an aberrant inner membrane architecture and impair mitochondrial function. Mitochondrial dysfunction and abnormalities hallmark several human conditions and diseases including neurodegeneration, cardiomyopathies and diabetes mellitus. Yet, they have long been regarded as secondary pathological effects. This review discusses emerging evidence of a direct relationship between protein- and lipid-dependent regulation of the inner mitochondrial membrane morphology and diseases such as fatal encephalopathy, Leigh syndrome, Parkinson's disease, and cancer.
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Affiliation(s)
- Indrani Mukherjee
- Department of Cellular Biochemistry, University Medical Center Göttingen, Germany
| | - Mausumi Ghosh
- Department of Cellular Biochemistry, University Medical Center Göttingen, Germany
| | - Michael Meinecke
- Department of Cellular Biochemistry, University Medical Center Göttingen, Germany.,Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, Göttingen, Germany
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19
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Skeletal Muscle Mitochondria Dysfunction in Genetic Neuromuscular Disorders with Cardiac Phenotype. Int J Mol Sci 2021; 22:ijms22147349. [PMID: 34298968 PMCID: PMC8307986 DOI: 10.3390/ijms22147349] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/03/2021] [Accepted: 07/05/2021] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial dysfunction is considered the major contributor to skeletal muscle wasting in different conditions. Genetically determined neuromuscular disorders occur as a result of mutations in the structural proteins of striated muscle cells and therefore are often combined with cardiac phenotype, which most often manifests as a cardiomyopathy. The specific roles played by mitochondria and mitochondrial energetic metabolism in skeletal muscle under muscle-wasting conditions in cardiomyopathies have not yet been investigated in detail, and this aspect of genetic muscle diseases remains poorly characterized. This review will highlight dysregulation of mitochondrial representation and bioenergetics in specific skeletal muscle disorders caused by mutations that disrupt the structural and functional integrity of muscle cells.
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20
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Zhu S, Chen Z, Zhu M, Shen Y, Leon LJ, Chi L, Spinozzi S, Tan C, Gu Y, Nguyen A, Zhou Y, Feng W, Vaz FM, Wang X, Gustafsson AB, Evans SM, Kunfu O, Fang X. Cardiolipin Remodeling Defects Impair Mitochondrial Architecture and Function in a Murine Model of Barth Syndrome Cardiomyopathy. Circ Heart Fail 2021; 14:e008289. [PMID: 34129362 PMCID: PMC8210459 DOI: 10.1161/circheartfailure.121.008289] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Cardiomyopathy is a major clinical feature in Barth syndrome (BTHS), an X-linked mitochondrial lipid disorder caused by mutations in Tafazzin (TAZ), encoding a mitochondrial acyltransferase required for cardiolipin remodeling. Despite recent description of a mouse model of BTHS cardiomyopathy, an in-depth analysis of specific lipid abnormalities and mitochondrial form and function in an in vivo BTHS cardiomyopathy model is lacking. METHODS We performed in-depth assessment of cardiac function, cardiolipin species profiles, and mitochondrial structure and function in our newly generated Taz cardiomyocyte-specific knockout mice and Cre-negative control mice (n≥3 per group). RESULTS Taz cardiomyocyte-specific knockout mice recapitulate typical features of BTHS and mitochondrial cardiomyopathy. Fewer than 5% of cardiomyocyte-specific knockout mice exhibited lethality before 2 months of age, with significantly enlarged hearts. More than 80% of cardiomyocyte-specific knockout displayed ventricular dilation at 16 weeks of age and survived until 50 weeks of age. Full parameter analysis of cardiac cardiolipin profiles demonstrated lower total cardiolipin concentration, abnormal cardiolipin fatty acyl composition, and elevated monolysocardiolipin to cardiolipin ratios in Taz cardiomyocyte-specific knockout, relative to controls. Mitochondrial contact site and cristae organizing system and F1F0-ATP synthase complexes, required for cristae morphogenesis, were abnormal, resulting in onion-shaped mitochondria. Organization of high molecular weight respiratory chain supercomplexes was also impaired. In keeping with observed mitochondrial abnormalities, seahorse experiments demonstrated impaired mitochondrial respiration capacity. CONCLUSIONS Our mouse model mirrors multiple physiological and biochemical aspects of BTHS cardiomyopathy. Our results give important insights into the underlying cause of BTHS cardiomyopathy and provide a framework for testing therapeutic approaches to BTHS cardiomyopathy, or other mitochondrial-related cardiomyopathies.
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Affiliation(s)
- Siting Zhu
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Ze’e Chen
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Mason Zhu
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Ying Shen
- Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, University Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
| | - Leonardo J Leon
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
| | - Liguo Chi
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
| | - Simone Spinozzi
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Changming Tan
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
- Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yusu Gu
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Anh Nguyen
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Yi Zhou
- Department of Molecular Biology, University of California, San Diego, La Jolla, California, USA
| | - Wei Feng
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Frédéric M Vaz
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and Pediatrics, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
- Core Facility Metabolomics, Amsterdam UMC
| | - Xiaohong Wang
- Department of Pharmacology and Tianjin Key Laboratory of Inflammation Biology, School of Basic Medical Sciences, Tianjin Medical University, 300070, Tianjin, China
| | - Asa B Gustafsson
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Sylvia M Evans
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Ouyang Kunfu
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Xi Fang
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
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21
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Pitt AS, Buchanan SK. A Biochemical and Structural Understanding of TOM Complex Interactions and Implications for Human Health and Disease. Cells 2021; 10:cells10051164. [PMID: 34064787 PMCID: PMC8150904 DOI: 10.3390/cells10051164] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/01/2021] [Accepted: 05/07/2021] [Indexed: 12/15/2022] Open
Abstract
The central role mitochondria play in cellular homeostasis has made its study critical to our understanding of various aspects of human health and disease. Mitochondria rely on the translocase of the outer membrane (TOM) complex for the bulk of mitochondrial protein import. In addition to its role as the major entry point for mitochondrial proteins, the TOM complex serves as an entry pathway for viral proteins. TOM complex subunits also participate in a host of interactions that have been studied extensively for their function in neurodegenerative diseases, cardiovascular diseases, innate immunity, cancer, metabolism, mitophagy and autophagy. Recent advances in our structural understanding of the TOM complex and the protein import machinery of the outer mitochondrial membrane have made structure-based therapeutics targeting outer mitochondrial membrane proteins during mitochondrial dysfunction an exciting prospect. Here, we describe advances in understanding the TOM complex, the interactome of the TOM complex subunits, the implications for the development of therapeutics, and our understanding of the structure/function relationship between components of the TOM complex and mitochondrial homeostasis.
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22
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Mitochondrial Structure and Bioenergetics in Normal and Disease Conditions. Int J Mol Sci 2021; 22:ijms22020586. [PMID: 33435522 PMCID: PMC7827222 DOI: 10.3390/ijms22020586] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/03/2021] [Accepted: 01/04/2021] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are ubiquitous intracellular organelles found in almost all eukaryotes and involved in various aspects of cellular life, with a primary role in energy production. The interest in this organelle has grown stronger with the discovery of their link to various pathologies, including cancer, aging and neurodegenerative diseases. Indeed, dysfunctional mitochondria cannot provide the required energy to tissues with a high-energy demand, such as heart, brain and muscles, leading to a large spectrum of clinical phenotypes. Mitochondrial defects are at the origin of a group of clinically heterogeneous pathologies, called mitochondrial diseases, with an incidence of 1 in 5000 live births. Primary mitochondrial diseases are associated with genetic mutations both in nuclear and mitochondrial DNA (mtDNA), affecting genes involved in every aspect of the organelle function. As a consequence, it is difficult to find a common cause for mitochondrial diseases and, subsequently, to offer a precise clinical definition of the pathology. Moreover, the complexity of this condition makes it challenging to identify possible therapies or drug targets.
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23
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Petit PX, Ardilla-Osorio H, Penalvia L, Nathan E. R. Tafazzin Mutation Affecting Cardiolipin Leads to Increased Mitochondrial Superoxide Anions and Mitophagy Inhibition in Barth Syndrome. Cells 2020; 9:cells9102333. [PMID: 33096711 PMCID: PMC7589545 DOI: 10.3390/cells9102333] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 01/01/2023] Open
Abstract
Tafazzin is a phospholipid transacylase that catalyzes the remodeling of cardiolipin, a mitochondrial phospholipid required for oxidative phosphorylation. Mutations of the tafazzin gene cause Barth syndrome, which is characterized by mitochondrial dysfunction and dilated cardiomyopathy, leading to premature death. However, the molecular mechanisms underlying the cause of mitochondrial dysfunction in Barth syndrome remain poorly understood. We again highlight the fact that the tafazzin deficiency is also linked to defective oxidative phosphorylation associated with oxidative stress. All the mitochondrial events are positioned in a context where mitophagy is a key element in mitochondrial quality control. Here, we investigated the role of tafazzin in mitochondrial homeostasis dysregulation and mitophagy alteration. Using a HeLa cell model of tafazzin deficiency, we show that dysregulation of tafazzin in HeLa cells induces alteration of mitophagy. Our findings provide some additional insights into mitochondrial dysfunction associated with Barth syndrome, but also show that mitophagy inhibition is concomitant with apoptosis dysfunction through the inability of abnormal mitochondrial cardiolipin to assume its role in cytoplasmic signal transduction. Our work raises hope that pharmacological manipulation of the mitophagic pathway together with mitochondrially targeted antioxidants may provide new insights leading to promising treatment for these highly lethal conditions.
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Affiliation(s)
- Patrice X. Petit
- SSPIN Saints-Pères Paris Institut de Neurosciences, CNRS UMR 8003, “Mitochondria, Apoptosis and Autophagy Signalling” Université de Paris—Campus Saint-Germain, 45 rue des Saints-Pères, 75006 Paris, France; (L.P.); (R.N.E.)
- Correspondence: or ; Tel.: +33(0)6-78-24-80-87
| | - Hector Ardilla-Osorio
- Laboratoire Cellules Souches et Prions, INSERM-S 1124, Université de Paris—Campus Saint-Germain, 45 rue des Saints Pères, 75006 Paris, France;
| | - Lucile Penalvia
- SSPIN Saints-Pères Paris Institut de Neurosciences, CNRS UMR 8003, “Mitochondria, Apoptosis and Autophagy Signalling” Université de Paris—Campus Saint-Germain, 45 rue des Saints-Pères, 75006 Paris, France; (L.P.); (R.N.E.)
| | - Rainey Nathan E.
- SSPIN Saints-Pères Paris Institut de Neurosciences, CNRS UMR 8003, “Mitochondria, Apoptosis and Autophagy Signalling” Université de Paris—Campus Saint-Germain, 45 rue des Saints-Pères, 75006 Paris, France; (L.P.); (R.N.E.)
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24
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Bozelli JC, Epand RM. Determinants of lipids acyl chain specificity: A tale of two enzymes. Biophys Chem 2020; 265:106431. [DOI: 10.1016/j.bpc.2020.106431] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 07/10/2020] [Indexed: 12/12/2022]
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25
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Li Y, Lou W, Grevel A, Böttinger L, Liang Z, Ji J, Patil VA, Liu J, Ye C, Hüttemann M, Becker T, Greenberg ML. Cardiolipin-deficient cells have decreased levels of the iron-sulfur biogenesis protein frataxin. J Biol Chem 2020; 295:11928-11937. [PMID: 32636300 PMCID: PMC7450130 DOI: 10.1074/jbc.ra120.013960] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 07/02/2020] [Indexed: 12/12/2022] Open
Abstract
Cardiolipin (CL) is the signature phospholipid of mitochondrial membranes, where it is synthesized locally and plays an important role in mitochondrial bioenergetics. Previous studies in the yeast model have indicated that CL is required for optimal iron homeostasis, which is disrupted by a mechanism not yet determined in the yeast CL mutant, crd1Δ. This finding has implications for the severe genetic disorder, Barth syndrome (BTHS), in which CL metabolism is perturbed because of mutations in the CL-remodeling enzyme, tafazzin. Here, we investigate the effects of tafazzin deficiency on iron homeostasis in the mouse myoblast model of BTHS tafazzin knockout (TAZ-KO) cells. Similarly to CL-deficient yeast cells, TAZ-KO cells exhibited elevated sensitivity to iron, as well as to H2O2, which was alleviated by the iron chelator deferoxamine. TAZ-KO cells exhibited increased expression of the iron exporter ferroportin and decreased expression of the iron importer transferrin receptor, likely reflecting a regulatory response to elevated mitochondrial iron. Reduced activities of mitochondrial iron-sulfur cluster enzymes suggested that the mechanism underlying perturbation of iron homeostasis was defective iron-sulfur biogenesis. We observed decreased levels of Yfh1/frataxin, an essential component of the iron-sulfur biogenesis machinery, in mitochondria from TAZ-KO mouse cells and in CL-deleted yeast crd1Δ cells, indicating that the role of CL in iron-sulfur biogenesis is highly conserved. Yeast crd1Δ cells exhibited decreased processing of the Yfh1 precursor upon import, which likely contributes to the iron homeostasis defects. Implications for understanding the pathogenesis of BTHS are discussed.
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Affiliation(s)
- Yiran Li
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Wenjia Lou
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Alexander Grevel
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Lena Böttinger
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Zhuqing Liang
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Jiajia Ji
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Vinay A Patil
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Jenney Liu
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Cunqi Ye
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Maik Hüttemann
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Thomas Becker
- Institute for Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signaling Studies, University of Freiburg, Freiburg, Germany
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
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26
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Colina-Tenorio L, Horten P, Pfanner N, Rampelt H. Shaping the mitochondrial inner membrane in health and disease. J Intern Med 2020; 287:645-664. [PMID: 32012363 DOI: 10.1111/joim.13031] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 12/19/2019] [Accepted: 01/20/2020] [Indexed: 12/16/2022]
Abstract
Mitochondria play central roles in cellular energetics, metabolism and signalling. Efficient respiration, mitochondrial quality control, apoptosis and inheritance of mitochondrial DNA depend on the proper architecture of the mitochondrial membranes and a dynamic remodelling of inner membrane cristae. Defects in mitochondrial architecture can result in severe human diseases affecting predominantly the nervous system and the heart. Inner membrane morphology is generated and maintained in particular by the mitochondrial contact site and cristae organizing system (MICOS), the F1 Fo -ATP synthase, the fusion protein OPA1/Mgm1 and the nonbilayer-forming phospholipids cardiolipin and phosphatidylethanolamine. These protein complexes and phospholipids are embedded in a network of functional interactions. They communicate with each other and additional factors, enabling them to balance different aspects of cristae biogenesis and to dynamically remodel the inner mitochondrial membrane. Genetic alterations disturbing these membrane-shaping factors can lead to human pathologies including fatal encephalopathy, dominant optic atrophy, Leigh syndrome, Parkinson's disease and Barth syndrome.
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Affiliation(s)
- L Colina-Tenorio
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - P Horten
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - N Pfanner
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - H Rampelt
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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27
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Chin MT, Conway SJ. Role of Tafazzin in Mitochondrial Function, Development and Disease. J Dev Biol 2020; 8:jdb8020010. [PMID: 32456129 PMCID: PMC7344621 DOI: 10.3390/jdb8020010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/19/2022] Open
Abstract
Tafazzin, an enzyme associated with the rare inherited x-linked disorder Barth Syndrome, is a nuclear encoded mitochondrial transacylase that is highly conserved across multiple species and plays an important role in mitochondrial function. Numerous studies have elucidated the mechanisms by which Tafazzin affects mitochondrial function, but its effects on development and susceptibility to adult disease are incompletely understood. The purpose of this review is to highlight previous functional studies across a variety of model organisms, introduce recent studies that show an important role in development, and also to provide an update on the role of Tafazzin in human disease. The profound effects of Tafazzin on cardiac development and adult cardiac homeostasis will be emphasized. These studies underscore the importance of mitochondrial function in cardiac development and disease, and also introduce the concept of Tafazzin as a potential therapeutic modality.
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Affiliation(s)
- Michael T. Chin
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA 02111, USA
- Correspondence: (M.T.C.); (S.J.C.); Tel.: +1-617-636-8776 (M.T.C.); +1-317-278-8780 (S.J.C.)
| | - Simon J. Conway
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Correspondence: (M.T.C.); (S.J.C.); Tel.: +1-617-636-8776 (M.T.C.); +1-317-278-8780 (S.J.C.)
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28
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Schlame M, Xu Y. The Function of Tafazzin, a Mitochondrial Phospholipid-Lysophospholipid Acyltransferase. J Mol Biol 2020; 432:5043-5051. [PMID: 32234310 DOI: 10.1016/j.jmb.2020.03.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 03/13/2020] [Accepted: 03/25/2020] [Indexed: 12/21/2022]
Abstract
Tafazzin is a mitochondrial enzyme that exchanges fatty acids between phospholipids by phospholipid-lysophospholipid transacylation. The reaction alters the molecular species composition and, as a result, the physical properties of lipids. In vivo, the most important substrate of tafazzin is the mitochondria-specific lipid cardiolipin. Tafazzin mutations cause the human disease Barth syndrome, which presents with cardiomyopathy, skeletal muscle weakness, fatigue, and other symptoms, probably all related to mitochondrial dysfunction. The reason why mitochondria require tafazzin is still not known, but recent evidence suggests that tafazzin may lower the energy cost associated with protein crowding in the inner mitochondrial membrane.
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Affiliation(s)
- Michael Schlame
- Departments of Anesthesiology and Cell Biology, New York University School of Medicine, New York, NY 10016, USA.
| | - Yang Xu
- Departments of Anesthesiology and Cell Biology, New York University School of Medicine, New York, NY 10016, USA
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29
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Chowdhury A, Aich A, Jain G, Wozny K, Lüchtenborg C, Hartmann M, Bernhard O, Balleiniger M, Alfar EA, Zieseniss A, Toischer K, Guan K, Rizzoli SO, Brügger B, Fischer A, Katschinski DM, Rehling P, Dudek J. Defective Mitochondrial Cardiolipin Remodeling Dampens HIF-1α Expression in Hypoxia. Cell Rep 2019; 25:561-570.e6. [PMID: 30332638 PMCID: PMC6205837 DOI: 10.1016/j.celrep.2018.09.057] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 08/20/2018] [Accepted: 09/17/2018] [Indexed: 12/28/2022] Open
Abstract
Mitochondria fulfill vital metabolic functions and act as crucial cellular signaling hubs, integrating their metabolic status into the cellular context. Here, we show that defective cardiolipin remodeling, upon loss of the cardiolipin acyl transferase tafazzin, decreases HIF-1α signaling in hypoxia. Tafazzin deficiency does not affect posttranslational HIF-1α regulation but rather HIF-1α gene expression, a dysfunction recapitulated in iPSC-derived cardiomyocytes from Barth syndrome patients with tafazzin deficiency. RNA-seq analyses confirmed drastically altered signaling in tafazzin mutant cells. In hypoxia, tafazzin-deficient cells display reduced production of reactive oxygen species (ROS) perturbing NF-κB activation and concomitantly HIF-1α gene expression. Tafazzin-deficient mice hearts display reduced HIF-1α levels and undergo maladaptive hypertrophy with heart failure in response to pressure overload challenge. We conclude that defective mitochondrial cardiolipin remodeling dampens HIF-1α signaling due to a lack of NF-κB activation through reduced mitochondrial ROS production, decreasing HIF-1α transcription. Defective remodeling of mitochondrial cardiolipin dampens HIF-1α signaling ROS-mediated NF-κB activation is impaired in cardiolipin-deficient cells Defective NF-κB-mediated HIF-1α gene induction decreases the cellular response to hypoxia Deregulated cardiac response to pressure overload in Barth syndrome mouse
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Affiliation(s)
- Arpita Chowdhury
- Department of Cellular Biochemistry, University Medical Center Göttingen, GZMB, 37073 Göttingen, Germany
| | - Abhishek Aich
- Department of Cellular Biochemistry, University Medical Center Göttingen, GZMB, 37073 Göttingen, Germany
| | - Gaurav Jain
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Katharina Wozny
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Heidelberg 69120, Germany
| | - Christian Lüchtenborg
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Heidelberg 69120, Germany
| | - Magnus Hartmann
- Department of Cellular Biochemistry, University Medical Center Göttingen, GZMB, 37073 Göttingen, Germany
| | - Olaf Bernhard
- Department of Cellular Biochemistry, University Medical Center Göttingen, GZMB, 37073 Göttingen, Germany
| | - Martina Balleiniger
- Department of Cellular Biochemistry, University Medical Center Göttingen, GZMB, 37073 Göttingen, Germany
| | - Ezzaldin Ahmed Alfar
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Anke Zieseniss
- Institute of Cardiovascular Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Karl Toischer
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Göttingen, Germany
| | - Kaomei Guan
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Silvio O Rizzoli
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Heidelberg 69120, Germany
| | - Andrè Fischer
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany; Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Dörthe M Katschinski
- Institute of Cardiovascular Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, GZMB, 37073 Göttingen, Germany; Max Planck Institute for Biophysical Chemistry, 37073, Göttingen, Germany.
| | - Jan Dudek
- Department of Cellular Biochemistry, University Medical Center Göttingen, GZMB, 37073 Göttingen, Germany
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30
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Assembly of the complexes of oxidative phosphorylation triggers the remodeling of cardiolipin. Proc Natl Acad Sci U S A 2019; 116:11235-11240. [PMID: 31110016 DOI: 10.1073/pnas.1900890116] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cardiolipin (CL) is a mitochondrial phospholipid with a very specific and functionally important fatty acid composition, generated by tafazzin. However, in vitro tafazzin catalyzes a promiscuous acyl exchange that acquires specificity only in response to perturbations of the physical state of lipids. To identify the process that imposes acyl specificity onto CL remodeling in vivo, we analyzed a series of deletions and knockdowns in Saccharomyces cerevisiae and Drosophila melanogaster, including carriers, membrane homeostasis proteins, fission-fusion proteins, cristae-shape controlling and MICOS proteins, and the complexes I-V. Among those, only the complexes of oxidative phosphorylation (OXPHOS) affected the CL composition. Rather than any specific complex, it was the global impairment of the OXPHOS system that altered CL and at the same time shortened its half-life. The knockdown of OXPHOS expression had the same effect on CL as the knockdown of tafazzin in Drosophila flight muscles, including a change in CL composition and the accumulation of monolyso-CL. Thus, the assembly of OXPHOS complexes induces CL remodeling, which, in turn, leads to CL stabilization. We hypothesize that protein crowding in the OXPHOS system imposes packing stress on the lipid bilayer, which is relieved by CL remodeling to form tightly packed lipid-protein complexes.
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31
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The role of cardiolipin concentration and acyl chain composition on mitochondrial inner membrane molecular organization and function. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1039-1052. [PMID: 30951877 DOI: 10.1016/j.bbalip.2019.03.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/19/2019] [Accepted: 03/30/2019] [Indexed: 12/28/2022]
Abstract
Cardiolipin (CL) is a key phospholipid of the mitochondria. A loss of CL content and remodeling of CL's acyl chains is observed in several pathologies. Strong shifts in CL concentration and acyl chain composition would presumably disrupt mitochondrial inner membrane biophysical organization. However, it remains unclear in the literature as to which is the key regulator of mitochondrial membrane biophysical properties. We review the literature to discriminate the effects of CL concentration and acyl chain composition on mitochondrial membrane organization. A widely applicable theme emerges across several pathologies, including cardiovascular diseases, diabetes, Barth syndrome, and neurodegenerative ailments. The loss of CL, often accompanied by increased levels of lyso-CLs, impairs mitochondrial inner membrane organization. Modest remodeling of CL acyl chains is not a major driver of impairments and only in cases of extreme remodeling is there an influence on membrane properties.
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32
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Ghosh S, Iadarola DM, Ball WB, Gohil VM. Mitochondrial dysfunctions in barth syndrome. IUBMB Life 2019; 71:791-801. [PMID: 30746873 DOI: 10.1002/iub.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/14/2019] [Accepted: 01/15/2019] [Indexed: 12/18/2022]
Abstract
Barth syndrome (BTHS) is a rare multisystemic genetic disorder caused by mutations in the TAZ gene. TAZ encodes a mitochondrial enzyme that remodels the acyl chain composition of newly synthesized cardiolipin, a phospholipid unique to mitochondrial membranes. The clinical abnormalities observed in BTHS patients are caused by perturbations in various mitochondrial functions that rely on remodeled cardiolipin. However, the contribution of different cardiolipin-dependent mitochondrial functions to the pathology of BTHS is not fully understood. In this review, we will discuss recent findings from different genetic models of BTHS, including the yeast model of cardiolipin deficiency that has uncovered the specific in vivo roles of cardiolipin in mitochondrial respiratory chain biogenesis, bioenergetics, intermediary metabolism, mitochondrial dynamics, and quality control. We will also describe findings from higher eukaryotic models of BTHS that highlight a link between cardiolipin-dependent mitochondrial function and its impact on tissue and organ function. © 2019 IUBMB Life, 9999(9999):1-11, 2019.
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Affiliation(s)
- Sagnika Ghosh
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Donna M Iadarola
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Writoban Basu Ball
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
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33
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Overexpression of branched-chain amino acid aminotransferases rescues the growth defects of cells lacking the Barth syndrome-related gene TAZ1. J Mol Med (Berl) 2019; 97:269-279. [PMID: 30604168 DOI: 10.1007/s00109-018-1728-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 11/23/2018] [Accepted: 12/03/2018] [Indexed: 10/27/2022]
Abstract
The yeast protein Taz1 is the orthologue of human Tafazzin, a phospholipid acyltransferase involved in cardiolipin (CL) remodeling via a monolyso CL (MLCL) intermediate. Mutations in Tafazzin lead to Barth syndrome (BTHS), a metabolic and neuromuscular disorder that primarily affects the heart, muscles, and immune system. Similar to observations in fibroblasts and platelets from patients with BTHS or from animal models, abolishing yeast Taz1 results in decreased total CL amounts, increased levels of MLCL, and mitochondrial dysfunction. However, the biochemical mechanisms underlying the mitochondrial dysfunction in BTHS remain unclear. To better understand the pathomechanism of BTHS, we searched for multi-copy suppressors of the taz1Δ growth defect in yeast cells. We identified the branched-chain amino acid transaminases (BCATs) Bat1 and Bat2 as such suppressors. Similarly, overexpression of the mitochondrial isoform BCAT2 in mammalian cells lacking TAZ improves their growth. Elevated levels of Bat1 or Bat2 did not restore the reduced membrane potential, altered stability of respiratory complexes, or the defective accumulation of MLCL species in yeast taz1Δ cells. Importantly, supplying yeast or mammalian cells lacking TAZ1 with certain amino acids restored their growth behavior. Hence, our findings suggest that the metabolism of amino acids has an important and disease-relevant role in cells lacking Taz1 function. KEY MESSAGES: Bat1 and Bat2 are multi-copy suppressors of retarded growth of taz1Δ yeast cells. Overexpression of Bat1/2 in taz1Δ cells does not rescue known mitochondrial defects. Supplementation of amino acids enhances growth of cells lacking Taz1 or Tafazzin. Altered metabolism of amino acids might be involved in the pathomechanism of BTSH.
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34
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Herwaldt EJ, Rivett ED, White AJ, Hegg EL. Cox15 interacts with the cytochrome bc 1 dimer within respiratory supercomplexes as well as in the absence of cytochrome c oxidase. J Biol Chem 2018; 293:16426-16439. [PMID: 30181213 DOI: 10.1074/jbc.ra118.002496] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 08/15/2018] [Indexed: 11/06/2022] Open
Abstract
The heme a molecule is an obligatory cofactor in the terminal enzyme complex of the electron transport chain, cytochrome c oxidase. Heme a is synthesized from heme o by a multi-spanning inner membrane protein, heme a synthase (Cox15 in the yeast Saccharomyces cerevisiae). The insertion of heme a is critical for cytochrome c oxidase function and assembly, but this process has not been fully elucidated. To improve our understanding of heme a insertion into cytochrome c oxidase, here we investigated the protein-protein interactions that involve Cox15 in S. cerevisiae In addition to observing Cox15 in homooligomeric complexes, we found that a portion of Cox15 also associates with the mitochondrial respiratory supercomplexes. When supercomplex formation was abolished, as in the case of stalled cytochrome bc 1 or cytochrome c oxidase assembly, Cox15 maintained an interaction with select proteins from both respiratory complexes. In the case of stalled cytochrome bc 1 assembly, Cox15 interacted with the late-assembling cytochrome c oxidase subunit, Cox13. When cytochrome c oxidase assembly was stalled, Cox15 unexpectedly maintained its interaction with the cytochrome bc 1 protein, Cor1. Our results indicate that Cox15 and Cor1 continue to interact in the cytochrome bc 1 dimer even in the absence of supercomplexes or when the supercomplexes are destabilized. These findings reveal that Cox15 not only associates with respiratory supercomplexes, but also interacts with the cytochrome bc 1 dimer even in the absence of cytochrome c oxidase.
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Affiliation(s)
- Emily J Herwaldt
- From the Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Elise D Rivett
- From the Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Antoineen J White
- From the Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Eric L Hegg
- From the Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
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35
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Barth syndrome cells display widespread remodeling of mitochondrial complexes without affecting metabolic flux distribution. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3650-3658. [PMID: 30251684 DOI: 10.1016/j.bbadis.2018.08.041] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 07/25/2018] [Accepted: 08/30/2018] [Indexed: 12/31/2022]
Abstract
Barth syndrome (BTHS) is a rare X-linked disorder that is characterized by cardiac and skeletal myopathy, neutropenia and growth abnormalities. The disease is caused by mutations in the tafazzin (TAZ) gene encoding an enzyme involved in the acyl chain remodeling of the mitochondrial phospholipid cardiolipin (CL). Biochemically, this leads to decreased levels of mature CL and accumulation of the intermediate monolysocardiolipin (MLCL). At a cellular level, this causes mitochondrial fragmentation and reduced stability of the respiratory chain supercomplexes. However, the exact mechanism through which tafazzin deficiency leads to disease development remains unclear. We therefore aimed to elucidate the pathways affected in BTHS cells by employing proteomic and metabolic profiling assays. Complexome profiling of patient skin fibroblasts revealed significant effects for about 200 different mitochondrial proteins. Prominently, we found a specific destabilization of higher order oxidative phosphorylation (OXPHOS) supercomplexes, as well as changes in complexes involved in cristae organization and CL trafficking. Moreover, the key metabolic complexes 2-oxoglutarate dehydrogenase (OGDH) and branched-chain ketoacid dehydrogenase (BCKD) were profoundly destabilized in BTHS patient samples. Surprisingly, metabolic flux distribution assays using stable isotope tracer-based metabolomics did not show reduced flux through the TCA cycle. Overall, insights from analyzing the impact of TAZ mutations on the mitochondrial complexome provided a better understanding of the resulting functional and structural consequences and thus the pathological mechanisms leading to Barth syndrome.
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36
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Dudek J, Hartmann M, Rehling P. The role of mitochondrial cardiolipin in heart function and its implication in cardiac disease. Biochim Biophys Acta Mol Basis Dis 2018; 1865:810-821. [PMID: 30837070 DOI: 10.1016/j.bbadis.2018.08.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/14/2018] [Accepted: 08/17/2018] [Indexed: 01/21/2023]
Abstract
Mitochondria play an essential role in the energy metabolism of the heart. Many of the essential functions are associated with mitochondrial membranes and oxidative phosphorylation driven by the respiratory chain. Mitochondrial membranes are unique in the cell as they contain the phospholipid cardiolipin. The important role of cardiolipin in cardiovascular health is highlighted by several cardiac diseases, in which cardiolipin plays a fundamental role. Barth syndrome, Sengers syndrome, and Dilated cardiomyopathy with ataxia (DCMA) are genetic disorders, which affect cardiolipin biosynthesis. Other cardiovascular diseases including ischemia/reperfusion injury and heart failure are also associated with changes in the cardiolipin pool. Here, we summarize molecular functions of cardiolipin in mitochondrial biogenesis and morphology. We highlight the role of cardiolipin for the respiratory chain, metabolite carriers, and mitochondrial metabolism and describe links to apoptosis and mitochondria specific autophagy (mitophagy) with possible implications in cardiac disease.
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Affiliation(s)
- Jan Dudek
- Institute of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany
| | - Magnus Hartmann
- Institute of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany
| | - Peter Rehling
- Institute of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany; Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany.
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37
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Agarwal P, Cole LK, Chandrakumar A, Hauff KD, Ravandi A, Dolinsky VW, Hatch GM. Phosphokinome Analysis of Barth Syndrome Lymphoblasts Identify Novel Targets in the Pathophysiology of the Disease. Int J Mol Sci 2018; 19:ijms19072026. [PMID: 30002286 PMCID: PMC6073761 DOI: 10.3390/ijms19072026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/06/2018] [Accepted: 07/09/2018] [Indexed: 12/25/2022] Open
Abstract
Barth Syndrome (BTHS) is a rare X-linked genetic disease in which the specific biochemical deficit is a reduction in the mitochondrial phospholipid cardiolipin (CL) as a result of a mutation in the CL transacylase tafazzin. We compared the phosphokinome profile in Epstein-Barr-virus-transformed lymphoblasts prepared from a BTHS patient with that of an age-matched control individual. As expected, mass spectrometry analysis revealed a significant (>90%) reduction in CL in BTHS lymphoblasts compared to controls. In addition, increased oxidized phosphatidylcholine (oxPC) and phosphatidylethanolamine (PE) levels were observed in BTHS lymphoblasts compared to control. Given the broad shifts in metabolism associated with BTHS, we hypothesized that marked differences in posttranslational modifications such as phosphorylation would be present in the lymphoblast cells of a BTHS patient. Phosphokinome analysis revealed striking differences in the phosphorylation levels of phosphoproteins in BTHS lymphoblasts compared to control cells. Some phosphorylated proteins, for example, adenosine monophosphate kinase, have been previously validated as bonafide modified phosphorylation targets observed in tafazzin deficiency or under conditions of reduced cellular CL. Thus, we report multiple novel phosphokinome targets in BTHS lymphoblasts and hypothesize that alteration in the phosphokinome profile may provide insight into the pathophysiology of BTHS and potential therapeutic targets.
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Affiliation(s)
- Prasoon Agarwal
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM), Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada.
- Manitoba Developmental Origins of Chronic Diseases in Children Network (DEVOTION), University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
| | - Laura K Cole
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
| | - Abin Chandrakumar
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
- Clinical Research Unit, Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada.
| | - Kristin D Hauff
- Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 2B5, Canada.
| | - Amir Ravandi
- Physiology and Pathophysiology, University of Manitoba, St. Boniface Hospital Research Center, Winnipeg, MB R2H 2A6, Canada.
| | - Vernon W Dolinsky
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM), Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada.
- Manitoba Developmental Origins of Chronic Diseases in Children Network (DEVOTION), University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
| | - Grant M Hatch
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM), Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada.
- Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
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38
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Ogunbona OB, Baile MG, Claypool SM. Cardiomyopathy-associated mutation in the ADP/ATP carrier reveals translation-dependent regulation of cytochrome c oxidase activity. Mol Biol Cell 2018; 29:1449-1464. [PMID: 29688796 PMCID: PMC6014099 DOI: 10.1091/mbc.e17-12-0700] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 03/16/2018] [Accepted: 04/18/2018] [Indexed: 01/07/2023] Open
Abstract
How the absence of the major mitochondrial ADP/ATP carrier in yeast, Aac2p, results in a specific defect in cytochrome c oxidase (COX; complex IV) activity is a long-standing mystery. Aac2p physically associates with respiratory supercomplexes, which include complex IV, raising the possibility that its activity is dependent on its association with Aac2p. Here, we have leveraged a transport-dead pathogenic AAC2 point mutant to determine the basis for the reduced COX activity in the absence of Aac2p. The steady-state levels of complex IV subunits encoded by the mitochondrial genome are significantly reduced in the absence of Aac2p function, whether its association with respiratory supercomplexes is preserved or not. This diminution in COX amounts is not caused by a reduction in the mitochondrial genome copy number or the steady-state level of its transcripts, and does not reflect a defect in complex IV assembly. Instead, the absence of Aac2p activity, genetically or pharmacologically, results in an aberrant pattern of mitochondrial translation. Interestingly, compared with the complete absence of Aac2p, the complex IV-related defects are greater in mitochondria expressing the transport-inactive Aac2p mutant. Our results highlight a critical role for Aac2p transport in mitochondrial translation whose disturbance uniquely impacts cytochrome c oxidase.
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Affiliation(s)
- Oluwaseun B. Ogunbona
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185
| | | | - Steven M. Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185
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39
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Basu Ball W, Baker CD, Neff JK, Apfel GL, Lagerborg KA, Žun G, Petrovič U, Jain M, Gohil VM. Ethanolamine ameliorates mitochondrial dysfunction in cardiolipin-deficient yeast cells. J Biol Chem 2018; 293:10870-10883. [PMID: 29866881 DOI: 10.1074/jbc.ra118.004014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 05/29/2018] [Indexed: 01/24/2023] Open
Abstract
Cardiolipin (CL) is a signature phospholipid of the mitochondria required for the formation of mitochondrial respiratory chain (MRC) supercomplexes. The destabilization of MRC supercomplexes is the proximal cause of the pathology associated with the depletion of CL in patients with Barth syndrome. Thus, promoting supercomplex formation could ameliorate mitochondrial dysfunction associated with CL depletion. However, to date, physiologically relevant small-molecule regulators of supercomplex formation have not been identified. Here, we report that ethanolamine (Etn) supplementation rescues the MRC defects by promoting supercomplex assembly in a yeast model of Barth syndrome. We discovered this novel role of Etn while testing the hypothesis that elevating mitochondrial phosphatidylethanolamine (PE), a phospholipid suggested to overlap in function with CL, could compensate for CL deficiency. We found that the Etn supplementation rescues the respiratory growth of CL-deficient Saccharomyces cerevisiae cells in a dose-dependent manner but independently of its incorporation into PE. The rescue was specifically dependent on Etn but not choline or serine, the other phospholipid precursors. Etn improved mitochondrial function by restoring the expression of MRC proteins and promoting supercomplex assembly in CL-deficient cells. Consistent with this mechanism, overexpression of Cox4, the MRC complex IV subunit, was sufficient to promote supercomplex formation in CL-deficient cells. Taken together, our work identifies a novel role of a ubiquitous metabolite, Etn, in attenuating mitochondrial dysfunction caused by CL deficiency.
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Affiliation(s)
- Writoban Basu Ball
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Charli D Baker
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - John K Neff
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Gabriel L Apfel
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Kim A Lagerborg
- the Departments of Medicine and Pharmacology, University of California, San Diego, La Jolla, California 92093
| | - Gašper Žun
- the Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia.,the Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia, and
| | - Uroš Petrovič
- the Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia.,the Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Mohit Jain
- the Departments of Medicine and Pharmacology, University of California, San Diego, La Jolla, California 92093
| | - Vishal M Gohil
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843,
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40
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Kimura T, Kimura AK, Ren M, Berno B, Xu Y, Schlame M, Epand RM. Substantial Decrease in Plasmalogen in the Heart Associated with Tafazzin Deficiency. Biochemistry 2018; 57:2162-2175. [PMID: 29557170 PMCID: PMC5893435 DOI: 10.1021/acs.biochem.8b00042] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tafazzin is the mitochondrial enzyme that catalyzes transacylation between a phospholipid and a lysophospholipid in remodeling. Mutations in tafazzin cause Barth syndrome, a potentially life-threatening disease with the major symptom being cardiomyopathy. In the tafazzin-deficient heart, cardiolipin (CL) acyl chains become abnormally heterogeneous unlike those in the normal heart with a single dominant linoleoyl species, tetralinoleoyl CL. In addition, the amount of CL decreases and monolysocardiolipin (MLCL) accumulates. Here we determine using high-resolution 31P nuclear magnetic resonance with cryoprobe technology the fundamental phospholipid composition, including the major but oxidation-labile plasmalogens, in the tafazzin-knockdown (TAZ-KD) mouse heart as a model of Barth syndrome. In addition to confirming a lower level of CL (6.4 ± 0.1 → 2.0 ± 0.4 mol % of the total phospholipid) and accumulation of MLCL (not detected → 3.3 ± 0.5 mol %) in the TAZ-KD, we found a substantial reduction in the level of plasmenylcholine (30.8 ± 2.8 → 18.1 ± 3.1 mol %), the most abundant phospholipid in the control wild type. A quantitative Western blot revealed that while the level of peroxisomes, where early steps of plasmalogen synthesis take place, was normal in the TAZ-KD model, expression of Far1 as a rate-determining enzyme in plasmalogen synthesis was dramatically upregulated by 8.3 (±1.6)-fold to accelerate the synthesis in response to the reduced level of plasmalogen. We confirmed lyso-plasmenylcholine or plasmenylcholine is a substrate of purified tafazzin for transacylation with CL or MLCL, respectively. Our results suggest that plasmenylcholine, abundant in linoleoyl species, is important in remodeling CL in the heart. Tafazzin deficiency thus has a major impact on the cardiac plasmenylcholine level and thereby its functions.
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Affiliation(s)
- Tomohiro Kimura
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Atsuko K. Kimura
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Mindong Ren
- Department of Cell Biology, NYU Langone Medical Center, New York, NY 10016
| | - Bob Berno
- Department of Chemistry, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Yang Xu
- Department of Anesthesiology, NYU Langone Medical Center, New York, NY 10016
| | - Michael Schlame
- Department of Cell Biology, NYU Langone Medical Center, New York, NY 10016
- Department of Anesthesiology, NYU Langone Medical Center, New York, NY 10016
| | - Richard M. Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
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41
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Mejia EM, Zegallai H, Bouchard ED, Banerji V, Ravandi A, Hatch GM. Expression of human monolysocardiolipin acyltransferase-1 improves mitochondrial function in Barth syndrome lymphoblasts. J Biol Chem 2018; 293:7564-7577. [PMID: 29563154 DOI: 10.1074/jbc.ra117.001024] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 03/01/2018] [Indexed: 12/12/2022] Open
Abstract
The mitochondrial polyglycerophospholipid cardiolipin (CL) is remodeled to obtain specific fatty acyl chains. This is predominantly accomplished by the transacylase enzyme tafazzin (TAZ). Barth syndrome (BTHS) patients with TAZ gene mutations exhibit impaired TAZ activity and loss in mitochondrial respiratory function. Previous studies identified monolysocardiolipin acyltransferase-1 (MLCL AT-1) as a mitochondrial enzyme capable of remodeling CL with fatty acid. In this study, we analyzed what relationship, if any, exists between TAZ and MLCL AT-1 with regard to CL remodeling and whether transfection of BTHS lymphoblasts with an MLCL AT-1 expression construct improves mitochondrial respiratory function. In healthy lymphoblasts, reduction in TAZ expression through TAZ RNAi transfection resulted in a compensatory increase in MLCL AT-1 mRNA, protein, and enzyme activity, but CL mass was unaltered. In contrast, BTHS lymphoblasts exhibited decreased TAZ gene and protein expression but in addition decreased MLCL AT-1 expression and CL mass. Transfection of BTHS lymphoblasts with MLCL AT-1 expression construct increased CL, improved mitochondrial basal respiration and protein leak, and decreased the proportion of cells producing superoxide but did not restore CL molecular species composition to control levels. In addition, BTHS lymphoblasts exhibited higher rates of glycolysis compared with healthy controls to compensate for reduced mitochondrial respiratory function. Mitochondrial supercomplex assembly was significantly impaired in BTHS lymphoblasts, and transfection of BTHS lymphoblasts with MLCL AT-1 expression construct did not restore supercomplex assembly. The results suggest that expression of MLCL AT-1 depends on functional TAZ in healthy cells. In addition, transfection of BTHS lymphoblasts with an MLCL AT-1 expression construct compensates, but not completely, for loss of mitochondrial respiratory function.
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Affiliation(s)
- Edgard M Mejia
- From the Department of Pharmacology and Therapeutics and.,Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, Manitoba R3E 0T6, Canada
| | - Hana Zegallai
- From the Department of Pharmacology and Therapeutics and
| | - Eric D Bouchard
- Research Institute in Oncology and Hematology, Cancer Care Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
| | - Versha Banerji
- Research Institute in Oncology and Hematology, Cancer Care Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
| | - Amir Ravandi
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Center, Winnipeg, Manitoba R2H 2A6, Canada, and
| | - Grant M Hatch
- From the Department of Pharmacology and Therapeutics and .,Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, Manitoba R3E 0T6, Canada.,Diabetes Research Envisioned and Accomplished in Manitoba (DREAM), Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba R3E 3P4, Canada
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42
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de Taffin de Tilques M, Lasserre JP, Godard F, Sardin E, Bouhier M, Le Guedard M, Kucharczyk R, Petit PX, Testet E, di Rago JP, Tribouillard-Tanvier D. Decreasing cytosolic translation is beneficial to yeast and human Tafazzin-deficient cells. ACTA ACUST UNITED AC 2018; 5:220-232. [PMID: 29796387 PMCID: PMC5961916 DOI: 10.15698/mic2018.05.629] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cardiolipin (CL) optimizes diverse mitochondrial processes, including oxidative phosphorylation (OXPHOS). To function properly, CL needs to be unsaturated, which requires the acyltransferase Tafazzin (TAZ). Loss-of-function mutations in the TAZ gene are responsible for the Barth syndrome (BTHS), a rare X-linked cardiomyopathy, presumably because of a diminished OXPHOS capacity. Herein we show that a partial inhibition of cytosolic protein synthesis, either chemically with the use of cycloheximide or by specific genetic mutations, fully restores biogenesis and the activity of the oxidative phosphorylation system in a yeast BTHS model (taz1Δ). Interestingly, the defaults in CL were not suppressed, indicating that they are not primarily responsible for the OXPHOS deficiency in taz1Δ yeast. Low concentrations of cycloheximide in the picomolar range were beneficial to TAZ-deficient HeLa cells, as evidenced by the recovery of a good proliferative capacity. These findings reveal that a diminished capacity of CL remodeling deficient cells to preserve protein homeostasis is likely an important factor contributing to the pathogenesis of BTHS. This in turn, identifies cytosolic translation as a potential therapeutic target for the treatment of this disease.
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Affiliation(s)
- Maxence de Taffin de Tilques
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 rue Camille Saint-Saëns, 33077 Bordeaux cedex, France
| | - Jean-Paul Lasserre
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 rue Camille Saint-Saëns, 33077 Bordeaux cedex, France
| | - François Godard
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 rue Camille Saint-Saëns, 33077 Bordeaux cedex, France
| | - Elodie Sardin
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 rue Camille Saint-Saëns, 33077 Bordeaux cedex, France
| | - Marine Bouhier
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 rue Camille Saint-Saëns, 33077 Bordeaux cedex, France
| | - Marina Le Guedard
- Laboratoire de Biogenèse Membranaire, CNRS UMR 5200, Université de Bordeaux, INRA Bordeaux Aquitaine, Villenave d'Ornon, France.,LEB Aquitaine Transfert-ADERA, FR-33883 Villenave d'Ornon, Cedex, France
| | - Roza Kucharczyk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Patrice X Petit
- CNRS FR3636 Fédération de recherché en Neuroscience, Université Paris-Descartes, 45, rue des Saints-Pères, 75006 Paris, France
| | - Eric Testet
- Laboratoire de Biogenèse Membranaire, CNRS UMR 5200, Université de Bordeaux, INRA Bordeaux Aquitaine, Villenave d'Ornon, France
| | - Jean-Paul di Rago
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 rue Camille Saint-Saëns, 33077 Bordeaux cedex, France
| | - Déborah Tribouillard-Tanvier
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 rue Camille Saint-Saëns, 33077 Bordeaux cedex, France
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43
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Basu Ball W, Neff JK, Gohil VM. The role of nonbilayer phospholipids in mitochondrial structure and function. FEBS Lett 2017; 592:1273-1290. [PMID: 29067684 DOI: 10.1002/1873-3468.12887] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 12/18/2022]
Abstract
Mitochondrial structure and function are influenced by the unique phospholipid composition of its membranes. While mitochondria contain all the major classes of phospholipids, recent studies have highlighted specific roles of the nonbilayer-forming phospholipids phosphatidylethanolamine (PE) and cardiolipin (CL) in the assembly and activity of mitochondrial respiratory chain (MRC) complexes. The nonbilayer phospholipids are cone-shaped molecules that introduce curvature stress in the bilayer membrane and have been shown to impact mitochondrial fusion and fission. In addition to their overlapping roles in these mitochondrial processes, each nonbilayer phospholipid also plays a unique role in mitochondrial function; for example, CL is specifically required for MRC supercomplex formation. Recent discoveries of mitochondrial PE- and CL-trafficking proteins and prior knowledge of their biosynthetic pathways have provided targets for precisely manipulating nonbilayer phospholipid levels in the mitochondrial membranes in vivo. Thus, the genetic mutants of these pathways could be valuable tools in illuminating molecular functions and biophysical properties of nonbilayer phospholipids in driving mitochondrial bioenergetics and dynamics.
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Affiliation(s)
- Writoban Basu Ball
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - John K Neff
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
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44
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Wang C, Hata Y, Hirono K, Takasaki A, Ozawa SW, Nakaoka H, Saito K, Miyao N, Okabe M, Ibuki K, Nishida N, Origasa H, Yu X, Bowles NE, Ichida F. A Wide and Specific Spectrum of Genetic Variants and Genotype-Phenotype Correlations Revealed by Next-Generation Sequencing in Patients with Left Ventricular Noncompaction. J Am Heart Assoc 2017; 6:e006210. [PMID: 28855170 PMCID: PMC5634278 DOI: 10.1161/jaha.117.006210] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/29/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND Left ventricular noncompaction (LVNC) has since been classified as a primary genetic cardiomyopathy, but the genetic basis is not fully evaluated. The aim of the present study was to identify the genetic spectrum using next-generation sequencing and to evaluate genotype-phenotype correlations in LVNC patients. METHODS AND RESULTS Using next-generation sequencing, we targeted and sequenced 73 genes related to cardiomyopathy in 102 unrelated LVNC patients. We identified 43 pathogenic variants in 16 genes in 39 patients (38%); 28 were novel variants. Sarcomere gene variants accounted for 63%, and variants in genes associated with channelopathies accounted for 12%. MYH7 and TAZ pathogenic variants were the most common, and rare variant collapsing analysis showed variants in these genes contributed to the risk of LVNC, although patients carrying MYH7 and TAZ pathogenic variants displayed different phenotypes. Patients with pathogenic variants had early age of onset and more severely decreased left ventricular ejection fractions. Survival analysis showed poorer prognosis in patients with pathogenic variants, especially those with multiple variants: All died before their first birthdays. Adverse events were noted in 17 patients, including 13 deaths, 3 heart transplants, and 1 implantable cardioverter-defibrillator insertion. Congestive heart failure at diagnosis and pathogenic variants were independent risk factors for these adverse events. CONCLUSIONS Next-generation sequencing revealed a wide spectrum of genetic variations and a high incidence of pathogenic variants in LVNC patients. These pathogenic variants were independent risk factors for adverse events. Patients harboring pathogenic variants showed poor prognosis and should be followed closely.
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Affiliation(s)
- Ce Wang
- Departments of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yukiko Hata
- Legal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Keiichi Hirono
- Departments of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Asami Takasaki
- Departments of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan
| | | | - Hideyuki Nakaoka
- Departments of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Kazuyoshi Saito
- Departments of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Nariaki Miyao
- Departments of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Mako Okabe
- Departments of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Keijiro Ibuki
- Departments of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Naoki Nishida
- Legal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Hideki Origasa
- Biostatistics and Clinical Epidemiology, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Xianyi Yu
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Neil E Bowles
- Department of Pediatrics (Cardiology), University of Utah, Salt Lake City, UT
| | - Fukiko Ichida
- Departments of Pediatrics, Faculty of Medicine, University of Toyama, Toyama, Japan
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45
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de Taffin de Tilques M, Tribouillard-Tanvier D, Tétaud E, Testet E, di Rago JP, Lasserre JP. Overexpression of mitochondrial oxodicarboxylate carrier (ODC1) preserves oxidative phosphorylation in a yeast model of Barth syndrome. Dis Model Mech 2017; 10:439-450. [PMID: 28188263 PMCID: PMC5399564 DOI: 10.1242/dmm.027540] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 02/04/2017] [Indexed: 12/21/2022] Open
Abstract
Cardiolipin (CL) is a diglycerol phospholipid mostly found in mitochondria where it optimizes numerous processes, including oxidative phosphorylation (OXPHOS). To function properly, CL needs to be unsaturated, which requires the acyltransferase tafazzin. Loss-of-function mutations in this protein are responsible for Barth syndrome (BTHS), presumably because of a diminished OXPHOS capacity. Here, we show that overexpressing Odc1p, a conserved oxodicarboxylic acid carrier located in the mitochondrial inner membrane, fully restores oxidative phosphorylation in a yeast model (taz1Δ) of BTHS. The rescuing activity involves the recovery of normal expression of key components that sustain oxidative phosphorylation, including cytochrome c and electron transport chain complexes IV and III, which are strongly downregulated in taz1Δ yeast. Interestingly, overexpression of Odc1p was also shown previously to rescue yeast models of mitochondrial diseases caused by defects in the assembly of ATP synthase and by mutations in the MPV17 protein that result in hepatocerebral mitochondrial DNA depletion syndrome. These findings define the transport of oxodicarboxylic acids across the inner membrane as a potential therapeutic target for a large spectrum of mitochondrial diseases, including BTHS.
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Affiliation(s)
- Maxence de Taffin de Tilques
- Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, 1 rue Camille Saint-Saëns, Bordeaux cedex 33077, France
| | - Déborah Tribouillard-Tanvier
- Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, 1 rue Camille Saint-Saëns, Bordeaux cedex 33077, France
| | - Emmanuel Tétaud
- Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, 1 rue Camille Saint-Saëns, Bordeaux cedex 33077, France
| | - Eric Testet
- Université de Bordeaux, Laboratoire de biogenèse membranaire, CNRS UMR 5200, INRA Bordeaux Aquitaine BP81, 33883 Villenave d'Ornon Cédex, France
| | - Jean-Paul di Rago
- Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, 1 rue Camille Saint-Saëns, Bordeaux cedex 33077, France
| | - Jean-Paul Lasserre
- Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, 1 rue Camille Saint-Saëns, Bordeaux cedex 33077, France
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46
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Dudek J, Maack C. Barth syndrome cardiomyopathy. Cardiovasc Res 2017; 113:399-410. [PMID: 28158532 DOI: 10.1093/cvr/cvx014] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/19/2016] [Accepted: 01/04/2017] [Indexed: 02/02/2023] Open
Abstract
Barth syndrome (BTHS) is an inherited form of cardiomyopathy, caused by a mutation within the gene encoding the mitochondrial transacylase tafazzin. Tafazzin is involved in the biosynthesis of the unique phospholipid cardiolipin (CL), which is almost exclusively found in mitochondrial membranes. CL directly interacts with a number of essential protein complexes in the mitochondrial membranes including the respiratory chain, mitochondrial metabolite carriers, and proteins, involved in shaping mitochondrial morphology. Here we describe, how in BTHS CL deficiency causes changes in the morphology of mitochondria, structural changes in the respiratory chain, decreased respiration, and increased generation of reactive oxygen species. A large number of cellular and animal models for BTHS have been established to elucidate how mitochondrial dysfunction induces sarcomere disorganization and reduced contractility, resulting in dilated cardiomyopathy in vivo.
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Affiliation(s)
- Jan Dudek
- Department of Cellular Biochemistry, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Christoph Maack
- Klinik für Innere Medizin III, Universitätsklinikum des Saarlandes, 66421 Homburg/Saar, Germany
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47
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Abstract
Mitochondria have to import the vast majority of their proteins, which are synthesized as precursors on cytosolic ribosomes. The translocase of the outer membrane (TOM complex) forms the general entry gate for the precursor proteins, which are subsequently sorted by protein machineries into the mitochondrial subcompartments: the outer and inner membrane, the intermembrane space and the mitochondrial matrix. The transport across and into the inner membrane is driven by the membrane potential, which is generated by the respiratory chain. Recent studies revealed that the lipid composition of mitochondrial membranes is important for the biogenesis of mitochondrial proteins. Cardiolipin and phosphatidylethanolamine exhibit unexpectedly specific functions for the activity of distinct protein translocases. Both phospholipids are required for full activity of respiratory chain complexes and thus to maintain the membrane potential for protein import. In addition, cardiolipin is required to maintain structural integrity of mitochondrial protein translocases. Finally, the low sterol content in the mitochondrial outer membrane may contribute to the targeting of some outer membrane proteins with a single α-helical membrane anchor. Altogether, mitochondrial lipids modulate protein import on various levels involving precursor targeting, membrane potential generation, stability and activity of protein translocases.
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48
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Römpler K, Müller T, Juris L, Wissel M, Vukotic M, Hofmann K, Deckers M. Overlapping Role of Respiratory Supercomplex Factor Rcf2 and Its N-terminal Homolog Rcf3 in Saccharomyces cerevisiae. J Biol Chem 2016; 291:23769-23778. [PMID: 27662906 DOI: 10.1074/jbc.m116.734665] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial electron transport chain consists of individual protein complexes arranged into large macromolecular structures, termed respiratory chain supercomplexes or respirasomes. In the yeast Saccharomyces cerevisiae, respiratory chain supercomplexes form by association of the bc1 complex with the cytochrome c oxidase. Formation and maintenance of these assemblies are promoted by specific respiratory supercomplex factors, the Rcf proteins. For these proteins a regulatory function in bridging the electron transfer within supercomplexes has been proposed. Here we report on the maturation of Rcf2 into an N- and C-terminal peptide. We show that the previously uncharacterized Rcf3 (YBR255c-A) is a homolog of the N-terminal Rcf2 peptide, whereas Rcf1 is homologous to the C-terminal portion. Both Rcf3 and the C-terminal fragment of Rcf2 associate with monomeric cytochrome c oxidase and respiratory chain supercomplexes. A lack of Rcf2 and Rcf3 increases oxygen flux through the respiratory chain by up-regulation of the cytochrome c oxidase activity. A double gene deletion of RCF2 and RCF3 affects cellular survival under non-fermentable growth conditions, suggesting an overlapping role for both proteins in the regulation of the OXPHOS activity. Furthermore, our data suggest an association of all three Rcf proteins with the bc1 complex in the absence of a functional cytochrome c oxidase and identify a supercomplex independent interaction network of the Rcf proteins.
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Affiliation(s)
- Katharina Römpler
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Tobias Müller
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Lisa Juris
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Mirjam Wissel
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Milena Vukotic
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
| | - Kay Hofmann
- the Institute for Genetics, University of Cologne, D-50674 Cologne, Germany
| | - Markus Deckers
- From the Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany and
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49
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Biosynthesis, remodeling and turnover of mitochondrial cardiolipin. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:3-7. [PMID: 27556952 DOI: 10.1016/j.bbalip.2016.08.010] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 08/03/2016] [Accepted: 08/17/2016] [Indexed: 12/15/2022]
Abstract
Among mitochondrial lipids, cardiolipin occupies a unique place. It is the only phospholipid that is specific to mitochondria and although it is merely a minor component, accounting for 10-20% of the total phospholipid content, cardiolipin plays an important role in the molecular organization, and thus the function of the cristae. This review covers the formation of cardiolipin, a phospholipid dimer containing two phosphatidyl residues, and its assembly into mitochondrial membranes. While a large body of literature exists on this topic, the review focuses on papers that appeared in the past three years. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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50
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Ellenrieder L, Mårtensson CU, Becker T. Biogenesis of mitochondrial outer membrane proteins, problems and diseases. Biol Chem 2016; 396:1199-213. [PMID: 25980382 DOI: 10.1515/hsz-2015-0170] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 05/08/2015] [Indexed: 12/25/2022]
Abstract
Proteins of the mitochondrial outer membrane are synthesized as precursors on cytosolic ribosomes and sorted via internal targeting sequences to mitochondria. Two different types of integral outer membrane proteins exist: proteins with a transmembrane β-barrel and proteins embedded by a single or multiple α-helices. The import pathways of these two types of membrane proteins differ fundamentally. Precursors of β-barrel proteins are first imported across the outer membrane via the translocase of the outer membrane (TOM complex). The TOM complex is coupled to the sorting and assembly machinery (SAM complex), which catalyzes folding and membrane insertion of these precursors. The mitochondrial import machinery (MIM complex) promotes import of proteins with multiple α-helical membrane spans. Depending on the topology precursors of proteins with a single α-helical membrane anchor are imported via several distinct routes. We summarize current models and open questions of biogenesis of mitochondrial outer membrane proteins and discuss the impact of malfunctions of protein sorting on the development of diseases.
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