Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Mutations in the phospholipid remodeling gene SERAC1 impair mitochondrial function and intracellular cholesterol trafficking and cause dystonia and deafness

Abstract

Using exome sequencing, we identify SERAC1 mutations as the cause of MEGDEL syndrome, a recessive disorder of dystonia and deafness with Leigh-like syndrome, impaired oxidative phosphorylation and 3-methylglutaconic aciduria. We localized SERAC1 at the interface between the mitochondria and the endoplasmic reticulum in the mitochondria-associated membrane fraction that is essential for phospholipid exchange. A phospholipid analysis in patient fibroblasts showed elevated concentrations of phosphatidylglycerol-34:1 (where the species nomenclature denotes the number of carbon atoms in the two acyl chains:number of double bonds in the two acyl groups) and decreased concentrations of phosphatidylglycerol-36:1 species, resulting in an altered cardiolipin subspecies composition. We also detected low concentrations of bis(monoacyl-glycerol)-phosphate, leading to the accumulation of free cholesterol, as shown by abnormal filipin staining. Complementation of patient fibroblasts with wild-type human SERAC1 by lentiviral infection led to a decrease and partial normalization of the mean ratio of phosphatidylglycerol-34:1 to phosphatidylglycerol-36:1. Our data identify SERAC1 as a key player in the phosphatidylglycerol remodeling that is essential for both mitochondrial function and intracellular cholesterol trafficking.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Key phospholipids and a schematic representation of SERAC1.
Figure 2: SERAC1 and its role in phosphatidylglycerol remodeling and cholesterol trafficking.
Figure 3: Cardiolipin species composition in patients and controls.
Figure 4: Subcellular localization of SERAC1.
Figure 5: The ratio of phosphatidylglycerol (PG)-34:1 to phosphatidylglycerol-36:1 in patient fibroblasts complemented with wild-type SERAC1.

Similar content being viewed by others

Accession codes

Accessions

NCBI Reference Sequence

References

  1. Hullin-Matsuda, F. et al. De novo biosynthesis of the late endosome lipid, bis(monoacylglycero)phosphate. J. Lipid Res. 48, 1997–2008 (2007).

    Article  CAS  Google Scholar 

  2. Schlame, M., Rua, D. & Greenberg, M.L. The biosynthesis and functional role of cardiolipin. Prog. Lipid Res. 39, 257–288 (2000).

    Article  CAS  Google Scholar 

  3. Kobayashi, T. et al. Late endosomal membranes rich in lysobisphosphatidic acid regulate cholesterol transport. Nat. Cell Biol. 1, 113–118 (1999).

    Article  CAS  Google Scholar 

  4. Schlame, M. & Ren, M. The role of cardiolipin in the structural organization of mitochondrial membranes. Biochim. Biophys. Acta 1788, 2080–2083 (2009).

    Article  CAS  Google Scholar 

  5. Schug, Z.T. & Gottlieb, E. Cardiolipin acts as a mitochondrial signalling platform to launch apoptosis. Biochim. Biophys. Acta 1788, 2022–2031 (2009).

    Article  CAS  Google Scholar 

  6. Houtkooper, R.H. et al. The enigmatic role of tafazzin in cardiolipin metabolism. Biochim. Biophys. Acta 1788, 2003–2014 (2009).

    Article  CAS  Google Scholar 

  7. Barth, P.G. et al. An X-linked mitochondrial disease affecting cardiac muscle, skeletal muscle and neutrophil leucocytes. J. Neurol. Sci. 62, 327–355 (1983).

    Article  CAS  Google Scholar 

  8. Wortmann, S.B., Kluijtmans, L.A., Engelke, U.F., Wevers, R.A. & Morava, E. The 3-methylglutaconic acidurias: what's new? J. Inherit. Metab. Dis. 35, 13–22 (2012).

    Article  CAS  Google Scholar 

  9. Bione, S. et al. A novel X-linked gene, G4.5, is responsible for Barth syndrome. Nat. Genet. 12, 385–389 (1996).

    Article  CAS  Google Scholar 

  10. Wortmann, S. et al. Association of 3-methylglutaconic aciduria with sensori-neural deafness, encephalopathy, and Leigh-like syndrome (MEGDEL association) in four patients with a disorder of the oxidative phosphorylation. Mol. Genet. Metab. 88, 47–52 (2006).

    Article  CAS  Google Scholar 

  11. Wortmann, S.B. et al. Biochemical and genetic analysis of 3-methylglutaconic aciduria type IV: a diagnostic strategy. Brain 132, 136–146 (2009).

    Article  Google Scholar 

  12. Gilissen, C. et al. Exome sequencing identifies WDR35 variants involved in Sensenbrenner syndrome. Am. J. Hum. Genet. 87, 418–423 (2010).

    Article  CAS  Google Scholar 

  13. Derewenda, Z.S. & Sharp, A.M. News from the interface: the molecular structures of triacylglyceride lipases. Trends Biochem. Sci. 18, 20–25 (1993).

    Article  CAS  Google Scholar 

  14. Ng, P.C. & Henikoff, S. Predicting deleterious amino acid substitutions. Genome Res. 11, 863–874 (2001).

    Article  CAS  Google Scholar 

  15. Adzhubei, I.A. et al. A method and server for predicting damaging missense mutations. Nat. Methods 7, 248–249 (2010).

    Article  CAS  Google Scholar 

  16. Chevallier, J. et al. Lysobisphosphatidic acid controls endosomal cholesterol levels. J. Biol. Chem. 283, 27871–27880 (2008).

    Article  CAS  Google Scholar 

  17. Reiners, J.J. Jr., Kleinman, M., Kessel, D., Mathieu, P.A. & Caruso, J.A. Nonesterified cholesterol content of lysosomes modulates susceptibility to oxidant-induced permeabilization. Free Radic. Biol. Med. 50, 281–294 (2011).

    Article  CAS  Google Scholar 

  18. Hayashi, T. & Su, T.P. σ-1 receptor chaperones at the ER-mitochondrion interface regulate Ca2+ signaling and cell survival. Cell 131, 596–610 (2007).

    Article  CAS  Google Scholar 

  19. Lewis, J.A. & Tata, J.R. A rapidly sedimenting fraction of rat liver endoplasmic reticulum. J. Cell Sci. 13, 447–459 (1973).

    CAS  PubMed  Google Scholar 

  20. Vance, J.E. Phospholipid synthesis in a membrane fraction associated with mitochondria. J. Biol. Chem. 265, 7248–7256 (1990).

    CAS  PubMed  Google Scholar 

  21. Miller, S.A., Dykes, D.D. & Polesky, H.F. A simple salting out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res. 16, 1215 (1988).

    Article  CAS  Google Scholar 

  22. Purcell, S. et al. PLINK: a tool set for whole-genome association and population-based linkage analyses. Am. J. Hum. Genet. 81, 559–575 (2007).

    Article  CAS  Google Scholar 

  23. Houtkooper, R.H. et al. Cardiolipin and monolysocardiolipin analysis in fibroblasts, lymphocytes, and tissues using high-performance liquid chromatography-mass spectrometry as a diagnostic test for Barth syndrome. Anal. Biochem. 387, 230–237 (2009).

    Article  CAS  Google Scholar 

  24. Ledvinová, J. & Elleder, M. Filipin test for diagnosis of Niemann-Pick disease type C. Sb. Lek. 94, 137–143 (1993).

    PubMed  Google Scholar 

Download references

Acknowledgements

We thank the patients and their parents for participating in this study. The study was financially supported by the Dutch Brain Foundation (2010(1)-30 to A.P.M.d.B. and 2011(1)-101 to E.M.), the EU 7th framework programme (grant 241995 (GENCODYS) to H.v.B.), the Netherlands Organisation for Health Research and Development (ZonMW 916.86.016 to L.E.L.M.V. and ZonMW 917.66.363 to J.A.V.) and the Ministry of Science, Education and Sports of the Republic of Croatia (108-1081870-1885 to I.B.). S.B.W. is supported by the 'Stichting Energy4all'. T.G. is a recipient of the 'IGMD junior scientist grant 2010'. J.M.G. is a recipient of an EMBO long-term fellowship cofunded by Marie Curie Actions EMBO long-term fellowship 1066_2011 (including MCA-EMBOCOFUND2010 and GA-2010-267146). J.N.S. is supported by the Academy of Finland (Centre of Excellence funding), the Tampere University Hospital Medical Research Fund (9J119, 9K126 and 9L097) and the Netherlands Organization for Scientific Research (NWO: VICI grant 865.10.004). We are grateful to B. van den Ende, M. Seders and S. van de Velde-Vissers (Department of Human Genetics, RUNMC, Nijmegen), as well as to K. Janssen and A. van Heck-Kappen (Department of Laboratory Medicine, RUNMC, Nijmegen), A. Leenders (Department of Pediatrics, RUNMC, Nijmegen), the colleagues of the tissue culture lab of the LGEM (Department of Laboratory Medicine, RUNMC, Nijmegen) and F.S. Stet (University of Amsterdam) for excellent technical assistance. For technical assistance, data analysis, critical discussion and exome sequencing, we are grateful to the Genomic Disorders groups of the Department of Human Genetics, RUNMC, Nijmegen (headed by H. Brunner) and the Department of Medical Genetics, University Medical Center, Utrecht (headed by E. Cuppen). We also thank F.A.J. Muskiet, F. Preijers, A. van Kampen and J. van Dam for useful discussions.

Author information

Authors and Affiliations

Authors

Contributions

S.B.W., E.M., R.A.W. and A.P.M.d.B. designed and supervised the study. S.B.W. and E.M. characterized MEGDEL syndrome and collected clinical data and patient tissues. L.A.J.K. performed and supervised the metabolic metabolite screening. P.M.v.H., I.B., E.P., S.K.U., K.N., K.K.S., Z.K. and J.A.M.S. diagnosed and referred patients. L.E.L.M.V., C.G., J.H.M.S.-H., J.A.V., M.H., W. Kloosterman, H.v.B. and A.P.M.d.B. performed the genetic studies and identified the causative genetic defect. G.H.R., R.J.R., T.G. and A.P.M.d.B. performed the lentiviral complementation. F.M.V., C.C. and W. Kulik performed the phospholipid spectra analysis and interpreted the data together with S.B.W., E.M., R.A.W. and A.P.M.d.B. D.J.L. performed and interpreted the filipin staining. A.G. and C.K. performed and interpreted the studies on autophagy and mitophagy. T.G., L.G.J.N., T.K., J.M.G. and J.N.S. performed colocalization and western blotting studies on SERAC1. T.K. performed the studies on fusion-fission. R.J.R. performed and interpreted oxidative phosphorylation measurements. M.L. captured and interpreted electron microscopic pictures of muscle tissue. F.M.V. and E.M. contributed to the draft manuscript. S.B.W., R.A.W. and A.P.M.d.B. prepared the final manuscript.

Corresponding authors

Correspondence to Saskia B Wortmann or Ron A Wevers.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Text and Figures

Supplementary Note, Supplementary Figures 1–13 and Supplementary Tables 1–6. (PDF 3824 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Wortmann, S., Vaz, F., Gardeitchik, T. et al. Mutations in the phospholipid remodeling gene SERAC1 impair mitochondrial function and intracellular cholesterol trafficking and cause dystonia and deafness. Nat Genet 44, 797–802 (2012). https://doi.org/10.1038/ng.2325

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ng.2325

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing