FBXL4 deficiency increases mitochondrial removal by autophagy
Abstract Pathogenic variants in FBXL4 cause a severe encephalopathic syndrome associated with mtDNA depletion and deficient oxidative phosphorylation. To gain further insight into the enigmatic pathophysiology caused by FBXL4 deficiency, we generated homozygous Fbxl4 knockout mice and found that the...
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| Format: | Article |
| Language: | English |
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Springer Nature
2020-06-01
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| Series: | EMBO Molecular Medicine |
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| Online Access: | https://doi.org/10.15252/emmm.201911659 |
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| author | David Alsina Oleksandr Lytovchenko Aleksandra Schab Ilian Atanassov Florian A Schober Min Jiang Camilla Koolmeister Anna Wedell Robert W Taylor Anna Wredenberg Nils‐Göran Larsson |
| author_facet | David Alsina Oleksandr Lytovchenko Aleksandra Schab Ilian Atanassov Florian A Schober Min Jiang Camilla Koolmeister Anna Wedell Robert W Taylor Anna Wredenberg Nils‐Göran Larsson |
| author_sort | David Alsina |
| collection | DOAJ |
| description | Abstract Pathogenic variants in FBXL4 cause a severe encephalopathic syndrome associated with mtDNA depletion and deficient oxidative phosphorylation. To gain further insight into the enigmatic pathophysiology caused by FBXL4 deficiency, we generated homozygous Fbxl4 knockout mice and found that they display a predominant perinatal lethality. Surprisingly, the few surviving animals are apparently normal until the age of 8–12 months when they gradually develop signs of mitochondrial dysfunction and weight loss. One‐year‐old Fbxl4 knockouts show a global reduction in a variety of mitochondrial proteins and mtDNA depletion, whereas lysosomal proteins are upregulated. Fibroblasts from patients with FBXL4 deficiency and human FBXL4 knockout cells also have reduced steady‐state levels of mitochondrial proteins that can be attributed to increased mitochondrial turnover. Inhibition of lysosomal function in these cells reverses the mitochondrial phenotype, whereas proteasomal inhibition has no effect. Taken together, the results we present here show that FBXL4 prevents mitochondrial removal via autophagy and that loss of FBXL4 leads to decreased mitochondrial content and mitochondrial disease. |
| format | Article |
| id | doaj-art-a1607124f7c84b129339028002683006 |
| institution | Kabale University |
| issn | 1757-4676 1757-4684 |
| language | English |
| publishDate | 2020-06-01 |
| publisher | Springer Nature |
| record_format | Article |
| series | EMBO Molecular Medicine |
| spelling | doaj-art-a1607124f7c84b1293390280026830062025-08-20T03:43:26ZengSpringer NatureEMBO Molecular Medicine1757-46761757-46842020-06-0112711610.15252/emmm.201911659FBXL4 deficiency increases mitochondrial removal by autophagyDavid Alsina0Oleksandr Lytovchenko1Aleksandra Schab2Ilian Atanassov3Florian A Schober4Min Jiang5Camilla Koolmeister6Anna Wedell7Robert W Taylor8Anna Wredenberg9Nils‐Göran Larsson10Department of Medical Biochemistry and Biophysics, Karolinska InstitutetDepartment of Medical Biochemistry and Biophysics, Karolinska InstitutetDepartment of Medical Biochemistry and Biophysics, Karolinska InstitutetProteomics Core Facility, Max Planck Institute for Biology of AgeingMax Planck Institute Biology of Ageing ‐ Karolinska Institutet Laboratory, Karolinska InstitutetKey Laboratory of Growth Regulation and Translation Research of Zhejiang Province, School of Life Sciences, Westlake UniversityDepartment of Medical Biochemistry and Biophysics, Karolinska InstitutetDepartment of Molecular Medicine and Surgery, Karolinska InstitutetWellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle UniversityDepartment of Medical Biochemistry and Biophysics, Karolinska InstitutetDepartment of Medical Biochemistry and Biophysics, Karolinska InstitutetAbstract Pathogenic variants in FBXL4 cause a severe encephalopathic syndrome associated with mtDNA depletion and deficient oxidative phosphorylation. To gain further insight into the enigmatic pathophysiology caused by FBXL4 deficiency, we generated homozygous Fbxl4 knockout mice and found that they display a predominant perinatal lethality. Surprisingly, the few surviving animals are apparently normal until the age of 8–12 months when they gradually develop signs of mitochondrial dysfunction and weight loss. One‐year‐old Fbxl4 knockouts show a global reduction in a variety of mitochondrial proteins and mtDNA depletion, whereas lysosomal proteins are upregulated. Fibroblasts from patients with FBXL4 deficiency and human FBXL4 knockout cells also have reduced steady‐state levels of mitochondrial proteins that can be attributed to increased mitochondrial turnover. Inhibition of lysosomal function in these cells reverses the mitochondrial phenotype, whereas proteasomal inhibition has no effect. Taken together, the results we present here show that FBXL4 prevents mitochondrial removal via autophagy and that loss of FBXL4 leads to decreased mitochondrial content and mitochondrial disease.https://doi.org/10.15252/emmm.201911659autophagyFBXL4mitochondrial diseasemtDNAoxidative phosphorylation |
| spellingShingle | David Alsina Oleksandr Lytovchenko Aleksandra Schab Ilian Atanassov Florian A Schober Min Jiang Camilla Koolmeister Anna Wedell Robert W Taylor Anna Wredenberg Nils‐Göran Larsson FBXL4 deficiency increases mitochondrial removal by autophagy EMBO Molecular Medicine autophagy FBXL4 mitochondrial disease mtDNA oxidative phosphorylation |
| title | FBXL4 deficiency increases mitochondrial removal by autophagy |
| title_full | FBXL4 deficiency increases mitochondrial removal by autophagy |
| title_fullStr | FBXL4 deficiency increases mitochondrial removal by autophagy |
| title_full_unstemmed | FBXL4 deficiency increases mitochondrial removal by autophagy |
| title_short | FBXL4 deficiency increases mitochondrial removal by autophagy |
| title_sort | fbxl4 deficiency increases mitochondrial removal by autophagy |
| topic | autophagy FBXL4 mitochondrial disease mtDNA oxidative phosphorylation |
| url | https://doi.org/10.15252/emmm.201911659 |
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