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Impact of mutations within the [Fe-S] cluster or the lipoic acid biosynthesis pathways on mitochondrial protein expression profiles in fibroblasts from patients.
- Source :
-
Molecular genetics and metabolism [Mol Genet Metab] 2017 Nov; Vol. 122 (3), pp. 85-94. Date of Electronic Publication: 2017 Aug 03. - Publication Year :
- 2017
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Abstract
- Lipoic acid (LA) is the cofactor of the E2 subunit of mitochondrial ketoacid dehydrogenases and plays a major role in oxidative decarboxylation. De novo LA biosynthesis is dependent on LIAS activity together with LIPT1 and LIPT2. LIAS is an iron‑sulfur (Fe-S) cluster-containing mitochondrial protein, like mitochondrial aconitase (mt-aco) and some subunits of respiratory chain (RC) complexes I, II and III. All of them harbor at least one [Fe-S] cluster and their activity is dependent on the mitochondrial [Fe-S] cluster (ISC) assembly machinery. Disorders in the ISC machinery affect numerous Fe-S proteins and lead to a heterogeneous group of diseases with a wide variety of clinical symptoms and combined enzymatic defects. Here, we present the biochemical profiles of several key mitochondrial [Fe-S]-containing proteins in fibroblasts from 13 patients carrying mutations in genes encoding proteins involved in either the lipoic acid (LIPT1 and LIPT2) or mitochondrial ISC biogenesis (FDX1L, ISCA2, IBA57, NFU1, BOLA3) pathway. Ten of them are new patients described for the first time. We confirm that the fibroblast is a good cellular model to study these deficiencies, except for patients presenting mutations in FDX1L and a muscular clinical phenotype. We find that oxidative phosphorylation can be affected by LA defects in LIPT1 and LIPT2 patients due to excessive oxidative stress or to another mechanism connecting LA and respiratory chain activity. We confirm that NFU1, BOLA3, ISCA2 and IBA57 operate in the maturation of [4Fe-4S] clusters and not in [2Fe-2S] protein maturation. Our work suggests a functional difference between IBA57 and other proteins involved in maturation of [Fe-S] proteins. IBA57 seems to require BOLA3, NFU1 and ISCA2 for its stability and NFU1 requires BOLA3. Finally, our study establishes different biochemical profiles for patients according to their mutated protein.<br /> (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Subjects :
- Acyltransferases genetics
Adolescent
Biosynthetic Pathways genetics
Carrier Proteins genetics
Child
Child, Preschool
Female
Fibroblasts chemistry
Humans
Infant
Male
Mitochondria metabolism
Oxidative Phosphorylation
Oxidative Stress
Phenotype
Proteins genetics
Thioctic Acid genetics
Fibroblasts metabolism
Iron-Sulfur Proteins genetics
Mitochondrial Proteins genetics
Mutation
Thioctic Acid biosynthesis
Subjects
Details
- Language :
- English
- ISSN :
- 1096-7206
- Volume :
- 122
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Molecular genetics and metabolism
- Publication Type :
- Academic Journal
- Accession number :
- 28803783
- Full Text :
- https://doi.org/10.1016/j.ymgme.2017.08.001