Mitochondrial Bol1 and Bol3 function as assembly factors for specific iron-sulfur proteins
Abstract
Assembly of mitochondrial iron-sulfur (Fe/S) proteins is a key process of cells, and defects cause many rare diseases. In the first phase of this pathway, ten Fe/S cluster (ISC) assembly components synthesize and insert [2Fe-2S] clusters. The second phase is dedicated to the assembly of [4Fe-4S] proteins, yet this part is poorly understood. Here, we characterize the BOLA family proteins Bol1 and Bol3 as specific mitochondrial ISC assembly factors that facilitate [4Fe-4S] cluster insertion into a subset of mitochondrial proteins such as lipoate synthase and succinate dehydrogenase. Bol1-Bol3 perform largely overlapping functions, yet cannot replace the ISC protein Nfu1 that also participates in this phase of Fe/S protein biogenesis. Bol1 and Bol3 form dimeric complexes with both monothiol glutaredoxin Grx5 and Nfu1. Complex formation differentially influences the stability of the Grx5-Bol-shared Fe/S clusters. Our findings provide the biochemical basis for explaining the pathological phenotypes of patients with mutations in BOLA3.
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Author details
Funding
Deutsche Forschungsgemeinschaft (SPP 1927)
- Roland Lill
European Commission (iNEXT 653706)
- Lucia Banci
Deutsche Forschungsgemeinschaft (SFB 987)
- Ulrich Mühlenhoff
- Roland Lill
European strategy forum on research infrastructures (Instruct)
- Lucia Banci
LOEWE program of state Hesse, Germany (Synmikro)
- Roland Lill
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Nikolaus Pfanner, University of Freiburg, Germany
Version history
- Received: April 6, 2016
- Accepted: August 8, 2016
- Accepted Manuscript published: August 17, 2016 (version 1)
- Version of Record published: September 7, 2016 (version 2)
- Version of Record updated: September 8, 2016 (version 3)
Copyright
© 2016, Uzarska et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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