| Overexpression of the yeast frataxin homolog (Yfh1): contrasting effects on iron-sulfur cluster assembly, heme synthesis and resistance to oxidative stress. | |
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MedLine Citation:
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PMID: 19460301 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Friedreich's ataxia is generally associated with defects in [Fe-S] cluster assembly/stability and heme synthesis and strong susceptibility to oxidative stress. We used the yeast (Saccharomyces cerevisiae) model of Friedreich's ataxia to study the physiological consequences of modulating the expression of the frataxin gene (YFH1). We show that the number of frataxin molecules per wild-type cell varies from less than 200 to 1500 according to the iron concentration in the medium. Cells overexpressing YFH1 on a plasmid (2muYFH1; about 3500 molecules Yfh1/cell) took up more iron than wild-type cells and displayed defective [Fe-S] cluster assembly/stability in vivo. By contrast, endogenous mitochondrial iron was more available to ferrochelatase in 2muYFH1 cells than in wild-type cells, resulting in higher levels of heme synthesis in vitro. Frataxin overproduction resulted in a shift from frataxin trimers to frataxin oligomers of higher molecular mass in the mitochondrial matrix. Much fewer carbonylated proteins were present in 2muYFH1 cells, and these cells were more resistant to oxidizing agents than wild-type cells, which probably resulted from the lower production of hydrogen peroxide by the mitochondria of 2muYFH1 cells compared to wild-type cells. To our knowledge, this work is the first description where major frataxin-related phenotypes ([Fe-S] cluster assembly and heme synthesis) can be split in vivo, suggesting that frataxin has independent roles in both processes, and that the optimal conditions for these independent roles are different. |
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Authors:
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Alexandra Seguin; Aurélien Bayot; Andrew Dancis; Adelina Rogowska-Wrzesinska; Françoise Auchère; Jean-Michel Camadro; Anne-Laure Bulteau; Emmanuel Lesuisse |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2009-01-22 |
Journal Detail:
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Title: Mitochondrion Volume: 9 ISSN: 1872-8278 ISO Abbreviation: Mitochondrion Publication Date: 2009 Apr |
Date Detail:
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Created Date: 2009-05-25 Completed Date: 2009-07-02 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 100968751 Medline TA: Mitochondrion Country: Netherlands |
Other Details:
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Languages: eng Pagination: 130-8 Citation Subset: IM |
Affiliation:
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Laboratoire d'Ingéniérie des Protéines et Contrôle Métabolique, Département de Biologie des Génomes, Institut Jacques Monod, UMR7592 CNRS, Université Paris Diderot and UPMC, Tour 43, 2 Place Jussieu, F-75251 Paris cedex 05, France. |
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| MeSH Terms | |
Descriptor/Qualifier:
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Ferrochelatase
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metabolism Gene Dosage* Heme / biosynthesis* Iron / metabolism Iron-Binding Proteins / biosynthesis*, genetics Iron-Sulfur Proteins / metabolism* Mitochondria / chemistry Oxidative Stress* Plasmids Saccharomyces cerevisiae / enzymology, metabolism*, physiology* Saccharomyces cerevisiae Proteins / metabolism Stress, Physiological* |
| Chemical | |
Reg. No./Substance:
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0/Iron-Binding Proteins; 0/Iron-Sulfur Proteins; 0/Saccharomyces cerevisiae Proteins; 0/frataxin; 14875-96-8/Heme; 7439-89-6/Iron; EC 4.99.1.1/Ferrochelatase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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