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Título:
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Frataxin depletion in yeast triggers up-regulation of iron transport systems before affecting iron-sulfur enzyme activities
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Autor/a:
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Moreno Cermeño, Armando J.; Obis Monné, Èlia; Bellí i Martínez, Gemma; Cabiscol Català, Elisa; Ros Salvador, Joaquim; Tamarit Sumalla, Jordi
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Notas:
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The primary function of frataxin, a mitochondrial protein
involved in iron homeostasis, remains controversial. Using a
yeast model of conditional expression of the frataxin homologue
YFH1, we analyzed the primary effects of YFH1 depletion.
The main conclusion unambiguously points to the upregulation
of iron transport systems as a primary effect of
YFH1 down-regulation. We observed that inactivation of aconitase,
an iron-sulfur enzyme, occurs long after the iron uptake
system has been activated. Decreased aconitase activity should
be considered part of a group of secondary events promoted by
iron overloading, which includes decreased superoxide dismutase
activity and increased protein carbonyl formation. Impaired
manganese uptake, which contributes to superoxide
dismutase deficiency, has also been observed in YFH1-deficient
cells. This low manganese content can be attributed to
the down-regulation of the metal ion transporter Smf2. Low
Smf2 levels were not observed in AFT1/YFH1 double mutants,
indicating that high iron levels could be responsible for the
Smf2 decline. In summary, the results presented here indicate
that decreased iron-sulfur enzyme activities in YFH1-deficient
cells are the consequence of the oxidative stress conditions
suffered by these cells. |
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Materia(s):
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-SOD
-superoxide dismutase
-CBB |
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Derechos:
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(c) The American Society for Biochemistry and Molecular Biology, 2010
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Tipo de documento:
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article
publishedVersion |
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Editor:
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The American Society for Biochemistry and Molecular Biology
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