MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Borghouts, C.
Right arrow Articles by Osiewacz, H. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Borghouts, C.
Right arrow Articles by Osiewacz, H. D.

Molecular and Cellular Biology, January 2001, p. 390-399, Vol. 21, No. 2
0270-7306/01/$04.00+0   DOI: 10.1128/MCB.21.2.390-399.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

Copper-Modulated Gene Expression and Senescence in the Filamentous Fungus Podospora anserina

Corina Borghouts, Alexandra Werner, Thomas Elthon,dagger and Heinz D. Osiewacz*

Botanisches Institut, Johann Wolfgang Goethe-Universität, D-60439 Frankfurt am Main, Germany

Received 28 August 2000/Accepted 9 October 2000

We have previously shown that the control of cellular copper homeostasis by the copper-modulated transcription factor GRISEA has an important impact on the phenotype and lifespan of Podospora anserina. Here we demonstrate that copper depletion leads to the induction of an alternative respiratory pathway and to an increase in lifespan. This response compensates mitochondrial dysfunctions via the expression of PaAox, a nuclear gene coding for an alternative oxidase. It resembles the retrograde response in Saccharomyces cerevisiae. In P. anserina, this pathway appears to be induced by specific impairments of the copper-dependent cytochrome c oxidase. It is not induced as the result of a general decline of mitochondrial functions during senescence. We cloned and characterized PaAox. Transcript levels are decreased when cellular copper, superoxide, and hydrogen peroxide levels are raised. Copper also controls transcript levels of PaSod2, the gene encoding the mitochondrial manganese superoxide dismutase (PaSOD2). PaSod2 is a target of transcription factor GRISEA. During the senescence of wild-type strain s, the activity of PaSOD2 decreases, whereas the activity of the cytoplasmic copper/zinc superoxide dismutase (PaSOD1) increases. Collectively, the data explain the postponed senescence of mutant grisea as a defined consequence of copper depletion, ultimately leading to a reduction of oxidative stress. Moreover, they suggest that during senescence of the wild-type strain, copper is released from mitochondria. The involved mechanism is unknown. However, it is striking that the permeability of mitochondrial membranes in animal systems changes during apoptosis and that mitochondrial proteins with an important impact on this type of cellular death are released.

* Corresponding author. Mailing address: Botanisches Institut, Johann Wolfgang Goethe-Universität, Marie-Curie-Strasse 9, D-60439 Frankfurt am Main, Germany. Phone: 49 69 798 29264. Fax: 49 69 798 29363. E-mail: osiewacz{at}em.uni-frankfurt.de.

dagger Present address: University of Nebraska, School of Biological Sciences, 348 Manter Hall, Lincoln, NE 68588-0118.

Molecular and Cellular Biology, January 2001, p. 390-399, Vol. 21, No. 2
0270-7306/01/$04.00+0   DOI: 10.1128/MCB.21.2.390-399.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2001 by the American Society for Microbiology. All rights reserved.