Characterization of a split respiratory pathway in the wheat "take-all" fungus, Gaeumannomyces graminis var. tritici.
J Biol Chem
; 273(18): 11127-33, 1998 May 01.
Article
en En
| MEDLINE
| ID: mdl-9556599
This article describes the first detailed analysis of mitochondrial electron transfer and oxidative phosphorylation in the pathogenic filamentous fungus, Gaeumannomyces graminis var. tritici. While oxygen consumption was cyanide insensitive, inhibition occurred following treatment with complex III inhibitors and the alternative oxidase inhibitor, salicylhydroxamic acid (SHAM). Similarly, maintenance of a Deltapsi across the mitochondrial inner membrane was unaffected by cyanide but sensitive to antimycin A and SHAM when succinate was added as the respiratory substrate. As a result, ATP synthesis through complex V was demonstrated to be sensitive to these two inhibitors but not to cyanide. Analysis of the cytochrome content of mitochondria indicated the presence of those cytochromes normally associated with electron transport in eukaryotic mitochondria together with a third, b-type heme, exhibiting a dithionite-reduced absorbance maxima at 560 nm and not associated with complex III. Antibodies raised to plant alternative oxidase detected the presence of both the monomeric and dimeric forms of this oxidase. Overall this study demonstrates that a novel respiratory chain utilizing the terminal oxidases, cytochrome c oxidase and alternative oxidase, are present and constitutively active in electron transfer in G. graminis tritici. These results are discussed in relation to current understanding of fungal electron transfer and to the possible contribution of alternative redox centers in ATP synthesis.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ascomicetos
/
Triticum
Idioma:
En
Revista:
J Biol Chem
Año:
1998
Tipo del documento:
Article
País de afiliación:
Reino Unido
Pais de publicación:
Estados Unidos