Effects of mitochondrial complex III disruption in the respiratory chain of Neurospora crassa

• Type: Article in International Scientific Journal
• Date: 2009

Authors

duarte, m (Author) ICBAS; videira, a (Author) ICBAS

Journal

Title: Molecular Microbiology

Vol. 72

Pages: 246-258

ISSN: 0950-382X

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-003-M97

DOI: 10.1111/j.1365-2958.2009.06643.x

Abstract (EN): In mitochondria from most organisms, including Neurospora crassa, dimeric complex III was found associated with complex I. Additional association of complex IV with this core structure leads to the formation of a respirasome. It was recently described for bacteria and mammals that complex III is needed for the assembly/stability of complex I. To elucidate the role of complex III in the organization of the respiratory chain of N. crassa, we analysed strains devoid of either the Rieske iron-sulphur or the COREII polypeptide subunits. The mutants display reduced growth, are female sterile and lack active complex III. The supramolecular organization of the oxidative phosphorylation system was characterized by electrophoretic analyses and the efficiency of the respiratory chain analysed by oxygen consumption measurements. The results obtained indicate that absence of complex III activity is not associated with the absence of complex I or complex IV, and leads to the induction of alternative oxidase. Complex III mutant mitochondria are devoid of respirasomes but contain significant amounts of dimeric complex I (I(2)) and of the supercomplex I(1)IV(1). Moreso, for the first time the alternative oxidase was found associated with dimeric complex IV and with supercomplex I(1)IV(1).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13