Eukaryotic Cell Visit the journal of Applied and Environmental Biology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Other Versions of this Article:
EC.00149-07v1
6/12/2391    most recent
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 arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Google Scholar
Right arrow Articles by Marques, I.
Right arrow Articles by Krause, F.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Marques, I.
Right arrow Articles by Krause, F.
Eukaryotic Cell, December 2007, p. 2391-2405, Vol. 6, No. 12
1535-9778/07/$08.00+0     doi:10.1128/EC.00149-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Supramolecular Organization of the Respiratory Chain in Neurospora crassa Mitochondria{triangledown}

Isabel Marques,1 Norbert A. Dencher,2 Arnaldo Videira,1,3 and Frank Krause2*

Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal,1 Physical Biochemistry, Department of Chemistry, Technische Universität Darmstadt, Petersenstrasse 22, D-64287 Darmstadt, Germany,2 Instituto de Ciências Biomédicas de Abel Salazar, Largo Prof. Abel Salazar 2, Universidade do Porto, 4050 Porto, Portugal3

Received 29 April 2007/ Accepted 4 September 2007

The existence of specific respiratory supercomplexes in mitochondria of most organisms has gained much momentum. However, its functional significance is still poorly understood. The availability of many deletion mutants in complex I (NADH:ubiquinone oxidoreductase) of Neurospora crassa, distinctly affected in the assembly process, offers unique opportunities to analyze the biogenesis of respiratory supercomplexes. Herein, we describe the role of complex I in assembly of respiratory complexes and supercomplexes as suggested by blue and colorless native polyacrylamide gel electrophoresis and mass spectrometry analyses of mildly solubilized mitochondria from the wild type and eight deletion mutants. As an important refinement of the fungal respirasome model, we found that the standard respiratory chain of N. crassa comprises putative complex I dimers in addition to I-III-IV and III-IV supercomplexes. Three Neurospora mutants able to assemble a complete complex I, lacking only the disrupted subunit, have respiratory supercomplexes, in particular I-III-IV supercomplexes and complex I dimers, like the wild-type strain. Furthermore, we were able to detect the I-III-IV supercomplexes in the nuo51 mutant with no overall enzymatic activity, representing the first example of inactive respirasomes. In addition, III-IV supercomplexes were also present in strains lacking an assembled complex I, namely, in four membrane arm subunit mutants as well as in the peripheral arm nuo30.4 mutant. In membrane arm mutants, high-molecular-mass species of the 30.4-kDa peripheral arm subunit comigrating with III-IV supercomplexes and/or the prohibitin complex were detected. The data presented herein suggest that the biogenesis of complex I is linked with its assembly into supercomplexes.


* Corresponding author. Mailing address: Physical Biochemistry, Department of Chemistry, Technische Universität Darmstadt, Petersenstrasse 22, D-64287 Darmstadt, Germany. Phone: 49 (0) 6151 165376. Fax: 49 (0) 6151 164171. E-mail: f_krause{at}hrzpub.tu-darmstadt.de

{triangledown} Published ahead of print on 14 September 2007.


Eukaryotic Cell, December 2007, p. 2391-2405, Vol. 6, No. 12
1535-9778/07/$08.00+0     doi:10.1128/EC.00149-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.







HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Appl. Environ. Microbiol. Infect. Immun. J. Bacteriol.
Mol. Cell Biol. Microbiol. Mol. Biol. Rev. ALL ASM JOURNALS
Copyright © 2007 by the American Society for Microbiology.