Details
| Original language | English |
|---|---|
| Pages (from-to) | 265-272 |
| Number of pages | 8 |
| Journal | Plant physiology and biochemistry |
| Volume | 48 |
| Issue number | 4 |
| Publication status | Published - 22 Jan 2010 |
Abstract
The protein complexes of the mitochondrial respiratory chain associate in defined ways forming supramolecular structures called respiratory supercomplexes or respirasomes. In plants, additional oxidoreductases participate in respiratory electron transport, e.g. the so-called "alternative NAD(P)H dehydrogenases" or an extra terminal oxidase called "alternative oxidase" (AOX). These additional enzymes were previously reported not to form part of respiratory supercomplexes. However, formation of respiratory supercomplexes might indirectly affect "alternative respiration" because electrons can be channeled within the supercomplexes which reduces access of the alternative enzymes towards their electron donating substrates. Here we report an investigation on the supramolecular organization of the respiratory chain in thermogenic Arum maculatum appendix mitochondria, which are known to have a highly active AOX for heat production. Investigations based on mild membrane solubilization by digitonin and protein separation by blue native PAGE revealed a very special organization of the respiratory chain in A. maculatum, which strikingly differs to the one described for the model plant Arabidopsis thaliana: (i) complex I is not present in monomeric form but exclusively forms part of a I + III2 supercomplex, (ii) the III2 + IV and I + III2 + IV supercomplexes are detectable but of low abundance, (iii) complex II has fewer subunits than in A. thaliana, and (iv) complex IV is mainly present as a monomer in a larger form termed "complex IVa". Since thermogenic tissue of A. maculatum at the same time has high AOX and I + III2 supercomplex abundance and activity, negative regulation of the alternative oxidase by supercomplex formation seems not to occur. Functional implications are discussed.
Keywords
- Alternative oxidase, Arum maculatum, Mitochondria, Oxidative phosphorylation, Respiratory supercomplexes, Thermogenesis
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Physiology
- Biochemistry, Genetics and Molecular Biology(all)
- Genetics
- Agricultural and Biological Sciences(all)
- Plant Science
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In: Plant physiology and biochemistry, Vol. 48, No. 4, 22.01.2010, p. 265-272.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Supramolecular structure of the OXPHOS system in highly thermogenic tissue of Arum maculatum
AU - Sunderhaus, Stephanie
AU - Klodmann, Jennifer
AU - Lenz, Christof
AU - Braun, Hans Peter
N1 - Funding information: We thank the “Berggarten” in Hannover, Germany, for providing Arum maculatum . Furthermore, we wish to thank Tom Elton, University of Nebraska, USA, for providing the antibodies directed against the AOX. This research was supported by the Deutsche Forschungsgemeinschaft (grants Br 1829/7-3 and Br 1829/8-1 ).
PY - 2010/1/22
Y1 - 2010/1/22
N2 - The protein complexes of the mitochondrial respiratory chain associate in defined ways forming supramolecular structures called respiratory supercomplexes or respirasomes. In plants, additional oxidoreductases participate in respiratory electron transport, e.g. the so-called "alternative NAD(P)H dehydrogenases" or an extra terminal oxidase called "alternative oxidase" (AOX). These additional enzymes were previously reported not to form part of respiratory supercomplexes. However, formation of respiratory supercomplexes might indirectly affect "alternative respiration" because electrons can be channeled within the supercomplexes which reduces access of the alternative enzymes towards their electron donating substrates. Here we report an investigation on the supramolecular organization of the respiratory chain in thermogenic Arum maculatum appendix mitochondria, which are known to have a highly active AOX for heat production. Investigations based on mild membrane solubilization by digitonin and protein separation by blue native PAGE revealed a very special organization of the respiratory chain in A. maculatum, which strikingly differs to the one described for the model plant Arabidopsis thaliana: (i) complex I is not present in monomeric form but exclusively forms part of a I + III2 supercomplex, (ii) the III2 + IV and I + III2 + IV supercomplexes are detectable but of low abundance, (iii) complex II has fewer subunits than in A. thaliana, and (iv) complex IV is mainly present as a monomer in a larger form termed "complex IVa". Since thermogenic tissue of A. maculatum at the same time has high AOX and I + III2 supercomplex abundance and activity, negative regulation of the alternative oxidase by supercomplex formation seems not to occur. Functional implications are discussed.
AB - The protein complexes of the mitochondrial respiratory chain associate in defined ways forming supramolecular structures called respiratory supercomplexes or respirasomes. In plants, additional oxidoreductases participate in respiratory electron transport, e.g. the so-called "alternative NAD(P)H dehydrogenases" or an extra terminal oxidase called "alternative oxidase" (AOX). These additional enzymes were previously reported not to form part of respiratory supercomplexes. However, formation of respiratory supercomplexes might indirectly affect "alternative respiration" because electrons can be channeled within the supercomplexes which reduces access of the alternative enzymes towards their electron donating substrates. Here we report an investigation on the supramolecular organization of the respiratory chain in thermogenic Arum maculatum appendix mitochondria, which are known to have a highly active AOX for heat production. Investigations based on mild membrane solubilization by digitonin and protein separation by blue native PAGE revealed a very special organization of the respiratory chain in A. maculatum, which strikingly differs to the one described for the model plant Arabidopsis thaliana: (i) complex I is not present in monomeric form but exclusively forms part of a I + III2 supercomplex, (ii) the III2 + IV and I + III2 + IV supercomplexes are detectable but of low abundance, (iii) complex II has fewer subunits than in A. thaliana, and (iv) complex IV is mainly present as a monomer in a larger form termed "complex IVa". Since thermogenic tissue of A. maculatum at the same time has high AOX and I + III2 supercomplex abundance and activity, negative regulation of the alternative oxidase by supercomplex formation seems not to occur. Functional implications are discussed.
KW - Alternative oxidase
KW - Arum maculatum
KW - Mitochondria
KW - Oxidative phosphorylation
KW - Respiratory supercomplexes
KW - Thermogenesis
UR - http://www.scopus.com/inward/record.url?scp=77949486574&partnerID=8YFLogxK
U2 - 10.15488/11662
DO - 10.15488/11662
M3 - Article
C2 - 20144873
AN - SCOPUS:77949486574
VL - 48
SP - 265
EP - 272
JO - Plant physiology and biochemistry
JF - Plant physiology and biochemistry
SN - 0981-9428
IS - 4
ER -