TY - JOUR
T1 - Respiratory chain supercomplexes in plant mitochondria
AU - Eubel, Holger
AU - Heinemeyer, J.
AU - Sunderhaus, S.
AU - Braun, H-P.
PY - 2004
Y1 - 2004
N2 - Supercomplexes are defined associations of protein complexes, which are important for several cellular functions. This "quintenary" organization level of protein structure recently was also described for the respiratory chain of plant mitochondria. Except succinate dehydrogenase (complex II), all complexes of the oxidative phosphorylation (OXPOS) system (complexes I, III, IV and V) were found to form part of supercomplexes. Compositions of these supramolecular structures were systematically investigated using digitonin solubilizations of mitochondrial fractions and two-dimensional Blue-native (BN) polyacrylamide gel electrophoresis. The most abundant supercomplex of plant mitochondria includes complexes I and III at a 1:2 ratio (I-1 + III2 supercomplex). Furthermore, some supercomplexes of lower abundance could be described, which have I-2 + III4, V-2, III2 + IV1-2, and I-1 + III2 + IV1-4 compositions. Supercomplexes consisting of complexes I plus III plus IV were proposed to be called "respirasome", because they autonomously can carry out respiration in the presence of ubiquinone and cytochrome c. Plant specific alternative oxidoreductases of the respiratory chain were not associated with supercomplexes under all experimental conditions tested. However, formation of supercomplexes possibly indirectly regulates alternative respiratory pathways in plant mitochondria on the basis of electron channeling. In this review, procedures to characterize the supermolecular organization of the plant respiratory chain and results concerning supercomplex structure and function are summarized and discussed. (C) 2005 Elsevier SAS. All rights reserved.
AB - Supercomplexes are defined associations of protein complexes, which are important for several cellular functions. This "quintenary" organization level of protein structure recently was also described for the respiratory chain of plant mitochondria. Except succinate dehydrogenase (complex II), all complexes of the oxidative phosphorylation (OXPOS) system (complexes I, III, IV and V) were found to form part of supercomplexes. Compositions of these supramolecular structures were systematically investigated using digitonin solubilizations of mitochondrial fractions and two-dimensional Blue-native (BN) polyacrylamide gel electrophoresis. The most abundant supercomplex of plant mitochondria includes complexes I and III at a 1:2 ratio (I-1 + III2 supercomplex). Furthermore, some supercomplexes of lower abundance could be described, which have I-2 + III4, V-2, III2 + IV1-2, and I-1 + III2 + IV1-4 compositions. Supercomplexes consisting of complexes I plus III plus IV were proposed to be called "respirasome", because they autonomously can carry out respiration in the presence of ubiquinone and cytochrome c. Plant specific alternative oxidoreductases of the respiratory chain were not associated with supercomplexes under all experimental conditions tested. However, formation of supercomplexes possibly indirectly regulates alternative respiratory pathways in plant mitochondria on the basis of electron channeling. In this review, procedures to characterize the supermolecular organization of the plant respiratory chain and results concerning supercomplex structure and function are summarized and discussed. (C) 2005 Elsevier SAS. All rights reserved.
U2 - 10.1016/j.plaphy.2004.09.010
DO - 10.1016/j.plaphy.2004.09.010
M3 - Article
C2 - 15707832
SN - 0981-9428
VL - 42
SP - 937
EP - 942
JO - Plant Physiology and Biochemistry
JF - Plant Physiology and Biochemistry
IS - 12
ER -