Life without complex I

Proteome analyses of an Arabidopsis mutant lacking the mitochondrial NADH dehydrogenase complex

authored by

Steffanie Fromm, Jennifer Senkler, Holger Eubel, Christoph Peterhänsel, Hans Peter Braun

Abstract

The mitochondrial NADH dehydrogenase complex (complex I) is of particular importance for the respiratory chain in mitochondria. It is the major electron entry site for the mitochondrial electron transport chain (mETC) and therefore of great significance for mitochondrial ATP generation. We recently described an Arabidopsis thaliana double-mutant lacking the genes encoding the carbonic anhydrases CA1 and CA2, which both form part of a plant-specific 'carbonic anhydrase domain' of mitochondrial complex I. The mutant lacks complex I completely. Here we report extended analyses for systematically characterizing the proteome of the ca1ca2 mutant. Using various proteomic tools, we show that lack of complex I causes reorganization of the cellular respiration system. Reduced electron entry into the respiratory chain at the first segment of the mETC leads to induction of complexes II and IV as well as alternative oxidase. Increased electron entry at later segments of the mETC requires an increase in oxidation of organic substrates. This is reflected by higher abundance of proteins involved in glycolysis, the tricarboxylic acid cycle and branched-chain amino acid catabolism. Proteins involved in the light reaction of photosynthesis, the Calvin cycle, tetrapyrrole biosynthesis, and photorespiration are clearly reduced, contributing to the significant delay in growth and development of the double-mutant. Finally, enzymes involved in defense against reactive oxygen species and stress symptoms are much induced. These together with previously reported insights into the function of plant complex I, which were obtained by analysing other complex I mutants, are integrated in order to comprehensively describe 'life without complex I'.

Organisation(s)

Section Plant Molecular Biology and Plant Proteomics
Institute of Plant Genetics
Institute of Botany

Type

Article

Journal

Journal of experimental botany

Volume

67

Pages

3079-3093

No. of pages

15

ISSN

0022-0957

Publication date

27.04.2016

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Physiology, Plant Science

Electronic version(s)

https://doi.org/10.1093/jxb/erw165 (Access: Open)