Research Dr. Etienne Meyer
Respiration is a key metabolic pathway providing ATP to fuel cellular functions. Cellular respiration is composed of three main pathways, the glycolysis, the TCA cycle and the oxidative phosphorylation (OXPHOS) system. The OXPHOS system uses the redox energy stored in cofactors by the glycolysis and the TCA cycle to create an electrochemical gradient across the mitochondrial inner membrane that will be used for ATP synthesis. The OXPHOS system is composed of five main complexes (complexes I to V) conserved from bacteria to higher eukaryotes. The OXPHOS system of plants contains additional enzymes that allow alternative routes for electrons. Besides, each of the complexes I to V contains plant-specific subunits. The roles of these plant specific features are not well understood. Our current research aims at resolving the composition, function and regulation of the OXPHOS system.
Complex I is the largest complex of the OXPHOS system and it contains subunits encoded by the mitochondrial and nuclear genomes. We use complex I as a model to study interactions between mitochondria and the rest of the cell (coordination of the assembly of subunits originating from two different compartments, regulation of metabolic fluxes by complex I activity).
Using bioinformatics analysis (Hansen et al 2018), we have built a list of complex I related genes, mostly encoding proteins of unknown functions. These proteins are candidate assembly or regulatory factors. Using reverse genetic approaches, we are currently investigating the role of these proteins.
Using systems biology approaches, we are also studying the consequences of the absence of complex I on cellular metabolism. We have recently identified complex I as a negative regulator of respiratory fluxes in mutants of the model plant Arabidopsis thaliana (Kühn et al 2015) but also in the parasitic plant Viscum album (European mistletoe) that lost complex I (Maclean et al 2018). We are currently investigating the mechanisms involved in this regulatory role in both systems.
Currently funded projects
Control of complex I proteostasis in plants
Selected publications:
- Wu GZ, Meyer EH, Richter AS, Schuster M, Ling Q, Schottler MA, Walther D, Zoschke R, Grimm B, Jarvis RP, Bock R (2019) Control of retrograde signalling by protein import and cytosolic folding stress. Nature plants 5 (5):525-538.
- Meyer EH*, Welchen E, Carrie C. Assembly of the complexes of the oxidative phosphorylation system in plant mitochondria. Annu Rev Plant Biol 70:23-50. (* corresponding author)
- Ligas J, Pineau E, Bock R, Huynen MA, Meyer EH. (2018) The assembly pathway of Complex I in Arabidopsis thaliana. Plant J. 97(3):447-459.
- Maclean AE, Hertle AP, Ligas J, Bock R, Balk J, Meyer EH. (2018) Absence of complex I is associated with diminished respiratory chain function in European mistletoe. Current Biology. 28(10):1614-1619.
- Meyer EH*, Lehmann C, Boivin S, Brings L, De Cauwer I, Bock R, Kühn K, Touzet P. (2018) CMS-G from Beta vulgaris ssp. maritima is maintained in natural populations despite containing an atypical cytochrome c oxidase. Biochem J. 475(4):759-773. (* corresponding author)
- Hansen BO*, Meyer EH*, Ferrari C, Vaid N, Movahedi S, Vandepoele K, Nikoloski Z, Mutwil M. (2018) Ensemble gene function prediction database reveals genes important for complex I formation in Arabidopsis thaliana. New Phytol. 217(4):1521-1534. (* co-first authors)
- Schimmeyer J, Bock R, Meyer EH. (2016) L‑Galactono‑1,4‑lactone dehydrogenase is an assembly factor of the membrane arm of mitochondrial complex I in Arabidopsis. Plant Mol. Biol. 90 (1-2):117-126.
- Kühn K, Obata T, Feher K, Bock R, Fernie AR, Meyer EH. (2015) Complete mitochondrial complex I deficiency induces an upregulation of respiratory fluxes that is abolished by traces of functional complex I. Plant Physiol. 168 (4):1537-1549.
- Meyer EH*, Solheim C, Tanz SK, Bonnard G and Millar AH. (2011) Insights into the composition and assembly of the membrane arm of plant complex I through analysis of subcomplexes in Arabidopsis mutant lines. J. Biol. Chem. 286(29):26081-26092. (* corresponding author)
- Meyer EH, Tomaz T, Carroll AJ, Estavillo G, Delannoy E, Tanz SK, Small ID, Pogson BJ, Millar AH. (2009) Remodeled respiration in ndusf4 with low phosphorylation efficiency suppresses Arabidopsis germination and growth and alters control of metabolism at night. Plant Physiol. 151(2):603-619.
- Meyer EH, Giegé P, Gelhaye E, Rayapuram N, Ahuja U, Thöny-Meyer L, Grienenberger JM, Bonnard G. (2005) AtCCMH, an essential component of the c-type cytochrome maturation pathway in Arabidopsis, interacts with apocytochrome c. Proc. Natl. Acad. Sci., 102.16113-16118.