Alternative NADH dehydrogenase (NDH2): intermembrane-space-facing counterpart of mitochondrial complex I in the procyclic Trypanosoma brucei

0392793 - BC 2014 RIV GB eng J - Journal Article
Verner, Zdeněk - Škodová, Ingrid - Poláková, S. - Ďurišová-Benkovičková, V. - Horváth, A. - Lukeš, Julius
Alternative NADH dehydrogenase (NDH2): intermembrane-space-facing counterpart of mitochondrial complex I in the procyclic Trypanosoma brucei.
Parasitology. Roč. 140, č. 3 (2013), s. 328-337. ISSN 0031-1820. E-ISSN 1469-8161
R&D Projects: GA MŠMT LC07032; GA ČR GA204/09/1667
Institutional support: RVO:60077344
Keywords : Trypanosoma * mitochondrion * dehydrogenase * respiration * NDH2
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 2.350, year: 2013
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8838254

The respiratory chain of the procyclic stage of Trypanosoma brucei contains the standard complexes I through IV, as well as several alternative enzymes contributing to electron flow. In this work, we studied the function of an alternative NADH: ubiquinone oxidoreductase (NDH2). Depletion of target mRNA was achieved using RNA interference (RNAi). In the non-induced and RNAi-induced cell growth, membrane potential change, alteration in production of reactive oxygen species, overall respiration, enzymatic activities of complexes I, III and/or IV and distribution of NADH: ubiquinone oxidoreductase activities in glycerol gradient fractions were measured. Finally, respiration using different substrates was tested on digitonin-permeabilized cells. The induced RNAi cell line exhibited slower growth, decreased mitochondrial membrane potential and lower sensitivity of respiration to inhibitors. Mitochondrial glycerol-3-phosphate dehydrogenase was the only enzymatic activity that has significantly changed in the interfered cells. This elevation as well as a decrease of respiration usingNADHwas confirmed on digitonin-permeabilized cells. The data presented here together with previously published findings on complex I led us to propose thatNDH2 is the majorNADH: ubiquinone oxidoreductase responsible for cytosolic and not for mitochondrial NAD+ regeneration in the mitochondrion of procyclic T. brucei.
Permanent Link: http://hdl.handle.net/11104/0225110