title: Complex I (NADH:ubiquinone oxidoreductase) is active in but non-essential for procyclic Trypanosoma brucei.
abstract: The requirement of complex I (NADH:ubiquionone oxidoreductase) for respiration in Trypanosoma brucei is controversial. Recent identification of homologues of its subunits in mitochondrial proteome resolved a question of its presence or absence. However, with one exception, no data have been available concerning the function(s) of complex I or its subunits. Here we present a functional RNAi study of three (NUBM, NUKM, NUEM) putative subunits of this complex. Although no changes were detected in growth, mitochondrial membrane potential or reactive oxygen species production in cell lines depleted for target transcript, the NUBM and NUKM RNAi knock-downs showed decreased specific NADH:ubiquinone oxidoreductase activity. Moreover, glycerol gradients of all cell lines revealed the presence of two distinct peaks of NADH dehydrogenase activity, with shifted sensitivity to inhibitors of complex I upon RNAi induction. Thus complex I is not only present in the procyclic stage of T. brucei 29-13 strain, but it does participate in electron transport chain.
authors.affiliation: Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Ceské Budejovice Budweis, Czech Republic.
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Verner
authors.forename: Petra
authors.initials: P
authors.lastname: Cermáková
authors.forename: Ingrid
authors.initials: I
authors.lastname: Skodová
authors.forename: Eva
authors.initials: E
authors.lastname: Kriegová
authors.forename: Anton
authors.initials: A
authors.lastname: Horváth
authors.forename: Julius
authors.initials: J
authors.lastname: Lukes
mesh_terms: D019069:Cell Respiration; D042967:Electron Transport Complex I / Q000235:genetics / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D050296:Microbial Viability; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014346:Trypanosoma brucei brucei / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*
chemical_list: D021122:Protein Subunits; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D042967:Electron Transport Complex I