Characterization of an internal type-II NADH dehydrogenase from Chlamydomonas reinhardtii mitochondria

Curr Genet. 2012 Aug;58(4):205-16. doi: 10.1007/s00294-012-0378-2. Epub 2012 Jul 20.

Abstract

Type-II NAD(P)H dehydrogenases form a multigene family that comprise six members in the green microalga Chlamydomonas. To date, only one enzyme (Nda2) located in the chloroplast has been characterized in this alga and demonstrated to participate in the reduction of the plastoquinone pool. We present here the functional characterization of Nda1. The enzyme is located on the inner face of the inner mitochondrial membrane. Its downregulation leads to a slight decrease of NADH:ferricyanide activity and of dark whole cell respiration. To determine whether the reduction of Nda1 combined with the lack of complex I would affect mitochondrial processes, double mutants affected in both Nda1 and complex I were isolated. Respiration and growth rates in heterotrophic conditions were significantly altered in the double mutants investigated, suggesting that Nda1 plays a role in the oxidation of matrix NADH in the absence of complex I.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chlamydomonas reinhardtii / enzymology*
  • Chlamydomonas reinhardtii / genetics
  • Gene Expression Regulation, Enzymologic
  • Mitochondria / enzymology*
  • Mutation
  • NADH Dehydrogenase / genetics*
  • NADH Dehydrogenase / metabolism
  • Oxidation-Reduction
  • Photosynthesis

Substances

  • NADH dehydrogenase II
  • NADH Dehydrogenase