Article (Scientific journals)
A type II NAD(P)H dehydrogenase mediates light-independent plastoquinone reduction in the chloroplast of Chlamydomonas
Jans, Frédéric; Mignolet, Emmanuel; Houyoux, Pierre-Alain et al.
2008In Proceedings of the National Academy of Sciences of the United States of America, 105 (51), p. 20546-51
Peer Reviewed verified by ORBi
 

Files


Full Text
PNAS-2008-Jans-20546-51.pdf
Publisher postprint (397.32 kB)
Request a copy
Annexes
2008 NDA2 pnas supplemental.pdf
Publisher postprint (772.55 kB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
type II NAD(P)H dehydrogenase; Chlamydomonas
Abstract :
[en] In photosynthetic eukaryotes, nonphotochemical plastoquinone (PQ) reduction is important for the regulation of photosynthetic electron flow. In green microalgae where this process has been demonstrated, the chloroplastic enzyme that catalyses nonphotochemical PQ reduction has not been identified yet. Here, we show by an RNA interference (RNAi) approach that the NDA2 gene, belonging to a type II NAD(P)H dehydrogenases family in the green microalga Chlamydomonas reinhardtii, encodes a chloroplastic dehydrogenase that functions to reduce PQ nonphotochemically in this alga. Using a specific antibody, we show that the Nda2 protein is localized in chloroplasts of wild-type cells and is absent in two Nda2-RNAi cell lines. In both mutant cell lines, nonphotochemical PQ reduction is severely affected, as indicated by altered chlorophyll fluorescence transients after saturating illumination. Compared with wild type, change in light excitation distribution between photosystems ('state transition') upon inhibition of mitochondrial electron transport is strongly impaired in transformed cells because of inefficient PQ reduction. Furthermore, the amount of hydrogen produced by Nda2-RNAi cells under sulfur deprivation is substantially decreased compared with wild type, which supports previous assumptions that endogenous substrates serve as source of electrons for hydrogen formation. These results demonstrate the importance of Nda2 for nonphotochemical PQ reduction and associated processes in C. reinhardtii.
Research center :
Institut de Botanique
Disciplines :
Genetics & genetic processes
Biochemistry, biophysics & molecular biology
Author, co-author :
Jans, Frédéric ;  Université de Liège - ULiège > Département des sciences de la vie > Biologie moléculaire et biotechnologie végétales
Mignolet, Emmanuel ;  Université de Liège - ULiège > Département des sciences de la vie > Biochimie végétale
Houyoux, Pierre-Alain
Cardol, Pierre  ;  Université de Liège - ULiège > Département des sciences de la vie > Génétique
Ghysels, Bart ;  Université de Liège - ULiège > Labo de Bioénergétique
Cuiné, S
Cournac, Laurent
Peltier, Gilles
Remacle, Claire  ;  Université de Liège - ULiège > Département des sciences de la vie > Génétique
Franck, Fabrice ;  Université de Liège - ULiège > Département des sciences de la vie > Biochimie végétale
Language :
English
Title :
A type II NAD(P)H dehydrogenase mediates light-independent plastoquinone reduction in the chloroplast of Chlamydomonas
Publication date :
2008
Journal title :
Proceedings of the National Academy of Sciences of the United States of America
ISSN :
0027-8424
eISSN :
1091-6490
Publisher :
National Academy of Sciences, Washington, United States - District of Columbia
Volume :
105
Issue :
51
Pages :
20546-51
Peer reviewed :
Peer Reviewed verified by ORBi
Name of the research project :
Micro-H2
Funders :
FRIA - Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture [BE]
Commentary :
C Remacle and F Franck are co-corresponding authors
Available on ORBi :
since 30 November 2009

Statistics


Number of views
194 (40 by ULiège)
Number of downloads
4 (4 by ULiège)

Scopus citations®
 
171
Scopus citations®
without self-citations
132
OpenCitations
 
148

Bibliography


Similar publications



Contact ORBi