Reference : A type II NAD(P)H dehydrogenase mediates light-independent plastoquinone reduction in th...
Scientific journals : Article
Life sciences : Biochemistry, biophysics & molecular biology
Life sciences : Genetics & genetic processes
http://hdl.handle.net/2268/30377
A type II NAD(P)H dehydrogenase mediates light-independent plastoquinone reduction in the chloroplast of Chlamydomonas
English
Jans, Frédéric mailto [Université de Liège - ULg > Département des sciences de la vie > Biologie moléculaire et biotechnologie végétales >]
Mignolet, Emmanuel [Université de Liège - ULg > Département des sciences de la vie > Biochimie végétale >]
Houyoux, Pierre-Alain [> >]
Cardol, Pierre mailto [Université de Liège - ULg > Département des sciences de la vie > Génétique >]
Ghysels, Bart mailto [Université de Liège - ULg > > Labo de Bioénergétique >]
Cuiné, S [> >]
Cournac, Laurent [> > > >]
Peltier, Gilles [> > > >]
Remacle, Claire mailto [Université de Liège - ULg > Département des sciences de la vie > Génétique >]
Franck, Fabrice mailto [Université de Liège - ULg > Département des sciences de la vie > Biochimie végétale >]
2008
Proceedings of the National Academy of Sciences of the United States of America
National Academy of Sciences
105
51
20546-51
Yes (verified by ORBi)
International
0027-8424
1091-6490
Washington
DC
[en] type II NAD(P)H dehydrogenase ; Chlamydomonas
[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.
Institut de Botanique
FRIA - FNRS
Micro-H2
Researchers ; Professionals ; Students
http://hdl.handle.net/2268/30377
also: http://hdl.handle.net/2268/147870
10.1073/pnas.0806896105
http://www.pnas.org/content/105/51/20546.long
C Remacle and F Franck are co-corresponding authors

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Restricted access
PNAS-2008-Jans-20546-51.pdfPublisher postprint388.01 kBRequest copy

Additional material(s):

File Commentary Size Access
Restricted access
2008 NDA2 pnas supplemental.pdf754.45 kBRequest copy

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.