Format

Send to

Choose Destination
Plant Cell Physiol. 2016 Oct;57(10):2122-2132. Epub 2016 Aug 1.

CHLORORESPIRATORY REDUCTION 9 is a Novel Factor Required for Formation of Subcomplex A of the Chloroplast NADH Dehydrogenase-Like Complex.

Author information

1
Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan.
2
CREST, Japan Science and Technology Agency Chiyoda-ku Tokyo, 102-0076 Japan.
3
Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
4
Department of Bioinformatics, Ritsumeikan University, Kusatsu, Shiga, 525-8577 Japan.
5
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192 Japan.
6
Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan shikanai@pmg.bot.kyoto-u.ac.jp.

Abstract

In vascular plants, the chloroplast NADH dehydrogenase-like (NDH) complex, a homolog of respiratory NADH:quinone oxidoreductase (Complex I), mediates plastoquinone reduction using ferredoxin as an electron donor in cyclic electron transport around PSI in the thylakoid membrane. In angiosperms, chloroplast NDH is composed of five subcomplexes and forms a supercomplex with PSI. The modular assembly of stroma-protruded subcomplex A, which corresponds to the Q module of Complex I, was recently reported. However, the factors involved in the specific assembly steps have not been completely identified. Here, we isolated an Arabidopsis mutant, chlororespiratory reduction 9 (crr9), defective in NDH activity. The CRR9 gene encodes a novel stromal protein without any known functional domains or motifs. CRR9 is highly conserved in cyanobacteria and land plants but not in green algae, which do not have chloroplast NDH. Blue native-PAGE and immunoblot analyses of thylakoid proteins indicated that formation of subcomplex A was impaired in crr9 CRR9 was specifically required for the accumulation of NdhK, a subcomplex A subunit, in NDH assembly intermediates in the stroma. Furthermore, two-dimensional clear native/SDS-PAGE analysis of the stroma fraction indicated that incorporation of NdhM into NDH assembly intermediate complex 400 was impaired in crr9 These results suggest that CRR9 is a novel factor required for the formation of NDH subcomplex A.

KEYWORDS:

Arabidopsis; Assembly factor; Chloroplast; Chloroplast NDH; Cyclic electron transport around PSI

PMID:
27481895
DOI:
10.1093/pcp/pcw130
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center