title: NdhV subunit regulates the activity of type-1 NAD(P)H dehydrogenase under high light conditions in cyanobacterium Synechocystis sp. PCC 6803.
abstract: The cyanobacterial NAD(P)H dehydrogenase (NDH-1) complexes play crucial roles in variety of bioenergetic reactions. However, the regulative mechanism of NDH-1 under stressed conditions is still unclear. In this study, we detected that the NDH-1 activity is partially impaired, but the accumulation of NDH-1 complexes was little affected in the NdhV deleted mutant (ΔndhV) at low light in cyanobacterium Synechocystis sp. PCC 6803. ΔndhV grew normally at low light but slowly at high light under inorganic carbon limitation conditions (low pH or low CO2), meanwhile the activity of CO2 uptake was evidently lowered than wild type even at pH 8.0. The accumulation of NdhV in thylakoids strictly relies on the presence of the hydrophilic subcomplex of NDH-1. Furthermore, NdhV was co-located with hydrophilic subunits of NDH-1 loosely associated with the NDH-1L, NDH-1MS' and NDH-1M complexes. The level of the NdhV was significantly increased at high light and deletion of NdhV suppressed the up-regulation of NDH-1 activity, causing the lowered the photosynthetic oxygen evolution at pH 6.5 and high light. These data indicate that NdhV is an intrinsic subunit of hydrophilic subcomplex of NDH-1, required for efficient operation of cyclic electron transport around photosystem I and CO2 uptake at high lights.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, 300 Fenglin Road, Shanghai 200032, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, 300 Fenglin Road, Shanghai 200032, China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: He
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, 300 Fenglin Road, Shanghai 200032, China.
authors.forename: Min
authors.initials: M
authors.lastname: Xu
authors.affiliation: Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Lianwei
authors.initials: L
authors.lastname: Peng
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, 300 Fenglin Road, Shanghai 200032, China.
authors.forename: Hualing
authors.initials: H
authors.lastname: Mi
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D008027:Light; D009252:NADPH Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D045331:Photosystem I Protein Complex / Q000378:metabolism; D021122:Protein Subunits / Q000235:genetics*; D046939:Synechocystis / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D020524:Thylakoids / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D045331:Photosystem I Protein Complex; D021122:Protein Subunits; D002245:Carbon Dioxide; D009252:NADPH Dehydrogenase