Redox of Plastoquinone Pool Regulates the Expression and Activity of NADPH Dehydrogenase Supercomplex in <Emphasis Type="Italic">Synechocystis</Emphasis> sp. Strain PCC 6803 |
| |
Authors: | Weimin Ma Yong Deng Hualing Mi |
| |
Institution: | (1) College of Life & Environment Sciences, Shanghai Normal University, Guilin Road 100, Shanghai, 200234, China;(2) National Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Fenglin Road 300, Shanghai, 200032, China |
| |
Abstract: | A highly active NADPH dehydrogenase supercomplex, which is essential for cyclic electron transport around photosystem I (cyclic
PSI) and respiration, was newly identified in cyanobacteria. Synechocystis sp. strain PCC 6803 cells were treated with exogenous glucose (Glc) or 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU); subsequently,
active staining of NADPH-nitroblue tetrazolium oxidoreductase, western blot, and the initial rate of P700+ dark reduction were assessed in the cyanobacterium at several time points. The expression and enzyme activity levels of NADPH
dehydrogenase supercomplex were gradually inhibited and closely associated with the decrease in the rate of cyclic PSI accompanying
the addition of exogenous Glc to the cultures. In contrast, the activity levels were significantly stimulated but did not
cause an increase in the rate of cyclic PSI as expected in the presence of DCMU. Since Glc results in the partial reduction
of the plastoquinone (PQ) pool while DCMU results in the overoxidation of the PQ pool, the present results demonstrate that
the expression and activity of NADPH dehydrogenase supercomplex are under the influence of the redox control of the PQ pool
while the operation of cyclic PSI as mediated by this supercomplex requires an appropriate redox poise of the PQ pool. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|