RNA helicase, CrhR is indispensable for the energy redistribution and the regulation of photosystem stoichiometry at low temperature in Synechocystis sp. PCC6803
| Autor: | Pilla Sankara Krishna, Prasanna Mohanty, Jogadhenu S. S. Prakash, Kodru Sireesha, Nellaepalli Sreedhar, Rajagopal Subramanyam, Balaga Radharani |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Photosystem II
Mutant Biophysics Plastoquinone Biology Photosystem I Biochemistry chemistry.chemical_compound Low temperature Synechocystis sp. PCC6803 Photosystem Photosystem stoichiometry Photosystem I Protein Complex Synechocystis Wild type Photosystem II Protein Complex Cell Biology biology.organism_classification RNA Helicase A Cold Temperature ∆crhR mutant chemistry Gene Expression Regulation Redox regulation Energy Metabolism RNA Helicases |
| Zdroj: | Biochimica et biophysica acta. 1817(9) |
| ISSN: | 0006-3002 |
| Popis: | We investigated the role of a cold-inducible and redox-regulated RNA helicase, CrhR, in the energy redistribution and adjustment of stoichiometry between photosystem I (PSI) and photosystem II (PSII), at low temperature in Synechocystis sp. PCC 6803. The results suggest that during low temperature incubation, i.e., when cells are shifted from 34 °C to 24 °C, wild type cells exhibited light-induced state transitions, whereas the mutant deficient in CrhR failed to perform the same. At low temperature, wild type cells maintained the plastoquinone (PQ) pool in the reduced state due to enhanced respiratory electron flow to the PQ pool, whereas in ∆crhR mutant cells the PQ pool was in the oxidized state. Wild type cells were in state 2 and ∆crhR cells were locked in state 1 at low temperature. In both wild type and ∆crhR cells, a fraction of PSI trimers were changed to PSI monomers. However, in ∆crhR cells, the PSI trimer content was significantly decreased. Expression of photosystem I genes, especially the psaA and psaB, was strongly down-regulated due to oxidation of downstream components of PQ in ∆crhR cells at low temperature. We demonstrated that changes in the low temperature-induced energy redistribution and regulation of photosystem stoichiometry are acclimatization responses exerted by Synechocystis cells, essentially regulated by the RNA helicase, CrhR, at low temperature. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|