Refereed journal article or data article (A1)
Functional redundancy between flavodiiron proteins and NDH-1 in Synechocystis sp. PCC 6803
List of Authors: Nikkanen L, Sanchez AS, Ermakova M, Rogner M, Cournac L, Allahverdiyeva Y
Publisher: WILEY
Publication year: 2020
Journal: Plant Journal
Journal name in source: PLANT JOURNAL
Journal acronym: PLANT J
Volume number: 103
Issue number: 4
Start page: 1460
End page: 1476
Number of pages: 17
ISSN: 0960-7412
eISSN: 1365-313X
DOI: http://dx.doi.org/10.1111/tpj.14812
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/49678134
In oxygenic photosynthetic organisms, excluding angiosperms, flavodiiron proteins (FDPs) catalyze light-dependent reduction of O(2)to H2O. This alleviates electron pressure on the photosynthetic apparatus and protects it from photodamage. InSynechocystissp. PCC 6803, four FDP isoforms function as hetero-oligomers of Flv1 and Flv3 and/or Flv2 and Flv4. An alternative electron transport pathway mediated by the NAD(P)H dehydrogenase-like complex (NDH-1) also contributes to redox hemostasis and the photoprotection of photosynthesis. Four NDH-1 types have been characterized in cyanobacteria: NDH-1(1)and NDH-1(2), which function in respiration; and NDH-1(3)and NDH-1(4), which function in CO(2)uptake. All four types are involved in cyclic electron transport. Along with single FDP mutants ( increment flv1and Delta flv3) and the double NDH-1 mutants ( increment d1d2, which is deficient in NDH-1(1,2)and increment d3d4, which is deficient in NDH-1(3,4)), we studied triple mutants lacking one of Flv1 or Flv3, and NDH-1(1,2)or NDH-1(3,4). We show that the presence of either Flv1/3 or NDH-1(1,2), but not NDH-1(3,4), is indispensable for survival during changes in growth conditions from high CO2/moderate light to low CO2/high light. Our results show functional redundancy between FDPs and NDH-1(1,2)under the studied conditions. We suggest that ferredoxin probably functions as a primary electron donor to both Flv1/3 and NDH-1(1,2), allowing their functions to be dynamically coordinated for efficient oxidation of photosystem I and for photoprotection under variable CO(2)and light availability.
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