Thiol redox switches regulate the oligomeric state of cyanobacterial Rre1, RpaA and RpaB response regulators.
Rowden, Stephen JL
Cramer, William A
Howe, Christopher J
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Ibrahim, I. M., Rowden, S. J., Cramer, W. A., Howe, C. J., & Puthiyaveetil, S. (2022). Thiol redox switches regulate the oligomeric state of cyanobacterial Rre1, RpaA and RpaB response regulators.. FEBS Lett https://doi.org/10.1002/1873-3468.14340
Funder: Spicer Consulting Ltd
Cyanobacteria employ two-component sensor-response regulator systems to monitor and respond to environmental challenges. The response regulators RpaA, RpaB, Rre1 and RppA are integral to circadian clock function and abiotic stress acclimation in cyanobacteria. RpaA, RpaB and Rre1 are known to interact with ferredoxin or thioredoxin, raising the possibility of their thiol regulation. Here, we report that Synechocystis sp. PCC 6803 Rre1, RpaA and RpaB exist as higher-order oligomers under oxidising conditions and that reduced thioredoxin A converts them to monomers. We further show that these response regulators contain redox-responsive cysteine residues with an Em7 around -300 mV. These findings suggest a direct thiol modulation of the activity of these response regulators, independent of their cognate sensor kinases.
Research Letter, Research Letters, Hik2, RpaA, RpaB, Rre1, thiol regulation, TrxA
Engineering and Physical Sciences Research Council (EP/F047940/1)
Biotechnology and Biological Sciences Research Council (BB/L014130/1)
External DOI: https://doi.org/10.1002/1873-3468.14340
This record's URL: https://www.repository.cam.ac.uk/handle/1810/335980