The RsfSR two-component system regulates SigF function by monitoring the state of the respiratory electron transport chain in Mycobacterium smegmatis.

Autor: Oh Y; Department of Integrated Biological Science, Pusan National University, Busan, Korea., Oh JI; Department of Integrated Biological Science, Pusan National University, Busan, Korea; Microbiological Resource Research Institute, Pusan National University, Busan, Korea. Electronic address: joh@pusan.ac.kr.
Jazyk: angličtina
Zdroj: The Journal of biological chemistry [J Biol Chem] 2024 Mar; Vol. 300 (3), pp. 105764. Date of Electronic Publication: 2024 Feb 16.
DOI: 10.1016/j.jbc.2024.105764
Abstrakt: In Mycobacterium smegmatis, the transcriptional activity of the alternative sigma factor SigF is posttranslationally regulated by the partner switching system consisting of SigF, the anti-SigF RsbW1, and three anti-SigF antagonists (RsfA, RsfB, and RsbW3). We previously demonstrated that expression of the SigF regulon is strongly induced in the Δaa 3 mutant of M. smegmatis lacking the aa 3 cytochrome c oxidase, the major terminal oxidase in the respiratory electron transport chain. Here, we identified and characterized the RsfSR two-component system involved in regulating the phosphorylation state of the major anti-SigF antagonist RsfB. RsfS (MSMEG_6130) is a histidine kinase with the cyclase/histidine kinase-associated sensing extracellular 3 domain at its N terminus, and RsfR (MSMEG_6131) is a receiver domain-containing protein phosphatase 2C-type phosphatase that can dephosphorylate phosphorylated RsfB. We demonstrated that phosphorylation of RsfR on Asp74 by RsfS reduces the phosphatase activity of RsfR toward phosphorylated RsfB and that the cellular abundance of the active unphosphorylated RsfB is increased in the Δaa 3 mutant relative to the WT strain. We also demonstrated that the RsfSR two-component system is required for induction of the SigF regulon under respiration-inhibitory conditions such as inactivation of the cytochrome bcc 1 complex and aa 3 cytochrome c oxidase, as well as hypoxia, electron donor-limiting, high ionic strength, and low pH conditions. Collectively, our results reveal a key regulatory element involved in regulating the SigF signaling system by monitoring the state of the respiratory electron transport chain.
Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article.
(Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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