Molecular Mechanism of the Escherichia Coli AhpC in the Function of a Chaperone Under Heat-shock Conditions
Affiliations
Peroxiredoxins (Prxs) are ubiquitous antioxidants utilizing a reactive cysteine for peroxide reduction and acting as a molecular chaperone under various stress conditions. Besides other stimulating factors, oxidative- and heat stress conditions trigger their ATP-independent chaperoning function. So far, many studies were intended to reveal the chaperoning mechanisms of the so-called sensitive Prxs of eukaryotes, which are susceptible to inactivation by over-oxidation of its reactive cysteine during HO reduction. In contrast, the chaperone mechanisms of bacterial Prxs, which are mostly robust against inactivation by over-oxidation, are not well understood. Herein, comprehensive biochemical and biophysical studies demonstrate that the Escherichia coli alkyl hydroperoxide reductase subunit C (EcAhpC) acquires chaperone activity under heat stress. Interestingly, their chaperoning activity is independent of its redox-states but is regulated in a temperature-dependent manner. Data are presented, showing that oxidized EcAhpC, which forms dimers at 25 °C, self-assembled into high molecular weight (HMW) oligomers at higher temperatures and supressed aggregation of client proteins at heat-shock conditions. In addition, we unravelled the essential role of the C-terminal tail of EcAhpC on heat-induced HMW oligomer formation and chaperoning activity. Our findings suggest a novel molecular mechanism for bacterial Prxs to function as chaperone at heat-shock conditions.
Kaur A, Russell I, Liu R, Holland A, Bhandari R, Potnis N Evol Appl. 2025; 18(1):e70069.
PMID: 39816160 PMC: 11732741. DOI: 10.1111/eva.70069.
The antibacterial activity of a photoactivatable diarylacetylene against Gram-positive bacteria.
Waite R, Adams C, Chisholm D, Sims C, Hughes J, Dias E Front Microbiol. 2023; 14:1243818.
PMID: 37808276 PMC: 10556703. DOI: 10.3389/fmicb.2023.1243818.
Kaidow A, Ishii N, Suzuki S, Shiina T, Kasahara H Int J Mol Sci. 2022; 23(21).
PMID: 36361576 PMC: 9659236. DOI: 10.3390/ijms232112786.
Kirthika P, Jawalagatti V, Senevirathne A, Lee J Gut Microbes. 2022; 14(1):2064705.
PMID: 35438052 PMC: 9037549. DOI: 10.1080/19490976.2022.2064705.
Relevance of peroxiredoxins in pathogenic microorganisms.
de Oliveira M, Tairum C, Netto L, de Oliveira A, Aleixo-Silva R, Montanhero Cabrera V Appl Microbiol Biotechnol. 2021; 105(14-15):5701-5717.
PMID: 34258640 DOI: 10.1007/s00253-021-11360-5.