The Helicobacter pylori HspR-Modulator CbpA Is a Multifunctional Heat-Shock Protein

Abstract

The medically important human pathogen Helicobacter pylori relies on a collection of highly conserved heat-shock and chaperone proteins to preserve the integrity of cellular polypeptides and to control their homeostasis in response to external stress and changing environmental conditions. Among this set of chaperones, the CbpA protein has been shown to play a regulatory role in heat-shock gene regulation by directly interacting with the master stress-responsive repressor HspR. Apart from this regulatory role, little is known so far about CbpA functional activities. Using biochemistry and molecular biology approaches, we have started the in vitro functional characterization of H. pylori CbpA. Specifically, we show that CbpA is a multifunctional protein, being able to bind DNA and to stimulate the ATPase activity of the major chaperone DnaK. In addition, we report a preliminary observation suggesting that CbpA DNA-binding activity can be affected by the direct interaction with the heat-shock master repressor HspR, supporting the hypothesis of a reciprocal crosstalk between these two proteins. Thus, our work defines novel functions for H. pylori CbpA and stimulates further studies aimed at the comprehension of the complex regulatory interplay among chaperones and heat-shock transcriptional regulators.

Insights into the Orchestration of Gene Transcription Regulators in Helicobacter pylori

“…Moreover, it has been recently demonstrated that H. pylori CbpA is a multifunctional protein, able to stimulate the ATPase activity of the major chaperone DnaK and to bind DNA. In addition, this DNA-binding activity can be modulated upon the direct interaction with the heat-shock master repressor HspR, suggesting the existence of reciprocal crosstalk between these two proteins [105].…”

Genomic Analysis of Serratia plymuthica MBSA-MJ1: A Plant Growth Promoting Rhizobacteria That Improves Water Stress Tolerance in Greenhouse Ornamentals

“…Irrigation and weekly treatments were then resumed until week 8 when observations of visual quality were evaluated. In addition to encoding for genes involved in ROS defense protection, the genome of MBSA-MJ1 also encodes for multiple universal stress proteins that confer resistance to oxidative stress (uspABCEG), multiple heat shock proteins (grpE, htpX, hspQ, and hslR), and chaperone proteins (dnaJ, dnaK, groES/EL, clpB, cbpM, and cbpA; Supplementary Table S4; Kornitzer et al, 1991;Squires et al, 1991;Gragerov et al, 1992;Korber et al, 2000;Chae et al, 2004;Shimuta et al, 2004;Nachin et al, 2005;Pepe et al, 2020).…”