Comparative proteomics reveal distinct chaperone-client interactions in supporting bacterial acid resistance.
HdeA and HdeB constitute the essential chaperone system that functions in the unique periplasmic space of Gram-negative enteric bacteria to confer acid resistance. How this two-chaperone machinery cooperates to protect a broad range of client proteins from acid denaturation while avoiding nonspecific binding during bacterial passage through the highly acidic human stomach remains unclear. We have developed a comparative proteomic strategy that combines the genetically encoded releasable protein photocross-linker with 2D difference gel electrophoresis, which allows an unbiased side-by-side comparison of the entire client pools from these two acid-activated chaperones in Escherichia coli Our results reveal distinct client specificities between HdeA and HdeB in vivo that are determined mainly by their different responses to pH stimulus. The intracellular acidity serves as an environmental cue to determine the folding status of both chaperones and their clients, enabling specific chaperone-client binding and release under defined pH conditions. This cooperative and synergistic mode of action provides an efficient, economical, flexible, and finely tuned protein quality control strategy for coping with acid stress.
Beijing National Laboratory for Molecular Sciences, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China;
Shuai
S
Zhang
Beijing National Laboratory for Molecular Sciences, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China;
Dan
D
He
Beijing National Laboratory for Molecular Sciences, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China;
Yi
Y
Yang
Beijing National Laboratory for Molecular Sciences, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China;
Shixian
S
Lin
Beijing National Laboratory for Molecular Sciences, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China; Academy for Advanced Interdisciplinary Studies, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China.
Meng
M
Zhang
Beijing National Laboratory for Molecular Sciences, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China;
Shizhong
S
Dai
Beijing National Laboratory for Molecular Sciences, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China; Academy for Advanced Interdisciplinary Studies, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China pengchen@pku.edu.cn.
Peng R
PR
Chen
D000143:Acids / Q000494:pharmacology*; D003432:Cross-Linking Reagents / Q000737:chemistry; D015180:Electrophoresis, Gel, Two-Dimensional; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008027:Light; D018832:Molecular Chaperones / Q000378:metabolism*; D017433:Protein Structure, Secondary; D040901:Proteomics / Q000379:methods*; D013312:Stress, Physiological / Q000187:drug effects; D053719:Tandem Mass Spectrometry
D000143:Acids; D003432:Cross-Linking Reagents; D029968:Escherichia coli Proteins; D018832:Molecular Chaperones; C084501:hdeA protein, E coli; C084502:hdeB protein, E coli
2D-DIGE; bacteria acid resistance; comparative proteomics; conditionally disordered chaperones; photocross-linking