Bacterial Hsp90 mediates the degradation of aggregation-prone Hsp70-Hsp40 substrates preferentially by HslUV proteolysis

BioRxiv : the Preprint Server for Biology
Bruno FauvetPierre Goloubinoff


Whereas in eukaryotic cells, the Hsp90s are profusely-studied molecular chaperones controlling protein homeostasis together with Hsp70s, in bacteria, the function of Hsp90 (HtpG) and its collaboration with Hsp70 (DnaK) remains unknown. To uncover physiological processes depending on HtpG and DnaK, we performed comparative quantitative proteomic analyses of insoluble and total protein fractions from unstressed wild type E. coli, and from knockout mutants ΔdnaKdnaJ (ΔKJ), ΔhtpG (ΔG) and ΔdnaKdnaJΔhtpG (ΔKJG) and compared their growth rates under heat-stress also with ΔdnaKdnaJΔhslV. Whereas, expectedly, mutant ΔG showed no proteomic differences with wild-type, ΔKJ expressed more chaperones, proteases and ribosomes and dramatically less metabolic and respiratory enzymes. Unexpectedly, we found that ΔKJG showed higher levels of metabolic and respiratory enzymes and both ΔKJG and ΔdnaKdnaJΔhslV grew better at 37°C than ΔKJ. The results indicate that bacterial Hsp90 mediates the degradation of aggregation-prone Hsp70-Hsp40 substrates, preferably by the HslUV protease.

Related Concepts

Bacterial Proteins
Escherichia coli
Peptide Hydrolases
Respiration Disorders
HtpG protein, bacteria
Molecular Chaperones
Heat-Shock Proteins 70
HSP90 Heat-Shock Proteins
Heat-Shock Response

Related Feeds

BioRxiv & MedRxiv Preprints

BioRxiv and MedRxiv are the preprint servers for biology and health sciences respectively, operated by Cold Spring Harbor Laboratory. Here are the latest preprint articles (which are not peer-reviewed) from BioRxiv and MedRxiv.

American Thoracic Society: Allergy, Immunology & Inflammation

This feed has been developed in conjunction with the American Thoracic Society for the benefit of its Allergy, Immunology, and Inflammation Assembly. It highlights new and impactful papers on allergy, asthma, genetics, and the pathogenesis of lung diseases.