GeLC-MS-based proteomics of Chromobacterium violaceum: comparison of proteome changes elicited by hydrogen peroxide

Abstract

Chromobacterium violaceum is a free-living bacillus with several genes that enables it survival under different harsh environments such as oxidative and temperature stresses. Here we performed a label-free quantitative proteomic study to unravel the molecular mechanisms that enable C. violaceum to survive oxidative stress. To achieve this, total proteins extracted from control and C. violaceum cultures exposed during two hours with 8 mM hydrogen peroxide were analyzed using GeLC-MS proteomics. Analysis revealed that under the stress condition, the bacterium expressed proteins that protected it from the damage caused by reactive oxygen condition and decreasing the abundance of proteins responsible for bacterial growth and catabolism. GeLC-MS proteomics analysis provided an overview of the metabolic pathways involved in the response of C. violaceum to oxidative stress ultimately aggregating knowledge of the response of this organism to environmental stress. This study identified approximately 1500 proteins, generating the largest proteomic coverage of C. violaceum so far. We also detected proteins with unknown function that we hypothesize to be part of new mechanisms related to oxidative stress defense. Finally, we identified the mechanism of clustered regularly interspaced short palindromic repeats (CRISPR), which has not yet been reported for this organism.

EmrR-Dependent Upregulation of the Efflux Pump EmrCAB Contributes to Antibiotic Resistance in Chromobacterium violaceum

“…Indeed, we verify that an antioxidant enzyme involved in C. violaceum resistance to peroxide ( Previato-Mello et al, 2017 ) was regulated by EmrR. Accordingly, in both E. coli and C. violaceum EmrR was found to be induced under oxidant conditions ( Sakamoto et al, 2015 ; Lima et al, 2016 ). Thus, it will be interesting to investigate whether EmrR can act as a redox sensing regulator, as is the case for other MarR family transcription factors related to antibiotic resistance (MgrA, MexR, OspR) ( Chen et al, 2011 ).…”

Disrupting quorum sensing alters social interactions in Chromobacterium violaceum

“…A total of 889 out of the 4 397 (i.e., 20.2%) proteins of CV 12472 were detected and identified (Uniprot database) (Supplementary Data 1 ). These 889 proteins were clustered by biological functions according to the GO database using the DAVID bioinformatic tool 22 (Fig. 2a ).…”