Proteomic analysis reveals the non-coding small RNA Qrr5 influences autoaggregation and growth competition in Vibrio parahaemolyticus

Abstract

Vibrio parahaemolyticus, a sea-born bacterial pathogen, is a primary inducement of food-borne gastroenteritis. Previous studies have shown that non-coding small RNA plays a vital role in the regulation of multiple biological processes in pathogenic bacteria, especially autoaggregation and growth competition. However, the inherent mechanisms have not yet to be fully understood. As important regulators in Vibrios, the involvement of Qrr sRNAs in V. parahaemolyticus is largely unknown. Here, we carried out the Qrr5 deletion mutant and utilized a proteomic method to describe global proteomic alterations in response to Qrr5 deletion. A total of 297 significantly expressed proteins were determined between the Qrr5 deletion mutant and wild-type strain, among which 137 proteins were upregulated and 160 proteins were downregulated. The upregulated proteins principally participated in membrane transporters and signal transcription, while the downregulated proteins participated in the two-component system and transcription factor binding. Notably, transcriptional regulator LysR, outer membrane protein OmpA, and conjugal transfer protein TraA-related proteins were upregulated, causing the promotion of autoaggregation ability and growth competition ability against E. coli. This study provides insights into the regulatory network of sRNA in this bacterium, which will facilitate further explorations of important biological processes in pathogenic bacteria. SIGNIFICANCE: sRNA Qrr5 is an important regulator involved in bacterial multiple physiological processes, including auto-aggregation and growth competition among food-borne pathogens Vibrio parahaemolyticus. Here, utilizing a TMT-labeling proteomic approach, we identified 137 proteins were upregulated and 160 proteins were downregulated between the Qrr5 deletion mutant and wild-type strain. The upregulated proteins were involved in membrane transporters and signal transcription, while downregulated proteins were involved in the two-component system and transcription factor binding. Moreover, the LysR, OmpA, and TraA proteins were significantly upregulated, causing the promotion of autoaggregation and commensal growth competition ability. The mechanism of how Qrr5 regulates the targeted genes remains unclarified and need great efforts to explore.

Keywords: Autoaggregation; Growth competition; Non-coding small RNA; Proteome; Qrr5; Vibrio parahaemolyticus.