Regulation of outer-membrane proteins (OMPs) A and F, during <i>hlyF</i>-induced outer-membrane vesicle (OMV) biosynthesis.



van der Westhuizen, Wouter André, Theron, Chrispian William ORCID: 0000-0002-8522-6417, Boucher, Charlotte Enastacia ORCID: 0000-0002-9810-5892 and Bragg, Robert Richard
(2019) Regulation of outer-membrane proteins (OMPs) A and F, during <i>hlyF</i>-induced outer-membrane vesicle (OMV) biosynthesis. Heliyon, 5 (7). e02014 - ?.

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Abstract

<h4>Background</h4>Gram-negative bacteria actively secrete outer membrane vesicles into the surrounding environment and these vesicles have been shown to play various physiological and protective roles such as carrying antibiotic-degrading enzymes and acting as decoys against host defences, therefore promoting the pathogenesis of the bacterium. It has been shown that avian pathogenic <i>Escherichia coli</i> species can increase vesicle biosynthesis through the acquisition of the <i>hlyF</i> gene but the effect this has on the cell by scavenging outer-membrane associated proteins (OmpA, OmpF) into the vesicles during vesicle release have not yet been investigated.<h4>Results</h4>Relative quantitative real-time PCR data obtained from <i>hlyF</i> expressing and non-expressing cells showed that during <i>hlyF</i> induction, <i>ompF</i> showed a nearly 2-fold down regulation relative to the non-expressing cells during the entire 24 hours, while <i>ompA</i> was expressed at the same level as the non-expressing cells during the first 8 hours of expression. At 24 hours post-<i>hlyF</i> expression, <i>ompA</i> was up-regulated 4-fold.<h4>Conclusions</h4>The regulatory effects of the newly described outer-membrane vesicle biosynthesis-related gene, <i>hlyF</i>, on <i>E. coli</i> has not previously been investigated. As <i>hlyF</i>-induced vesicles contain OmpA and OmpF scavenged from the bacterial outer-membrane, potential regulatory effects on the host was investigated. An increase in <i>ompA</i> expression and an insignificant decrease in <i>ompF</i> expression was observed during <i>hlyF</i> induction demonstrating that <i>hlyF</i>-related biosynthesis is not related to decreased <i>ompA</i> expression, which is one of the potential mechanisms discussed in literature for biosynthesis. Outer-membrane vesicle biosynthesis during <i>hlyF</i> over-expression could potentially be accomplished through a different mechanism(s).

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 13 Aug 2019 15:41
Last Modified: 09 Apr 2021 11:06
DOI: 10.1016/j.heliyon.2019.e02014
Open Access URL: https://doi.org/10.1016/j.heliyon.2019.e02014
URI: https://livrepository.liverpool.ac.uk/id/eprint/3051657