La Trobe
Burkholderia pseudomallei proteins.pdf (2.18 MB)
Download file

The burkholderia pseudomallei proteins BapA and BapC Are Secreted TTSS3 Effectors and BapB levels modulate expression of BopE

Download (2.18 MB)
journal contribution
posted on 16.02.2021, 05:49 by P Treerat, P Alwis, T D'Cruze, Meabh CullinaneMeabh Cullinane, J Vadivelu, RJ Devenish, M Prescott, B Adler, JD Boyce
© 2015 Treerat et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Many Gram-negative pathogens use a type III secretion system (TTSS) for the injection of bacterial effector proteins into host cells. The injected effector proteins play direct roles in modulation of host cell pathways for bacterial benefit. Burkholderia pseudomallei, the causative agent of melioidosis, expresses three different TTSSs. One of these systems, the TTSS3, is essential for escape from host endosomes and therefore intracellular survival and replication. Here we have characterized three putative TTSS3 proteins; namely BapA, BapB and BapC. By employing a tetracysteine (TC)-FlAsHlabelling technique to monitor the secretion of TC-Tagged fusion proteins, BapA and BapC were shown to be secreted during in vitro growth in a TTSS3-dependant manner, suggesting a role as TTSS3 effectors. Furthermore, we constructed B. pseudomallei bapA, bapB and bapC mutants and used the well-characterized TTSS3 effector BopE as a marker of secretion to show that BapA, BapB and BapC are not essential for the secretion process. However, BopE transcription and secretion were significantly increased in the bapB mutant, suggesting that BapB levels modulate BopE expression. In a BALB/c mouse model of acute melioidosis, the bapA, bapB and bapC mutants showed a minor reduction of in vivo fitness. Thus, this study defines BapA and BapC as novel TTSS3 effectors, BapB as a regulator of BopE production, and all three as necessary for full B. pseudomallei in vivo fitness.

History

Publication Date

01/01/2015

Journal

PLoS One

Volume

10

Issue

12

Article Number

ARTN e0143916

Pagination

19p.

Publisher

Public Library of Science

ISSN

1932-6203

Rights Statement

The Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.