DNA alternate polymerase PolB mediates inhibition of type III secretion in Pseudomonas aeruginosa

Opportunistic pathogen Pseudomonas aeruginosa uses a variety of virulence factors to cause acute and chronic infections. We previously found that alternate DNA polymerase gene polB inhibits P. aeruginosa pyocyanin production. We investigated whether polB also affects T3SS expression. polB overexpression significantly reduced T3SS transcription and repressed translation of the master T3SS regulator ExsA, while not affecting exsA mRNA transcript abundance. Further, polB does not act through previously described genetic pathways that post-transcriptionally regulate ExsA. Our results show a novel T3SS regulatory component which may lead to development of future drugs to target this mechanism. (c) 2020 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Automated summary

The overexpression of polB significantly reduced T3SS transcription and repressed translation of the master T3SS regulator ExsA. Furthermore, polB does not act through previously described genetic pathways that post-transcriptionally regulate ExsA.