Post-transcriptional regulation of the Pseudomonas aeruginosa heme assimilation system (Has) fine-tunes extracellular heme sensing.

ABSTRACT: Pseudomonas aeruginosa is an opportunistic pathogen that utilizes heme as a primary iron source within the host. Extracellular heme is sensed via a heme assimilation system (has) that encodes an extracytoplasmic function (ECF) σ factor system. Herein, using has deletion mutants, quantitative PCR analyses, and immunoblotting, we show that the activation of the σ factor HasI requires heme release from the hemophore HasAp to the outer-membrane receptor HasR. Using RT-PCR and 5'-RACE, we observed that following transcriptional activation of the co-transcribed hasRAp, it is further processed into specific mRNAs varying in stability. We noted that the processing and variation in stability of the hasAp and hasR mRNAs in response to heme provide a mechanis

SUBMITTER: Dent AT 

PROVIDER: S-EPMC6393591 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature