Elucidation of the mechanism of regulation of expression of ferritin operon genes by the chaperone RNA - Hfq protein of Listeria monocytogenes and its role in the metabolism of heme iron and adaptation to various stresses

Principal Investigator: Agata Krawczyk-Balska (Project partner: Birgitte Kallipolitis)

Hfq is RNA-binding protein highly conserved in prokaryotes. It is best known as a RNA chaperone involved in post-transcriptional regulation of gene expression by promoting interaction between sRNA and mRNA. Hfq function as sRNA-mRNA matchmaker is well established in Gram-negative species, in Gram-positive ones is still inconclusive. While, the ability of Hfq from different Gram-positive species to bind sRNA is well documented, so far only a single sRNA from Gram-positive species is known to rely on Hfq for stability and base pairing to target mRNAs, namely Listeria monocytogenes LhrA. Besides of LhrA, sRNAs from LhrC family are known to interact with the chaperone Hfq of L. monocytogenes. However, so far the interactions between LhrCs and mRNAs targets have been shown to be Hfq-independent.

Our preliminary studies revealed that LhrC5 belongs to the ferritin operon of L. monocytogenes, and what's more, Hfq interacts in vivo with mRNAs of genes from the operon. In the project, we will establish whether Hfq and LhrC5 of L. monocytogenes are involved in regulation of expression of the ferritin operon genes in various stress conditions and subsequently elucidate the molecular mechanism of the regulation. 

The results of the project will provide a new data concerning the regulatory mechanisms of Hfq in Gram-positive bacteria and a more comprehensive view of the post-transcriptional regulation of stress response in L. monocytogenes

FUNDING SOURCES: Sonata Bis 5 grant, National Science Centre, Poland