Defining a role for Hfq in Gram-positive bacteria: evidence for Hfq-dependent antisense regulation in Listeria monocytogenes.
Small trans-encoded RNAs (sRNAs) modulate the translation and decay of mRNAs in bacteria. In Gram-negative species, antisense regulation by trans-encoded sRNAs relies on the Sm-like protein Hfq. In contrast to this, Hfq is dispensable for sRNA-mediated riboregulation in the Gram-positive species studied thus far. Here, we provide evidence for Hfq-dependent translational repression in the Gram-positive human pathogen Listeria monocytogenes, which is known to encode at least 50 sRNAs. We show that the Hfq-binding sRNA LhrA controls the translation and degradation of its target mRNA by an antisense mechanism, and that Hfq facilitates the binding of LhrA to its target. The work presented here provides the first experimental evidence for Hfq-dependent riboregulation in a Gram-positive bacterium. Our findings indicate that modulation of translation by trans-encoded sRNAs may occur by both Hfq-dependent and -independent mechanisms, thus adding another layer of complexity to sRNA-mediated riboregulation in Gram-positive species.
Nielsen
Jesper Sejrup
JS
Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
Lei
Lisbeth Kristensen
LK
Ebersbach
Tine
T
Olsen
Anders Steno
AS
Klitgaard
Janne Kudsk
JK
Valentin-Hansen
Poul
P
Kallipolitis
Birgitte Haahr
BH
D020029:Base Pairing; D001483:Base Sequence; D015964:Gene Expression Regulation, Bacterial; D035001:Host Factor 1 Protein / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008089:Listeria monocytogenes / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010442:Peptide Chain Initiation, Translational; D014176:Protein Biosynthesis; D020871:RNA Stability; D016372:RNA, Antisense / Q000737:chemistry* / Q000235:genetics; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D022661:RNA, Untranslated / Q000737:chemistry* / Q000235:genetics
D035001:Host Factor 1 Protein; D016372:RNA, Antisense; D012333:RNA, Messenger; D022661:RNA, Untranslated