TY - JOUR
T1 - An antisense RNA that governs the expression kinetics of a multifunctional virulence gene
AU - Lee, Eun Jin
AU - Groisman, Eduardo A.
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2010/5
Y1 - 2010/5
N2 - Genome-wide transcriptome analyses of several bacterial species have recently uncovered a hitherto unappreciated amount of antisense transcription. However, the physiological role, regulation and significance of such antisense transcripts are presently unclear. We now report the identification of a cis-encoded 1.2 kb long antisense RNA - termed AmgR - that is complementary to the mgtC portion of the mgtCBR polycistronic message from Salmonella enterica. The mgtCBR mRNA specifies the MgtC protein, which is necessary for survival within macrophages, virulence in mice and growth in low Mg2+; the Mg2+ transporter MgtB with no apparent role in virulence; and the membrane peptide MgtR mediating MgtC degradation. Expression of AmgR dimished both MgtC and MgtB protein levels in a process requiring RNase E but independent of RNase III, the RNA chaperone Hfq, and the regulatory peptide MgtR. Inactivation of the chromosomal amgR promoter increased MgtC and MgtB protein levels and enhanced Salmonella virulence. Surprisingly, AmgR transcription is governed by the regulatory protein PhoP, which also directs transcription of the sense mgtCBR mRNA. AmgR may function as a timing device that alters MgtC and MgtB levels after the onset of PhoP-inducing conditions.
AB - Genome-wide transcriptome analyses of several bacterial species have recently uncovered a hitherto unappreciated amount of antisense transcription. However, the physiological role, regulation and significance of such antisense transcripts are presently unclear. We now report the identification of a cis-encoded 1.2 kb long antisense RNA - termed AmgR - that is complementary to the mgtC portion of the mgtCBR polycistronic message from Salmonella enterica. The mgtCBR mRNA specifies the MgtC protein, which is necessary for survival within macrophages, virulence in mice and growth in low Mg2+; the Mg2+ transporter MgtB with no apparent role in virulence; and the membrane peptide MgtR mediating MgtC degradation. Expression of AmgR dimished both MgtC and MgtB protein levels in a process requiring RNase E but independent of RNase III, the RNA chaperone Hfq, and the regulatory peptide MgtR. Inactivation of the chromosomal amgR promoter increased MgtC and MgtB protein levels and enhanced Salmonella virulence. Surprisingly, AmgR transcription is governed by the regulatory protein PhoP, which also directs transcription of the sense mgtCBR mRNA. AmgR may function as a timing device that alters MgtC and MgtB levels after the onset of PhoP-inducing conditions.
UR - http://www.scopus.com/inward/record.url?scp=77952128269&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77952128269&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2958.2010.07161.x
DO - 10.1111/j.1365-2958.2010.07161.x
M3 - Article
C2 - 20398218
AN - SCOPUS:77952128269
VL - 76
SP - 1020
EP - 1033
JO - Molecular Microbiology
JF - Molecular Microbiology
SN - 0950-382X
IS - 4
ER -