TY - JOUR
T1 - A Small Non-Coding RNA Mediates Transcript Stability and Expression of Cytochrome bd Ubiquinol Oxidase Subunit I in Rickettsia conorii
AU - Narra, Hema P.
AU - Alsing, Jessica
AU - Sahni, Abha
AU - Montini, Michelle
AU - Zafar, Yasim
AU - Sahni, Sanjeev K.
N1 - Funding Information:
This research was funded by the National Institute of Allergy and Infectious Diseases (NIAID), grant numbers 5R01AI127899-04 and 5R21AI149358-02, and pilot funding from the Institute for Human Infections and Immunity at the University of Texas Medical Branch, Galveston, TX, USA.
Publisher Copyright:
© 2023 by the authors.
PY - 2023/2
Y1 - 2023/2
N2 - Small regulatory RNAs (sRNAs) are now widely recognized for their role in the post-transcriptional regulation of bacterial virulence and growth. We have previously demonstrated the biogenesis and differential expression of several sRNAs in Rickettsia conorii during interactions with the human host and arthropod vector, as well as the in vitro binding of Rickettsia conorii sRNA Rc_sR42 to bicistronic cytochrome bd ubiquinol oxidase subunits I and II (cydAB) mRNA. However, the mechanism of regulation and the effect of sRNA binding on the stability of the cydAB bicistronic transcript and the expression of the cydA and cydB genes are still unknown. In this study, we determined the expression dynamics of Rc_sR42 and its cognate target genes, cydA and cydB, in mouse lung and brain tissues during R. conorii infection in vivo and employed fluorescent and reporter assays to decode the role of sRNA in regulating cognate gene transcripts. Quantitative RT-PCR revealed significant changes in the expression of sRNA and its cognate target gene transcripts during R. conorii infection in vivo, and a greater abundance of these transcripts was observed in the lungs compared to brain tissue. Interestingly, while Rc_sR42 and cydA exhibited similar patterns of change in their expression, indicating the influence of sRNA on the mRNA target, the expression of cydB was independent of sRNA expression. Further, we constructed reporter plasmids of sRNA and cydAB bicistronic mRNA to decipher the role of sRNA on CydA and CydB expression. We observed increased expression of CydA in the presence of sRNA but detected no change in CydB expression in the presence or absence of sRNA. In sum, our results demonstrate that the binding of Rc_sR42 is required for the regulation of cydA but not cydB. Further studies on understanding the influence of this interaction on the mammalian host and tick vector during R. conorii infection are in progress.
AB - Small regulatory RNAs (sRNAs) are now widely recognized for their role in the post-transcriptional regulation of bacterial virulence and growth. We have previously demonstrated the biogenesis and differential expression of several sRNAs in Rickettsia conorii during interactions with the human host and arthropod vector, as well as the in vitro binding of Rickettsia conorii sRNA Rc_sR42 to bicistronic cytochrome bd ubiquinol oxidase subunits I and II (cydAB) mRNA. However, the mechanism of regulation and the effect of sRNA binding on the stability of the cydAB bicistronic transcript and the expression of the cydA and cydB genes are still unknown. In this study, we determined the expression dynamics of Rc_sR42 and its cognate target genes, cydA and cydB, in mouse lung and brain tissues during R. conorii infection in vivo and employed fluorescent and reporter assays to decode the role of sRNA in regulating cognate gene transcripts. Quantitative RT-PCR revealed significant changes in the expression of sRNA and its cognate target gene transcripts during R. conorii infection in vivo, and a greater abundance of these transcripts was observed in the lungs compared to brain tissue. Interestingly, while Rc_sR42 and cydA exhibited similar patterns of change in their expression, indicating the influence of sRNA on the mRNA target, the expression of cydB was independent of sRNA expression. Further, we constructed reporter plasmids of sRNA and cydAB bicistronic mRNA to decipher the role of sRNA on CydA and CydB expression. We observed increased expression of CydA in the presence of sRNA but detected no change in CydB expression in the presence or absence of sRNA. In sum, our results demonstrate that the binding of Rc_sR42 is required for the regulation of cydA but not cydB. Further studies on understanding the influence of this interaction on the mammalian host and tick vector during R. conorii infection are in progress.
KW - CydAB
KW - cytochrome bd oxidases
KW - host–pathogen interaction
KW - non-coding RNA
KW - pXG plasmids
KW - Rickettsia conorii
KW - small RNA mediated gene regulation
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U2 - 10.3390/ijms24044008
DO - 10.3390/ijms24044008
M3 - Article
C2 - 36835430
AN - SCOPUS:85148576073
SN - 1661-6596
VL - 24
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 4
M1 - 4008
ER -