TY - JOUR
T1 - DksA-dependent regulation of RpoS contributes to Borrelia burgdorferi tick-borne transmission and mammalian infectivity
AU - Boyle, William K.
AU - Richards, Crystal L.
AU - Dulebohn, Daniel P.
AU - Zalud, Amanda K.
AU - Shaw, Jeff A.
AU - Lovas, Sándor
AU - Gherardini, Frank C.
AU - Bourret, Travis J.
N1 - Funding Information:
TJB is supported by Creighton University (https://www.creighton.edu/) startup funds and FCG is supported by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA (Grant no.: AI000905). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank Patricia Rosa for the BBD18 antibody, and Sandy Stewart and Benjamin Schwarz for providing valuable insights and supporting this work.
Publisher Copyright:
© This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
PY - 2021/2/18
Y1 - 2021/2/18
N2 - Throughout its enzootic cycle, the Lyme disease spirochete Borreliella (Borrelia) burgdorferi, senses and responds to changes in its environment using a small repertoire of transcription factors that coordinate the expression of genes required for infection of Ixodes ticks and various mammalian hosts. Among these transcription factors, the DnaK suppressor protein (DksA) plays a pivotal role in regulating gene expression in B. burgdorferi during periods of nutrient limitation and is required for mammalian infectivity. In many pathogenic bacteria, the gene regulatory activity of DksA, along with the alarmone guanosine penta- and tetraphosphate ((p)ppGpp), coordinate the stringent response to various environmental stresses, including nutrient limitation. In this study, we sought to characterize the role of DksA in regulating the transcriptional activity of RNA polymerase and its role in the regulation of RpoS-dependent gene expression required for B. burgdorferi infectivity. Using in vitro transcription assays, we observed recombinant DksA inhibits RpoD-dependent transcription by B. burgdorferi RNA polymerase independent of ppGpp. Additionally, we determined the pH-inducible expression of RpoS-dependent genes relies on DksA, but this relationship is independent of (p)ppGpp produced by Relbbu. Subsequent transcriptomic and western blot assays indicate DksA regulates the expression of BBD18, a protein previously implicated in the post-transcriptional regulation of RpoS. Moreover, we observed DksA was required for infection of mice following intraperitoneal inoculation or for transmission of B. burgdorferi by Ixodes scapularis nymphs. Together, these data suggest DksA plays a central role in coordinating transcriptional responses in B. burgdorferi required for infectivity through DksA's interactions with RNA polymerase and post-transcriptional control of RpoS.
AB - Throughout its enzootic cycle, the Lyme disease spirochete Borreliella (Borrelia) burgdorferi, senses and responds to changes in its environment using a small repertoire of transcription factors that coordinate the expression of genes required for infection of Ixodes ticks and various mammalian hosts. Among these transcription factors, the DnaK suppressor protein (DksA) plays a pivotal role in regulating gene expression in B. burgdorferi during periods of nutrient limitation and is required for mammalian infectivity. In many pathogenic bacteria, the gene regulatory activity of DksA, along with the alarmone guanosine penta- and tetraphosphate ((p)ppGpp), coordinate the stringent response to various environmental stresses, including nutrient limitation. In this study, we sought to characterize the role of DksA in regulating the transcriptional activity of RNA polymerase and its role in the regulation of RpoS-dependent gene expression required for B. burgdorferi infectivity. Using in vitro transcription assays, we observed recombinant DksA inhibits RpoD-dependent transcription by B. burgdorferi RNA polymerase independent of ppGpp. Additionally, we determined the pH-inducible expression of RpoS-dependent genes relies on DksA, but this relationship is independent of (p)ppGpp produced by Relbbu. Subsequent transcriptomic and western blot assays indicate DksA regulates the expression of BBD18, a protein previously implicated in the post-transcriptional regulation of RpoS. Moreover, we observed DksA was required for infection of mice following intraperitoneal inoculation or for transmission of B. burgdorferi by Ixodes scapularis nymphs. Together, these data suggest DksA plays a central role in coordinating transcriptional responses in B. burgdorferi required for infectivity through DksA's interactions with RNA polymerase and post-transcriptional control of RpoS.
UR - http://www.scopus.com/inward/record.url?scp=85102500890&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85102500890&partnerID=8YFLogxK
U2 - 10.1371/JOURNAL.PPAT.1009072
DO - 10.1371/JOURNAL.PPAT.1009072
M3 - Article
C2 - 33600418
AN - SCOPUS:85102500890
VL - 17
JO - PLoS Pathogens
JF - PLoS Pathogens
SN - 1553-7366
IS - 2
M1 - e1009072
ER -