Browsing by Author "Brissette, Catherine A."

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    Borrelia burgdorferi SpoVG DNA- and RNA-Binding Protein Modulates the Physiology of the Lyme Disease Spirochete
    Savage, Christina R.; Jutras, Brandon L.; Bestor, Aaron; Tilly, Kit; Rosa, Patricia A.; Tourand, Yvonne; Stewart, Philip E.; Brissette, Catherine A.; Stevenson, Brian (American Society for Microbiology, 2018-06-01)
    The SpoVG protein of Borrelia burgdorferi, the Lyme disease spirochete, binds to specific sites of DNA and RNA. The bacterium regulates transcription of spoVG during the natural tick-mammal infectious cycle and in response to some changes in culture conditions. Bacterial levels of spoVG mRNA and SpoVG protein did not necessarily correlate, suggesting that posttranscriptional mechanisms also control protein levels. Consistent with this, SpoVG binds to its own mRNA, adjacent to the ribosome-binding site. SpoVG also binds to two DNA sites in the glpFKD operon and to two RNA sites in glpFKD mRNA; that operon encodes genes necessary for glycerol catabolism and is important for colonization in ticks. In addition, spirochetes engineered to dysregulate spoVG exhibited physiological alterations.
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    The Lyme disease spirochete's BpuR DNA/RNA-binding protein is differentially expressed during the mammal-tick infectious cycle, which affects translation of the SodA superoxide dismutase
    Jutras, Brandon L.; Savage, Christina R.; Arnold, William K.; Lethbridge, Kathryn G.; Carroll, Dustin W.; Tilly, Kit; Bestor, Aaron; Zhu, Haining; Seshu, Janakiram; Zuckert, Wolfram R.; Stewart, Philip E.; Rosa, Patricia A.; Brissette, Catherine A.; Stevenson, Brian (2019-07)
    When the Lyme disease spirochete, Borrelia burgdorferi, transfers from a feeding tick into a human or other vertebrate host, the bacterium produces vertebrate-specific proteins and represses factors needed for arthropod colonization. Previous studies determined that the B. burgdorferi BpuR protein binds to its own mRNA and autoregulates its translation, and also serves as co-repressor of erp transcription. Here, we demonstrate that B. burgdorferi controls transcription of bpuR, expressing high levels of bpuR during tick colonization but significantly less during mammalian infection. The master regulator of chromosomal replication, DnaA, was found to bind specifically to a DNA sequence that overlaps the bpuR promoter. Cultured B. burgdorferi that were genetically manipulated to produce elevated levels of BpuR exhibited altered levels of several proteins, although BpuR did not impact mRNA levels. Among these was the SodA superoxide dismutase, which is essential for mammalian infection. BpuR bound to sodA mRNA in live B. burgdorferi, and a specific BpuR-binding site was mapped 5 ' of the sodA open reading frame. Recognition of posttranscriptional regulation of protein levels by BpuR adds another layer to our understanding of the B. burgdorferi regulome, and provides further evidence that bacterial protein levels do not always correlate directly with mRNA levels.
  • The Lyme disease spirochete’s BpuR DNA- / RNA-binding protein is differentially expressed during the mammal-tick infectious cycle, and affects translation of the SodA superoxide dismutase
    Jutras, Brandon L.; Arnold, William; Savage, Christina R.; Tilly, Kit; Beastor, Aaron; Rosa, Patti; Brissette, Catherine A.; Stevenson, Brian (Wiley, 2019-09)