Impacts of Borrelia Burgdorferi Gac Protein on Infectivity and Regulation of Virulence Protein Expression

ABSTRACT We recently found that the Borrelia burgdorferi Gac protein has high affinity for specific DNA sequences, and functions as a transcriptional repressor of the essential ospC gene. RNA-sequencing (RNA-Seq) analyses of a gac mutant revealed that Gac impacts levels of transcripts of several other virulence-associated proteins, including the alternative sigma factor RpoN. The planned studies will further investigate the functions of Gac in the Lyme disease spirochete, including its roles during mammalian and tick infection, molecular characterization of Gac’s impacts on rpoN expression, and molecular analyses of how B. burgdorferi controls production of Gac. To date, Borrelia species are the only bacteria known to produce Gac.