title: Borrelia burgdorferi CheY2 Is Dispensable for Chemotaxis or Motility but Crucial for the Infectious Life Cycle of the Spirochete.
abstract: The requirements for bacterial chemotaxis and motility range from dispensable to crucial for host colonization. Even though more than 50% of all sequenced prokaryotic genomes possess at least one chemotaxis signaling system, many of those genomes contain multiple copies of a chemotaxis gene. However, the functions of most of those additional genes are unknown. Most motile bacteria possess at least one CheY response regulator that is typically dedicated to the control of motility and which is usually essential for virulence. Borrelia burgdorferi appears to be notably different, in that it has three cheY genes, and our current studies on cheY2 suggests that it has varied effects on different aspects of the natural infection cycle. Mutants deficient in this protein exhibit normal motility and chemotaxis in vitro but show reduced virulence in mice. Specifically, the cheY2 mutants were severely attenuated in murine infection and dissemination to distant tissues after needle inoculation. Moreover, while ΔcheY2 spirochetes are able to survive normally in the Ixodes ticks, mice fed upon by the ΔcheY2-infected ticks did not develop a persistent infection in the murine host. Our data suggest that CheY2, despite resembling a typical response regulator, functions distinctively from most other chemotaxis CheY proteins. We propose that CheY2 serves as a regulator for a B. burgdorferi virulence determinant that is required for productive infection within vertebrate, but not tick, hosts.
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
authors: Hui
authors: H
authors: Xu
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
authors: Syed
authors: S
authors: Sultan
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
authors: Aaron
authors: A
authors: Yerke
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
authors: Ki Hwan
authors: KH
authors: Moon
authors: Department of Medical Microbiology and Immunology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, USA.
authors: R Mark
authors: RM
authors: Wooten
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA motalebm@ecu.edu.
authors: M A
authors: MA
authors: Motaleb
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D025065:Borrelia burgdorferi / Q000235:genetics*; D002633:Chemotaxis / Q000235:genetics*; D018884:Ixodes / Q000382:microbiology; D008018:Life Cycle Stages / Q000235:genetics*; D008193:Lyme Disease / Q000382:microbiology; D051379:Mice; D008809:Mice, Inbred C3H; D009154:Mutation / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics; D013144:Spirochaetales / Q000235:genetics*; D013145:Spirochaetales Infections / Q000382:microbiology; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors
keywords: Borrelia burgdorferi; CheY; Lyme disease; chemotaxis; chemotaxis/motility; flagella; pathogenesis; response regulator; spirochetes; tick-mouse; virulence