JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Caimano, M. J.
Right arrow Articles by Radolf, J. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Caimano, M. J.
Right arrow Articles by Radolf, J. D.

 Previous Article  |  Next Article 

Journal of Bacteriology, November 2005, p. 7845-7852, Vol. 187, No. 22
0021-9193/05/$08.00+0     doi:10.1128/JB.187.22.7845-7852.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Alternate Sigma Factor RpoS Is Required for the In Vivo-Specific Repression of Borrelia burgdorferi Plasmid lp54-Borne ospA and lp6.6 Genes

Melissa J. Caimano,1*,{dagger} Christian H. Eggers,1,{dagger} Cynthia A. Gonzalez,1 and Justin D. Radolf1,2

Departments of Medicine,1 Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, Connecticut 060302

Received 11 July 2005/ Accepted 21 August 2005

While numerous positively regulated loci have been characterized during the enzootic cycle of Borrelia burgdorferi, very little is known about the mechanism(s) involved in the repression of borrelial loci either during tick feeding or within the mammalian host. Here, we report that the alternative sigma factor RpoS is required for the in vivo-specific repression of at least two RpoD-dependent B. burgdorferi loci, ospA and lp6.6. The downregulation of ospA and Ip6.6 appears to require either a repressor molecule whose expression is RpoS dependent or an accessory factor which enables RpoS to directly interact with the ospA and Ip6.6 promoter elements, thereby blocking transcription by RpoD. The central role for RpoS during the earliest stages of host adaptation suggests that tick feeding imparts signals to spirochetes that trigger the RpoS-dependent repression, as well as expression, of in vivo-specific virulence factors critical for the tick-to-mammalian host transition.

* Corresponding author. Mailing address: Department of Medicine, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06030-3715. Phone: (860) 679-8390. Fax: (860) 679-1358. E-mail: mcaima{at}up.uchc.edu.

{dagger} M.J.C. and C.H.E. contributed equally to this work.

Journal of Bacteriology, November 2005, p. 7845-7852, Vol. 187, No. 22
0021-9193/05/$08.00+0     doi:10.1128/JB.187.22.7845-7852.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2005 by the American Society for Microbiology. All rights reserved.