Differential Requirements for VirB1 and VirB2 during Brucella abortus Infection
Open Access
- 1 September 2004
- journal article
- Published by American Society for Microbiology in Infection and Immunity
- Vol. 72 (9), 5143-5149
- https://doi.org/10.1128/iai.72.9.5143-5149.2004
Abstract
The Brucella abortus virB operon, encoding a type IV secretion system (T4SS), is required for intracellular replication and persistent infection in the mouse model. The products of the first two genes of the virB operon, virB1 and virB2 , are predicted to be localized at the bacterial surface, where they could potentially interact with host cells. Studies to date have focused on characterization of transposon mutations in these genes, which are expected to exert polar effects on downstream genes in the operon. In order to determine whether VirB1 and VirB2 are required for the function of the T4SS apparatus, we constructed and characterized nonpolar deletion mutations of virB1 and virB2 . Both mutants were shown to be nonpolar, as demonstrated by their ability to express the downstream gene virB5 during stationary phase of growth in vitro. Both VirB1 and VirB2 were essential for intracellular replication in J774 macrophages. The nonpolar virB2 mutant was unable to cause persistent infection in the mouse model, demonstrating the essential role of VirB2 in the function of the T4SS apparatus during infection. In contrast, the nonpolar virB1 mutant persisted at wild-type levels, showing that the function of VirB1 is dispensable in the mouse model of persistent infection.Keywords
This publication has 29 references indexed in Scilit:
- VirB1 Orthologs fromBrucella suisand pKM101 Complement Defects of the Lytic Transglycosylase Required for Efficient Type IV Secretion fromAgrobacterium tumefaciensJournal of Bacteriology, 2004
- BrucellaEvades Macrophage Killing via VirB-dependent Sustained Interactions with the Endoplasmic ReticulumThe Journal of Experimental Medicine, 2003
- Functional and Mutational Analysis of P19, a DNA Transfer Protein with Muramidase ActivityJournal of Bacteriology, 2001
- Identification of Brucella suis Genes Affecting Intracellular Survival in an In Vitro Human Macrophage Infection Model by Signature-Tagged Transposon MutagenesisInfection and Immunity, 2000
- Localization of the protein VirB1 involved in contact formation during conjugation amongAgrobacteriumcellsFEMS Microbiology Letters, 1998
- Identification of a new iron regulated locus of Salmonella typhiGene, 1996
- Pilus Assembly by Agrobacterium T-DNA Transfer GenesScience, 1996
- Entry and Intracellular Localization of Brucella spp. in Vero Cells: Fluorescence and Electron MicroscopyVeterinary Pathology, 1990
- Macrophage variants in oxygen metabolism.The Journal of Experimental Medicine, 1980
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970