TY - JOUR
T1 - Differential requirements for VirB1 and VirB2 during Brucella abortus infection
AU - Den Hartigh, Andreas B.
AU - Sun, Yao Hui
AU - Sondervan, David
AU - Heuvelmans, Niki
AU - Reinders, Marjolein O.
AU - Ficht, Thomas A.
AU - Tsolis, Renee M
PY - 2004/9
Y1 - 2004/9
N2 - 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.
AB - 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.
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U2 - 10.1128/IAI.72.9.5143-5149.2004
DO - 10.1128/IAI.72.9.5143-5149.2004
M3 - Article
C2 - 15322008
AN - SCOPUS:4544342031
VL - 72
SP - 5143
EP - 5149
JO - Infection and Immunity
JF - Infection and Immunity
SN - 0019-9567
IS - 9
ER -