MilliporeSigma
  • The iron-sensing fur regulator controls expression timing and levels of salmonella pathogenicity island 2 genes in the course of environmental acidification.

The iron-sensing fur regulator controls expression timing and levels of salmonella pathogenicity island 2 genes in the course of environmental acidification.

Infection and immunity (2014-03-20)
Eunna Choi, Hyunkeun Kim, Hwiseop Lee, Daesil Nam, Jeongjoon Choi, Dongwoo Shin
ABSTRACT

In order to survive inside macrophages, Salmonella produces a series of proteins encoded by genes within Salmonella pathogenicity island 2 (SPI-2). In the present study, we report that Fur, a central regulator of iron utilization, negatively controls the expression of SPI-2 genes. Time course analysis of SPI-2 expression after the entry of Salmonella into macrophages revealed that SPI-2 genes are induced earlier and at higher levels in the absence of the Fur regulator. It was hypothesized that Fur repressed the SPI-2 expression that was activated during acidification of the phagosome. Indeed, as pH was lowered from pH 7.0 to pH 5.5, the lack of Fur enabled SPI-2 gene expression to be induced at higher pH and to be expressed at higher levels. Fur controlled SPI-2 genes via repression of the SsrB response regulator, a primary activator of SPI-2 expression. Fur repressed ssrB expression both inside macrophages and under acidic conditions, which we ascribe to the direct binding of Fur to the ssrB promoter. Our study suggests that Salmonella could employ iron inside the phagosome to precisely control the timing and levels of SPI-2 expression inside macrophages.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Iron, puriss. p.a., carbonyl-Iron powder, low in magnesium and manganese compounds, ≥99.5% (RT)
Iron, IRMM®, certified reference material, 0.5 mm wire
Iron, foil, 10mm disks, thickness 0.15mm, hard, 99.5%
Iron, foil, 15mm disks, thickness 0.015mm, 99.99+%
Iron, foil, not light tested, 150x150mm, thickness 0.008mm, 99.85%
Iron, foil, not light tested, 100x100mm, thickness 0.006mm, 99.85%
Iron, foil, not light tested, 50x50mm, thickness 0.001mm, 99.85%
Iron, tube, 200mm, outside diameter 12.0mm, inside diameter 10mm, wall thickness 1.0mm, annealed, 99.5%
Iron, foil, 50x50mm, thickness 0.20mm, hard, 99.5%
Iron, foil, 25x25mm, thickness 2mm, as rolled, 99.99+%
Iron, tube, 200mm, outside diameter 10.0mm, inside diameter 7mm, wall thickness 1.5mm, annealed, 99.5%
Iron, wire reel, 1m, diameter 0.5mm, as drawn, 99.998%
Iron, wire reel, 0.5m, diameter 1.0mm, as drawn, 99.99+%
Iron, wire reel, 1m, diameter 1.0mm, as drawn, 99.99+%
Iron, tube, 200mm, outside diameter 2.0mm, inside diameter 1.6mm, wall thickness 0.2mm, as drawn, 99.5%
Iron, foil, 50x50mm, thickness 0.5mm, hard, 99.5%
Iron, wire reel, 5m, diameter 0.25mm, hard, 99.99+%
Iron, foil, 300x300mm, thickness 0.20mm, hard, 99.5%
Iron, wire reel, 100m, diameter 0.065mm, hard, 99.5%
Sigma-Aldrich
Iron, nanopowder, 35-45 nm particle size, 99.5% trace metals basis
Iron, tube, 500mm, outside diameter 6.35mm, inside diameter 5.35mm, wall thickness 0.5mm, as drawn, 99.8%
Iron, foil, 10mm disks, thickness 0.003mm, 99.85%
Iron, tube, 500mm, outside diameter 2.38mm, inside diameter 1.6mm, wall thickness 0.39mm, as drawn, 99.8+%
Iron, tube, 200mm, outside diameter 3.18mm, inside diameter 1.96mm, wall thickness 0.61mm, as drawn, 99.5%
Iron, foil, 10mm disks, thickness 0.0125mm, 99.85%
Iron, wire reel, 0.5m, diameter 0.13mm, hard, 99.99+%
Iron, tube, 200mm, outside diameter 12.0mm, inside diameter 9mm, wall thickness 1.5mm, annealed, 99.5%
Iron, foil, 50x50mm, thickness 0.25mm, as rolled, 99.99+%
Iron, foil, 10m coil, thickness 0.038mm, hard, 99.5%
Iron, tube, 500mm, outside diameter 8.0mm, inside diameter 5mm, wall thickness 1.5mm, annealed, 99.5%