Iron is known to catalyze a wide range of biochemical reactions essential for most living organisms, including Campylobacter jejuni. Paradoxically, this iron reactivity is also responsible for the generation of hydroxyl radicals (·OH), which are particularly biotoxic. In order to avoid iron toxicity, microorganisms must achieve an effective iron homeostasis by tightly regulating the expression of genes encoding the proteins involved in iron acquisition, metabolism and oxidative stress defences in response to iron availability. Interestingly, in addition to the classical ferric uptake regulator Fur, C. jejuni carries another member of the Fur family of metalloregulators, PerR. PerR is a peroxide-sensing regulator and typically regulates peroxide stress response in Gram-positive bacteria. Recent work indicates that the regulatory functions of Fur and PerR extend beyond their classically ascribed roles. These diverse functions include energy metabolism, protein glycosylation and flagella biogenesis. Moreover, the Fur and PerR regulons appear to overlap and co-regulate key genes at specific junctions.

Further reading: Iron Uptake and Homeostasis in Microorganisms

Labels: Campylobacter, Iron acquisition mechanisms, Iron transporters, Iron uptake in Campylobacter, Iron uptake systems, Iron-homeostasis, Iron-metabolism, Iron-uptake