Premium
The Role of the Ferric Uptake Regulator (Fur) in Regulation of Helicobacter pylori Iron Uptake
Author(s) -
Van Vliet Arnoud H. M.,
Stoof Jeroen,
Vlasblom Ronald,
Wainwright Stuart A.,
Hughes Nicola J.,
Kelly David J.,
Bereswill Stefan,
Bijlsma Jetta J. E.,
Hoogenboezem Theo,
VandenbrouckeGrauls Christina M. J. E.,
Kist Manfred,
Kuipers Ernst J.,
Kusters Johannes G.
Publication year - 2002
Publication title -
helicobacter
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.206
H-Index - 79
eISSN - 1523-5378
pISSN - 1083-4389
DOI - 10.1046/j.1523-5378.2002.00088.x
Subject(s) - mutant , helicobacter pylori , ferric , iron deficiency , psychological repression , gene expression , gene , biology , repressor , bacteria , regulator , chemistry , biochemistry , microbiology and biotechnology , genetics , medicine , organic chemistry , anemia
Background. Availability of the essential nutrient iron is thought to vary greatly in the gastric mucosa, and thus the human gastric pathogen Helicobacter pylori requires regulatory responses to these environmental changes. Bacterial iron‐responsive regulation is often mediated by Ferric Uptake Regulator (Fur) homologs, and in this study we have determined the role of H. pylori Fur in regulation of H. pylori iron uptake. Methods. Wild‐type H. pylori and fur mutant derivatives were compared after growth in iron‐restricted and iron‐replete conditions. Iron‐uptake was measured using 55 Fe‐labeled iron, whereas gene expression was monitored at the transcriptional level using Northern hybridization and lacZ reporter gene fusions. Results. Iron‐uptake and total cellular iron content were approximately five‐fold increased in the fur mutant compared with the wild‐type strain, which indicated that in the fur mutant iron‐uptake is not repressed by excess iron. A comprehensive screening of all H. pylori genes encoding putative iron‐uptake proteins indicated that some of these H. pylori genes are constitutively expressed, while others are iron‐ and Fur‐regulated. Conclusions. Iron uptake in H. pylori is in part differently regulated compared with other bacteria, since in H. pylori some iron‐uptake systems are constitutively expressed. However, other iron uptake systems of H. pylori display the iron‐ and Fur‐mediated repression that is common in bacteria. Taken together, this Fur‐mediated modulation of iron‐uptake capacity may be a specific adaptation to the conditions in the human stomach, where iron starvation and iron overload can be encountered in relatively short time intervals.