A Gastric Pathogen Moves Chemotaxis in a New Direction

ABSTRACT For almost 50 years, Escherichia coli has been the model for understanding how bacteria orient their movement in response to chemical cues, but recent studies of chemotaxis in other bacteria have revealed interesting variations from prevailing paradigms. Investigating the human pathogenHelicobacter pylori, Amieva and colleagues [mBio 2(4):e00098-11, 2011] discov-ered a new chemotaxis regulator, ChePep, which modulates swimming behavior through the canonical histidine-aspartate phos-phorelay system. Functionally conserved among the epsilonproteobacteria, ChePep is essential forH. pylori to navigate deep into the stomach’s gastric glands andmay be an attractive target for novel antibiotics. Bacterial chemotaxis is one of the best-studied signal networksin biology, having been exhaustively investigated with genet-ics, biochemistry, and mathematical modeling (1). Hence, it is exciting when a brand-new player in the process is discovered. In the July/August issue ofmBio, Howitt and colleagues (2) described a new chemotaxis regulator, ChePep, that they discovered in the gastric pathogenHelicobacter pylori and showed to be functionally conserved among the epsilonproteobacteria. Chemotaxis is the directed movement of cells in response to chemical cues. In bacterial cells, chemoreceptors perceive chemi