IcsA heads to the pole

Abstract

The localization of specific bacterial proteins to certain parts of the cell envelope can be visualized using fluorescence microscopy. These studies have shown that certain bacterial proteins have the capacity to be partitioned to specific areas of the cell where they perform their specific function. One such protein is the Shigella flexneri virulence factor IcsA, which is located toward one pole of the bacterium and requires this location to mediate intracellular motility. In a recent paper, Charles et al. 1 Charles M. et al. Polar targeting of Shigella virulence factor IcsA in Enterobacteriaceae and Vibrio. Proc. Natl. Acad. Sci. U. S. A. 2001; 98: 9871-9876 Crossref PubMed Scopus (87) Google Scholar used various IcsA–GFP fusion constructs to identify the IcsA polar-localization domain. Not only did the investigators find two distinct IcsA polar-targeting domains, but they also discovered evidence for a conserved polar-localization mechanism in species of Enterobacteriaceae and Vibrio.