Cell Cycle Modulating Toxins Produced by Escherichia coli
István Tóth and Domonkos Sváb
from: Pathogenic Escherichia coli: Molecular and Cellular Microbiology (Edited by: Stefano Morabito). Caister Academic Press, U.K. (2014)
Pathogenic bacteria deploy numerous virulence mechanisms including adhesion/colonization, invasion, overcoming of host defences, and subversion of host cellular functions via/through/by secreted toxins and effectors (Kaper et al., 2004; Pizarro-Cerdá, and Cossart, 2006). Bacterial toxins and effectors that modulate the eukaryotic cell cycle establish a toxin family, termed cyclomodulins (Nougayrède et al., 2005; Oswald et al., 2005). Cyclomodulins are an emerging functional family of toxins that perturb the eukaryotic cell cycle machinery with various mechanisms and determine whether the infected cell will grow and divide or die (Oswald et al., 2005). In E. coli, so far four kinds of cyclomodulins have been identified: the Rho GTPase-activating cytotoxic necrotising factor toxins (CNF) 1 to 3 (Lemonnier et al., 2007), cytolethal lethal distending toxins (CDTs) I to V (Tóth et al., 2009), the cycle-inhibiting factor (Cif; Marchès et al., 2003) and the recently discovered colibactin (Nougayrède et al., 2006). CDTs, Cif, and colibactin block mitosis, while CNFs promote DNA replication without cytokinesis. CDTs and colibactin are genotoxins, while Cif does not cut the double-stranded DNA. Cyclomodulins are encoded by mobile genetic elements including genomic islands (CNF, colibactin, CDT), plasmids (CNF, CDT) and bacteriophages (Cif, CDT). In this review, we summarise the cyclomodulins produced by E. coli read more ...