BACKGROUND: Bacterial genotoxins provoke DNA damage and carcinogenesis. The Escherichia coli uropathogenic-specific protein gene, usp, and its linked genes, imu1-3, are associated with strains from pyelonephritis, prostatitis, and bacteremia of urinary tract origin. While the Usp C-terminal domain exhibits similarity with DNase-like colicins and pyocins, its role and mechanisms of action, as well as those of the 3 associated proteins, is unknown. METHODS: We isolated Usp and Imu1-3 and examined their activity on plasmid DNA, human umbilical vein endothelial cells, and human embryonic kidney cells (cell line HEK293). The affect of Usp and Imu1-3 was assessed by MTT and Comet assays, infection assays, caspase 3/7 activity, fluorescently labeled actin staining, and Western blotting. RESULTS: Usp possesses DNase activity and, particularly when coapplied with Imu2, exhibits genotoxic activity in mammalian cells. Infection assays demonstrated that E. coli usp(+) imu1-3(+) affects the viability of mammalian cells, induces increased caspase 3/7 activity, and perturbs cell cytoskeleton structure. CONCLUSIONS: Usp is a novel E. coli genotoxin active against mammalian cells. Optimal in vivo activity of Usp requires Imu2. Infection with E. coli usp(+) imu1-3(+) induces a response characteristic of apoptosis.
BACKGROUND: Bacterial genotoxins provoke DNA damage and carcinogenesis. The Escherichia coli uropathogenic-specific protein gene, usp, and its linked genes, imu1-3, are associated with strains from pyelonephritis, prostatitis, and bacteremia of urinary tract origin. While the Usp C-terminal domain exhibits similarity with DNase-like colicins and pyocins, its role and mechanisms of action, as well as those of the 3 associated proteins, is unknown. METHODS: We isolated Usp and Imu1-3 and examined their activity on plasmid DNA, human umbilical vein endothelial cells, and humanembryonic kidney cells (cell line HEK293). The affect of Usp and Imu1-3 was assessed by MTT and Comet assays, infection assays, caspase 3/7 activity, fluorescently labeled actin staining, and Western blotting. RESULTS: Usp possesses DNase activity and, particularly when coapplied with Imu2, exhibits genotoxic activity in mammalian cells. Infection assays demonstrated that E. coli usp(+) imu1-3(+) affects the viability of mammalian cells, induces increased caspase 3/7 activity, and perturbs cell cytoskeleton structure. CONCLUSIONS: Usp is a novel E. coli genotoxin active against mammalian cells. Optimal in vivo activity of Usp requires Imu2. Infection with E. coli usp(+) imu1-3(+) induces a response characteristic of apoptosis.
Entities:
Keywords:
Escherichia coli; bacteriocin-like; genotoxin; uropathogenic specific protein
Authors: Panayiota Pissaridou; Luke P Allsopp; Sarah Wettstadt; Sophie A Howard; Despoina A I Mavridou; Alain Filloux Journal: Proc Natl Acad Sci U S A Date: 2018-11-19 Impact factor: 11.205
Authors: Connor Sharp; James Bray; Nicholas G Housden; Martin C J Maiden; Colin Kleanthous Journal: PLoS Comput Biol Date: 2017-07-17 Impact factor: 4.475
Authors: Micheál Mac Aogáin; Helen Miajlovic; Geraldine Moloney; Sanjay H Chotirmall; Thomas R Rogers; Stephen G J Smith Journal: JMM Case Rep Date: 2016-10-31