The EHEC Type III Effector NleL Is an E3 Ubiquitin Ligase That Modulates Pedestal Formation

• DOI: 10.1371/journal.pone.0019331
• Publication Date: 2011-04-26T21:39:11Z
• Authors: Heather Piscatelli; Shalaka A. Kotkar; Megan E. McBee; Sureshkumar Muthu...; David B. Schauer; Robert E. Mandrell; John M. Leong; Daoguo Zhou
• Keywords: 0301 basic medicine; Virulence; Science; Escherichia coli Proteins; Recombinant Fusion Proteins; Ubiquitin-Protein Ligases; Q; R; Ubiquitination; Down-Regulation; Escherichia coli O157; 3. Good health; Mice, Inbred C57BL; Mice; Protein Transport; 03 medical and health sciences; Medicine; Animals; Citrobacter rodentium; Humans; Mutant Proteins; Cell Surface Extensions; Research Article; HeLa Cells

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 causes hemorrhagic colitis and may result in potentially fatal hemolytic uremia syndrome humans. EHEC colonize the intestinal mucosa promote formation of actin-rich pedestals via translocated type III effectors. Two secreted effectors, Tir EspFu/TccP, are key players for pedestal formation. We discovered that an effector protein called Non-LEE-encoded Ligase (NleL) is E3 ubiquitin ligase. In vitro, we showed NleL C753 residue critical its ligase activity. Functionally, demonstrated activity involved modulating Tir-mediated Surprisingly, mutant strain deficient induced more than wild-type strain. The canonical EPEC E2348/69 normally lacks nleL gene, ectopic expression nleL, but not catalytically-deficient nleL(C753A) mutant, this resulted fewer pedestals. Furthermore, C. rodentium homolog a required efficient infection murine colonic epithelial cells vivo. summary, our study utilizes to modulate