Determinants of pH-dependent modulation of translocation in dermonecrotic G-protein-deamidating toxins

• Published in: Toxins Vol. 5; no. 6; pp. 1167 - 1179
• Main Authors: Repella, Tana L, Ho, Mengfei, Wilson, Brenda A
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.06.2013
• Subjects: Ammonium Chloride - pharmacology; Bacterial Toxins - genetics; Bacterial Toxins - metabolism; Bacterial Toxins - toxicity; Cytochalasin D - pharmacology; cytotoxic necrotizing factor; Cytotoxins - genetics; Cytotoxins - metabolism; Cytotoxins - toxicity; dermonecrotic toxin; drug-delivery; endosomal acidification; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Escherichia coli Proteins - toxicity; GTP-Binding Proteins - metabolism; HEK293 Cells; Humans; Hydrogen-Ion Concentration; intoxication; Macrolides - pharmacology; Monensin - pharmacology; Nigericin - pharmacology; Nocodazole - pharmacology; Pasteurella multocida toxin; Protein Transport; Proton-Translocating ATPases - antagonists & inhibitors; Recombinant Proteins - toxicity; toxin-based therapeutics
• ISSN: 2072-6651; 2072-6651
• DOI: 10.3390/toxins5061167

Cytotoxic necrotizing factors from E. coli (CNF1, CNF2) and Yersinia (CNFy)share N-terminal sequence similarity with Pasteurella multocida toxin (PMT). This common N-terminal region harbors the receptor-binding and translocation domains that mediate uptake and delivery of the C-terminal catalytic cargo domains into the host cytosol. Subtle variations in the N-terminal ~500 amino acids of CNFs and PMT could allow for selective recognition of cellular receptors and thus, selective target cell specificity. Through studies with cellular inhibitors, we have identified an additional novel function for this region in modulating responses of these toxin proteins to changes in pH during intoxication and delivery of the catalytic cargo domain into the cytosol.