We report on the role of conserved stress-response pathways for cellular tolerance to a pore forming toxin. First, we observed that small molecular weight inhibitors including of eIF2α-phosphatase, jun-N-terminal kinase (JNK), and PI3-kinase sensitized normal mouse embryonal fibroblasts (MEFs) to the small pore forming S. aureus α-toxin. Sensitization depended on expression of mADAM10, the muri...

Objective(s): A newly-introduced protein toxin from a sea anemone, namely fragaceatoxin C is a protein with molecular weight of 20 kDa and pore-forming capability against cell membranes has recently grasped great attentions for its function. In this study, its coding sequence cloned as a fusion protein with His-tag for simple production and rapid purification. Materials and Methods: After PCR a...

The pore-forming toxin aerolysin is secreted by Aeromonas hydrophila as an inactive precursor. Based on chemical cross-linking and gel filtration, we show here that proaerolysin exists as a monomer at low concentrations but is dimeric above 0.1 mg/ml. At intermediate concentrations, monomers and dimers appeared to be in rapid equilibrium. All together our data indicate that, at low concentratio...

Vibrio vulnificus secrets a pore-forming toxin called Vibrio vulnificus hemolysin (VVH). In this study, we showed that methyl-beta-cyclodextrin (MβCD), an oligosaccharide, decreased binding of VVH to Chinese hamster ovary (CHO) cells, resulting in inhibition of its cytotoxicity. When the VVH was incubated with MβCD, cytotoxicity of the toxin was inhibited from 100.3 ± 7.2% to 19.6 ± 5.3%. Bindi...

NetB (necrotic enteritis toxin B) is a recently identified β-pore-forming toxin produced by Clostridium perfringens. This toxin has been shown to play a major role in avian necrotic enteritis. In recent years, a dramatic increase in necrotic enteritis has been observed, especially in countries where the use of antimicrobial growth promoters in animal feedstuffs has been banned. The aim of this ...

Clostridium septicum alpha-toxin is a beta-barrel pore-forming cytolysin that is functionally similar to aerolysin. Residues important in receptor binding, oligomerization, and pore formation have been identified; however, little is known about the activity of the toxin in an infection, although it is essential for disease. We have now shown that deletion of a small portion of the transmembrane...

Clostridium perfringens is an anaerobic bacterium that causes numerous important human and animal diseases, primarily as a result of its ability to produce many different protein toxins. In chickens, C. perfringens causes necrotic enteritis, a disease of economic importance to the worldwide poultry industry. The secreted pore-forming toxin NetB is a key virulence factor in the pathogenesis of a...

The human pathogen Streptococcus pneumoniae produces soluble pneumolysin monomers that bind host cell membranes to form ring-shaped, oligomeric pores. We have determined three-dimensional structures of a helical oligomer of pneumolysin and of a membrane-bound ring form by cryo-electron microscopy. Fitting the four domains from the crystal structure of the closely related perfringolysin reveals ...