Helicobacter pylori VacA is a channel-forming toxin unrelated to other known bacterial toxins. Most H. pylori strains contain a vacA gene, but there is marked variation among strains in VacA toxin activity. This variation is attributable to strain-specific variations in VacA amino acid sequences, as well as variations in the levels of VacA transcription and secretion. In this review, we discuss...

The Helicobacter pylori VacA toxin is an 88-kDa secreted protein that causes multiple alterations in mammalian cells and is considered an important virulence factor in the pathogenesis of peptic ulcer disease and gastric cancer. We have shown previously that a VacA mutant protein lacking amino acids 6 to 27 (Delta6-27p88 VacA) is able to inhibit many activities of wild-type VacA in a dominant-n...

The Helicobacter pylori vacuolating toxin VacA causes several effects on mammalian cells in vitro, including intracellular vacuolation, formation of pores in the plasma membrane and apoptosis. When added to cells, VacA becomes associated with detergent-resistant membranes, indicating that it binds preferentially to lipid rafts. In the present study, we have used atomic force microscopy to exami...

AIM The cagA and vacA profiles and their association with clinical findings show a distinct geographical distribution. In the present study, we aimed to determine the cagA status and vacA allelic subtypes in strains isolated from a university hospital in Ankara and to evaluate their associations with histopathological and endoscopic findings. MATERIALS AND METHODS A total of 120 H. pylori str...

Vacuolating cytotoxin A (VacA) is a secreted pore-forming toxin and one of the major virulence factors of Helicobacter pylori (H. pylori), which actively supports the persistence and survival of the bacteria in the special ecological niche of the human stomach. H. pylori genomes harbor different allelic forms of the vacA gene, which translate into functionally distinct VacA toxin types. VacA in...

The present report describes a novel method for genotyping the virulence-associated vacA intermediate (i) region of Helicobacter pylori in archive material. vacA i-region genotypes as determined by the novel method were completely concordant with those of sequence analysis and with those of functional vacuolation activity. The method was further validated directly in gastric biopsy specimens of...

Helicobacter pylori VacA is a secreted pore-forming toxin that is comprised of two domains, designated p33 and p55. The p55 domain has an important role in the binding of VacA to eukaryotic cell surfaces. A total of 111 residues at the amino terminus of p55 (residues 312 to 422) are essential for the intracellular activity of VacA, which suggests that this region may constitute a subdomain with...

Helicobacter pylori (H. pylori), a major cause of gastroduodenal diseases, produces VacA, a vacuolating cytotoxin associated with gastric inflammation and ulceration. The C-terminal domain of VacA plays a crucial role in receptor recognition on target cells. We have previously identified three proteins (i.e., RPTPα, RPTPβ, and LRP1) that serve as VacA receptors. These receptors contribute to th...