Work

Determinants of Raft Partitioning of the Helicobacter pylori Pore-Forming Toxin VacA

Year: 2018

Type: article

Abstract: vacuolating cytotoxin A (VacA) is a secreted pore-forming toxin that induces a wide range of cellular responses. Like many other bacterial toxins, VacA has been hypothesized to utilize lipid rafts to gain entry into host cells. Here, we used giant plasma membrane vesicles (GPMVs) as a model system to understand the preferential partitioning of VacA into lipid rafts. We show that a wild-type (WT) toxin predominantly associates with the raft phase. Acid activation of VacA enhances binding of the toxin to GPMVs but is not required for raft partitioning. VacA mutant proteins with alterations at the amino terminus (resulting in impaired membrane channel formation) and a nonoligomerizing VacA mutant protein retain the ability to preferentially associate with lipid rafts. Consistent with these results, the isolated VacA p55 domain was capable of binding to lipid rafts. We conclude that the affinity of VacA for rafts is independent of its capacity to oligomerize or form membrane channels.

Source: Infection and Immunity

DOI: 10.1128/iai.00872-17

Authors: Krishnan Raghunathan, Nora J. Foegeding, Anne M. Campbell, Timothy L. Cover, Melanie D. Ohi, Anne K. Kenworthy

Institutions: Vanderbilt University, Vanderbilt University Medical Center, VA Tennessee Valley Healthcare System, University of Michigan

Language: English

Topic: Helicobacter pylori-related gastroenterology studies

Subfield: Surgery

Field: Medicine

Domain: Health Sciences

Open Access status: green