Cloned Shiga Toxin 2 B Subunit Induces Apoptosis in Ramos Burkitt's Lymphoma B Cells
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Post-publication record
- Nature
- Retraction
- Reason
- Contamination of Materials;Error in Results and/or Conclusions;
- Date
- 7/1/2003 0:00
- Flagged by OpenAlex?
- Yes
Source: Retraction Watch, joined by DOI. OpenAlex records retraction as is_retracted, a boolean over a state space with at least four values, so it cannot express an expression of concern, a correction or a reinstatement — it reports them as false, which reads as “fine”.
Abstract
The Shiga toxins (Stx1 and Stx2), produced by Shigella dysenteriae type 1 and enterohemorrhagic Escherichia coli, consist of one A subunit and five B subunits. The Stx1 and Stx2 B subunits form a pentameric structure that binds to globotriaosylceramide (Gb3-Cer) receptors on eukaryotic cells and promotes endocytosis. The A subunit then inhibits protein biosynthesis, which triggers apoptosis in the affected cell. In addition to its Gb3-Cer binding activity, the data in the following report demonstrate that the Stx2 B pentamer induces apoptosis in Ramos Burkitt's lymphoma B cells independently of A subunit activity. Apoptosis was not observed in A subunit-free preparations of the Stx1 B pentamer which competitively inhibited Stx2 B pentamer-mediated apoptosis. The pancaspase inhibitor, Z-VAD-fmk, prevented apoptosis in Ramos cells exposed to the Stx2 B subunit, Stx1 or Stx2. Brefeldin A, an inhibitor of the Golgi transport system, also prevented Stx2 B subunit-mediated apoptosis. These observations suggest that the Stx2 B subunit must be internalized, via Gb3-Cer receptors, to induce Ramos cell apoptosis. Moreover, unlike the two holotoxins, Stx2 B subunit-mediated apoptosis does not involve inhibition of protein biosynthesis. This study provides further insight into the pathogenic potential of this family of potent bacterial exotoxins.
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The record
- Venue
- Infection and Immunity
- Topic
- Escherichia coli research studies
- Field
- Biochemistry, Genetics and Molecular Biology
- Canadian institutions
- University of Alberta
- Funders
- H2020 European Research Council
- Keywords
- Shiga toxinBiologyPentamerApoptosisProtein subunitMolecular biologyShigella dysenteriaeCell biologyBiochemistryEscherichia coli
- Has abstract in OpenAlex
- yes