Answer: They are all linked to protein toxins sneaking into our cells.
- Every day, in hospitals around the world, Pseudomonas aeruginosa infects immuno-compromised patients; its pathogenicity is highly dependent on the secreted exotoxin A.
- In 2009, the suspected white supremacist Ian Davison was arrested in possession of the deadly poison Ricin in Durham County in the United Kingdom. Purified from the beans of a relatively common ornamental plant, Ricin is considered to be one of the easiest bioweapons to produce, with as little as a few milligrams sufficient to kill a man.
- In the case of the recent Germany outbreak, the devastating effects of the enterotoxic E. coli that laced bean sprouts is dependent on the Shiga-like toxin.
These three toxins share a very similar mode of action: they highjack a complex cellular pathway known as retrograde traffic in order to penetrate cells and block the essential process of protein synthesis. This kill cells by blocking the essential process of protein synthesis.
In a study published on July 21st online in Developmental Cell, the lab of Frederic Bard at IMCB has used a high-throughput genetic technique to identify the components of the cellular machinery required for Ricin and Pseudomonas Exotoxin to kill cells. This study was led by biologist Dimitri Moreau with the critical help of bioinformatician Pankaj Kumar.
The results illustrate the complexities of toxin trafficking in human cells (see figure below).
Figure Legend: This study identifies many new human proteins required for the toxins’ actions and, consequently, these results may assist us in defining new strategies for the development of toxin antidotes that could enhance cell resistance to these toxins.
For more information on Frederic BARD’s laboratory, please click here.