Samuel Juillot and Winfried Römer
from: Pathogenic Escherichia coli: Molecular and Cellular Microbiology (Edited by: Stefano Morabito). Caister Academic Press, U.K. (2014)
Shiga toxins are virulence factors produced by Shigella dysenteriae and certain Escherichia coli strains called STEC. The toxins affect target cells already by binding to the plasma membrane through induction of signalling cascades that mainly lead to apoptosis. Furthermore, they inhibit protein biosynthesis by inactivating the 60S subunit of ribosomes. In order to reach their cytoplasmic target, Shiga toxins are endocytosed and transported through the retrograde trafficking pathway towards the endoplasmic reticulum (ER), from where the catalytically active subunit is retro-translocated to the cytosol with the help of ER chaperons and translocon components. Even though Shiga toxins are still a threat to human health, the receptor-binding subunit of Shiga toxins represents a powerful tool to study the mechanisms of intracellular transport and may be exploited as biomedical tool in immunotherapy and tumour imaging read more ...