Subtilase Cytotoxin: A New Bacterial AB5 Toxin Family
Adrienne W. Paton and James C. Paton
from: Microbial Toxins: Current Research and Future Trends (Edited by: Thomas Proft). Caister Academic Press, U.K. (2009)
Abstract
Subtilase cytotoxin (SubAB) is the recently-recognised prototype of a new AB5 toxin family secreted by Shiga toxigenic Escherichia coli (STEC). Its A subunit is a subtilase-like serine protease and cytotoxicity for eukaryotic cells is due to a highly specific, single-site cleavage of BiP/GRP78, an essential Hsp70 family chaperone located in the ER. This cleavage triggers a severe ER stress response, ultimately resulting in apoptosis. The B subunit has specificity for glycans terminating in the sialic acid N-glycolylneuraminic acid. Although its actual role in human disease remains to be established, SubAB is lethal for mice and induces pathological features overlapping those seen in the haemolytic uraemic syndrome, a life-threatening complication of STEC infection read more ...
