Cytotoxin-L

UniProtKB accession:  Q46342

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Precursor of a cytotoxin that targets the vascular endothelium, inducing an anti-inflammatory effect and resulting in lethal toxic shock syndrome (PubMed:19527792, PubMed:24919149, PubMed:29146177). TcsL constitutes the main toxin that mediates the pathology of P.sordellii infection, an anaerobic Gram-positive bacterium found in soil and in the gastrointestinal and vaginal tracts of animals and humans; although the majority of carriers are asymptomatic, pathogenic P.sordellii infections arise rapidly and are highly lethal (PubMed:29146177). This form constitutes the precursor of the toxin: it enters into host cells and mediates autoprocessing to release the active toxin (Glucosyltransferase TcsL) into the host cytosol (PubMed:17334356, PubMed:27303685, PubMed:32302524). Targets vascular endothelium by binding to the semaphorin proteins SEMA6A and SEMA6B, and enters host cells via clathrin-mediated endocytosis (PubMed:32302524). Once entered into host cells, acidification in the endosome promotes the membrane insertion of the translocation region and formation of a pore, leading to translocation of the GT44 and peptidase C80 domains across the endosomal membrane (By similarity). This activates the peptidase C80 domain and autocatalytic processing, releasing the N-terminal part (Glucosyltransferase TcsL), which constitutes the active part of the toxin, in the cytosol (PubMed:17334356, PubMed:27303685).