Special Issue Article
Masahiro Nagahama, Masataka
Abstract
Alpha-toxin (370 residues) of Clostridium perfringens is the key virulence determinant in gas gangrene and has also been implicated in the pathogenesis of sudden death syndrome in young animals. Alpha-toxin possesses phospholipase C (PLC), sphingomyelinase (SMase) and biological activities causing hemolysis and lethality. The structure of the toxin reveals two domains: the N-terminal domain containing the catalytic active site and the C-terminal domain involving the binding to membranes. Recent research data showed that alpha-toxin-induced biological activities are responsible for the activation of phospholipid metabolism via a pertussis toxin (PT)-sensitive GTP-binding protein, Gi. In this review, we summary the role of phospholipid metabolism and G protein in the biological activities induced by alpha-toxin. Discussed are activations of the arachidonic acid cascade (Section 1), the phospholipid metabolism (Section 2), the sphingomeylin metabolism (Section 3) and TrkA signaling (Section 4) induced by alpha-toxin.