anthrax lethal toxin

Anthrax lethal toxin (LeTx) is a potent bipartite exotoxin produced by *Bacillus anthracis*, consisting of two non-linked proteins: protective antigen (PA) and lethal factor (LF). PA acts as the cell-binding component, recognizing and binding to high-affinity cell surface receptors such as capillary morphogenesis protein 2 (CMG2) and tumor endothelial marker 8 (TEM8). Upon binding, PA is cleaved by furin-like proteases, allowing it to oligomerize and form a pore that facilitates the translocation of LF into the host cell cytosol. LF is a zinc-dependent metalloprotease that specifically targets and cleaves the N-terminal proline-rich region of most mitogen-activated protein kinase kinases (MAPKKs or MEKs), including MEK1, MEK2, MEK3, MEK4, MEK6, and MEK7. This cleavage inactivates the MEKs, thereby disrupting the MAPK/ERK, JNK, and p38 signaling pathways. While primarily a virulence factor in anthrax infection, LeTx has been investigated as a targeted antineoplastic agent due to its ability to inhibit the MAPK pathway, which is frequently dysregulated in cancers such as melanoma and other solid tumors.

Other names

Lethal toxinPA+LF