Shiga toxin 1 B subunit (Stx1B)

The Shiga toxin 1 B subunit (Stx1B) is the receptor-binding component of Shiga toxin 1, a potent AB5 exotoxin produced by Shigella dysenteriae and Shiga toxin-producing Escherichia coli (STEC) [2, 4]. It forms a non-toxic homopentamer that specifically recognizes and binds to the glycosphingolipid globotriaosylceramide (Gb3/CD77) on the surface of host cells, particularly endothelial cells in the kidneys and central nervous system [3, 6]. Following binding, Stx1B facilitates the internalization of the holotoxin and its retrograde transport through the Golgi apparatus to the endoplasmic reticulum, where the catalytic A subunit is released to inhibit protein synthesis [6, 13]. In the context of infectious disease, Stx1B is a primary therapeutic target for neutralizing antibodies and receptor mimics aimed at preventing the systemic complications of STEC infection, such as hemolytic-uremic syndrome (HUS) [5, 8]. Additionally, due to the overexpression of Gb3 in various human cancers, Stx1B is being extensively explored as a highly specific delivery vehicle for cytotoxic drugs and imaging agents in targeted cancer therapy [1, 16].

Other names

Verotoxin 1 B subunitShiga-like toxin 1 B subunitSLT-1BVT1BSTxB1Shiga-like toxin 1 subunit B

Neutralization of toxin binding to host cell receptors (Gb3) and inhibition of retrograde intracellular trafficking [5, 6, 13].