Heparin-binding EGF-like growth factor receptor (HB-EGF receptor)

The "diphtheria toxin-sensitive cell machinery" denotes the collective set of host components required for diphtheria toxin entry and cytotoxicity. The most critical component is the heparin-binding EGF-like growth factor receptor (HB-EGF receptor), which acts as the cell surface receptor mediating binding and internalization of diphtheria toxin[1][7]. Upon binding, the toxin-receptor complex is internalized via clathrin-mediated endocytosis, where acidification in endosomes facilitates membrane insertion and translocation of the catalytic A subunit into the cytosol. Intracellular chaperone systems including Hsp90 and co-chaperones assist with efficient cytosolic translocation of the enzymatic domain[3]. The diphtheria toxin A subunit ADP-ribosylates and inactivates elongation factor 2 (EF-2), causing cessation of protein synthesis and rapid cell death[6]. This machinery collectively determines cellular susceptibility to diphtheria toxin and can be experimentally targeted for cell ablation in research applications or forms the basis for understanding diphtheria pathology[1][3][6][7].

Other names

Diphtheria toxin receptorHBEGF receptor

Toxin binds to HB-EGF receptor, triggers endocytosis, toxin enters cytosol via endosomal acidification, enzymatic inhibition of elongation factor 2 (EF-2) by ADP-ribosylation, leads to inhibition of protein synthesis and cell death[1][3][5][6][7].