The heparin-binding domain of heparin-binding EGF-like growth factor can target Pseudomonas exotoxin to kill cells exclusively through heparan sulfate proteoglycans.
Heparin-binding EGF-like growth factor (HB-EGF) is a smooth muscle cell mitogen composed of both EGF receptor and heparin-binding domains. To better understand the function of its domains, intact HB-EGF or its heparin-binding (HB) domain (amino acids 1-45) were fused to a mutant Pseudomonas exotoxin with an inactivated cell-binding domain. The resulting chimeric toxins, HB-EGF-PE* and HB-PE*, were tested on tumor cells, proliferating smooth muscle cells and a mutant Chinese hamster ovary cell line deficient in heparan sulfate proteoglycans (HSPGs). Two targets were found for HB-EGF-PE*. Cells were killed mainly through EGF receptors, but the HB domain was responsible for killing via HSPGs. HB-PE* did not bind to the EGF receptor and thus was cytotoxic by interacting exclusively with HSPGs. We conclude that the HB domain of HB-EGF is able to mediate internalization through HSPGs, without requiring the EGF receptor.
Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
E A
EA
Mesri
M
M
Ono
R J
RJ
Kreitman
M
M
Klagsbrun
I
I
Pastan
D036002:ADP Ribose Transferases; D000818:Animals; D001427:Bacterial Toxins; D001483:Base Sequence; D001665:Binding Sites; D016466:CHO Cells; D002417:Cattle; D006224:Cricetinae; D003412:Cricetulus; D004815:Epidermal Growth Factor / Q000235:genetics / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D005098:Exotoxins / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D005813:Genes, Synthetic; D019812:Heparan Sulfate Proteoglycans; D006493:Heparin / Q000378:metabolism*; D066257:Heparin-binding EGF-like Growth Factor; D006497:Heparan Sulfate / Q000378:metabolism*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008024:Ligands; D008934:Mitogens / Q000378:metabolism; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011509:Proteoglycans / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D016211:Transforming Growth Factor alpha / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
D036002:ADP Ribose Transferases; D001427:Bacterial Toxins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D005098:Exotoxins; D019812:Heparan Sulfate Proteoglycans; D006493:Heparin; D066257:Heparin-binding EGF-like Growth Factor; D006497:Heparan Sulfate; D036341:Intercellular Signaling Peptides and Proteins; D008024:Ligands; D008934:Mitogens; D010446:Peptide Fragments; D011509:Proteoglycans; D011993:Recombinant Fusion Proteins; D016211:Transforming Growth Factor alpha; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; C587883:HBEGF protein, human