| First Author | Hooper KP | Year | 1996 |
| Journal | Biochem Biophys Res Commun | Volume | 220 |
| Issue | 3 | Pages | 675-80 |
| PubMed ID | 8607824 | Mgi Jnum | J:32453 |
| Mgi Id | MGI:79949 | Doi | 10.1006/bbrc.1996.0463 |
| Citation | Hooper KP, et al. (1996) Glutamic acid 141 of the diphtheria toxin receptor (HB-EGF precursor) is critical for toxin binding and toxin sensitivity. Biochem Biophys Res Commun 220(3):675-80 |
| abstractText | The transmembrane precursor of the monkey heparin-binding EGF-like growth factor also functions as a diphtheria toxin receptor. The mouse precursor does not bind the toxin. Previously, the most important region for binding the toxin in the monkey precursor was narrowed down to residues 122-148 through the expression of chimeric mouse/monkey precursors and subsequent toxin-sensitivity assays. To define further the toxin binding domain of the monkey precursor, distinct monkey/mouse chimeric precursors were expressed and assayed. The region between monkey residues 136-148 was found to be absolutely necessary for the retention of toxin sensitivity. Within this region, the monkey and mouse precursors differ in only two residues (residues 141 and 147). A toxin-insensitive monkey/mouse chimera that contained monkey residues 1-136 was converted to a toxin-sensitive chimera by the mutation of a single residue (His141 to Glu141). Expression of a mutant monkey precursor in which a single monkey residue (Glu141) was converted to the mouse residue (His141) yielded a cell line that was approximately 100-fold less sensitive to the toxin and the mutant precursor bound the toxin approximately 12-fold less tightly than the wild-type monkey precursor. Taken together, these results indicate that Glu 141 plays a critical role in toxin binding and toxin sensitivity. |
