| First Author | Brandt R | Year | 1994 |
| Journal | J Biol Chem | Volume | 269 |
| Issue | 25 | Pages | 17320-8 |
| PubMed ID | 8006041 | Mgi Jnum | J:18846 |
| Mgi Id | MGI:67068 | Doi | 10.1016/s0021-9258(17)32557-7 |
| Citation | Brandt R, et al. (1994) Identification and biological characterization of an epidermal growth factor-related protein: cripto-1. J Biol Chem 269(25):17320-8 |
| abstractText | The human and mouse cripto-1 (CR-1) genes can code for proteins related in structure to epidermal growth factor (EGF). A specific 36-kDa immunoreactive protein was detected by Western blot analysis in human cell lines that express CR-1 mRNA but not in cell lines that fail to express this transcript. Immunoprecipitation of GEO colon carcinoma or mouse embryonal carcinoma cells detected 27-29-kDa and 24-kDa proteins, respectively. Cell lysates and conditioned medium that were prepared from several CHO clones and were expressing either a recombinant human or mouse CR-1 cDNA contained immunospecific 27-29-kDa and 24-kDa proteins, respectively. Monensin or tunicamycin treatment resulted in a shift of the 27-29-kDa human CR-1 protein to 24 kDa and 20 kDa, respectively. The 20-kDa protein was also observed after digestion of the 27-29-kDa human CR-1 protein with N-glycosidase F. Using two CR-1 synthetic refolded peptides that correspond to the EGF-like domain of the human CR-1 sequence or conditioned medium obtained from human CR-1 expressing CHO cells, growth stimulatory activity could be detected on non-transformed human mammary epithelial cells and on two human breast cancer cell lines. EGF receptor-blocking antibody did not inhibit the growth stimulatory action of the CR-1 protein. Likewise, the CR-1 refolded peptides or conditioned medium from the human CR-1-expressing CHO cells failed to inhibit the binding of 125I-EGF in an EGF-radioreceptor assay. These data demonstrate that the CR-1 is a glycoprotein that can function as a growth factor through an EGF receptor-independent pathway. |
