Abstract
The transferrin receptor undergoes extensive co- and post-translational modifications during its biosynthesis. In this study, the functional and structural properties of the transferrin receptor from tunicamycin-treated A431 cells were examined. Incubation of A431 cells with this inhibitor of asparagine-linked glycosylation results in a shift of the apparent molecular weight of the transferrin receptor from 94,000 to 79,000. The electrophoretic mobility of the receptor from treated cells is that of a monomer under nonreducing conditions, whereas the transferrin receptor in untreated cells has the mobility of a dimer under identical conditions. This result indicates a lack of disulfide bond formation between subunits of the receptor from tunicamycin-treated cells. In solution no dimers can be detected with cross-linking studies. This unglycosylated receptor does not appear to stably bind transferrin as demonstrated by a lack of isolation of this form of the receptor with transferrin-linked Sepharose. It is not transported to the surface of A431 cells.
Original language | English (US) |
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Pages (from-to) | 7297-7301 |
Number of pages | 5 |
Journal | Journal of Biological Chemistry |
Volume | 263 |
Issue number | 15 |
State | Published - 1988 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology