Abstract
125I-glucagon was directly cross-linked to its receptor in isolated adipocyte plasma membranes using a UV irradiation procedure. This investigation resulted in identification of an adipocyte glucagon receptor complex of 62 kDa, present both in white and brown adipose tissues. The specificity of labeling was shown by interference of unlabeled hormone with incorporation of radioactive glucagon into 62 kDa species. Treatment of adipose plasma membranes with N-glycanase resulted in appearance of intermediate species, indicating that the glucagon receptor is modified with several N-linked oligosaccharide chains similarly to the hepatic glucagon receptor. Peptide mapping of the affinity labeled adipose membranes with Staphylococcus aureus V8 protease generated three distinct receptor fragments identical to that of the hepatic receptor. Overall, the biochemical characterization of the rat adipocyte glucagon receptor indicates that it closely resembles the hepatic glucagon receptor.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 257-261 |
| Number of pages | 5 |
| Journal | Molecular and Cellular Endocrinology |
| Volume | 101 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - May 1994 |
Bibliographical note
Funding Information:This work was supportedi n part by funds from the American Diabetes Association, Minnesota Chapter grant,t he American Cancer Societyg rantBC-688, and Universityo f Minnesotai nstitutionalA CS grantI N-13- 29-2( to V.I.). We thank Dr. Norman Kagan for critical readingo f this manuscript.
Keywords
- Adipocyte
- Affinity labeling
- Brown fat
- Glucagon
- Liver
- Receptor