Oligomerization of neuropeptide Y (NPY) Y2 receptors in CHO cells depends on functional pertussis toxin-sensitive G-proteins |
| |
Authors: | Parker S L Parker M S Sallee F R Balasubramaniam A |
| |
Institution: | Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163, USA. slparker@utmem.edu |
| |
Abstract: | Human neuropeptide Y Y2 receptors expressed in CHO cells are largely oligomeric, and upon solubilization are recovered by density gradient centrifugation as approximately 180 kDa complexes of receptor dimers and G-protein heterotrimers. A large fraction of the receptors is inactivated in the presence of pertussis toxin, in parallel with inactivation of Gi alpha subunits (with half-periods of about 4 h for both). This is accompanied by a very long-lasting loss of receptor dimers and of masked surface Y2 sites (an apparent receptor reserve pre-coupled mainly to Gi alpha subunit-containing G-proteins). However, surface Y2 receptors accessible to large peptide agonists are much less sensitive to the toxin. All surface Y2 receptors are rapidly blocked by Y2 antagonist BIIE0246, with a significant loss of the dimers, but with little change of basal Gi activity. However, both dimers and Y2 receptor compartmentalization are restored within 24 h after removal of the antagonist. In CHO cells, the maintenance and organization of Y2 receptors appear to critically depend on functional pertussis toxin-sensitive G-proteins. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|