Oligomerization of neuropeptide Y (NPY) Y2 receptors in CHO cells depends on functional pertussis toxin-sensitive G-proteins.
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.
Parker
S L
SL
Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163, USA. slparker@utmem.edu
Parker
M S
MS
Sallee
F R
FR
Balasubramaniam
A
A
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D019281:Dimerization; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism*; D006801:Humans; D037342:Pertussis Toxin / Q000494:pharmacology*; D021122:Protein Subunits; D017476:Receptors, Neuropeptide Y / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012995:Solubility
D001552:Benzazepines; D021122:Protein Subunits; D017476:Receptors, Neuropeptide Y; C095889:neuropeptide Y2 receptor; D001120:Arginine; D037342:Pertussis Toxin; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; C403256:BIIE 0246