Regulation of G protein levels

Expression of the Human β2‐Adrenoceptor in NCB20 Cells Results in Agonist Activation of Adenylyl Cyclase and Agonist‐Mediated Selective Down‐Regulation of Gsα

“…Although, as noted above, lP prostanoid receptor-mediated down-regulation of G sa has been noted in NG108-15 cells (Kelly et al ., 1990 ;McKenzie and Milligan, 1990 ;Ache et al ., 1992), no down-regulation of this polypeptide was reported following equivalent treatment of the related cell line NCB20 with iloprost (Kelly et al ., 1990) . As it had been argued that these two cell lines express very similar levels of the IP prostanoid receptor (Keen and Krane, 1991), these observations might be construed as indicating a resistance of G sa in NCB20 cells to agonist-induced downregulation . To address this point, in this study NCB20 cells have been stably transfected with a cDNA encoding the human /32-adrenoceptor, and subsequently the ability of a,8-adrenoceptor agonist to regulate adenylyl cyclase and cellular G protein levels has been assessed in two individual clones .…”