Selective activation of inhibitory G-protein alpha-subunits by partial agonists of the human 5-HT1A receptor.
Selective activation of inhibitory G-protein alpha-subunits by partial agonists of the human 5-HT1A receptor.
复制标题
人 5-HT1A 受体的部分激动剂选择性激活抑制性 G 蛋白 α 亚基。
DOI：
10.1021/bi00180a024
复制
发表时间：
1994
期刊：
影响因子：
2.9
通讯作者：
Raymond,JR
中科院分区：
文献类型：
--
作者：
Gettys,TW;Fields,TA;Raymond,JR
摘要：用5-羟色胺5-HTia受体转染的中国仓鼠卵巢（CHO）细胞的质膜与完全或部分受体激动剂和光反应性GTP类似物4-叠氮苯胺-[a-32P]-GTP （[32P]- aa -GTP）孵育，以表征所产生的受体- g蛋白相互作用。随后用抗gja -2或anti-GjŦ-3免疫球蛋白对膜进行增溶和免疫沉淀，发现完全和部分激动剂用[32P]-AA-GTP对各自的g蛋白产生浓度依赖性标记。5-HTiA受体的完全激动剂[5-羟色胺（5-HT）和8-羟基-2-（di-Ŧ-propylamino）四aline (8-OH-DPAT)]使G标记增加7-12倍；a-2和Gia-3，而部分激动剂（毛狼碱和ipsapione）通过相同的g蛋白产生较小的[32P]-AA-GTP掺入（2-5倍）。Gja-3 [5-HT， 48 ~ 1 nM]对[32P]-AA-GTP产生半最大结合的激动剂浓度；8-OH-DPAT, 28 - 1 nM；ipsapirone, 22 ~ 6 nM]；a-2 [5-HT, 124 ~ 38 nM；8-OH-DPAT, 40 - 1 nM, ipsapirone， 82 - 7 nM]与除rauwolscine外的所有激动剂相比都较低，其中ec50相似（G, a-2, 604 ą145 nM; Gja-3, 708 ą130 nM）。比较激动剂产生与Gja-2或Gja-3结合的[32P]-AA-GTP与腺苷基环化酶抑制作用的等级，发现Gja-2标记与腺苷基环化酶抑制作用的降低（5-HT> 8- o - dpat > rauwolsciine > ipsapirone）之间存在显著相关性。相比之下，与Gja-3标记相关的激动剂疗效等级顺序(8-OH-DPAT=
Revised Manuscript Received February 10, 1994Ū abstract: Plasma membranes from Chinese hamster ovary (CHO) cells transfected with the serotonin 5-HTia receptor have been incubated with full or partial receptor agonists and the photoreactive GTP analog, 4-azidoanilido-[a-32P]-GTP ([32P]-AA-GTP), to characterize the resulting receptor-G-protein interactions. Subsequent solubilization and immunoprecipitation of the membranes with anti-Gja-2 or anti-GjŦ-3 immunoglobulins revealed that full and partial agonists produce concentration-dependent labeling of the respective G-proteinswith [32P]-AA-GTP. Full agonists of the 5-HTiA receptor [serotonin 5-hydroxytryptamine (5-HT) and 8-hydroxy-2-(di-Ŧ-propylamino) tetraline (8-OH-DPAT)] produced a 7-12-fold increase in the labeling of G; a-2 and Gia-3, whereas partial agonists (rauwolscine and ipsapirone) produced a smaller incorporation (2-5-fold) of [32P]-AA-GTP by the same G-proteins. The concentration of agonist producinghalf-maximal binding of [32P]-AA-GTP by Gja-3 [5-HT, 48 ą 1 nM; 8-OH-DPAT, 28 ą 1 nM; ipsapirone, 22 ą 6 nM] compared to G; a-2 [5-HT, 124 ą 38 nM; 8-OH-DPAT, 40 ą 1 nM, ipsapirone, 82 ą 7 nM] was lower with all agonists except rauwolscine, where the EC5o’s were similar (G, a-2, 604 ą145 nM; Gja-3, 708 ą130 nM). Comparison of the rank order of agonist efficacy in producing [32P]-AA-GTP binding to Gja-2 or Gja-3 with the rank order of adenylylcyclase inhibition revealed a significant correlation between the decrements in Gja-2 labeling and adenylylcyclase inhibition (5-HT> 8-OH-DPAT> rauwolscine> ipsapirone). In contrast, the rank order of agonist efficacywith respect to Gja-3 labeling (8-OH-DPAT=