Expression of functional pituitary somatostatin receptors in Xenopus oocytes.
Expression of functional pituitary somatostatin receptors in Xenopus oocytes.
复制标题
非洲爪蟾卵母细胞中功能性垂体生长抑素受体的表达。
DOI：
10.1073/pnas.87.1.133
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发表时间：
1990
影响因子：
11.1
通讯作者：
Reisine,T
中科院分区：
文献类型：
--
作者：
White,MM;Reisine,T
注射从垂体前叶肿瘤细胞系AtT 20分离的RNA后，非洲爪蟾卵母细胞中表达功能性生长抑素（SRIF，生长激素释放抑制因子）受体。通过测量SRIF抑制单个卵母细胞中β 2-肾上腺素能激动剂刺激的cAMP形成的能力来检测SRIF受体。β 2肾上腺素能受体（β 2AR）通过共注射RNA在卵母细胞中表达，所述RNA通过体外转录β 2AR cDNA克隆与垂体细胞RNA制备。未注射的卵母细胞不表达可检测水平的β 2AR或SRIF受体。另一方面，在AtT 20和β 2AR RNA共注射的卵母细胞中，异丙肾上腺素处理导致cAMP水平增加2- 3倍，而SRIF共处理使这种积累减少50- 60%。SRIF前体生长抑素-28和环己肽激动剂MK 678也抑制cAMP的形成，而生长抑素-28的生物学上无活性的N-末端14-氨基酸片段无效。检测单个卵母细胞中cAMP水平变化的能力可以为SRIF受体cDNA和功能上与腺苷酸环化酶的刺激或抑制偶联的其他受体的表达克隆提供简单的程序。
Functional somatostatin (SRIF, somatotropin release-inhibiting factor) receptors were expressed in Xenopus oocytes after injection of RNA isolated from the anterior pituitary tumor cell line AtT20. SRIF receptors were detected by measuring the ability of SRIF to inhibit cAMP formation stimulated by beta 2-adrenergic agonists in individual oocytes. beta 2-Adrenergic receptors (beta 2ARs) were expressed in oocytes by coinjecting RNA prepared by in vitro transcription of a beta 2AR cDNA clone with the pituitary cell RNA. Uninjected oocytes do not express detectable levels of either beta 2ARs or SRIF receptors. In oocytes coinjected with AtT20 and beta 2AR RNA, on the other hand, isoproterenol treatment led to a 2- to 3-fold increase in cAMP levels, whereas cotreatment with SRIF reduced this accumulation by 50-60%. The SRIF precursor somatostatin-28 and the cyclohexapeptide agonist MK678 also inhibited cAMP formation, whereas the biologically inactive N-terminal 14-amino acid fragment of somatostatin-28 was ineffective. The ability to detect changes in cAMP levels in individual oocytes may provide a simple procedure for the expression cloning of SRIF receptor cDNAs and other receptors functionally coupled to stimulation or inhibition of adenylate cyclase.