Identity of an estrogen membrane receptor coupled to a G protein in human breast cancer cells
Identity of an estrogen membrane receptor coupled to a G protein in human breast cancer cells
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DOI：
10.1210/en.2004-1064
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发表时间：
2005-02-01
期刊：
影响因子：
4.8
通讯作者：
Dong, J
中科院分区：
文献类型：
--
作者：
Thomas, P;Pang, Y;Dong, J
尽管在许多组织中已经描述了在细胞表面启动的非经典雌激素作用，但介导这些作用的膜雌激素受体（mERs）的身份仍不清楚。本研究表明，GPR30是一种与核雌激素受体无关的孤儿受体，具有mER的所有结合和信号特征。在表达GPR30但缺乏核雌激素受体的SKBR3乳腺癌细胞的质膜中检测到一种高亲和力（解离常数为2.7 nM）、容量有限、可置换的雌激素特异性单结合位点。在SKBR3细胞中，黄体酮诱导的GPR30表达升高和小干扰rna诱导的GPR30表达降低伴随着特异性雌二醇-17 β (E2)结合的平行变化。转染GPR30的人胚胎肾293细胞的质膜（未转染细胞的质膜）和表达GPR30的人胎盘组织也表现出高亲和力、特异性的雌激素结合，这是典型的中东呼吸综合征。E2处理转染的细胞膜导致直接与受体偶联的刺激G蛋白激活，表明GPR30是G蛋白偶联受体（GPCR），并且腺苷酸环化酶活性也增加。抗雌激素药物他莫昔芬和ICI 182780，以及环境雌激素ortho，对二氯二苯基二氯乙烯（o,p'-DDE）对受体具有高结合亲和力，并模拟E2的作用，这一发现对雌激素依赖性乳腺癌的发展和治疗具有重要意义。GPR30在结构上与最近发现的gpcr样膜黄体酮受体家族无关。第二种不同类型的gpcr样类固醇膜受体的鉴定表明，gpcr在非经典类固醇激素作用中具有广泛的作用。
Although nonclassical estrogen actions initiated at the cell surface have been described in many tissues, the identities of the membrane estrogen receptors (mERs) mediating these actions remain unclear. Here we show that GPR30, an orphan receptor unrelated to nuclear estrogen receptors, has all the binding and signaling characteristics of a mER. A high-affinity (dissociation constant 2.7 nM), limited capacity, displaceable, single binding site specific for estrogens was detected in plasma membranes of SKBR3 breast cancer cells that express GPR30 but lack nuclear estrogen receptors. Progesterone-induced increases and small interfering RNA-induced decreases in GPR30 expression in SKBR3 cells were accompanied by parallel changes in specific estradiol-17beta(E2) binding. Plasma membranes of human embryonic kidney 293 cells transfected with GPR30, but not those of untransfected cells, and human placental tissues that express GPR30 also displayed high-affinity, specific estrogen binding typical of mERs. E2 treatment of transfected cell membranes caused activation of a stimulatory G protein that is directly coupled to the receptor, indicating GPR30 is a G protein-coupled receptor (GPCR), and also increased adenylyl cyclase activity. The finding that the antiestrogens tamoxifen and ICI 182,780, and an environmental estrogen, ortho, para-dichlorodiphenyldichloroethylene (o,p'-DDE), have high binding affinities to the receptor and mimic the actions of E2 has important implications for both the development and treatment of estrogen-dependent breast cancer. GPR30 is structurally unrelated to the recently discovered family of GPCR-like membrane progestin receptors. The identification of a second distinct class of GPCR-like steroid membrane receptors suggests a widespread role for GPCRs in nonclassical steroid hormone actions.