Identification and analysis of factors that regulate cell surface expression of G-protein coupled receptor

G蛋白偶联受体细胞表面表达调节因子的鉴定与分析

• 批准号: 11680770
• 负责人: UEZONO Yasuhito
• 金额: $ 2.24万
• 依托单位: Department of Pharmacology, Nagasaki University School of Medicine (2000)宮崎医科大学 (1999)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680770/
• 关键词: GABA-B receptors; G-protein coupled receptors; heteromultimerization; inwardly rectifying K+ channels; Xenopus oocytes; heterologous expression; adrenomedullin; calcitonin gene-related peptide; GABA-B受容体; heterodimerization; Xenopus oocyte; CFT

γ-Amino butyric acids (GABA) is known to act as an inhibitory neurotransmitter on the central and peripheral nervous system. Receptors for GABA are divided into two types : one belongs to ionotropic receptors (GABA_A and GABA_C) and another belongs to metabotoropic G-protein coupled receptors (GABA_B). GABA_B receptor has been cloned in 1997 as a GABA_<B1> receptor and since then, a lot of works have been focused on the heterologous functional expression of the cloned GABA_B receptors. However, none of the expression study has succeeded. Accodingly the failure of the expression study suggested us the existence of some additional protein (s) for the functional expression of GABA_B receptors. We have previously reported that functional GABA_B receptors are actually expressed in Xenopus oocytes expressing the rat brain poly(A)^+ RNA which abundantly express the GABA_B receptor (Uezono et al., Biochem. Biophys. Res. Commun. 241 : 476- (1997) ; Uezono et al., NeuroReport 9 : 583- (1998)). W … More e therefore determined to clone the 'GABA_B receptor expressing factor (s)' with the oocytes expressing both the rat poly(A)^+ RNA and cloned GABA_<B1> receptor.In the course of such experiments, others have demonstrated in late 1998 that heteromultimerization of GABA_<B1> and newly cloned GABA_<B2> receptors are required for functional expression of GABA_B receptors.So we have changed our mind to investigate the mechanism of how GABA_B receptors are required heteromultimerization to be functional, with the cloned GABA_<B2> and GABA_<B2> receptors. In the mean time, another type of metabotoropic receptor namely adrenomedullin receptor is found to form complex with calcitonin receptor-like receptor (CRLR) and small proteins called 'receptor-activity-modifying proteins (RAMPs)' to be functional. We then took advantage of adrenomedullin receptors (CRLR and RAMPs) and compared the mechanism of adrenomedullin receptor formation with that of GABA_B receptor formation.We are still in progress of our study and hope to continue to clarify the mechanism how GABA_B receptors are formed and why GABA_B receptors are required to be heteromultimer for their functional expression Less

γ-氨基丁酸（GABA）被认为是中枢和周围神经系统的一种抑制性神经递质。GABA受体分为两种类型，一种属于离子型受体（GABA_A和GABA_C），另一种属于代谢性g蛋白偶联受体（GABA_B）。GABA_B受体于1997年被克隆为GABA_<B1>受体，此后人们对克隆的GABA_B受体的异源功能表达进行了大量的研究。然而，没有一项表达研究成功。因此，表达研究的失败提示存在GABA_B受体功能表达的额外蛋白。我们之前报道过，功能GABA_B受体实际上在爪蟾卵母细胞中表达，这些卵母细胞表达大量表达GABA_B受体的大鼠脑poly(A)^+ RNA （Uezono et al., Biochem）。Biophys。共同决议。241:476- (1997)；Uezono等人，NeuroReport 9: 583-(1998))。因此，我们决定用同时表达大鼠poly(A)^+ RNA和克隆GABA_<B1>受体的卵母细胞克隆“GABA_B受体表达因子(s)”。在这类实验的过程中，其他人在1998年底证明GABA_<B1>和新克隆的GABA_<B2>受体的异多聚化是GABA_B受体功能表达所必需的。因此，我们改变了思路，利用克隆的GABA_<B2>和GABA_<B2>受体来研究GABA_B受体如何被异源多聚化才能发挥功能的机制。与此同时，另一种代谢受体，即肾上腺髓质素受体，被发现与降钙素受体样受体（CRLR）和称为“受体活性修饰蛋白（RAMPs）”的小蛋白质形成复合物，具有功能。然后我们利用肾上腺髓质素受体（CRLR和RAMPs），比较了肾上腺髓质素受体和GABA_B受体的形成机制。我们的研究仍在进行中，希望能继续阐明GABA_B受体的形成机制，以及GABA_B受体为何需要异聚体才能实现其功能表达

项目成果

Y.Uezono: "Analysis of signal transduction pathways caused by GABAb receptor subtypes-heterologous expression with Xenopus oocytes."Japanese Journal of Pharmacology. 82(Suppl.1). 137 (2000)

Y.Uezono：“GABAb 受体亚型引起的信号转导途径分析 - 非洲爪蟾卵母细胞异源表达”。《日本药理学杂志》。

Y.Nagase: "Propofol inhibits muscarinic acetylcholine receptor-mediated signal transduction in Xenopus oocytes expressing the rat M1 receptor."Japanese Journal of Pharmacology. 79. 319-325 (1999)

Y.Nagase：“异丙酚抑制表达大鼠 M1 受体的非洲爪蟾卵母细胞中毒蕈碱乙酰胆碱受体介导的信号转导。”《日本药理学杂志》。

A.Osajima: "Adrenomedullin inhibits transmural pressure-induced mesangial cell proliferation through activation of protein kinase A."Nephron. 83. 352-357 (1999)

A.Osajima：“肾上腺髓质素通过激活蛋白激酶 A 来抑制跨壁压力诱导的系膜细胞增殖。”肾单位。

C.Mullner: "Heterologous of facilitation of G protein-activated K+ channels by β-adrenergic stimulation via cAMP-dependent protein kinase."Journal of General Physiology. 115. 547-558 (2000)

C.Mullner：“通过 cAMP 依赖性蛋白激酶刺激 β-肾上腺素促进 G 蛋白激活 K+ 通道的异源性。”普通生理学杂志 115. 547-558 (2000)。

H.Kobayashi: "Adrenomedullin receptors in rat cerebral microvessels."Molecular Brain Research. 81. 1-6 (2000)

H.Kobayashi：“大鼠脑微血管中的肾上腺髓质素受体。”分子脑研究。