Backbone resonance assignments for G protein α(i3) subunit in the GTP-bound state
Backbone resonance assignments for G protein α(i3) subunit in the GTP-bound state
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G 蛋白 α(i3) 亚基在 GTP 结合状态下的骨架共振分配
DOI：
10.1007/s12104-012-9361-6
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发表时间：
2012
影响因子：
0.9
通讯作者：
Shimada I.
中科院分区：
文献类型：
--
作者：
Mase Y;Yokogawa M;Osawa M;Shimada I.
鸟嘌呤核苷酸结合蛋白(G蛋白)通过将细胞表面的G蛋白偶联受体(GPCRs)的激活与细胞内的反应偶联，在信号通路中扮演着分子开关的角色。静息状态下，G蛋白形成一个异三聚体，由G蛋白α亚基(Gα)和G蛋白βγ亚基(Gβγ)组成。与GPCRs的配基结合促进了Gα上Gdp-Gtp的交换，导致Gα(Gα(Gtp))和Gβγ的解离。然后，G蛋白(Gα，GTP)和Gβγ与其下游的效应酶或离子通道结合，调节其活性，导致多种细胞反应。最后，G-α通过与G-βγ的重新结合，将结合的gtp水解为国内生产总值，并返回到静止状态。根据G蛋白α的氨基酸序列，将G蛋白分为四个主要家族：I/o、S、Q/11和12/13。每个家族将信号从不同的GPCRs转导到特定的效应器。在这里，我们建立了人GαI3的主干共振归属，它是I/O家族的成员，分子量为41K，与GTP类似物GTPγS形成络合物。
Guanine-nucleotide binding proteins (G proteins) act as molecular switches in signaling pathways, by coupling the activation of G protein-coupled receptors (GPCRs) at the cell surface to intracellular responses. In the resting state, G protein forms a heterotrimer, consisting of GDP-bound form of the G protein α subunit (Gα(GDP)) and G protein βγ subunit (Gβγ). Ligand binding to GPCRs promotes the GDP-GTP exchange on Gα, leading to the dissociation of the GTP-bound form of Gα (Gα(GTP)) and Gβγ. Then, Gα(GTP) and Gβγ bind to their downstream effector enzymes or ion channels and regulate their activities, leading to a variety of cellular responses. Finally, Gα hydrolyzes the bound GTP to GDP and returns to the resting state by re-associating with Gβγ. G proteins are classified with four major families based on the amino acid sequences of Gα: i/o, s, q/11, and 12/13. Each family transduces the signaling from different GPCRs to the specific effectors. Here, we established the backbone resonance assignments of human Gαi3, a member of the i/o family, with a molecular weight of 41 K in complex with a GTP analogue, GTPγS.