The 6H1 orphan receptor, claimed to be the p2y5 receptor, does not mediate nucleotide-promoted second messenger responses.
The 6H1 orphan receptor, claimed to be the p2y5 receptor, does not mediate nucleotide-promoted second messenger responses.
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6H1孤儿受体，声称是p2y5受体，不介导核苷酸促进的第二信使反应。
DOI：
10.1006/bbrc.1997.6984
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发表时间：
1997
影响因子：
3.1
通讯作者：
Nicholas,RA
中科院分区：
文献类型：
--
作者：
Li,Q;Schachter,JB;Harden,TK;Nicholas,RA
一种孤儿G蛋白偶联受体，称为6 H1，与P2 Y受体具有约30%的序列同一性，仅基于与[35 S]dATPαS的放射性配体结合测定，已被认为是P2 Y受体（p2 y 5）[Webb et al.（1997）Biochem. Biophys.通信资源219：105-110]。我们实验室以前的工作表明，[35 S]-dATPαS不是P2 Y受体的一般配体，因此将p2 y 5受体纳入P2 Y受体家族是值得怀疑的。为了明确定义p2 γ 5受体是否是P2 γ受体，我们克隆了鸡p2 γ 5受体的火鸡同源物。序列分析表明，火鸡受体含有一个额外的32个氨基酸在其羧基末端相比，已公布的鸡序列。HA表位标记的火鸡p2 γ 5受体在1321 N1人星形细胞瘤细胞中稳定表达，并且通过基于完整细胞的ELISA显示表达HA标记的p2 γ 5受体的细胞用于确定第二信使水平的变化是否响应于一系列核苷酸而发生。ATP、ADP、UTP、UDP、dATPαS和A2 P4对表达p2 y 5受体的细胞中磷酸肌醇或环AMP浓度均无影响。在1321 N1细胞中表达的其他G蛋白偶联受体发生了强烈的肌醇磷酸和环AMP反应，这表明这些细胞含有产生这些第二信使反应所必需的所有信号成分。这些数据表明，6 H1/p2 y 5受体不是信号蛋白的P2 Y受体家族的成员。
An orphan G protein-coupled receptor, termed 6H1, with ∼30% sequence identity to P2Y receptors has been proposed to be a P2Y receptor (p2y5) based solely on a radioligand binding assay with [35S]dATPαS [Webb et al. (1997) Biochem. Biophys. Res. Commun. 219:105-110]. Previous work in our laboratory has shown that [35S]-dATPαS is not a general ligand for P2Y receptors, and thus inclusion of the p2y5 receptor in the family of P2Y receptors is questionable. To define unambiguously whether the p2y5 receptor is a P2Y receptor, we have cloned the turkey homologue of the chick p2y5 receptor. Sequence analysis indicated that the turkey receptor contains an additional 32 amino acids at its carboxy terminus compared to the published chick sequence. HA epitope-tagged turkey p2y5 receptors were stably expressed in 1321N1 human astrocytoma cells, and cells shown to express the HA-tagged p2y5 receptor by an intact cell-based ELISA were used to determine whether changes in second messenger levels occurred in response to a series of nucleotides. ATP, ADP, UTP, UDP, dATPαS, and A2P4had no effect on either inositol phosphate or cyclic AMP concentrations in cells expressing the p2y5 receptor. Robust inositol phosphate and cyclic AMP responses occurred to other G protein-coupled receptors expressed in 1321N1 cells, which indicate that these cells contain all of the necessary signaling components to generate these second messenger responses. These data indicate that the 6H1/p2y5 receptor is not a member of the P2Y receptor family of signaling proteins.