Alternative splicing of the muscarinic acetylcholine receptor GAR-3 in Caenorhabditis elegans
Alternative splicing of the muscarinic acetylcholine receptor GAR-3 in Caenorhabditis elegans
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DOI：
10.1016/s0006-291x(03)01508-0
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发表时间：
2003-09-05
影响因子：
3.1
通讯作者：
Cho, NJ
中科院分区：
文献类型：
--
作者：
Park, YS;Kim, S;Cho, NJ
在秀丽隐杆线虫（C. elegans）的三种G蛋白连接的乙酰胆碱（ACh）受体（GAR-1、GAR-2和GAR-3）中，GAR-3似乎与哺乳动物毒蕈碱型ACh受体（mAChRs）最相似。与哺乳动物mAChR基因不同，gar-3基因在编码区内含有内含子。在这项研究中，我们鉴定了GAR-3的一种选择性剪接异构体（GAR-3a），其与先前描述的GAR-3b的区别仅在于第三个胞内（0）环。与GAR-3b相比，GAR-3a在D环中具有26个氨基酸的插入。对阶段特异性RNA的逆转录-聚合酶链反应（RT-PCR）表明，这两种亚型在所有发育阶段都有表达，其中gar-3b比gar-3a表达更丰富。当这两种GAR-3亚型在中国仓鼠卵巢（CHO）细胞中表达时，它们表现出相似的配体结合特性。在卡巴胆碱治疗的反应中，两种亚型刺激磷脂酰肌醇水解具有相似的功效。结合我们早期观察到的GAR-1和GAR-2发生选择性剪接，本研究表明选择性剪接在促进C.优雅的。(C)2003年爱思唯尔公司All rights reserved.
Among the three G-protein-linked acetylcholine (ACh) receptors (GAR-1, -2, and -3) in Caenorhahditis elegans (C elegans), GAR-3 appears most similar to mammalian muscarinic ACh receptors (mAChRs). The gar-3 gene, unlike mammalian mAChR genes, contains introns within the coding region. in this study, we identified an alternatively spliced isoform of GAR-3 (GAR-3a), which differs only in the third intracellular (0) loop from the previously described one (GAR-3b). GAR-3a has a 26 amino acid insert in the D loop compared with GAR-3b. Reverse transcriptase-polymerase chain reaction (RT-PCR) on stage-specific RNAs indicated that both isoforms are expressed at all developmental stages examined, with gar-3b being more abundantly expressed than gar-3a. When these two GAR-3 isoforms were expressed in Chinese hamster ovary (CHO) cells, they exhibited similar ligand binding characteristics. In response to carbachol treatment, the two isoforms stimulated phosphatidylinositol hydrolysis with similar efficacy. Together with our earlier observations that GAR-1 and GAR-2 undergo alternative splicing, this study shows that alternative splicing plays an important role in promoting molecular diversity of G-protein-linked ACh receptors in C. elegans. (C) 2003 Elsevier Inc. All rights reserved.