Identification and characterization of two distinct GnRH receptor subtypes in a teleost, the medaka Oryzias latipes.
Identification and characterization of two distinct GnRH receptor subtypes in a teleost, the medaka Oryzias latipes.
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DOI：
10.1210/endo.142.11.8475
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发表时间：
2001-11
期刊：
影响因子：
4.8
通讯作者：
K. Okubo;S. Nagata;Rinkei Ko;H. Kataoka;Y. Yoshiura;H. Mitani;M. Kondo;K. Naruse;A. Shima;K. Aida
中科院分区：
文献类型：
--
作者：
K. Okubo;S. Nagata;Rinkei Ko;H. Kataoka;Y. Yoshiura;H. Mitani;M. Kondo;K. Naruse;A. Shima;K. Aida
我们报告的识别和两个不同的GnRH受体（GnRH-R）亚型，指定GnRH-R1和GnRH-R2，在一个模型硬骨鱼，青鳉Oryzias latipes。青鳉的这些七个跨膜受体含有细胞质C末端尾，这在迄今为止克隆的所有其他非哺乳动物GnRH-R中均已发现。GnRH-R1基因由三个外显子组成，由两个内含子分隔，而GnRH-R2基因有一个额外的内含子，因此由四个外显子和三个内含子组成。GnRH-R1和GnRH-R2基因在青鳉基因组中均为单拷贝基因，分别定位于连锁群3和16。使用转染GnRH-R1和GnRH-R2的COS-7细胞的肌醇磷酸测定表明，它们具有显著不同的配体敏感性，尽管两种受体对鸡II型GnRH表现出最高的偏好。系统发育分析表明，脊椎动物GnRH-Rs存在三个旁系同源谱系，并表明GnRH-R1和GnRH-R2都不是缺少胞质尾的哺乳动物GnRH-Rs的青鳉直系同源物。这一点，以及青鳉型GnRH对GnRH-R1和GnRH-R2的亲和力较低的观察结果，表明青鳉中可能存在第三种GnRH-R。
We report the identification and characterization of two distinct GnRH receptor (GnRH-R) subtypes, designated GnRH-R1 and GnRH-R2, in a model teleost, the medaka Oryzias latipes. These seven-transmembrane receptors of the medaka contain a cytoplasmic C-terminal tail, which has been found in all other nonmammalian GnRH-Rs cloned to date. The GnRH-R1 gene is composed of three exons separated by two introns, whereas the GnRH-R2 gene has an additional intron and therefore consists of four exons and three introns. The GnRH-R1 and GnRH-R2 genes, both of which exist as single-copy genes in the medaka genome, were mapped to linkage groups 3 and 16, respectively. Inositol phosphate assays using COS-7 cells transfected with GnRH-R1 and GnRH-R2 demonstrated that they had remarkably different ligand sensitivities, although both receptors showed highest preference for chicken-II-type GnRH. Phylogenetic analysis showed the presence of three paralogous lineages for vertebrate GnRH-Rs and indicated that neither GnRH-R1 nor GnRH-R2 is the medaka ortholog to mammalian GnRH-Rs that lack a cytoplasmic tail. This, together with an observation that medaka-type GnRH had low affinity for GnRH-R1 and GnRH-R2, suggests that a third GnRH-R may exist in the medaka.