Cloning of a human epididymis-specific mRNA, HE6, encoding a novel member of the seven transmembrane-domain receptor superfamily
Cloning of a human epididymis-specific mRNA, HE6, encoding a novel member of the seven transmembrane-domain receptor superfamily
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DOI：
10.1089/dna.1997.16.379
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发表时间：
1997-04-01
影响因子：
3.1
通讯作者：
Kirchhoff, C
中科院分区：
文献类型：
--
作者：
Osterhoff, C;Ivell, R;Kirchhoff, C
通过差异筛选从人附睾cDNA文库中克隆了一个与Tm 7受体超家族具有同源性的新基因产物HE 6。cDNA克隆代表了丰富的约5-kb的mRNA，包括0.01%的cDNA文库。北方印迹分析表明，在各种人类组织的附睾特异性表达，原位转录本杂交定位的mRNA内衬附睾管上皮细胞。Southern印迹分析，采用编码部分氨基末端胞外结构域的片段作为探针，确定了人类基因组中的常染色体单拷贝基因。同源cDNA产物显示90%的序列同一性，观察到在所有哺乳动物物种的附睾。将通过常规cDNA文库构建获得的约3.7-kb cDNA片段与重叠5'cDNA末端快速扩增（RACE）片段相结合的克隆和测序策略产生了4.7 kb的人mRNA的总序列信息。该序列包含3.1 kb的长开放阅读框。相关序列的同源性搜索显示最高的相似性（25%的氨基酸同一性）与促胰液素/血管活性肠肽（VLP）超家族的G-蛋白偶联受体。然而，预测的细胞外氨基末端的延伸，比其他成员长得多，并表现出高度糖基化的粘蛋白样细胞表面分子的相似性。
A novel gene product, HE6, showing homology to the seven transmembrane-domain (Tm7) receptor superfamily, has been cloned by differential screening from a human epididymal cDNA library. The cDNA clone represented an abundant approximately 5-kb mRNA, comprising 0.01% of the cDNA library. Northern blot analysis including various human tissues revealed an epididymis-specific expression, In situ transcript hybridization localized the mRNA within the epithelial cells lining the epididymal duct. Southern blot analysis, employing a fragment encoding part of the amino-terminal extracellular domain as a probe, identified an autosomal single-copy gene in the human genome. Homologous cDNA products showing 90% sequence identity were observed in the epididymides of all mammalian species investigated. A cloning and sequencing strategy, combining approximately 3.7-kb cDNA fragments obtained by conventional cDNA library construction with overlapping 5' rapid amplification of cDNA ends (RACE) fragments, yielded total sequence information of 4.7 kb for the human mRNA. This sequence comprises a long open reading frame of 3.1 kb. A homology search for related sequences revealed highest similarity (25% amino acid identity) with the secretin/vasoactive intestinal peptide (VLP) superfamily of G-protein-coupled receptors. The predicted extracellular aminoterminal extension, however, was much longer than in the other members, and showed similarity to highly glycosylated mucin-like cell-surface molecules.