Isolation and characterization of a complementary DNA (galanin) clone from estrogen-induced pituitary tumor messenger RNA.
Isolation and characterization of a complementary DNA (galanin) clone from estrogen-induced pituitary tumor messenger RNA.
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从雌激素诱导的垂体肿瘤信使 RNA 中分离和表征互补 DNA（甘丙肽）克隆。
DOI：
10.1016/s0021-9258(18)45446-4
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Friesen
中科院分区：
文献类型：
--
作者：
Maria E. VrontakisS;M. Laura;Peden;M. L. Duckworth;Henry;Friesen
高水平雌激素的管理是一个行之有效的方法产生催乳素分泌垂体瘤的啮齿动物，但肿瘤诱导的机制尚不清楚。在本文中，我们描述了一个cDNA克隆（pEIC）已从雌激素诱导的垂体瘤cDNA文库中分离。对应于pEIC克隆的mRNA转录物的长度为0.9倍，在正常垂体中检测不到，但在雌激素刺激后早在3小时就表达。对两个700个碱基对重组克隆的核苷酸序列分析表明，它们编码一种124个氨基酸的蛋白质，与猪甘丙肽前体有70%相同。由pEIC cDNA克隆编码的29个氨基酸残基的序列与猪甘丙肽的同源性为88%，仅在C末端附近有三个氨基酸取代。这种广泛的同源性表明pEIC cDNA克隆编码大鼠甘丙肽或属于甘丙肽基因家族的蛋白质。这些结果提供了第一个证据的生理调节剂（雌激素）的甘丙肽基因的表达。他们还暗示甘丙肽是由泌乳素分泌肿瘤分泌的。由于脑室内注射甘丙肽可以刺激催乳素分泌，而甘丙肽抑制下丘脑多巴胺释放，因此可以想象甘丙肽可能在催乳素分泌肿瘤的诱导中起作用。
The administration of high levels of estrogen is a well established method for producing prolactin-secreting pituitary tumors in rodents but the mechanism of tumor induction is not clear. In this paper we describe a cDNA clone (pEIC) which has been isolated from an estrogen-induced pituitary tumor cDNA library. The mRNA transcript corresponding to the pEIC clone is 0.9 kilobase in length and is not detectable in normal pituitaries but is expressed as early as 3 h after estrogen stimulation. Nucleotide sequence analysis of two 700-base pair recombinant clones shows that they encode a 124-amino acid protein which is 70% identical to the porcine galanin precursor. The sequence of 29 amino acid residues coded for by the pEIC cDNA clone is 88% identical with porcine galanin with only three amino acid substitutions near the C terminus. This extensive homology suggests that the pEIC cDNA clone codes for rat galanin or a protein belonging to the galanin gene family. These results provide the first evidence of a physiological regulator (estrogen) of the expression of the galanin gene. They also imply that galanin is secreted by prolactin-secreting tumors. Because intracerebroventricular injection of galanin can stimulate prolactin secretion and galanin inhibits hypothalamic dopamine release, it is conceivable that galanin may play a role in the induction of prolactin-secreting tumors.