Xenopus liver ferritin H subunit: cDNA sequence and mRNA production in the liver following estrogen treatment.
Xenopus liver ferritin H subunit: cDNA sequence and mRNA production in the liver following estrogen treatment.
复制标题
非洲爪蟾肝铁蛋白 H 亚基：雌激素处理后肝脏中的 cDNA 序列和 mRNA 产生。
DOI：
10.1021/bi00221a033
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发表时间：
1991
期刊：
影响因子：
2.9
通讯作者：
Bhattacharya,A
中科院分区：
文献类型：
--
作者：
Holland,LJ;Wall,AA;Bhattacharya,A
美国爱荷华大学医学院生理与生物物理系，美国爱荷华州爱荷华市52242摘要：体外翻译经雌激素处理的爪蟾肝脏mRNA可产生两个丰富的20 kDa范围内的多肽。这些翻译产物之一的DNA克隆被分离出来，并被证明是铁蛋白重亚基mRNA的互补。预测的非洲爪蟾氨基酸序列与牛蛙的铁蛋白重链有86%的一致性，与类似的哺乳动物和鸟类蛋白质有70%的一致性。通过杂交选择确认克隆的身份，并在体外翻译成19.5-20 kDa的翻译产物。这个几乎全长的cDNA克隆被称为XlferHl，包含868个核苷酸和22个聚(A)尾部的腺苷，包括134个5'-非翻译区，一个528个碱基的176个氨基酸编码区，和一个206个核苷酸的3'-非翻译区。该克隆缺少mRNA 5'端22个核苷酸。随着时间的推移，测定了雌激素处理青蛙肝脏中铁蛋白mRNA的水平。在给予雌二醇-17/3后14天，该mRNA相对于总RNA的量下降了约3倍。然而，这种激素也使肝脏中的总RNA升高了约24倍。因此，肝脏总铁蛋白mRNA含量增加到初始量的8倍左右。这种基因表达模式与血清视黄醇结合蛋白的表达模式非常相似。雌激素对这两种mrna的诱导似乎与肝脏RNA合成的总体刺激相似。相比之下，白蛋白mRNA相对于总RNA被抑制了约25倍，因此在雌激素治疗的这些条件下，肝脏中白蛋白mRNA的总量保持相当恒定。对非洲爪蟾（Xenopus laevis）进行激素治疗会导致肝脏中基因表达的多种变化。最显著的反应是诱导编码卵黄原蛋白的信使RNA (Ryffel et al., 1977; Baker & Shapiro, 1977)，卵黄原蛋白是蛋黄蛋白的前体，从肝脏中分泌出来，并被雌性发育中的卵母细胞吸收（Clemens, 1974）。另一种功能未知的分泌蛋白Ep45的诱导模式与卵黄原蛋白非常相似（Holland & Wangh, 1987）。除了这些对特定基因的影响外，主要由核糖体RNA组成的总RNA的合成也受到了极大的刺激(Holland &
Department of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa 52242 Received September 5, 1990; Revised Manuscript Received November 2, 1990 abstract: In vitro translation of liver mRNA from estrogen-treated Xenopus frogs yields two abundant polypeptides in the range of 20 kDa. DNA clones for one of these translation products were isolated and shown to be complementary to mRNA for the heavy subunit of ferritin. The predicted Xenopus amino acid sequence shares about 86% identity with the ferritin heavy chain from bullfrogs and about 70% identity with the comparable mammalian and avian proteins. Clone identity was confirmed by hybridization selection followed by in vitro translation into translation products of 19.5-20 kDa. The nearlyfull-length cDNA clone, termed XlferHl, comprises 868 nucleotides plus 22 adenosines of the poly (A) tail, including 134 nucleotides of the 5'-untranslated region, a 528-base coding region for 176 amino acids, and a 206-nucleotide 3'-untranslated region. The clone lacks 22 nucleotides from the 5'end of the mRNA. The level of ferritin mRNA in the liver of estrogen-treated frogs was determined over time. The amount of this mRNA relative to total RNA decreased about3-fold 14 days after estradiol-17/3 was administered. However, the hormone also elevated total RNA in the liver about 24-fold. Hence, the total ferritin mRNA content of the liver increased to about 8 times its initial amount. This pattern of gene expression was very similar to that for serum retinol binding protein. The estrogen induction of these two mRNAs appeared to parallel the overall stimulation of hepatic RNA synthesis. In contrast, albumin mRNA was suppressed about 25-fold relative to total RNA such that a fairly constant total amount of albumin mRNA was maintained in the liver under these conditions of estrogen treatment.ICstrogen treatment of Xenopus laevis frogs causes multiple changes in gene expression in the liver. The most dramatic response is induction of themessenger RNA coding for vitellogenin (Ryffel et al., 1977; Baker & Shapiro, 1977), the precursor of egg yolk proteins, which is screted from the liver and taken up by developing oocytes in the female (Clemens, 1974). Another secreted protein, of unknown function, called Ep45 has a pattern of induction very similar to vitellogenin (Holland & Wangh, 1987). In addition to these effects on specific genes, synthesis of total RNA, which consists mainly of ribosomal RNA, is dramatically stimulated (Holland &