Identification of a cis-acting element and a novel trans-acting factor of the glutamine synthetase gene in liver cells
Identification of a cis-acting element and a novel trans-acting factor of the glutamine synthetase gene in liver cells
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DOI：
10.1006/bbrc.2001.4967
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发表时间：
2001-06-08
影响因子：
3.1
通讯作者：
Gebhardt, R
中科院分区：
文献类型：
--
作者：
Gaunitz, F;Weber, S;Gebhardt, R
在哺乳动物肝脏中，谷氨酰胺合成酶（GS）的表达仅限于一小部分肝细胞。在表达GS酶的细胞中，高达细胞总蛋白的3.5%是GS。为了鉴定促进这种异常高水平表达的增强子元件，我们将重点放在了GS启动子上游约2.5 kbp的区域。凝胶迁移位移分析显示，在该区域的最远端有一种未知蛋白的结合，报告基因分析表明，在-2503位置下游大约60 bp的位置是蛋白质结合和增强子充分发挥作用所必需的。在紫外交联分析中，在大鼠肝细胞中鉴定出与该序列结合的38kda核蛋白。这种核蛋白被认为是GS基因的上游结合因子（UFGS），似乎在肝脏中GS的高水平表达中起重要作用。(C) 2001学术出版社。
In the mammalian liver the expression of the enzyme glutamine synthetase (GS) is restricted to a small population of hepatocytes. In cells expressing the enzyme up to 3.5% of total cellular protein is GS, In order to identify enhancer elements contributing to this extraordinarily high level of expression we focused on a region roughly 2.5 kbp upstream of the GS promoter. Gel mobility shift assays revealed binding of an unknown protein within the most distal part of this region and reportergene assays demonstrated that roughly 60 bp downstream from position -2503 are indispensable for protein binding and the full effect of the enhancer. In UV cross-link analysis a 38 kDa nuclear protein that binds to the sequence was identified in rat hepatocytes. This nuclear protein, designated as upstream binding factor of the GS gene (UFGS) seems to play an important role in high-level expression of GS in liver. (C) 2001 Academic Press.