ATF4 is a mediator of the nutrient-sensing response pathway that activates the human asparagine synthetase gene
ATF4 is a mediator of the nutrient-sensing response pathway that activates the human asparagine synthetase gene
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DOI：
10.1074/jbc.m201959200
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发表时间：
2002-07-05
影响因子：
4.8
通讯作者：
Kilberg, MS
中科院分区：
文献类型：
--
作者：
Siu, F;Bain, PJ;Kilberg, MS
从天冬酰胺合成酶（A.S.）在氨基酸（氨基酸反应）或葡萄糖（内质网应激反应）剥夺的反应中，这两个独立的途径在A.S.内的同一组基因组顺式元件上会聚。启动子被称为营养感应反应元件（NSRE）1和2，这两者都是基因激活所必需的。NSRE-1序列用于通过电泳迁移率变动测定和特异性抗体的超变动来筛选ATF/CREB家族成员。结果表明，ATF 4与NSRE-1序列结合，并且当测试来自氨基酸剥夺或葡萄糖剥夺细胞的提取物时，ATF 4复合物的量增加。使用电泳迁移率变动分析实验和含有NSRE-1和NSRE-2的探针，NSRE-1序列的突变完全阻止了含有ATF 4的复合物的形成，而NSRE-2序列的突变则没有。ATF 4的过表达增加了A.S.启动子驱动的转录，而抑制性显性负ATF 4突变体阻断基础和饥饿增强的转录。总的来说，这些结果为ATF 4在A.S.的转录激活中的作用提供了体外和体内证据。基因对营养缺乏的反应。
Transcription from the asparagine synthetase (A.S.) gene is increased in response to either amino acid (amino acid response) or glucose (endoplasmic reticulum stress response) deprivation. These two independent pathways converge on the same set of genomic cis-elements within the A.S. promoter referred to as nutrient-sensing response elements (NSRE) 1 and 2, both of which are necessary for gene activation. The NSRE-1 sequence was used to screen ATF/CREB family members by electrophoresis mobility shift assays and supershift by specific antibodies. The results indicated that ATF4 binds to the NSRE-1 sequence and that the amount of the ATF4 complex was increased when extracts from amino acid-deprived or glucose-deprived cells were tested. Using electrophoresis mobility shift assay experiments and a probe that contained both NSRE-1 and NSRE-2, mutation of the NSRE-1 sequence completely prevented formation of the ATF4-containing complexes, whereas mutation of the NSRE-2 sequence did not. Overexpression of ATF4 increased A.S. promoter-driven transcription, whereas an inhibitory dominant negative ATF4 mutant blocked both basal and starvation-enhanced transcription. Collectively, the results provide both in vitro and in vivo evidence for a role of ATF4 in the transcriptional activation of the A.S. gene in response to nutrient deprivation.