Arrest-defective-1 protein, an acetyltransferase, does not alter stability of hypoxia-inducible factor (HIF)-1α and is not induced by hypoxia or HIF
Arrest-defective-1 protein, an acetyltransferase, does not alter stability of hypoxia-inducible factor (HIF)-1α and is not induced by hypoxia or HIF
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DOI：
10.1074/jbc.m504482200
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发表时间：
2005-09-02
影响因子：
4.8
通讯作者：
Brahimi-Horn, MC
中科院分区：
文献类型：
--
作者：
Bilton, R;Mazure, N;Brahimi-Horn, MC
缺氧诱导因子（HIF）是哺乳动物细胞缺氧反应转录途径中的关键因子。HIF α亚基的翻译后修饰决定其半衰期和活性。在多个报道的修饰中，已报道通过称为抑制缺陷蛋白1（ARD 1）的乙酰转移酶的乙酰化降低HIF-1 α稳定性，从而影响缺氧基因表达。相反，我们报道ARD 1的过表达和沉默对HIF-1 α或-2 α的稳定性没有影响，并且ARD 1沉默的细胞维持HIF-1 α的低氧核定位。此外，我们发现，ARD 1的mRNA和蛋白水平不受缺氧在几个人类肿瘤细胞系，包括宫颈腺癌HeLa细胞，纤维肉瘤HT 1080细胞，腺病毒转化的人肾HEK 293细胞，和人乳腺癌MCF-7细胞。使用两种模型系统（（a）野生型和HIF-1 α-无效的小鼠胚胎成纤维细胞和（B）通过RNA干扰沉默HIF-1 α或-2 α的HeLa细胞），我们证明了ARD 1蛋白的表达水平与HIF-1 α和-2 α无关。我们还证明，ARD 1是一种稳定的，主要是在广泛的组织，肿瘤细胞系和内皮细胞中表达的胞质蛋白。总之，我们的研究结果表明，ARD 1对HIF信号通路的影响有限（如果有的话）。
The hypoxia-inducible factor (HIF) is a key player in a transcriptional pathway that controls the hypoxic response of mammalian cells. Post-translational modification of the alpha subunit of HIF determines its half-life and activity. Among the multiple reported modifications, acetylation, by an acetyltransferase termed arrest-defective-1 protein (ARD1), has been reported to decrease HIF-1 alpha stability and therefore impact on hypoxic gene expression. In contrast, we report that both overexpression and silencing of ARD1 had no impact on the stability of HIF-1 alpha or -2 alpha and that cells silenced for ARD1 maintained hypoxic nuclear localization of HIF-1 alpha. In addition, we show that the ARD1 mRNA and protein levels are not regulated by hypoxia in several human tumor cell lines, including cervical adenocarcinoma HeLa cells, fibrosarcoma HT1080 cells, adenovirus-transformed human kidney HEK293 cells, and human breast cancer MCF-7 cells. Using two model systems ((a) wild-type and HIF-1 alpha-null mouse embryo fibroblasts and (b) HeLa cells silenced for HIF-1 alpha or -2 alpha by RNA interference), we demonstrate that the level of expression of the ARD1 protein is independent of HIF-1 alpha and -2 alpha. We also demonstrate that ARD1 is a stable, predominantly cytoplasmic protein expressed in a broad range of tissues, tumor cell lines, and endothelial cells. Taken together, our findings demonstrate that ARD1 has limited, if any, impact on the HIF signaling pathway.