Beyer Sophie, Kristensen Malene Maag, Jensen Kim Steen, Johansen Jens Vilstrup, Staller Peter
Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark.
J Biol Chem. 2008 Dec 26;283(52):36542-52. doi: 10.1074/jbc.M804578200. Epub 2008 Nov 4.
Posttranslational histone modifications serve to store epigenetic information and control both nucleosome assembly and recruitment of non-histone proteins. Histone methylation occurs on arginine and lysine residues and is involved in the regulation of gene transcription. A dynamic control of these modifications is exerted by histone methyltransferases and the recently discovered histone demethylases. Here we show that the hypoxia-inducible factor HIF-1alpha binds to specific recognition sites in the genes encoding the jumonji family histone demethylases JMJD1A and JMJD2B and induces their expression. Accordingly, hypoxic cells express elevated levels of JMJD1A and JMJD2B mRNA and protein. Furthermore, we find increased expression of JMJD1A and JMJD2B in renal cancer cells that have lost the von Hippel Lindau tumor suppressor protein VHL and therefore display a deregulated expression of hypoxia-inducible factor. Studies on ectopically expressed JMJD1A and JMJD2B indicate that both proteins retain their histone lysine demethylase activity in hypoxia and thereby might impact the hypoxic gene expression program.
翻译后组蛋白修饰用于存储表观遗传信息,并控制核小体组装和非组蛋白的募集。组蛋白甲基化发生在精氨酸和赖氨酸残基上,并参与基因转录的调控。这些修饰的动态控制由组蛋白甲基转移酶和最近发现的组蛋白去甲基化酶发挥作用。在此我们表明,缺氧诱导因子HIF-1α结合到编码jumonji家族组蛋白去甲基化酶JMJD1A和JMJD2B的基因中的特定识别位点,并诱导它们的表达。相应地,缺氧细胞中JMJD1A和JMJD2B的mRNA和蛋白质水平升高。此外,我们发现在失去了冯·希佩尔-林道肿瘤抑制蛋白VHL并因此显示缺氧诱导因子表达失调的肾癌细胞中,JMJD1A和JMJD2B的表达增加。对异位表达的JMJD1A和JMJD2B的研究表明,这两种蛋白在缺氧状态下均保留其组蛋白赖氨酸去甲基化酶活性,因此可能影响缺氧基因表达程序。