组蛋白精氨酸去甲基化酶研究

Histone lysine methylation can be removed by demethylases, but the existence of arginine demethylases is highly controversial. In our preliminary study, we performed a high-content cell-based screening and identified 1G11 as a histone arginine demethylase specific for H3R2me2a. Overexpression of 1G11 reduced the level of H3R2me2a in cells. Purified recombinant 1G11 removed methylation from H3R2me2a in vitro. We also discovered that 1G11 was overexpressed in breast cancer, which was related to poor survival of cancer patients. Based on these results, we proposed to (1) identify the catalytic domain by domain mapping and mutagenesis, (2) study its role in breast cancer cell proliferation, (3) investigate the molecular mechanism for regulating breast cancer cell proliferation . This study will identify the first arginine demethylase, reveal the reversibility of arginine methylation, discover its role in breast cancer cell proliferation and the underlined molecular mechanism, which will help to achieve goals 1 and 2 of this research program.

组蛋白甲基化发生在赖氨酸和精氨酸上，通过调控基因表达和染色质结构参与个体发育和疾病发生发展。2004年以来，陆续有22个组蛋白赖氨酸去甲基化酶被发现，但组蛋白精氨酸去甲基化酶仍未找到。我们在前期工作中用高通量筛选方法发现了1个组蛋白精氨酸去甲基化酶1G11：细胞内高表达1G11可特异地降低H3R2me2a水平；表达纯化的蛋白质在体外可特异地去除该位点的甲基化；还发现1G11在乳腺癌组织中高表达，并与预后相关。因此，我们申请培育项目以继续研究（1）该酶的催化结构域及参与催化的氨基酸残基，（2）该酶在乳腺癌细胞生长中的作用，（3）该酶调控乳腺癌细胞生长的机制。该研究将鉴定第一个组蛋白精氨酸去甲基化酶，证明组蛋白精氨酸甲基化是可逆的，发现其调控乳腺癌细胞生长，并揭示其调控机制,为实现该重大研究计划总体目标一和二:发现和阐明生物大分子化学修饰的动态属性，揭示其生物学效应和调控机制做出贡献。

我们在前期工作中用高通量筛选方法发现了1个组蛋白精氨酸去甲基化酶1G11：细胞内高表达1G11可特异地降低H3R2me2a水平；表达纯化的蛋白质在体外可特异地去除该位点的甲基化；还发现1G11在乳腺癌组织中高表达，并与预后相关。通过该培育项目的研究，我们发现（1）酶活催化结构域在蛋白质的C端，（2）敲低该酶乳腺癌细胞生长受阻，（3）敲低该酶，rDNA的转录受阻。该研究发现了一个组蛋白精氨酸去甲基化酶，发现其调控乳腺癌细胞生长，并揭示其调控机制,为实现该重大研究计划总体目标一和二:发现和阐明生物大分子化学修饰的动态属性，揭示其生物学效应和调控机制做出贡献。