Chromatin remodeling activity of C-module-binding factor from Dictyostelium discoideum

动态组蛋白甲基化在转录调控、基因组稳定性和表观遗传中起着重要作用。在过去的十年中，在大量的出版物中已经确定，组蛋白H3和H4的氨基末端尾部中的不同赖氨酸和精氨酸残基的甲基化可以被组蛋白脱甲基酶逆转。这些酶中的大多数具有Jumonji（JmjC）结构域，其能够通过氧化去甲基化反应从组蛋白中去除甲基。网柄类是古老的单细胞生物，具有兼性多细胞阶段，其中细胞分化成几种细胞类型并合作建立子实体。在模型dictyostelid，Dictyosteliddiscoideum的基因表达，已被研究得非常详细，但我们的知识，在这种生物体中的基因调控的染色质重塑的贡献是稀缺的。D. discoideum编码13种JmjC蛋白，这些蛋白被认为是推定的组蛋白去甲基化酶。我们将表达这些JmjC蛋白在一个网柄藻为基础的表达系统，并研究其催化活性的基础上，在体外脱甲基化试验，使用合成的组蛋白肽。此外，我们将扩大我们以前的工作JmjC家族转录调节因子CbfA和调查中，多蛋白复合物CbfA的行为，无论是激活或抑制其靶基因在D。discoideum基因组

Dynamic histone methylation plays an important role in the regulation of transcription, genome stability and epigenetic inheritance. It has been established in a multitude of publications over the last ten years that methylations of distinct lysine and arginine residues in the amino-terminal tails of histones H3 and H4 can be reversed by histone demethylases. Most of these enzymes possess Jumonji (JmjC) domains that are capable of removing methyl groups from histones by an oxidative demethylation reaction. Dictyostelids are ancient unicellular organisms that have a facultative multicellular phase in which the cells differentiate into several cell types and collaborate to build up fruiting bodies. Gene expression in the model dictyostelid, Dictyostelium discoideum, has been studied in much detail, but our knowledge on the contribution of chromatin remodeling to gene regulation in this organism is scarce. The genome of D. discoideum encodes 13 JmjC proteins that come into consideration as putative histone demethylases. We will express these JmjC proteins in a Dictyostelium-based expression system and investigate their catalytic activities based on in vitro demethylation assays using synthetic histone peptides. In addition, we will expand our previous work on the JmjC family transcription regulator CbfA and investigate in which multiprotein complexes CbfA acts to either activate or suppress the expression of its target genes in the D. discoideum genome.