A novel strategy to identify proteins that interpret histone methylation patterns deposited by Set1 and Set2

不依赖于DNA序列的基因表达调控被称为表观遗传控制;它影响染色质的结构和可接近性，特别是通过组蛋白修饰（例如，乙酰化、甲基化）。不适当的表观遗传调控在肿瘤发生中起着关键作用。例如，人类白血病原癌基因MIL和NSD 1在不同形式的白血病中发生突变，但它们如何导致肿瘤发生尚不清楚。MLL和NSD 1都编码组蛋白甲基转移酶，它们的酵母直向同源物Set 1和Set 2分别在赖氨酸残基4和36处甲基化组蛋白H3。最近的数据表明，Set 1和Set 2的功能，防止沉默的染色质的扩散。本项目的目的是获得新的见解Set 1和Set 2拮抗基因沉默的机制。为此，我将确定Set 1和Set 2的下游效应子，并研究它们在抗沉默中的作用。特别是，我将采用一种新的全基因组方法，使用DamiD技术来识别以依赖于Set 1或Set 2活性的方式被招募到组蛋白的蛋白质。将通过其对防止异染色质扩散的贡献在体内和通过生物化学结合研究在体外进一步表征所鉴定的候选物。

Regulation of gene expression independent of the DMA sequence is referred to as epigenetic control; it affects the structure and accessibility of chromatin, particularly through histone modifications (e.g., acetylation, methylation). Inappropriate epigenetic regulation plays a key role in tumorigenesis. For example, the human leukemia protooncogenes MIL and NSD1 are mutated in different forms of leukemia, but how they contribute to tumorigenesis is not well understood. Both MLL and NSD1 encode histone methyltransferases, and their yeast orthologs, Set1 and Set2, methylate histone H3 at lysine residues 4 and 36, respectively. Recent data indicated that Set1 and Set2 function in preventing the spreading of silenced chromatin. The intention of this project is to gain new insights into the mechanisms by which Set1 and Set2 antagonize gene silencing. To this end, I will identify downstream effectors of Set1 and Set2, and study their role in anti-silencing. In particular, I will take a novel genome-wide approach using the DamiD technique to identify proteins that are recruited to histones in a manner that is dependent on Set1 or Set2 activity. Identified candidates will be further characterized in vivo by their contribution to prevent the spreading of heterochromatin and in vitro by biochemical binding studies.