Deciphering the role of Arabidopsis SERRATE in transcription and splicing

基因的表达可以在不同的水平上进行调控，例如在转录、RNA加工或翻译水平上。植物必需蛋白锯齿酸(SE)是基因表达的重要调节因子。SE蛋白充当与其他蛋白质和RNA相互作用的支架蛋白。机制上，SE通过直接与靶基因染色质结合来增强转录，促进初级microRNA的加工，促进内含子的剪接，并影响RNA的稳定性。此外，SE的后生动物同系物ARS2参与了额外的RNA加工事件，如3‘端加工或RNA运输。在这项研究中，我们将重点研究SE在基因表达调控中的两个不同功能：首先，虽然SE促进转录的功能已经确立，但我们观察到SE抑制转录的机制尚不清楚。其次，SE与剪接体U1 SnRNP复合体形成复合体，但这种相互作用对SE的剪接功能似乎是必不可少的。我们将研究SE和U1SnRNP之间相互作用的替代功能，这可能对调控植物中的基因表达具有重要意义。

Gene expression can be controlled a various levels, e.g at the level of transcription, RNA processing or translation. The essential plant protein SERRATE (SE) is an important regulator of gene expression. The SE protein acts as a scaffold protein that mediates interactions with other proteins and RNAs. Mechanistically, SE enhances transcription by directly binding to the chromatin of its target genes, it promotes primary microRNA processing, it facilitates splicing of a subset of introns and it affects RNA stability. Furthermore, the metazoan homologue of SE, ARS2, has been implicated in additional RNA processing events such as 3’end processing or RNA transport. In this proposal, we will focus on two distinct function of SE in regulating gene expression: Firstly, while SE’s function in promoting transcription is established, we observed that SE represses transcription by an yet unknown mechanism. Secondly, SE forms complexes with the spliceosomal U1 snRNP complex, but this interaction seems to be dispensable for SE’s function in splicing. We will investigate alternative functions of the interaction between SE and the U1 snRNP, which might have important implication for regulating gene expression in plants.