Deciphering the role of Arabidopsis SERRATE in transcription and splicing

基因表达可以在不同的水平上控制，例如在转录、RNA加工或翻译的水平上。植物必需蛋白SERRATE （SE）是基因表达的重要调控因子。SE蛋白作为支架蛋白，介导与其他蛋白和rna的相互作用。从机制上讲，SE通过直接结合靶基因的染色质来增强转录，促进初级microRNA加工，促进内含子子集的剪接，并影响RNA的稳定性。此外，SE的后生同系物ARS2也参与了其他RNA加工事件，如3 '端加工或RNA运输。在本提案中，我们将重点关注SE在调节基因表达方面的两种不同功能：首先，虽然SE促进转录的功能已经确立，但我们观察到SE通过一种未知的机制抑制转录。其次，SE与剪接体U1 snRNP复合物形成复合物，但这种相互作用对于SE在剪接中的功能似乎是必不可少的。我们将研究SE与U1 snRNP相互作用的其他功能，这可能对调节植物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.