ANALYSIS OF OXIDATIVE STRESS PROTEINS IN S POMBE

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。真核细胞在应激反应中重新编程其基因表达的全局模式。最近对pombe Schizosaccharomyces的研究表明，rna结合蛋白Csx1在氧化应激过程中控制基因表达起核心作用。它通过稳定atf1(+) mRNA来实现这一点，该mRNA编码氧化应激过程中基因表达所需的bZIP转录因子的一个亚基。在这里，我们描述了两个相关蛋白，Cip1和Cip2，通过多维蛋白鉴定技术（MudPIT）鉴定为与Csx1共沉淀的蛋白。Cip1和Cip2是具有RNA识别基序（RRMs）的细胞质蛋白。这两种蛋白质都不是生存所必需的，但cip1Delta cip2Delta菌株生长不良，并改变了细胞形态。遗传上位性研究和全基因组表达谱表明，Cip1和Cip2以一种被Csx1抵消的方式对基因表达进行转录后控制。值得注意的是，csx1Delta细胞对氧化应激的敏感性以及它们无法诱导atf1依赖基因的表达，部分地被cip1Delta和cip2Delta突变所挽救。本研究强调了mRNA稳定性在真核生物应激反应途径中的重要性，并为rna结合蛋白在氧化应激反应中的作用提供了新的信息。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Eukaryotic cells reprogram their global patterns of gene expression in response to stress. Recent studies in Schizosaccharomyces pombe showed that the RNA-binding protein Csx1 plays a central role in controlling gene expression during oxidative stress. It does so by stabilizing atf1(+) mRNA, which encodes a subunit of a bZIP transcription factor required for gene expression during oxidative stress. Here, we describe two related proteins, Cip1 and Cip2, that were identified by multidimensional protein identification technology (MudPIT) as proteins that coprecipitate with Csx1. Cip1 and Cip2 are cytoplasmic proteins that have RNA recognition motifs (RRMs). Neither protein is essential for viability, but a cip1Delta cip2Delta strain grows poorly and has altered cellular morphology. Genetic epistasis studies and whole genome expression profiling show that Cip1 and Cip2 exert posttranscriptional control of gene expression in a manner that is counteracted by Csx1. Notably, the sensitivity of csx1Delta cells to oxidative stress and their inability to induce expression of Atf1-dependent genes are partially rescued by cip1Delta and cip2Delta mutations. This study emphasizes the importance of a modulated mRNA stability in the eukaryotic stress response pathways and adds new information to the role of RNA-binding proteins in the oxidative stress response.