Regulation of Selenoprotein Synthesis by SECIS-binding Proteins

SECIS 结合蛋白对硒蛋白合成的调节

基本信息

批准号：
7296381
负责人：
DONNA M DRISCOLL
金额：
$ 29.36万
依托单位：
CLEVELAND CLINIC LERNER COM-CWRU
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-07-11 至 2011-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7296381
关键词：
3&apos Untranslated Regions Affinity Affinity Chromatography Amino Acids Antioxidants Be++ element Beryllium Binding Binding Proteins Biochemical Biogenesis Biological Assay Brain Cell Nucleolus Cell Nucleus Cells Cellular biology Cis-Acting Sequence Codon Nucleotides Complementary DNA Complex Condition Cytoplasm DNA Insertion Elements DNA Sequencing Facility Development Dietary Selenium Endocrine Glands Eukaryota Eukaryotic Cell Functional RNA Gene Expression Gene Targeting Genetic Translation Health Health Benefit IS Elements In Vitro Indium Individual Laboratories Lead Life Mammalian Cell Mass Spectrum Analysis Mediating Messenger RNA Micronutrients Molecular Biology Mus Pathway interactions Play Proteins RNA RNA-Binding Proteins Reading Recruitment Activity Regulation Regulatory Pathway Reproduction Research Personnel Ribosomes Role Selenium Selenocysteine Specificity Structure System Terminator Codon Testing Thyroid Hormones Tissue Extracts Tissues Trans-Activators Translations base glutathione peroxidase hormone metabolism in vivo inhibitor/antagonist male novel nucleolin phospholipid-hydroperoxide glutathione peroxidase programs research study ribosomal protein L30 selenium deficiency selenocysteine insertion sequence binding protein 2 selenoprotein stem thioredoxin reductase 1 transposon/insertion element

项目摘要

DESCRIPTION (provided by applicant): Selenium is an essential micronutrient that exerts many important health benefits. The element is incorporated into selenoproteins as selenocysteine (Sec), the 21st amino acid. The mammalian selenoproteins perform important functions in anti-oxidant defense, thyroid hormone metabolism, male reproduction, and development. Sec is encoded by a UGA codon, which is normally read as a stop codon. The receding of UGA as Sec requires a Sec Insertion Sequence (SECIS) element in the 3' untranslated region of the selenoprotein mRNA. We previously identified two SECIS-binding proteins, SECIS Binding Protein 2 (SBP2) and ribosomal protein L30, which play critical roles in the receding mechanism. Although much progress has been made in understanding the Sec incorporation machinery, less is known about the regulation of this pathway. During selenium deficiency, the element is preferentially utilized in the brain and endocrine organs. There is also a hierarchy of expression of individual selenoproteins. Even under selenium adequate conditions, certain selenoproteins are essential for life and health whereas others are not. The central hypothesis of our proposal is that cis-acting sequences in the SECIS recruit multiple trans-acting factors, which prioritize the utilization of selenium is a tissue-specific and selenoprotein-dependent manner. We recently discovered two additional SECIS-binding proteins: a 110 kDa protein which was purified by RNA affinity chromatography and identified as nucleolin by mass spectrometry analysis, and an unknown protein of - 45 kDa, referred to here as SBP45. Unlike SBP2 and L30, nucleolin and SBP45 can distinguish between selenoprotein mRNAs. The two proteins have distinct binding specificities, with nucleolin preferentially binding to SECIS elements from selenoproteins that are essential for normal health and development. We also show that nucleolin specifically regulates UGA receding in vitro. In this project, we propose to use a variety of biochemical, cell biology, and molecular biology approaches to: 1) identify functionally important interactions between nucleolin and the SECIS element; 2) elucidate the function of nucleolin in regulating selenoprotein mRNA translation, and 3) identify SBP45 and determine its function in regulating selenoprotein expression. The successful pursuit of these aims may identify limiting factors and regulatory pathways that could be used therapeutically to modulate selenoprotein expression in vivo.

描述（由申请人提供）：硒是一种必需的微量营养素，具有许多重要的健康益处。该元素以第 21 个氨基酸硒代半胱氨酸 (Sec) 的形式融入硒蛋白中。哺乳动物硒蛋白在抗氧化防御、甲状腺激素代谢、雄性生殖和发育中发挥重要功能。 Sec 由 UGA 密码子编码，通常被解读为终止密码子。 UGA 作为 Sec 的后退需要硒蛋白 mRNA 3' 非翻译区中的 Sec 插入序列 (SECIS) 元件。我们之前鉴定了两种 SECIS 结合蛋白，SECIS 结合蛋白 2 (SBP2) 和核糖体蛋白 L30，它们在消退机制中发挥着关键作用。尽管在理解 SEC 合并机制方面已经取得了很大进展，但对该途径的监管却知之甚少。缺硒时，该元素优先在大脑和内分泌器官中利用。各个硒蛋白的表达也存在层次结构。即使在硒充足的条件下，某些硒蛋白对于生命和健康也是必需的，而另一些则不是。我们建议的中心假设是 SECIS 中的顺式作用序列招募多种反式作用因子，这些因子优先利用组织特异性和硒蛋白依赖的方式利用硒。我们最近发现了另外两种 SECIS 结合蛋白：一种是通过 RNA 亲和层析纯化并通过质谱分析鉴定为核仁素的 110 kDa 蛋白，另一种是 45 kDa 的未知蛋白，此处称为 SBP45。与 SBP2 和 L30 不同，核仁素和 SBP45 可以区分硒蛋白 mRNA。这两种蛋白质具有不同的结合特异性，核仁素优先与硒蛋白中的 SECIS 元件结合，而硒蛋白对正常健康和发育至关重要。我们还表明核仁素在体外特异性调节 UGA 消退。在这个项目中，我们建议使用各种生物化学、细胞生物学和分子生物学方法来：1）识别核仁素和 SECIS 元件之间功能上重要的相互作用； 2) 阐明核仁素在调节硒蛋白 mRNA 翻译中的功能，以及 3) 鉴定 SBP45 并确定其在调节硒蛋白表达中的功能。成功实现这些目标可能会确定可用于治疗性调节体内硒蛋白表达的限制因素和调节途径。