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：
7886508
负责人：
DONNA M DRISCOLL
金额：
$ 28.48万
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 2011-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7886508
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 Cytoplasm DNA Insertion Elements DNA Sequencing Facility Development Dietary Selenium Endocrine Glands Eukaryota Functional RNA Gene Expression Gene Targeting Genetic Translation Health Health Benefit IS Elements In Vitro 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

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）：硒是具有许多重要健康益处的必不可少的微量营养素。该元素被掺入硒蛋白中为硒代半胱氨酸（SEC），第21氨基酸。哺乳动物硒蛋白在抗氧化剂防御，甲状腺激素代谢，男性繁殖和发育中发挥重要作用。 SEC由UGA密码子编码，该密码子通常将其读为终止密码子。 UGA作为SEC的后退需要在硒蛋白mRNA的3'未翻译区域中的SEC插入序列（SECIS）元件。我们先前鉴定了两种secis结合蛋白，即secis结合蛋白2（SBP2）和核糖体蛋白L30，它们在后退机制中起着关键作用。尽管在理解SEC掺入机械方面取得了很多进展，但对该途径的调节知之甚少。在硒缺乏症中，该元素优先在大脑和内分泌器官中使用。也有单个硒蛋白表达的层次结构。即使在适当的条件下，某些硒蛋白对于生活和健康至关重要，而其他硒则不是。我们建议的中心假设是，SECIS中的顺式作用序列募集了多个跨作用因子，这些因素优先考虑硒的利用率是组织特异性和硒蛋白依赖性的方式。我们最近发现了另外两个结合蛋白：一种110 kDa蛋白，该蛋白通过RNA亲和色谱法纯化，并通过质谱分析鉴定为核素，而-45 kDa的未知蛋白，此处称为SBP45。与SBP2和L30不同，核醇蛋白和SBP45可以区分硒蛋白mRNA。这两种蛋白具有独特的结合特异性，核仁素优先结合了来自硒蛋白的Secis元素，这对于正常健康和发育至关重要。我们还表明，核仁素特异性调节体外退缩的UGA。在这个项目中，我们建议使用各种生化，细胞生物学和分子生物学方法：1）识别核仁与SECIS元素之间在功能上重要的相互作用； 2）阐明核仁在调节硒蛋白mRNA翻译中的功能，3）识别SBP45并确定其在调节硒蛋白表达的功能。对这些目标的成功追求可能会确定限制因素和调节途径，这些因素和调节途径可以治疗来调节体内硒蛋白的表达。