Regulation of the Drosophila Fragile X Protein by siRNA Pathway Components

siRNA 通路成分对果蝇脆性 X 蛋白的调节

• 批准号: 7904143
• 负责人: THOMAS A JONGENS
• 金额: $ 19.52万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-31 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7904143
• 关键词: Affect; Aubergine; Autistic Disorder; Behavior; Behavioral; Candidate Disease Gene; Cognition; Cytoplasmic Granules; Data; Defect; Development; Drosophila genus; Elements; FMR1; FXTAS; Fragile X Mental Retardation Protein; Fragile X Syndrome; Future; Gene Expression Regulation; Gene Targeting; Genes; Germ Lines; Goals; Homologous Gene; Human; Inherited; Lead; Mental Retardation; Messenger RNA; MicroRNAs; Modeling; Mus; Nature; Nervous system structure; Neuromuscular Junction; Neurons; Ovarian; Pathway interactions; Premature Ovarian Failure; Prevention; Process; Proteins; Publications; RNA Databases; Reagent; Recommendation; Regulation; Regulatory Element; Regulatory Pathway; Role; Small Interfering RNA; Small RNA; Study Section; Symptoms; Synapses; Synaptic plasticity; Testing; Thinking; Translations; Up-Regulation; Update; base; dFMR1 gene; fly; human DICER1 protein; human disease; meetings; member; mouse model; mutant; novel; piRNA; protein expression; public health relevance; research study; response

DESCRIPTION (provided by applicant): Studies of the Fragile X Mental Retardation Protein 1 (FMRP) in humans and its mouse and fly homologs have shown that its proper expression is important for proper development and behavior. Loss, or very low levels of FMRP expression, leads to Fragile X syndrome in humans and analogous behavioral and neuro-anatomical defects in mice and flies. Over-expression studies in the mouse and fly have identified behavioral and neuro-anatomical defects as well. In addition to the importance of proper steady state levels of FMRP, studies in the mice have shown that transient modulation of FMRP levels in response to synaptic activation are crucial for proper synaptic plasticity. Given the importance of the proper regulation of FMRP levels, very little is known about how the levels of this protein are regulated. Recently we discovered that expression of the fly homologue of FMRP, called dFMR1, is regulated by components of the siRNA pathway. Loss of the core members of this pathway (AGO2, R2D2 and Dicer-2) leads to significant upregulation of dFMR1 protein levels in the germline and nervous system that cause specific germ line and neuronal defects due to dFMR1 misregulation. Although recent studies have identified that there is a functioning endogenous siRNA pathway in flies, our results indicate that this pathway is not being used to regulate dFMR1 expression through its canonically defined mechanism. In fact we have found genes, involved in other small RNA pathways, but outside of the canonical siRNA pathway, that also regulate dFMR1 expression. In the first subaim we will screen a candidate set of genes that includes genes in the piRNA pathway, genes that act in multiple small RNA pathways as well as genes that interact with small RNA pathways for a role in regulating dfmr1 expression. In the second subaim we will define the dfmr1 cis-elements required for its regulation by the siRNA pathway members. In the third subaim we will define the basic mechanism by which the siRNA pathway components regulate dfmr1 expression. Results from these studies will more precisely define a novel regulatory pathway that controls dfmr1 expression, providing valuable information as to how this medically important gene is regulated. PUBLIC HEALTH RELEVANCE: The proper regulation of the Fragile X Mental Retardation is fundamentally important for normal cognition and the prevention of at least three human diseases (Fragile X mental retardation, FXTAS and premature ovarian failure). In this application we put forth experiments to further define and characterize a novel regulatory pathway that we have found to be important for the proper regulation dfmr1 expression and the prevention of ovarian and neuronal defects due to dfmr1 misexpression. These studies will provide a better understanding about how this medically important gene is regulated, as well as may identify other genes that lead to other human diseases due to FMR1 misregulation.

描述（由申请人提供）：对人类及其小鼠和飞行同源物中脆弱X智力低下蛋白1（FMRP）的研究表明，其适当的表达对于正确的发育和行为很重要。 丢失或非常低的FMRP表达，导致人类中的X综合征，小鼠和果蝇的类似行为和神经 - 动物缺陷。 小鼠和苍蝇中的过表达研究也鉴定出行为和神经 - 动物缺陷。除了适当的FMRP稳态水平的重要性外，对小鼠的研究表明，FMRP水平的瞬时调节对突触激活而言对于适当的突触可塑性至关重要。 鉴于FMRP水平适当调节的重要性，对于如何调节该蛋白质的水平，知之甚少。最近，我们发现FMRP的苍蝇同源物（称为DFMR1）的表达受siRNA途径的组件调节。 该途径的核心成员的丧失（AGO2，R2D2和DICER-2）导致生殖线和神经系统中DFMR1蛋白水平的显着上调，从而导致由于DFMR1误导引起的特定生殖线和神经元缺陷。尽管最近的研究表明，苍蝇中有一个功能正常的内源性siRNA途径，但我们的结果表明，该途径并未用于通过其规范定义的机制来调节DFMR1的表达。 实际上，我们发现了与其他小的RNA途径有关的基因，但是在规范siRNA途径之外也调节了DFMR1表达。在第一个Subaim中，我们将筛选一组候选基因，其中包括PIRNA途径中的基因，在多个小RNA途径中起作用的基因以及与小RNA途径相互作用的基因，在调节DFMR1表达中发挥作用。在第二个Subaim中，我们将定义siRNA途径成员对其调节所需的DFMR1顺式元素。 在第三个Subaim中，我们将定义siRNA途径成分调节DFMR1表达的基本机制。这些研究的结果将更精确地定义一种控制DFMR1表达的新型调节途径，从而提供了有关如何调节这种医学重要基因的宝贵信息。公共卫生相关性：脆弱X智力迟缓的适当调节对于正常认知和预防至少三种人类疾病（脆弱的X智力低下，FXTA和早产卵巢衰竭）至关重要。在此应用中，我们提出了实验，以进一步定义和表征一种新型的调节途径，我们发现，我们发现，由于DFMR1 Misexpression引起的适当调控DFMR1表达以及预防卵巢和神经元缺陷。这些研究将更好地了解该医学上重要的基因如何受到调节，并可以鉴定由于FMR1失调而导致其他人类疾病的其他基因。