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

基本信息

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
项目类别：
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

项目摘要

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）：对人类及其小鼠和果蝇同源物中脆性 X 智力迟钝蛋白 1 (FMRP) 的研究表明，其正确表达对于正确发育和行为非常重要。 FMRP 表达缺失或水平极低会导致人类出现脆性 X 综合征，并导致小鼠和果蝇出现类似的行为和神经解剖缺陷。对小鼠和果蝇的过度表达研究也发现了行为和神经解剖学缺陷。除了 FMRP 适当稳态水平的重要性之外，对小鼠的研究表明，响应突触激活而瞬时调节 FMRP 水平对于适当的突触可塑性至关重要。鉴于正确调节 FMRP 水平的重要性，人们对如何调节这种蛋白质的水平知之甚少。最近，我们发现果蝇 FMRP 同源物（称为 dFMR1）的表达受到 siRNA 途径组件的调节。该通路核心成员（AGO2、R2D2 和 Dicer-2）的丢失会导致种系和神经系统中 dFMR1 蛋白水平显着上调，从而因 dFMR1 失调而导致特定的种系和神经元缺陷。尽管最近的研究已经确定果蝇中存在功能正常的内源 siRNA 通路，但我们的结果表明该通路并未通过其规范定义的机制用于调节 dFMR1 表达。事实上，我们已经发现参与其他小 RNA 途径但在经典 siRNA 途径之外的基因也调节 dFMR1 表达。在第一个子目标中，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 途径相互作用以调节 dfmr1 表达的基因。在第二个子目标中，我们将定义 siRNA 途径成员调节所需的 dfmr1 顺式元件。在第三个子目标中，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控制 dfmr1 表达的新调控途径，为如何调控这一医学上重要的基因提供有价值的信息。公众健康相关性：对脆性 X 型智力低下的适当调节对于正常认知和预防至少三种人类疾病（脆性 X 型智力低下、FXTAS 和卵巢早衰）至关重要。在本申请中，我们进行了实验来进一步定义和表征一种新的调节途径，我们发现该途径对于正确调节 dfmr1 表达以及预防由于 dfmr1 错误表达引起的卵巢和神经元缺陷非常重要。这些研究将让人们更好地了解这一医学上重要的基因是如何被调节的，并可能识别出因 FMR1 失调而导致其他人类疾病的其他基因。