ORB GENE REGULATION OF TRANSLATION

ORB基因翻译调控

• 批准号: 7723642
• 负责人: Paul D Schedl
• 金额: $ 0.81万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7723642
• 关键词: Axon; Binding; Biochemical; Candidate Disease Gene; Cell Nucleus; Cells; Complex; Computer Retrieval of Information on Scientific Projects Database; Coupled; Dendrites; Deposition; Development; Drosophila genus; Elements; Embryo; Ensure; Eukaryota; Eukaryotic Cell; Event; Family; Feedback; Funding; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Genetic Translation; Goals; Grant; Growth; Homeostasis; Institution; Learning; Localized; Location; Masks; Mating Types; Memory; Messenger RNA; Microtubule-Associated Proteins; Movement; Mutation; Neurons; Nurses; Oocytes; Ovarian; Ovary; Play; Process; Protein Biosynthesis; Proteins; Purpose; RNA Recognition Motif; RNA-Binding Proteins; Research; Research Personnel; Resources; Role; Signal Transduction; Site; Somatic Cell; Source; Synaptic plasticity; Testing; Translating; Translational Activation; Translational Regulation; Translations; United States National Institutes of Health; Untranslated Regions; Yeasts; daughter cell; egg; fly; in vivo; member; mutant; prevent; segregation

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. mRNA localization plays a pivotal role in the establishment of polarity in the Drosophila egg and embryo. It typically begins with the transcription and packaging of the localized mRNAs in RNP complexes in nurse cell nuclei. These complexes 'mask' the mRNAs, preventing them from being translated while in transit, and 'mark' them for localization. The masked mRNAs are transported through the nurse cells and deposited in the oocyte. Depending upon their cis-acting localization elements, the mRNAs are then targeted to specific locations in the oocyte where they are anchored to the cytosketal network. Translational activation of the localized message provides a spatially restricted source of the protein product. Alternatively the mRNAs can be stored in a masked form until an appropriate signal, such as egg deposition, activates translation. This provides a mechanism for coordinating the localized synthesis of the protein with other developmental events. While the importance of mRNA localization (coupled with 'on site' translational regulation) was first documented in fly ovaries and early embryos, it is now clear that this regulatory mechanism is employed in many different contexts and occurs in virtually every eukaryote. For example, in yeast, the asymmetric segregation of ash-1 mRNA to the daughter cell provides a mechanism for ensuring that mating type switching does not occur in that cell. mRNA localization in somatic cells also occurs during the processes of movement, differentiation or growth. In neuronal cells, mRNAs encoding MAP2, a dendrite-specific microtubule-associated protein, and aCaMKII accumulate in the dendrites, but not in the axons. Localized mRNA translation has also been implicated in synaptic plasticity and learning and memory. In all of these cases, it is likely that the steps involved in mRNA localization and translational regulation are similar in broad outline to those described above in fly ovaries The proposed studies focus on the Drosophila orb gene which is one of the key components of the fly ovarian mRNA localization machinery. Orb is a founding member of the highly conserved CPEB family of RRM RNA binding proteins. In previous studies, we have shown that orb functions at the last step in the mRNA localization process, regulating the translation of the mRNA once it is on site. Orb binds to the 3? UTR of many localized mRNAs in vivo oskar (osk) Bicudal-D (Bic-D), and K(10) and is required to promote the translation of these mRNAs. In addition, Orb protein autoregulates its own expression by binding to the 3? UTR of localized orb mRNA and activating translation. This positive feedback loop is critical for the proper expression of Orb in the developing oocyte. The goal of our studies is to better understand how Orb autoregulates its own expression and how it controls the on site translation of mRNAs encoding factors critical for establishing oocyte/nurse cell identity and defining the polarity of the egg chamber and embryo. Part of the answer to these questions will come from identifying and characterizing other genes that are important for Orb autoregulation and/or function. For this purpose we propose to isolate proteins that are associated with Orb in vivo and identify them by Mass Spec analysis. To validate these biochemical studies we have devised a sensitized orb mutant background. The sensitized background will permit us to test mutations in candidate genes which encode proteins that are associated Orb in vivo for genetic interactions with Orb.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 mRNA定位在果蝇卵和胚胎极性的建立中起着关键作用。 它通常始于保育细胞核中RNP复合物中定位mRNA的转录和包装。这些复合物“掩盖”mRNA，防止它们在运输过程中被翻译，并“标记”它们进行定位。 被掩蔽的mRNA通过保育细胞运输并沉积在卵母细胞中。根据其顺式作用定位元件，mRNA随后被靶向卵母细胞中的特定位置，并锚定在细胞骨架网络上。 定位信息的翻译激活提供了蛋白质产物的空间受限来源。 或者，mRNA可以以掩蔽的形式储存，直到适当的信号（例如卵子沉积）激活翻译。这提供了一种机制，用于协调蛋白质的局部合成与其他发育事件。 虽然mRNA定位的重要性（加上“现场”翻译调控）首先在苍蝇卵巢和早期胚胎中记录，但现在很清楚，这种调控机制在许多不同的情况下，几乎在每一个真核生物中都存在。例如，在酵母中，ash-1 mRNA向子细胞的不对称分离提供了一种确保该细胞中不发生交配型转换的机制。 mRNA在体细胞中的定位也发生在运动、分化或生长过程中。 在神经元细胞中，编码MAP 2（树突特异性微管相关蛋白）和aCaMKII的mRNA在树突中积累，但不在轴突中积累。 局部mRNA翻译也与突触可塑性以及学习和记忆有关。 在所有这些情况下，mRNA定位和翻译调节所涉及的步骤很可能与上述苍蝇卵巢中的步骤大致相似 拟开展的研究集中在果蝇orb基因，这是果蝇卵巢mRNA定位机制的关键组成部分之一。 Orb是RRM RNA结合蛋白高度保守的CPEB家族的创始成员。 在以前的研究中，我们已经表明，orb在mRNA定位过程的最后一步起作用，一旦它在现场，就调节mRNA的翻译。宝珠和3号绑定？Oskar（osk）Bicudal-D（Bic-D）和K（10）是许多体内定位mRNA的UTR，并且是促进这些mRNA翻译所必需的。 此外，Orb蛋白通过与3？定位的orb mRNA的UTR和激活翻译。这种正反馈回路对于Orb在发育中的卵母细胞中的正确表达至关重要。 我们研究的目标是更好地了解Orb如何自动调节自身表达，以及它如何控制mRNA编码因子的现场翻译，这些因子对于建立卵母细胞/护士细胞身份和定义卵室和胚胎的极性至关重要。这些问题的部分答案将来自识别和表征对Orb自动调节和/或功能重要的其他基因。 为此，我们建议分离与Orb在体内相关的蛋白质，并通过质谱分析鉴定它们。 为了验证这些生物化学研究，我们设计了一个致敏的orb突变体背景。 敏感的背景将允许我们测试候选基因中的突变，这些基因编码与Orb在体内遗传相互作用的蛋白质。