Destabilization of axonal mRNAs by KHSRP complexes during axon regeneration

轴突再生过程中 KHSRP 复合物导致轴突 mRNA 不稳定

• 批准号: 10306001
• 负责人: JEFFERY L TWISS
• 金额: $ 40.74万
• 依托单位: UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10306001
• 关键词: Address; Adult; Affect; Affinity; Alleles; Appearance; Axon; Behavior; Binding; Binding Proteins; Bioinformatics; Biotinylation; Clinical; Collaborations; Complex; Data; Dendrites; Development; Elements; Environment; FMRP; Family; Funding; Genetic Transcription; Genetic Translation; Growth; Heterogeneous-Nuclear Ribonucleoproteins; Hippocampus (Brain); HuD antigen; Impairment; In Vitro; Injury; Knockout Mice; Knowledge; Link; Mediating; Memory; Memory impairment; Messenger RNA; MicroRNAs; Molecular; Mus; Natural regeneration; Nerve; Nerve Regeneration; Nervous system structure; Neuraxis; Neurons; Nuclear; Peripheral; Peripheral Nerves; Peripheral nerve injury; Physiological; Prefrontal Cortex; Protein Binding Domain; Protein Biosynthesis; Proteins; Proteome; RNA; RNA Binding; RNA analysis; RNA-Binding Proteins; RNA-Protein Interaction; Recovery of Function; Regenerative capacity; Regulation; Regulon; Ribonucleoproteins; Rodent; Role; Seizures; Stimulus; Testing; Time; Translating; Translational Regulation; Translations; Up-Regulation; Work; axon growth; axon injury; axon regeneration; base; cohort; exosome; extracellular; in vivo; link protein; mRNA Stability; mRNA Transcript Degradation; memory consolidation; neuron loss; neuronal cell body; neurotransmission; particle; peripheral nerve regeneration; presynaptic; protein complex; response; response to injury; stoichiometry; transcriptome

SUMMARY This application asks how localized mRNA stability modifies axonal regeneration capacity, focusing on contributions of the RNA binding protein [RBP] KHSRP. The nervous system makes extensive use of post- transcriptional mechanisms to regulate cellular proteomes in response to extracellular stimuli and physiologic environments during development, function, & in response to axonal injury. Since one mRNA can be translated into protein many times over, how long a given mRNA is available for translation impacts the amount of protein generated from that mRNA. Stability of mRNAs is indeed regulated, with interactions with RBPs stabilizing & destabilizing different mRNAs, as well as interactions with microRNAs targeting some targets for degradation. Translation of mRNAs clearly supports axon regeneration, but we have little knowledge for how stability of axonal mRNAs is locally regulated. We have shown that the RBPs HuD (also called ELAVL4) and KHSRP (also called FUBP2, MARTA1, & ZBP2) compete for binding to neuronal mRNAs with AU-rich elements, where HuD interaction stabilizes and KHSRP interaction destabilizes target mRNAs. At the molecular level, this interaction is impacted by an mRNA’s affinity for binding to HuD or KHSRP. Our work over years 01-05 show that loss of KHSRP increases KHSRP target mRNA levels, causes excessive axonal and dendritic growth, impairs memory consolidation in hippocampus & prefrontal cortex, and increases presynaptic activity in prefrontal cortex and hippocampus. KHSRP is expressed into adulthood, and we surprisingly find that axonal KHSRP levels rapidly increase in peripheral nerves after injury. This increase in axonal KHSRP occurs through intra-axonal translation of its encoding mRNA. Our preliminary data indicate that KHSRP knockout mice show accelerated nerve regeneration pointing to axon-intrinsic functions for KHSRP in regeneration. Based on these observations, we hypothesize that axonal KHSRP controls the rates of axon regeneration through regulation of localized mRNA stability. We will test this hypothesis with the following specific aims: 1) Does KHSRP regulate PNS axon regeneration through a neuron intrinsic mechanism? 2) Does increased axonal KHSRP limit axon regeneration by destabilizing axonal mRNAs encoding regeneration-associated proteins? and 3) Does KHSRP’s protein interactome influence its intra-axonal functions? Completion of the studies here will begin to fill this knowledge gap by focusing on RNA-protein interactions initiated in axons that can affect mRNA survival. This will provide the first subcellular analyses of RBP domain-specific RNA regulons and will bring the first systematic assessment for contributions of RNA survival to peripheral nerve regeneration.

概括 该应用询问局部mRNA稳定性如何修饰轴突再生能力，重点关注 RNA结合蛋白[RBP] KHSRP的贡献。神经系统广泛使用后 响应细胞外刺激和 发育，功能和响应轴突损伤期间的生理环境。由于一个mRNA 可以多次翻译成蛋白质，给定的mRNA多长时间可用于翻译影响 从该mRNA产生的蛋白质量。确实调节了mRNA的稳定性 与RBPS稳定和破坏不同mRNA的相互作用，以及与microRNA的相互作用 针对一些降解目标。 mRNA的翻译显然支持轴突再生，但是我们 关于轴突mRNA的稳定性如何在局部调节中几乎没有知识。我们已经证明了RBP HUD（也称为Elavl4）和KHSRP（也称为FUBP2，MARTA1和ZBP2）竞争与神经元的结合 具有丰富元素的mRNA，HUD相互作用稳定，KHSRP相互作用破坏了目标 mrnas。在分子水平上，这种相互作用受mRNA与HUD结合或 khsrp。我们的工作多年01-05表明，KHSRP的损失增加了KHSRP目标mRNA水平，原因是 过度的轴突和树突生长会损害海马和额叶皮层的记忆巩固， 并增加了前额叶皮层和海马的突触前活性。 KHSRP表示 成年，我们惊讶地发现，轴突KHSRP水平在外周神经系统中迅速增加 受伤。轴突KHSRP的这种增加是通过其编码mRNA的轴内翻译而发生的。我们的 初步数据表明KHSRP敲除小鼠表现出加速的神经再生指向 KHSRP再生的轴突内在功能。基于这些观察，我们假设 轴突KHSRP通过调节局部mRNA稳定性来控制轴突再生的速率。我们 将以以下特定目的检验该假设：1）KHSRP是否调节PNS轴突再生 通过神经元的内在机制？ 2）确实通过 不稳定编码与再生相关蛋白的轴突mRNA？ 3）KHSRP的蛋白质 互动影响其轴内功能？这里的研究完成将开始填补 通过关注可能影响mRNA存活的轴突中引发的RNA蛋白相互作用来通过关注知识差距。 这将提供RBP域特异性RNA法规的第一个亚细胞分析，并将带来第一个 RNA生存对周围神经再生的贡献的系统评估。