The Regulation and Function of Neuron-Specific Alternative Splicing

鉴于越来越多的证据表明RNA结合蛋白(RBPs)是遗传原因或易感风险 一系列神经系统疾病的潜在因素，迫切需要了解它们 发育和成熟大脑中的特定细胞功能。与转录因子类似，限制性商业惯例可能是 掌握某些细胞过程的调节器，因为它们有协调的目标集。与广泛研究的不同 在转录因子方面，限制性商业惯例的生理功能历来没有得到充分的研究。十几个人中的大多数 发现具有组织特异性表达的限制性商业惯例参与调节神经元的选择性剪接。我们 其他人揭示了胚胎大脑中选择性剪接的大规模遗传编程 发育，导致成熟大脑中神经元特异性的替代异构体。我们展示了其中的许多 剪接变化是由核RBP，多嘧啶结合蛋白2(PTBP2)介导的。PTBP2 在神经元分化过程中表现出动态的时间表达，并可能协调发育 实现神经元延长和连续的选择性剪接编程 形态变换。我们之前的研究表明，在PTBP2下调之前 突触发生是脊柱形成所必需的。我们的最新数据显示，PTBP2在 突触形成前的早期分化神经元。在强劲的初步数据的指导下，我们假设 PTBP2调控神经元特异性剪接，控制神经元极性的启动。这项提议将 解决神经元极性研究的多个关键障碍并提供一个新的功能 可选剪接的分析。我们研究大脑中的选择性剪接和PTBP2的悠久历史 使我们在推进这些领域方面处于独特的地位。我们的团队在遗传学方面有着互补的专业知识， 神经生物学、分子细胞生化和计算生物学已经证明是成功的。 合作。我们已经产生了新的工具和资源来彻底确定细胞和分子 Ptbp2基因敲除引起的皮质神经元缺陷。该项目的完成将使我们能够进一步发展我们的 长期目标是揭示新的遗传、分子和细胞控制的神经元极性和 能够形成神经回路的形态发生。

Given the increasing evidence that RNA binding proteins (RBPs) serve as genetic causes or predisposing risk factors underlying a wide spectrum of neurological diseases, a pressing need exists to understand their specific cellular functions in developing and mature brains. Similar to transcription factors, RBPs could be master regulators of certain cellular processes owing to their coordinated target sets. Unlike widely-studied transcription factors, the physiological functions of RBPs are historically underexplored. Most of the dozen RBPs found to exhibit tissue-specific expression are involved in regulating neuronal alternative splicing. We and others have revealed the large-scale genetic programming of alternative splicing during embryonic brain development, resulting in neuron-specific alternative isoforms in mature brains. We show many of these splicing changes are mediated by a nuclear RBP, polypyrimidine tract-binding protein 2 (PTBP2). PTBP2 exhibits dynamic temporal expression during neuronal differentiation and may orchestrate the developmental programming of alternative splicing in order to accomplish the prolonged and continuous neuronal morphological transformations. Our previous study shows that downregulation of PTBP2 prior to synaptogenesis is necessary for spine formation. Our newest data show that PTBP2 has additional functions in early differentiating neurons prior to synapse formation. Guided by strong preliminary data, we hypothesize that PTBP2 governs neuron-specific splicing to control the initiation of neuronal polarity. This proposal will address multiple critical barriers to the study of neuronal polarity and provide a new framework for functional analysis of alternative splicing. Our long history of researching alternative splicing and PTBP2 in the brain places us in a unique position to advance these fields. Our team, with complementary expertise in genetics, neurobiology, and molecular cellular biochemical and computational biology, has demonstrated successful collaborations. We have generated new tools and resource to thoroughly determine the cellular and molecular defects caused by Ptbp2 knockout in cortical neurons. Completion of this project will allow us to further our long-term goal of revealing new genetic, molecular and cellular controls of neuronal polarity and morphogenesis that enables neural circuit formation.