Roles of motor proteins in cerebellar Purkinje neuron biology

运动蛋白在小脑浦肯野神经元生物学中的作用

• 批准号: 10699720
• 负责人: JOHN A HAMMER
• 金额: $ 54.43万
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10699720
• 关键词: Axon; Biological Models; Biology; Cell Polarity; Cells; Cerebellar Cortex; Cerebellum; Congenital cerebellar hypoplasia; Defect; Development; Equilibrium; Exhibits; Filopodia; Future; Goals; Guanine Nucleotide Exchange Factors; Image; Knockout Mice; Learning; Lobe; MYO5A gene; Mediating; MicroRNAs; Molecular; Morphology; Motor; Mus; Myosin ATPase; Neurites; Neurons; Organ; Output; Process; Proteins; Role; Slice; Stains; Structure; Synaptic plasticity; Vertebral column; calbindin; density; design; in vivo; knock-down; knockout animal; motor learning; nerve supply; neuronal cell body

Myosin 10 function in cerebellar Purkinje neurons The Purkinje neuron (PN) is the master neuron of the cerebellum, as it receives all inputs into the cerebellar cortex, is the sole output from the cortex, and is essential for coordination, balance and learning precise motor tasks. We showed previously that myosin Va transports tubules of ER into PN spines to promote synaptic plasticity and motor learning (Wagner et al, Nat. Cell Biol. 2011), and that myosin 18A targets the guanine nucleotide exchange factor -Pix to PN spines to promote spine maturation (Alexander et al, FASEB J 2021). Here we describe ongoing efforts using to define the function of myosin 10 (Myo10) in PNs, which are unique among CNS neurons in possessing very high levels of this filopodial myosin, and in undergoing filopodia-to-spine conversion without prior innervation. At the whole organ level, six week-old Myo10 knockout (KO) mice (Heimsath et al, Sci. Rep. 2017) exhibit cerebellar hypoplasia and misshapen and/or missing cerebellar lobes. Additionally, Calbindin staining of cerebellar slices from these mice reveals defects in the alignment of PN soma and in the orientation of PN dendritic arbors within the molecule layer. Importantly, Calbindin staining of cerebellar slices from mature, six month-old Myo10 KO mice reveals major defects in PN morphology, including reduced dendritic arborization and greatly reduced spine density. Consistent with these observations, Myo10 KO mice exhibit significant defects in cerebellar function (e.g. maintaining balance). Finally, GFP-tagged Myo10 expressed in cultured PNs localizes dramatically at the tips of filopodia-like extensions at the leading edge of forming neurites, and the miRNA-mediated knockdown of Myo10 in these cells results in defects in spine maturation and cell polarity (reduced dendritic arborization, increased number of axons). Together, these results argue that Myo10 is required for normal cerebellar development, cerebellar function, and PN structure and function, and they pave the way for future efforts designed to identify the molecular mechanisms by which this MyTH4/FERM myosin promotes these processes.

小脑Purkinje神经元中的肌球蛋白10功能 Purkinje神经元（PN）是小脑的主神经元，因为它接收到小脑皮层的所有输入是皮质的唯一输出，对于协调，平衡和学习精确运动任务至关重要。我们先前表明，肌球蛋白VA将ER的小管转运到PN棘中，以促进突触可塑性和运动学习（Wagner等，Nat。CellBiol。2011），并且肌球蛋白18a靶向鸟嘌呤核苷酸交换因子-PN刺激PN刺激到PN棘以促进脊柱的成熟（Alexander等人（Alexander等）（Alexander等）（Alexander等人（Alexander等）（Alexander等，Faseb J 2021）。在这里，我们描述了用于定义PNS中肌球蛋白10（MyO10）功能的持续努力，PNS在中枢神经系统神经元中具有很高的这种丝状肌球蛋白，并且在没有事先支配的情况下进行了丝状肌动蛋白转换。在整个器官一级，六个星期大的Myo10敲除（KO）小鼠（Heimsath等，Sci。Pep。2017）表现出小脑发育不全和畸形和/或缺失小脑裂片。此外，这些小鼠的小脑切片的calbindin染色揭示了PN SOMA对齐的缺陷以及分子层中PN树突状乔木的方向。重要的是，六个月大的Myo10 KO小鼠对小脑切片的Calbindin染色显示出PN形态的主要缺陷，包括降低的树突状植物化和脊柱密度大大降低。与这些观察结果一致，Myo10 KO小鼠在小脑功能中表现出明显的缺陷（例如保持平衡）。最后，在培养的PNS中表达的GFP标记的Myo10在形成神经突的前缘的丝状延伸尖端，在这些细胞中的miRNA介导的MyO10的敲低位置，这些细胞中的myO10导致脊柱成熟和细胞极性的缺陷（减少了轴突的树突状养老金数量，轴突数量减少）。总之，这些结果表明，Myo10是正常的小脑发育，小脑功能以及PN的结构和功能所必需的，并且它们为未来的努力铺平了道路，旨在识别这种神话4/FERM肌球蛋白促进这些过程的分子机制。