| In vitro Time-lapse Imaging of Primary Cilium in Migrating Neuroblasts
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Author:
Date:
2020-11-20
[Abstract] Neuronal migration is a critical step for the development of neuronal circuits in the brain. Immature new neurons (neuroblasts) generated in the postnatal ventricular-subventricular zone (V-SVZ) show a remarkable potential to migrate for a long distance at a high speed in the postnatal mammalian brain, and are thus a powerful model to analyze the molecular and cellular mechanisms of neuronal migration. Here we describe a methodology for in vitro time-lapse imaging of the primary cilium and its related structures in migrating V-SVZ-derived neuroblasts using confocal or superresolution laser-scanning microscopy. The V-SVZ tissues are dissected from postnatal day 0-1 (P0-1) mouse brains and dissociated into single cells by trypsinization and gentle pipetting. These cells are then ...
[摘要] [摘要]神经元迁移是大脑中神经元回路发展的关键步骤。产后心室-脑室下区（V-SVZ）中产生的未成熟新神经元（神经母细胞）显示出巨大的潜力，可以在产后哺乳动物脑中高速长距离迁移，因此是分析分子和神经元的强大模型。神经元迁移的细胞机制。在这里，我们描述了一种使用共聚焦或超分辨率激光扫描显微镜对V-SVZ衍生的成神经细胞进行迁移的初级纤毛及其相关结构的体外延时成像方法。从出生后的第0-1天（P0-1）小鼠脑中解剖V-SVZ组织，并通过胰蛋白酶消化和温和的移液将其分离成单个细胞。然后用编码目的基因的质粒转导这些细胞，通过离心聚集，并在Matrigel中培养2天。通过共聚焦或超分辨率激光扫描显微镜获取培养的神经母细胞及其睫状结构（包括睫状膜和基体）迁移行为的时移图像。该方法提供了有关成神经细胞形态和睫状结构时空动态的信息，并且广泛适用于各种物种中各种类型的迁移神经元和非神经元细胞。
[背景]在出生后的大脑中，神经干细胞驻留在侧脑室侧壁内衬的心室-心室下区（V-SVZ）中，并不断生成未成熟的新神经元（神经母细胞）（Obernier和Alvarez-Buylla，2019）。这些成神经细胞形成链状细胞聚集体，并通过鼻尖迁移流（RMS）彼此迁移至嗅球（OB）（Luskin，1993; Lois and Alvarez-Buylla，1994; Lois et ...
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| In vitro Glutamylation Inhibition of Ubiquitin Modification and Phosphoribosyl-Ubiquitin Ligation Mediated by Legionella pneumophila Effectors
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Author:
Date:
2020-11-05
[Abstract] Glutamylation is a posttranslational modification where the amino group of a free glutamate amino acid is conjugated to the carboxyl group of a glutamate side chain within a target protein. SidJ is a Legionella kinase-like protein that has recently been identified to perform protein polyglutamylation of the Legionella SdeA Phosphoribosyl-Ubiquitin (PR-Ub) ligase to inhibit SdeA’s activity. The attachment of multiple glutamate amino acids to the catalytic glutamate residue of SdeA by SidJ inhibits SdeA’s modification of ubiquitin (Ub) and ligation activity. In this protocol, we will discuss a SidJ non-radioactive, in vitro glutamylation assay using its substrate SdeA. This will also include a second reaction to assay the inhibition of SdeA by using both modification of free Ub and ligation ...
[摘要] [摘要]谷氨酰化是翻译后修饰，其中游离谷氨酸氨基酸的氨基与目标蛋白内谷氨酸侧链的羧基缀合。SidJ是一种军团菌激酶样蛋白，最近被发现可对军团菌SdeA磷酸核糖泛素（PR- Ub ）连接酶进行蛋白多谷氨酰化，从而抑制SdeA的活性。SidJ将多个谷氨酸氨基酸附着到SdeA的催化谷氨酸残基上，从而抑制了SdeA对泛素的修饰（Ub ）和结扎活动。在此协议中，我们将讨论使用其底物SdeA的SidJ非放射性，体外谷氨酰化测定。这也将包括一个第二反应以测定抑制SdeA通过使用免费的两个修改泛素和结扎ADP-核糖基化的泛素（ADPR-泛素），以SdeA的基板Rab33b。在鉴定和公布SidJ的活性之前，尚无SdeA抑制试验。我们的小组和其他小组演示了各种方法来抑制SdeA的活性。备选方案包括使用放射性NAD测量Ub的ADP核糖基化，NAD水解以及SdeA对HA- Ub连接的蛋白质印迹分析。该方案将描述使用廉价的标准凝胶和考马斯染色对SdeA的泛素修饰和PR- Ub连接的抑制。
[背景]嗜肺军团菌是感染性细菌，其机会性感染肺泡巨噬细胞。这是通过吸入被污染的水气溶胶而发生的，引起潜在的致命性肺炎，称为军团菌病（McDade et ...
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| Superresolution Microscopy of Drosophila Indirect Flight Muscle Sarcomeres
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Author:
Date:
2020-06-20
[Abstract] Sarcomeres are extremely highly ordered macromolecular assemblies where proper structural organization is an absolute prerequisite to the functionality of these contractile units. Despite the wealth of information collected, the exact spatial arrangement of many of the H-zone and Z-disk proteins remained unknown. Recently, we developed a powerful nanoscopic approach to localize the sarcomeric protein components with a resolution well below the diffraction limit. The ease of sample preparation and the near crystalline structure of the Drosophila flight muscle sarcomeres make them ideally suitable for single molecule localization microscopy and structure averaging. Our approach allowed us to determine the position of dozens of H-zone and Z-disk proteins with a quasi-molecular, ...
[摘要] [摘要] 肉瘤是高度有序的大分子组装体，其中适当的结构组织是这些可收缩单位功能的绝对前提。尽管收集到大量信息，但许多H区和Z盘蛋白的确切空间排列最近未知的是，我们开发了一种强大的纳米方法来定位肌氨酸蛋白成分，其分辨率远低于衍射极限。样品制备的简便性和果蝇的近晶体结构 飞行肌肉瘤使其非常适合单分子定位显微镜检查和结构平均。我们的方法使我们能够以大约5-10 nm的准分子定位精度确定数十个H区和Z盘蛋白的位置。下文所述的协议为制备用于dSTORM成像的单个肌原纤维提供了一种简便且可重现的方法，此外还包括对定制的免费提供的软件工具箱的深入描述，以处理和定量分析原始定位数据。
[背景 ] 肉瘤的结构已通过X射线晶体学以及各种EM方法进行了详细研究，从而形成了来自许多物种的细丝和粗丝的准原子模型。尽管如此，这些检查取得了很好的结果对于肌动蛋白-肌球蛋白重叠区的了解，I带和H区复合物的空间排列仍是未知之数。荧光超分辨率显微镜（也称为纳米显微镜）的最新进展提供了远低于衍射极限的空间分辨率。值得注意的是，单分子定位显微镜（SMLM）可以非常高精度地提供多蛋白复合物的定位图，实际上达到了单个蛋白的大小分辨率（Sigal et al。，2018）。
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