| Multicolor Stimulated Emission Depletion (STED) Microscopy to Generate High-resolution Images of Respiratory Syncytial Virus Particles and Infected Cells
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Author:
Date:
2017-09-05
[Abstract] Human respiratory syncytial virus (RSV) infection in human lung epithelial A549 cells induces filopodia, cellular protrusions consisting of F-actin, that extend to neighboring uninfected cells (Mehedi et al., 2016). High-resolution imaging via stimulated emission depletion (STED) microscopy revealed filamentous RSV particles along these filopodia, suggesting that filopodia facilitate RSV cell-to-cell spread (Mehedi et al., 2016). In this protocol, we describe how to fix, permeabilize, immunostain, and mount RSV-infected A549 cells for STED imaging. We show that STED increases resolution compared to confocal microscopy, which can be further improved by image processing using deconvolution software.
[摘要] 人肺上皮A549细胞中的呼吸道合胞病毒（RSV）感染诱导丝状伪足，由F-肌动蛋白组成的细胞突起，延伸至相邻的未感染细胞（Mehedi等，2016）。 通过受激发射耗尽（STED）显微镜的高分辨率成像显示沿着这些丝状伪足的丝状RSV颗粒，表明丝状伪足有助于RSV细胞对细胞的扩散（Mehedi等，2016）。 在本协议中，我们描述如何修复，渗透，免疫染色和挂载RSV感染的A549细胞进行STED成像。 我们显示与共聚焦显微镜相比，STED增加了分辨率，可以通过使用去卷积软件的图像处理进一步改进。
【背景】RSV形成多形性病毒颗粒，其长度大约为直径约100nm，长度大约为10μm（Bachi和Howe，1973; Mehedi等，2016）。高分辨率光学显微技术是可视化RSV感染细胞和病毒颗粒之间相互作用的关键。在最近的一项研究中，我们使用超分辨率荧光显微镜来研究人肺上皮A549细胞中的RSV细胞对细胞的扩散。
STED显微镜是超分辨率显微镜技术之一，已被开发以规避约200nm衍射屏障的光限制（Hell和Wichmann，1994; Westphal等人，2008）。 ...
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| Design and Functional Analysis of Fluorescent Nitrate and Peptide Transporter Activity Sensors in Yeast Cultures
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Author:
Date:
2016-02-05
[Abstract] This protocol describes the methods used to engineer and deploy genetically encoded fluorescence activity reporters for nitrate and peptide transporter activity in yeast cells. Fusion of the dual-affinity nitrate transceptor CHL1/AtNRT1.1/AtNPF6.3 or four different peptide transporters (AtPTR1, 2, 4, and 5) from Arabidopsis to a pair of fluorescent proteins with different spectral properties, enabled us to engineer the NiTracs (nitrate transporter activity tracking sensors) and the PepTracs (peptide transporter activity tracking sensors), ratiometric fluorescence activity sensors that monitor the activity of the plasma membrane nitrate transceptor or the peptide transporters in vivo (Ho et al., 2014). The NiTrac1 sensor responds specifically and reversibly to ...
[摘要] 该协议描述了用于在酵母细胞中设计和部署遗传编码的荧光活性报告人硝酸盐和肽转运蛋白活性的方法。将双亲硝酸盐转运体CHL1 / AtNRT1.1 / AtNPF6.3或四种不同的肽转运蛋白（AtPTR1,2,4和5）从拟南芥融合成具有不同光谱性质的一对荧光蛋白，使我们能够设计NiTracs（硝酸盐转运蛋白活性跟踪传感器）和PepTracs（肽转运蛋白活性跟踪传感器），比例式荧光活性传感器，监测体外硝酸盐转运体或肽转运蛋白的活性（Ho et al。，2014）。 NiTrac1传感器特异性和可逆地响应于硝酸盐的添加，而PepTracs通过减少供体和受体发射来响应添加二肽，而受体激发的发射保持不变，或荧光团发射比例的变化。所有传感器都适用于比例成像。 NiTrac1传感器响应[从μM到mM（Liu和Tsay，2003）]和硝酸盐转运动力学的两相动力学的相似性暗示了NiTrac1在运输循环期间提供了关于构象重排的信息，从而报告在广泛的外部硝酸盐浓度范围内的转运蛋白活性。 NiTrac的几种变体已被设计，它们对硝酸盐（NiTrac1：CHL1; NiTracT101A：CHL1T101A）的亲和力不同。 NiTrac还能识别氯酸盐。在这里，我们描述了使用分光荧光计设计，实施和检测酵母细胞中硝酸盐受体活性的简单方法。
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| Preparation of Recombinant Galectin-3 for Cancer Studies
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Author:
Date:
2016-01-05
[Abstract] Galectin-3 is a member of a class of proteins termed Galectins, characterized by their ability to bind glycans containing β-galactose (Cummings and Liu, 2009). Galectin-3 binds preferentially to proteoglycans terminating with N-acetyllactosamine (LacNAc) chains (i.e., tandem repeats of galactose) (Newlaczyl and Yu, 2011). Galectin-3 is unique among the galectins in its chimeric structure. It shares a conserved carbohydrate recognition domain (CRD) with the other galectins, but has a long amino-terminal tail that is thought to be involved in protein aggregation. It can also form homodimers through its CRD (Cummings and Liu, 2009). Galectin-3 has been found to have diverse functions in tumorigenesis including: signaling, apoptosis inhibition, immune suppression, cell growth, and ...
[摘要] Galectin-3是称为Galectins的一类蛋白质的成员，其特征在于它们结合含有β-半乳糖的聚糖的能力（Cummings和Liu，2009）。 Galectin-3优先结合以N-乙酰乳糖胺（LacNAc）链（即半乳糖的串联重复）终止的蛋白聚糖（Newlaczyl和Yu，2011）。 Galectin-3在其嵌合结构中的半乳凝素中是独一无二的。它与其他半乳凝素共享保守的碳水化合物识别结构域（CRD），但具有被认为参与蛋白质聚集的长氨基末端尾部。它也可以通过CRD形成同型二聚体（Cummings和Liu，2009）。已经发现Galectin-3在肿瘤发生中具有多种功能，包括：信号转导，凋亡抑制，免疫抑制，细胞生长和转移等。 ...
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