| Cell-free Fluorescent Intra-Golgi Retrograde Vesicle Trafficking Assay
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Author:
Date:
2017-11-20
[Abstract] Intra-Golgi retrograde vesicle transport is used to traffic and sort resident Golgi enzymes to their appropriate cisternal locations. An assay was established to investigate the molecular details of vesicle targeting in a cell-free system. Stable cell lines were generated in which the trans-Golgi enzyme galactosyltransferase (GalT) was tagged with either CFP or YFP. Given that GalT is recycled to the cisterna where it is located at steady state, GalT-containing vesicles target GalT-containing cisternal membranes. Golgi membranes were therefore isolated from GalT-CFP expressing cells, ...
[摘要] 高尔基体内的逆行囊泡运输被用来运送和分类高尔基酶到适当的池内位置。建立了一个检测方法来研究无细胞系统中囊泡靶向的分子细节。生成了稳定的细胞系，其中反式 - 高尔基酶半乳糖基转移酶（GalT）用CFP或YFP标记。考虑到GalT被循环到稳定状态的小池中，含有GalT的囊泡将靶向含有GalT的池内膜。因此从表达GalT-CFP的细胞分离高尔基体膜，而从GalT-YFP表达细胞制备囊泡。在胞质溶胶和能量再生混合物的存在下，在37℃孵育CFP标记的高尔基体和YFP标记的囊泡，与在冰上孵育相比，在混合物的荧光成像后CFP-YFP共定位显着增加。该测定被验证需要能量，蛋白质和生理学重要的运输组分，如Rab GTP酶和保守寡聚体高尔基体系复合物。该测定法可用于调查影响高尔基体运输机器的生理和病理变化，特别是囊泡束缚。
【背景】细胞内囊泡靶向的分子机制对于解释糖基化稳态，神经递质释放，信号受体的调节和营养摄取等方面的解释是重要的（Ungar和Hughson，2003; ...
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| Accurate, Streamlined Analysis of mRNA Translation by Sucrose Gradient Fractionation
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Author:
Date:
2017-10-05
[Abstract] The efficiency with which proteins are produced from mRNA molecules can vary widely across transcripts, cell types, and cellular states. Methods that accurately assay the translational efficiency of mRNAs are critical to gaining a mechanistic understanding of post-transcriptional gene regulation. One way to measure translational efficiency is to determine the number of ribosomes associated with an mRNA molecule, normalized to the length of the coding sequence. The primary method for this analysis of individual mRNAs is sucrose gradient fractionation, which physically separates mRNAs based on ...
[摘要] 从mRNA分子产生蛋白质的效率可以在转录本，细胞类型和细胞状态之间广泛变化。准确测定mRNA翻译效率的方法对获得对转录后基因调控的机理理解至关重要。测量翻译效率的一种方法是确定与mRNA分子相关的核糖体的数目，归一化为编码序列的长度。分析单个mRNA的主要方法是蔗糖梯度分级，其基于结合核糖体的数目物理分离mRNA。在这里，我们描述了精确分析与核糖体的mRNA相关性的简化方案。与以前的方案相比，我们的方法结合内部控制和改进的缓冲条件，共同减少由非特异性mRNA - 核糖体相互作用引起的伪像。此外，我们的直接分数qRT-PCR方案消除了从梯度部分中RNA纯化的需要，这大大减少了所需的手动时间量，并促进了多个条件或基因靶标的并行分析。此外，在该过程中不产生苯酚废物。我们最初开发了协议来研究S-HAC1 mRNA的翻译抑制状态。但是我们还详细介绍了哺乳动物细胞系和组织的适应程序。
【背景】将mRNA翻译成蛋白质是一种高度调节的过程，其可以以不同的速率发生，这取决于基因，细胞环境或环境。翻译起始，延伸和终止的每个步骤可以是最终影响与mRNA相关的核糖体数量的调节点（Dever和Green，2012; ...
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