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Author:
Date:
2016-02-20
[Abstract] The Rab family of small GTPases are essential regulators of membrane trafficking events. As with other small GTPase families, Rab GTPases cycle between an inactive GDP- bound state and an active GTP-bound state. Guanine nucleotide exchange factors (GEFs) promote Rab activation with the exchange of bound GDP for GTP, while GTPase-activating proteins (GAPs) regulate Rab inactivation with GTP hydrolysis. Numerous methods have been established to monitor the activation status of Rab GTPases. Of those, FRET-based methods are used to identify when and where a Rab GTPase is activated in cells. Unfortunately, the generation of such probes is complex, and only a limited number of Rabs have been probed this way. Biochemical purification of activated Rabs from cell or tissue extracts is easily ...
[摘要] 小GTP酶的Rab家族是膜运输事件的必要调节剂。与其他小GTP酶家族一样，Rab GTP酶在不活动的GDP结合状态和活性GTP结合状态之间循环。鸟嘌呤核苷酸交换因子（GEF）促进Rab激活与交换绑定GDP GTP，而GTPase激活蛋白（GAP）调节Rab失活与GTP水解。已经建立了许多方法来监测Rab GTPases的活化状态。其中，基于FRET的方法用于鉴定细胞中Rab GTPase在何时和何地被激活。不幸的是，这种探针的产生是复杂的，并且只有有限数量的Rab已经以这种方式探测。来自细胞或组织提取物的活化的Rabs的生物化学纯化通过使用已知的Rab效应结构域以下拉特定的GTP结合的Rab形式是容易实现的。虽然这种方法不是理想的详细的亚细胞定位，它可以提供Rab活动的时间分辨率。越来越多的特异性效应物的鉴定现在允许在特定条件下测试许多Rab GTP酶的活化水平。在这里，我们描述了一种亲和纯化方法使用GST融合APPL1（一种已知的RAB21效应）来测试哺乳动物细胞中的RAB21激活。该方法成功地用于测定RAB21激活状态下营养丰富与饥饿条件下的变化，并测试在此过程中MTMR13 RAB21 GEF的需求。
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Author:
Date:
2016-02-20
[Abstract] Transmembrane proteins are rarely exclusively localized to a specific vesicle or an organelle. Most transmembrane proteins undergo complicated trafficking routes. Thus, transmembrane proteins are under constant flux, and at steady state, found on a variety of vesicles or organelles. This characteristic makes the study of their trafficking routes complex, since at any given moment, different molecules are often being trafficked in opposing directions. Pulse-chase experiments can temporally track a specific pool of a transmembrane protein of interest, allowing for the kinetic description of its trafficking route. This type of technique has been used extensively to follow a large array of plasma membrane localized proteins (Diril et al., 2006; Jean et al., 2010). Here, we ...
[摘要] 跨膜蛋白很少专门定位于特定的囊泡或细胞器。大多数跨膜蛋白经历复杂的运输路线。因此，跨膜蛋白在恒定通量下，并在稳定状态，发现在各种囊泡或细胞器。这个特征使得他们的贩运路线的研究复杂，因为在任何给定时刻，不同的分子通常在相反的方向上被贩运。脉冲追踪实验可以暂时跟踪感兴趣的跨膜蛋白的特定池，允许其运输路线的动力学描述。这种类型的技术已广泛用于跟踪大量的质膜定位蛋白质（Diril等人，2006; Jean等人，2010）。在这里，我们描述了一种方法，允许研究VAMP8贩运从质膜到内溶酶体隔室。该方法用于描述 MTMR13 和 RAB21 在调节VAMP8向内溶酶体的运输中的作用（Jean等人，，2015）。
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