Department of Biology/Chemistry, Biochemistry section, University of Osnabrück, Osnabrück 49076, Germany.
Traffic. 2011 Nov;12(11):1592-603. doi: 10.1111/j.1600-0854.2011.01252.x. Epub 2011 Aug 18.
A large number of proteins involved in the biogenesis of yeast endosomes and vacuoles have been identified based on screens that scored for inactivation of proteins. Such screens may, however, miss important regulators of the pathway. Here, we present a visual screen in which we examined the effects on vacuole morphology if any of the 6153 yeast open reading frames was overexpressed. Using a progressive screening procedure, we could identify a total of 53 genes. Among the most striking endosomal proteins are the CORVET/HOPS subunits Vps3, Vps18 and Vps39 and the putative tethering inhibitor Ivy1. Furthermore, six endosomal sorting complex related to transport (ESCRT) proteins led to altered vacuole morphology if overproduced. Among the novel proteins, we identify Yer128w as an endosomal protein that interacts with the AAA-ATPase Vps4, and therefore named it Vfa1 (Vps Four-Associated 1). We present evidence on the possible role of these novel proteins in trafficking to the vacuole. Our data provide novel insights into the regulation of protein trafficking.
大量参与酵母内体和液泡生物发生的蛋白质已通过筛选失活蛋白的方法被鉴定。然而，这种筛选方法可能会错过该途径的重要调节因子。在这里，我们进行了一个可视化筛选实验，如果酵母开放阅读框中的任何一个过表达，我们将检查其对液泡形态的影响。通过逐步筛选程序，我们总共可以鉴定出 53 个基因。在内体蛋白中，最引人注目的是 CORVET/HOPS 亚基 Vps3、Vps18 和 Vps39 以及假定的 tethering 抑制剂 Ivy1。此外，如果过表达六个内体分选复合物相关的运输（ESCRT）蛋白，也会导致液泡形态发生改变。在这些新蛋白中，我们鉴定出 Yer128w 是一种与 AAA-ATPase Vps4 相互作用的内体蛋白，并将其命名为 Vfa1（Vps Four-Associated 1）。我们提供了这些新蛋白在运输到液泡中可能发挥作用的证据。我们的数据为蛋白质运输的调控提供了新的见解。
