Charakterisierung eines neuen Sortierungsweges für ein Protein der Plasmamembran

真核细胞主要通过分泌途径合成质膜蛋白。这种转运途径始于将膜蛋白插入内质网（ER）的膜中，然后将货物囊泡转运至高尔基体并分选至最终目的地。最近的研究表明，一些分泌和膜蛋白的排序独立的sec途径。这些过程背后的分子机制是未知的。在酵母酿酒酵母中，多位膜蛋白Ist 2 p由在子细胞外周的ER附近发现的局部mRNA编码。我们已经表明，交付的Ist 2 p到PM是独立的sec介导的ER到高尔基体，内高尔基体和高尔基体到PM的运输，这表明Ist 2 p旅行的一个新的贩运途径PM。蛋白质的性质，定义他们作为货物的这种新的Ich denkepathway和介导的因素，他们的贩运是未知的。因此，我们的目标是表征Ist 2 p的分选信号，其介导sec-独立的运输到PM，并且我们将通过采用酵母遗传学来确定所涉及的因素。

Eukaryotic cells mainly use the secretory (sec)-pathway for the biogenesis of plasma membrane (PM) proteins. This transport route begins with the insertion of membrane proteins into the membrane of the endoplasmic reticulum (ER), followed by the vesicular transport of cargo to the Golgi-apparatus and the sorting to the final destination. Recent studies have suggested that some secreted and membrane proteins are sorted independently of the sec-pathway. The molecular mechanisms underlying these processes are unknown. In the yeast Saccharomyces cerevisiae, the polytopic membrane protein Ist2p is encoded by a localized mRNA that has been found in proximity of the ER at the periphery of daughter cells. We have shown hat the delivery of Ist2p to the PM is independent of sec-mediated ER to Golgi-, intra-Golgi and Golgi to PM-transport suggesting that Ist2p travels on a novel trafficking pathway to the PM. The properties of proteins that define them as cargo for this novel Ich denkepathway and the factors that mediate their trafficking are unknown. Therefore we aim to characterize the sorting signals of Ist2p, which mediate the sec-independent transport to the PM, and we are going to identify the involved factors by employing yeast genetics.