Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, United States.
Curr Opin Struct Biol. 2012 Apr;22(2):217-24. doi: 10.1016/j.sbi.2012.03.001. Epub 2012 Mar 21.
Biosynthesis of membrane proteins requires that hydrophobic transmembrane (TM) regions be shielded from the cytoplasm while being directed to the correct membrane. Tail-anchored (TA) membrane proteins, characterized by a single C-terminal TM, pose an additional level of complexity because they must be post-translationally targeted. In eukaryotes, the GET pathway shuttles TA-proteins to the endoplasmic reticulum. The key proteins required in yeast (Sgt2 and Get1-5) have been under extensive structural and biochemical investigation during recent years. The central protein Get3 utilizes nucleotide linked conformational changes to facilitate substrate loading and targeting. Here we analyze this complex process from a structural perspective, as understood in yeast, and further postulate on similar pathways in other domains of life.
膜蛋白的生物合成需要将疏水性跨膜（TM）区域与细胞质隔离，同时将其定向到正确的膜上。尾部锚定（TA）膜蛋白的特征是单个 C 末端 TM，这增加了复杂性，因为它们必须进行翻译后靶向。在真核生物中，GET 途径将 TA-蛋白运送到内质网。近年来，酵母中所需的关键蛋白（Sgt2 和 Get1-5）已经进行了广泛的结构和生化研究。中心蛋白 Get3 利用核苷酸连接的构象变化来促进底物加载和靶向。在这里，我们从酵母中理解的结构角度来分析这个复杂的过程，并进一步推测其他生命领域的类似途径。
