Characterization of the interaction of Get3 with the membrane bound receptors Get1 and Get2

将膜蛋白插入到正确的细胞膜中是一项重要的细胞任务。一类特殊的膜蛋白，被称为尾锚蛋白，由一个n端可溶性结构域和一个c端跨膜螺旋组成。将这些尾部固定的蛋白质插入到膜中需要一种特殊的机制，其中包括几种可溶性和膜结合的成分。在核糖体合成后，尾部锚定蛋白的跨膜螺旋被装载到蛋白Get3的疏水槽中。该蛋白以atp依赖的方式与两个膜结合受体Get1和Get2相互作用。虽然Get2对于将Get3招募到膜上很重要，但与Get1的相互作用打开了Get3的封闭构象并启动了插入过程。最近我们用Get1和Get2的可溶结构域求解了Get3在络合物中的结构。基于这些结果，我们现在建议研究整个复合物的结构和功能，包括跨膜部分。这两种受体分别由三个跨膜螺旋组成，并形成紧密的复合物。我们将使用诱变分析和插入试验来进一步表征这一关键过程。

The insertion of membrane proteins into the correct membrane of a cell is an important cellular task. A special class of membrane proteins, called tail-anchored proteins, consist of an N-terminal soluble domain and a single C-terminal transmembrane helix. Insertion of these tail-anchored proteins into membranes requires a specialized machinery that includes several soluble and membrane-bound components. After synthesis at the ribosome the transmembrane helix of the tail-anchored protein is loaded into a hydrophobic groove on the protein Get3. This protein interacts in an ATP-dependent manner with the two membrane bound receptors Get1 and Get2. While Get2 is important for recruiting Get3 to the membrane, the interaction with Get1 opens the closed conformation of Get3 and initiates the insertion process. Recently we have solved the structures of Get3 in complex with the soluble domains of Get1 and Get2. Based on these results we now propose to investigate the structure and function of the entire complex including the transmembrane parts. Both receptors consist of three transmembrane helices each and were shown to form a tight complex. We will use mutagenesis analysis and insertion assays to further characterize this crucial process.