The structural GDP/GTP cycle of Rab11 reveals a novel interface involved in the dynamics of recycling endosomes
The structural GDP/GTP cycle of Rab11 reveals a novel interface involved in the dynamics of recycling endosomes
复制标题
DOI：
10.1074/jbc.m310558200
复制
发表时间：
2004-03-19
影响因子：
4.8
通讯作者：
Cherfils, J
中科院分区：
文献类型：
--
作者：
Pasqualato, S;Senic-Matuglia, F;Cherfils, J
小GTP结合蛋白Rab 11是循环内体动力学的重要调节因子。在这里，我们报告的GDP/GTP周期的人Rab 11 a的晶体学分析，和基于结构的诱变研究，确定了一种新的突变表型。晶体结构显示核苷酸敏感开关1和2区域不同于其他Rab蛋白。在Rab 11-GDP中，它们有助于形成紧密堆积的对称二聚体，其可能与细胞膜相关，并允许Rab 11进行GDP/GTP循环而不回收到胞质溶胶中。活性Rab 11的结构描绘了一个三维网站，其中包括开关1，并从Rab 3/Rabphilin接口定义的网站分开。建议形成一种新的接口Rab 11合作伙伴兼容的同时结合的另一个合作伙伴在Rabphilin接口。Ser（29）突变为Phe在这个表位导致的形态学修饰的回收室，这是不同于那些诱导的经典显性阴性和组成型活性Rab 11突变体。回收核内体凝聚在核周区域，他们保留回收转铁蛋白，他们聚集Rab 11和EEA 1阳性膜。总而言之，我们的研究表明，这种突变损害了Rab 11相互作用的特定子集，可能是那些参与驱动缓慢循环途径的基于细胞因子的运动的分子。
The small GTP-binding protein Rab11 is an essential regulator of the dynamics of recycling endosomes. Here we report the crystallographic analysis of the GDP/GTP cycle of human Rab11a, and a structure-based mutagenesis study that identifies a novel mutant phenotype. The crystal structures show that the nucleotide-sensitive switch 1 and 2 regions differ from those of other Rab proteins. In Rab11-GDP, they contribute to a close packed symmetrical dimer, which may associate to membranes in the cell and allow Rab11 to undergo GDP/GTP cycles without recycling to the cytosol. The structure of active Rab11 delineates a three-dimensional site that includes switch 1 and is separate from the site defined by the Rab3/Rabphilin interface. It is proposed to form a novel interface for a Rab11 partner compatible with the simultaneous binding of another partner at the Rabphilin interface. Mutation of Ser(29) to Phe in this epitope resulted in morphological modifications of the recycling compartment that are distinct from those induced by the classical dominant-negative and constitutively active Rab11 mutants. Recycling endosomes condensed in the perinuclear region where they retained recycling transferrin, and they clustered Rab11- and EEA1-positive membranes. Altogether, our study suggests that this mutation impairs a specific subset of Rab11 interactions, possibly those involved in cytoskeleton-based movements driving the slow recycling pathway.