Antón-Plágaro Carlos, Chen Kai-En, Guo Qian, Liu Meihan, Evans Ashley J, Lewis Philip A, Heesom Kate J, Wilkinson Kevin A, Collins Brett M, Cullen Peter J
School of Biochemistry, Faculty of Life Sciences, Biomedical Sciences Building, University of Bristol, Bristol, UK.
The University of Queensland, Institute for Molecular Bioscience, St Lucia, Queensland, Australia.
Nat Commun. 2025 Jul 30;16(1):6990. doi: 10.1038/s41467-025-61802-1.
Endosomal retrieval and recycling of integral cargo proteins is essential for cell and organism development and homeostasis and is orchestrated through a specialised endosomal nanodomain, the retrieval sub-domain. Sub-domain dysfunction is associated with human disease, but our mechanistic understanding of its function remains poorly described. Here, using proximity proteomics of retrieval sub-domain components Retromer and Retriever we identify mechanistic details of retrieval sub-domain composition and organization, including an unrecognised complexity in the interface with RAB GTPase switching. Combining X-ray crystallography and in silico predictions with biochemical and cellular analysis, we reveal that Retromer directly associates and recruits the RAB10 regulators DENND4A, DENND4C, TBC1D1, and TBC1D4, and the RAB35 regulator TBC1D13 to regulate retrieval sub-domain function. The retrieval sub-domain therefore constitutes a hub for integrating cargo recycling with the regulated switching of selected RAB GTPases. We propose this constitutes a major component of the neuroprotective role of the retrieval sub-domain.
内体中整合型货物蛋白的回收和再循环对于细胞和生物体的发育及稳态至关重要，且是通过一个特殊的内体纳米结构域——回收亚结构域来精心安排的。亚结构域功能障碍与人类疾病相关，但我们对其功能的机制理解仍描述甚少。在此，我们利用回收亚结构域组分逆转录酶复合物（Retromer）和Retriever的邻近蛋白质组学方法，确定了回收亚结构域组成和组织的机制细节，包括与RAB GTP酶转换界面中未被认识到的复杂性。通过将X射线晶体学和计算机模拟预测与生化及细胞分析相结合，我们揭示逆转录酶复合物直接结合并招募RAB10调节因子DENND4A、DENND4C、TBC1D1和TBC1D4，以及RAB35调节因子TBC1D13来调节回收亚结构域功能。因此，回收亚结构域构成了一个将货物再循环与选定RAB GTP酶的调节转换整合在一起的枢纽。我们提出，这构成了回收亚结构域神经保护作用的一个主要组成部分。
