National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
引用
ジャーナル: Structure / 年: 2020 タイトル: Mammalian Retromer Is an Adaptable Scaffold for Cargo Sorting from Endosomes. 著者: Amy K Kendall / Boyang Xie / Peng Xu / Jue Wang / Rodger Burcham / Meredith N Frazier / Elad Binshtein / Hui Wei / Todd R Graham / Terunaga Nakagawa / Lauren P Jackson / 要旨: Metazoan retromer (VPS26/VPS35/VPS29) associates with sorting nexins on endosomal tubules to sort proteins to the trans-Golgi network or plasma membrane. Mechanisms of metazoan retromer assembly ...Metazoan retromer (VPS26/VPS35/VPS29) associates with sorting nexins on endosomal tubules to sort proteins to the trans-Golgi network or plasma membrane. Mechanisms of metazoan retromer assembly remain undefined. We combine single-particle cryoelectron microscopy with biophysical methods to uncover multiple oligomer structures. 2D class averages reveal mammalian heterotrimers; dimers of trimers; tetramers of trimers; and flat chains. These species are further supported by biophysical solution studies. We provide reconstructions of all species, including key sub-structures (∼5 Å resolution). Local resolution variation suggests that heterotrimers and dimers adopt multiple conformations. Our structures identify a flexible, highly conserved electrostatic dimeric interface formed by VPS35 subunits. We generate structure-based mutants to disrupt this interface in vitro. Equivalent mutations in yeast demonstrate a mild cargo-sorting defect. Our data suggest the metazoan retromer is an adaptable and plastic scaffold that accommodates interactions with different sorting nexins to sort multiple cargoes from endosomes their final destinations.