TY - JOUR TI - Determinants shaping the nanoscale architecture of the mouse rod outer segment AU - Pöge, Matthias AU - Mahamid, Julia AU - Imanishi, Sanae S AU - Plitzko, Jürgen M AU - Palczewski, Krzysztof AU - Baumeister, Wolfgang A2 - Zanetti, Giulia A2 - Pfeffer, Suzanne R A2 - Zanetti, Giulia VL - 10 PY - 2021 DA - 2021/12/21 SP - e72817 C1 - eLife 2021;10:e72817 DO - 10.7554/eLife.72817 UR - https://doi.org/10.7554/eLife.72817 AB - The unique membrane organization of the rod outer segment (ROS), the specialized sensory cilium of rod photoreceptor cells, provides the foundation for phototransduction, the initial step in vision. ROS architecture is characterized by a stack of identically shaped and tightly packed membrane disks loaded with the visual receptor rhodopsin. A wide range of genetic aberrations have been reported to compromise ROS ultrastructure, impairing photoreceptor viability and function. Yet, the structural basis giving rise to the remarkably precise arrangement of ROS membrane stacks and the molecular mechanisms underlying genetically inherited diseases remain elusive. Here, cryo-electron tomography (cryo-ET) performed on native ROS at molecular resolution provides insights into key structural determinants of ROS membrane architecture. Our data confirm the existence of two previously observed molecular connectors/spacers which likely contribute to the nanometer-scale precise stacking of the ROS disks. We further provide evidence that the extreme radius of curvature at the disk rims is enforced by a continuous supramolecular assembly composed of peripherin-2 (PRPH2) and rod outer segment membrane protein 1 (ROM1) oligomers. We suggest that together these molecular assemblies constitute the structural basis of the highly specialized ROS functional architecture. Our Cryo-ET data provide novel quantitative and structural information on the molecular architecture in ROS and substantiate previous results on proposed mechanisms underlying pathologies of certain PRPH2 mutations leading to blindness. KW - photoreceptor KW - rod outer segment KW - disk rim KW - protein scaffold KW - membrane curvature JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -