Architecture of the human erythrocyte ankyrin-1 complex

Cryo-EM structures of human erythrocyte ankyrin-1 complex offer insights into the architecture of the RBC membrane and show how ankyrins can simultaneously recruit different membrane proteins to enable functional organization of membrane transport processes. The stability and shape of the erythrocyte membrane is provided by the ankyrin-1 complex, but how it tethers the spectrin-actin cytoskeleton to the lipid bilayer and the nature of its association with the band 3 anion exchanger and the Rhesus glycoproteins remains unknown. Here we present structures of ankyrin-1 complexes purified from human erythrocytes. We reveal the architecture of a core complex of ankyrin-1, the Rhesus proteins RhAG and RhCE, the band 3 anion exchanger, protein 4.2, glycophorin A and glycophorin B. The distinct T-shaped conformation of membrane-bound ankyrin-1 facilitates recognition of RhCE and, unexpectedly, the water channel aquaporin-1. Together, our results uncover the molecular details of ankyrin-1 association with the erythrocyte membrane, and illustrate the mechanism of ankyrin-mediated membrane protein clustering.

Automated summary

The cryo-EM structures of the human erythrocyte ankyrin-1 complex provide insights into the architecture of the RBC membrane and demonstrate how ankyrins recruit different membrane proteins to enable membrane transport processes.