Crystal structures of wild type and disease mutant forms of the ryanodine receptor SPRY2 domain

Nat Commun. 2014 Nov 5;5:5397. doi: 10.1038/ncomms6397.

Abstract

Ryanodine receptors (RyRs) form channels responsible for the release of Ca(2+) from the endoplasmic and sarcoplasmic reticulum. The SPRY2 domain in the skeletal muscle isoform (RyR1) has been proposed as a direct link with L-type calcium channels (CaV1.1), allowing for direct mechanical coupling between plasma membrane depolarization and Ca(2+) release. Here we present the crystal structures of the SPRY2 domain from RyR1 and RyR2 at 1.34-1.84 Å resolution. They form two antiparallel β sheets establishing a core, and four additional modules of which several are required for proper folding. A buried disease mutation, linked to hypertrophic cardiomyopathy and loss-of-function, induces local misfolding and strong destabilization. Isothermal titration calorimetry experiments negate the RyR1 SPRY2 domain as the major link with CaV1.1. Instead, docking into full-length RyR1 cryo-electron microscopy maps suggests that the SPRY2 domain forms a link between the N-terminal gating ring and the clamp region.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cardiomyopathy, Hypertrophic / genetics
  • Humans
  • Mice
  • Molecular Docking Simulation
  • Molecular Sequence Data
  • Mutation
  • Protein Conformation
  • Rabbits
  • Ryanodine Receptor Calcium Release Channel / chemistry*
  • Ryanodine Receptor Calcium Release Channel / genetics

Substances

  • Ryanodine Receptor Calcium Release Channel