The foot structure from the type 1 ryanodine receptor is required for functional coupling to store-operated channels

J Biol Chem. 2005 Jul 1;280(26):24804-15. doi: 10.1074/jbc.M501487200. Epub 2005 May 4.

Abstract

In the present study we have explored structural determinants of the functional interaction between skeletal muscle ryanodine receptor (RyR1) and transient receptor potential channel 1 (TRPC1) channels expressed in Chinese hamster ovary cells. We have illustrated a functional interaction between TRPC1 channels and RyR1 for the regulation of store-operated calcium entry (SOCE) initiated after releasing calcium from a caffeine-sensitive intracellular calcium pool. RNA interference experiments directed to reduce the amount of TRPC1 protein indicate that RyR1 associates to at least two different types of store-operated channels (SOCs), one dependent and one independent of TRPC1. In contrast, bradykinin-induced SOCE is completely dependent on the presence of TRPC1 protein, as we have previously illustrated. Removing the foot structure from RyR1 results in normal caffeine-induced release of calcium from internal stores but abolishes the activation of SOCE, indicating that this structure is require for functional coupling to SOCs. The footless RyR1 protein shows a different cellular localization when compared with wild type RyR1. The later protein shows a higher percentage of colocalization with FM-464, a marker of plasma membrane. The implications of the foot structure for the functional and physical coupling to TRPC and SOCs is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Bradykinin / chemistry
  • Bradykinin / pharmacology
  • CHO Cells
  • Caffeine / pharmacology
  • Calcium / chemistry
  • Calcium / metabolism
  • Calcium Channels / chemistry*
  • Calcium Channels / metabolism
  • Calibration
  • Cell Membrane / metabolism
  • Cricetinae
  • Cytosol / metabolism
  • Dose-Response Relationship, Drug
  • Electrophysiology
  • Microscopy, Confocal
  • Microscopy, Fluorescence
  • Models, Biological
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA Interference
  • RNA, Double-Stranded
  • RNA, Messenger / metabolism
  • Rabbits
  • Reverse Transcriptase Polymerase Chain Reaction
  • Ryanodine Receptor Calcium Release Channel / chemistry*
  • Subcellular Fractions
  • Time Factors

Substances

  • Calcium Channels
  • RNA, Double-Stranded
  • RNA, Messenger
  • Ryanodine Receptor Calcium Release Channel
  • Caffeine
  • Bradykinin
  • Calcium