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Updated: May 9, 2026
11:31
Crystal Structure of the N-terminal Domain of Ryanodine Receptor from Plutella xylostella
Published on: November 30, 2018
Two potential calmodulin-binding sequences in the ryanodine receptor contribute to a mobile, intra-subunit
Xiaojun Huang1, Ying Liu, Ruiwu Wang
1Wadsworth Center, New York State Department of Health, Albany, New York 12201, USA.
Journal of Cell Science
|July 23, 2013
Summary
Calmodulin binds to multiple regions on the ryanodine receptor 2 (RyR2), forming an intra-subunit pocket. Caffeine induces conformational changes in these CaM-binding regions during RyR2 channel gating.
Area of Science:
- Molecular biology
- Biophysics
- Cardiology
Background:
- Calmodulin (CaM) is a calcium-sensing protein that modulates ryanodine receptor (RyR) function.
- Previous studies identified multiple potential CaM-binding regions within the RyR sequence.
Purpose of the Study:
- To map proposed CaM-binding sequences onto the 3D structure of cardiac RyR2.
- To investigate the conformational dynamics of these regions using FRET in live cells.
Main Methods:
- Cryo-electron microscopy was used to map GFP-tagged CaM-binding sequences.
- A FRET pair (CFP/YFP) was engineered into RyR2 at specific sites (Arg3595 and Lys4269).
- HEK293 cells expressing dual-labeled RyR2 were analyzed for FRET signals in response to caffeine.
Main Results:
- Two potential CaM-binding regions (Arg3595 and Lys4269) are in close proximity on the RyR2 structure.
- Significant FRET signals were detected in live cells, indicating interaction between the labeled regions.
- Caffeine treatment altered the FRET signal, suggesting conformational changes in response to channel activation.
Conclusions:
- Multiple RyR2 regions likely form an intra-subunit CaM-binding pocket.
- This pocket undergoes conformational changes during RyR2 channel gating, influenced by activators like caffeine.
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