RyR1-targeted drug discovery pipeline integrating FRET-based high-throughput screening and human myofiber dynamic Ca2+ assays

Robyn T. Rebbeck, Daniel P. Singh, Kevyn A. Janicek, Donald M. Bers, David D. Thomas, Bradley S. Launikonis, Razvan L. Cornea

Research output: Contribution to journalArticle


Elevated cytoplasmic [Ca2+] is characteristic in severe skeletal and cardiac myopathies, diabetes, and neurodegeneration, and partly results from increased Ca2+ leak from sarcoplasmic reticulum stores via dysregulated ryanodine receptor (RyR) channels. Consequently, RyR is recognized as a high-value target for drug discovery to treat such pathologies. Using a FRET-based high-throughput screening assay that we previously reported, we identified small-molecule compounds that modulate the skeletal muscle channel isoform (RyR1) interaction with calmodulin and FK506 binding protein 12.6. Two such compounds, chloroxine and myricetin, increase FRET and inhibit [3H]ryanodine binding to RyR1 at nanomolar Ca2+. Both compounds also decrease RyR1 Ca2+ leak in human skinned skeletal muscle fibers. Furthermore, we identified compound concentrations that reduced leak by > 50% but only slightly affected Ca2+ release in excitation-contraction coupling, which is essential for normal muscle contraction. This report demonstrates a pipeline that effectively filters small-molecule RyR1 modulators towards clinical relevance.

Original languageEnglish (US)
Article number1791
JournalScientific reports
Issue number1
StatePublished - Dec 1 2020


ASJC Scopus subject areas

  • General

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