Kinetics and mapping of Ca-driven calmodulin conformations on skeletal and cardiac muscle ryanodine receptors.

ABSTRACT: Calmodulin transduces [Ca²⁺] information regulating the rhythmic Ca²⁺ cycling between the sarcoplasmic reticulum and cytoplasm during contraction and relaxation in cardiac and skeletal muscle. However, the structural dynamics by which calmodulin modulates the sarcoplasmic reticulum Ca²⁺ release channel, the ryanodine receptor, at physiologically relevant [Ca²⁺] is unknown. Using fluorescence lifetime FRET, we resolve different structural states of calmodulin and Ca²⁺-driven shifts in the conformation of calmodulin bound to ryanodine receptor. Skeletal and cardiac ryanodine receptor isoforms show different calmodulin-ryanodine receptor conformations, as well as binding and structural kinetics with 0.2-ms resolution, which reflect differ

SUBMITTER: Rebbeck RT 

PROVIDER: S-EPMC11180167 | biostudies-literature | 2024 Jun

REPOSITORIES: biostudies-literature