BN Seminar - Rouslan Efremov (VIB Brussels): "Structural insight into calcium signalling in muscular contraction."





Room E


Structural insight into calcium signalling in muscular contraction. 

Rouslan Efremov

SBRC, VIB, Vrije Universiteit Brussel, Brussels, Belgium

Concentration of calcium ions in cytoplasm of eukaryotic cells regulates many physiological processes including transcription, cell cycle, apoptosis and muscular contraction. Muscles are contracted at high and relaxed at low calcium concentration in the cytoplasm. Muscle contraction is initiated by the release of Ca2+ from the sarcoplasmic reticulum into the cytoplasm of myocytes through ryanodine receptors (RyR). RyRs are the 2.2 MDa homotetrameric ion channels that are primarily gated by changes in concentration of calcium ions in the cytoplasm and are regulated by multiple factors including ions, small organic molecules, and interactions with other proteins.  Hundreds of mutations in RyRs have been associated with human diseases. The molecular mechanism underlying the complex regulation of RyR is still poorly understood. I will present the architecture of RyR determined by single particle cryo-EM and will show how changes in calcium concentration induce conformational changes in RyR resulting in the channel gating.