8e56
From Proteopedia
Rabbit L-type voltage-gated calcium channel Cav1.1 in the presence of Amiodarone at 2.8 Angstrom resolution
Structural highlights
FunctionCAC1S_RABIT Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The isoform alpha-1S gives rise to L-type calcium currents. Long-lasting (L-type) calcium channels belong to the 'high-voltage activated' (HVA) group. They are blocked by dihydropyridines (DHP), phenylalkylamines, benzothiazepines, and by omega-agatoxin-IIIA (omega-Aga-IIIA). They are however insensitive to omega-conotoxin-GVIA (omega-CTx-GVIA) and omega-agatoxin-IVA (omega-Aga-IVA). Calcium channels containing the alpha-1S subunit play an important role in excitation-contraction coupling in skeletal muscle. Publication Abstract from PubMedDrug-drug interaction of the antiviral sofosbuvir and the antiarrhythmics amiodarone has been reported to cause fatal heartbeat slowing. Sofosbuvir and its analog, MNI-1, were reported to potentiate the inhibition of cardiomyocyte calcium handling by amiodarone, which functions as a multi-channel antagonist, and implicate its inhibitory effect on L-type Ca(v) channels, but the molecular mechanism has remained unclear. Here we present systematic cryo-EM structural analysis of Ca(v)1.1 and Ca(v)1.3 treated with amiodarone or sofosbuvir alone, or sofosbuvir/MNI-1 combined with amiodarone. Whereas amiodarone alone occupies the dihydropyridine binding site, sofosbuvir is not found in the channel when applied on its own. In the presence of amiodarone, sofosbuvir/MNI-1 is anchored in the central cavity of the pore domain through specific interaction with amiodarone and directly obstructs the ion permeation path. Our study reveals the molecular basis for the physical, pharmacodynamic interaction of two drugs on the scaffold of Ca(v) channels. Structural basis for the severe adverse interaction of sofosbuvir and amiodarone on L-type Ca(v) channels.,Yao X, Gao S, Wang J, Li Z, Huang J, Wang Y, Wang Z, Chen J, Fan X, Wang W, Jin X, Pan X, Yu Y, Lagrutta A, Yan N Cell. 2022 Nov 17:S0092-8674(22)01370-8. doi: 10.1016/j.cell.2022.10.024. PMID:36417914[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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