1. Academic Validation
  2. Selective blockade of Cav1.2 (α1C) versus Cav1.3 (α1D) L-type calcium channels by the black mamba toxin calciseptine

Selective blockade of Cav1.2 (α1C) versus Cav1.3 (α1D) L-type calcium channels by the black mamba toxin calciseptine

  • Nat Commun. 2024 Jan 2;15(1):54. doi: 10.1038/s41467-023-43502-w.
Pietro Mesirca 1 2 Jean Chemin # 3 4 Christian Barrère # 3 4 Eleonora Torre 3 4 Laura Gallot 3 4 Arnaud Monteil 3 4 5 Isabelle Bidaud 3 4 Sylvie Diochot 4 6 Michel Lazdunski 4 6 Tuck Wah Soong 7 Stéphanie Barrère-Lemaire 3 4 Matteo E Mangoni 3 4 Joël Nargeot 8 9
Affiliations

Affiliations

  • 1 Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094, Montpellier, France. pietro.mesirca@igf.cnrs.fr.
  • 2 Laboratory of Excellence Ion Channels, Science & Therapeutics, F-06560, Valbonne, France. pietro.mesirca@igf.cnrs.fr.
  • 3 Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094, Montpellier, France.
  • 4 Laboratory of Excellence Ion Channels, Science & Therapeutics, F-06560, Valbonne, France.
  • 5 Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
  • 6 Université Côte d'Azur, CNRS, IPMC (Institut de Pharmacologie Moléculaire et Cellulaire), FHU InovPain (Fédération Hospitalo-Universitaire "Innovative Solutions in Refractory Chronic Pain"), F-06560, Valbonne, France.
  • 7 Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
  • 8 Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094, Montpellier, France. joel.nargeot@igf.cnrs.fr.
  • 9 Laboratory of Excellence Ion Channels, Science & Therapeutics, F-06560, Valbonne, France. joel.nargeot@igf.cnrs.fr.
  • # Contributed equally.
Abstract

L-type voltage-gated calcium channels are involved in multiple physiological functions. Currently available antagonists do not discriminate between L-type channel isoforms. Importantly, no selective blocker is available to dissect the role of L-type isoforms CAv1.2 and CAv1.3 that are concomitantly co-expressed in the heart, neuroendocrine and neuronal cells. Here we show that calciseptine, a snake toxin purified from mamba venom, selectively blocks CAv1.2 -mediated L-type calcium currents (ICaL) at concentrations leaving CAv1.3-mediated ICaL unaffected in both native cardiac myocytes and HEK-293T cells expressing recombinant CAv1.2 and CAv1.3 channels. Functionally, calciseptine potently inhibits cardiac contraction without altering the pacemaker activity in sino-atrial node cells, underscoring differential roles of CAv1.2- and CAv1.3 in cardiac contractility and automaticity. In summary, calciseptine is a selective L-type CAv1.2 CA2+ channel blocker and should be a valuable tool to dissect the role of these L-channel isoforms.

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