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. 2025 Jan;182(1):181-197.
doi: 10.1111/bph.17357. Epub 2024 Oct 7.

Inactivation induced by pathogenic Cav1.3 L-type Ca2+-channel variants enhances sensitivity for dihydropyridine Ca2+ channel blockers

Ferenc Török  1 , Sarah Salamon  2 , Nadine J Ortner  1 , Monica L Fernández-Quintero  3 , Jan Matthes  2 , Jörg Striessnig  1
Affiliations

Inactivation induced by pathogenic Cav1.3 L-type Ca2+-channel variants enhances sensitivity for dihydropyridine Ca2+ channel blockers

Ferenc Török et al. Br J Pharmacol. 2025 Jan.

Abstract

Background and purpose: Pathogenic gain-of-function mutations in Cav1.3 L-type voltage-gated Ca2+-channels (CACNA1D) cause neurodevelopmental disorders with or without endocrine symptoms. We aimed to confirm a pathogenic gain-of function phenotype of CACNA1D de novo missense mutations A749T and L271H, and investigated the molecular mechanism causing their enhanced sensitivity for the Ca2+-channel blocker isradipine, a potential therapeutic for affected patients.

Experimental approach: Wildtype and mutant channels were expressed in tsA-201 cells and their gating analysed using whole-cell and single-channel patch-clamp recordings. The voltage-dependence of isradipine action was quantified using protocols inducing variable fractions of inactivated channels. The molecular basis for altered channel gating in the mutants was investigated using in silico modelling and molecular dynamics simulations.

Key results: Both mutations were confirmed pathogenic due to characteristic shifts of voltage-dependent activation and inactivation towards negative potentials (~20 mV). At negative holding potentials both mutations showed significantly higher isradipine sensitivity compared to wildtype. The affinity for wildtype and mutant channels increased with channel inactivation as predicted by the modulated receptor hypothesis (30- to 40-fold). The IC50 was indistinguishable for wildtype and mutants when >50% of channels were inactivated.

Conclusions and implications: Mutations A749T and L271H induce pathogenic gating changes. Like wildtype, isradipine inhibition is strongly voltage-dependent. Our data explains their apparent higher drug sensitivity at a given negative voltage by the availability of more inactivated channels due to their more negative inactivation voltage range. Low nanomolar isradipine concentrations will only inhibit Cav1.3 channels in neurons during prolonged depolarized states without selectivity for mutant channels.

Keywords: CACNA1D; channelopathies; gain‐of‐function mutations; isradipine; voltage‐gated calcium channels.

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References

REFERENCES

    1. Abraham, M. J., Murtola, T., Schulz, R., Páll, S., Smith, J. C., Hess, B., & Lindahl, E. (2015). GROMACS: High performance molecular simulations through multi‐level parallelism from laptops to supercomputers. SoftwareX, 1‐2, 19–25. https://doi.org/10.1016/j.softx.2015.06.001
    1. Alexander, S. P. H., Kelly, E., Mathie, A., Peters, J. A., Veale, E. L., Armstrong, J. F., Buneman, O. P., Faccenda, E., Harding, S. D., Spedding, M., Cidlowski, J. A., Fabbro, D., Davenport, A. P., Striessnig, J., Davies, J. A., Ahlers‐Dannen, K. E., … Zolghadri, Y. (2023). The Concise Guide to PHARMACOLOGY 2023/24: Introduction and other protein targets. British Journal of Pharmacology, 180, S1–S22. https://doi.org/10.1111/bph.16176
    1. Alexander, S. P. H., Mathie, A. A., Peters, J. A., Veale, E. L., Striessnig, J., Kelly, E., Armstrong, J. F., Faccenda, E., Harding, S. D., Davies, J. A., Aldrich, R. W., Attali, B., Baggetta, A. M., Becirovic, E., Biel, M., Bill, R. M., Caceres, A. I., Catterall, W. A., Conner, A. C., … Zhu, M. (2023). The Concise Guide to PHARMACOLOGY 2023/24: Ion channels. British Journal of Pharmacology, 180(Suppl 2), S145–s222. https://doi.org/10.1111/bph.16178
    1. Alexander, S. P. H., Roberts, R. E., Broughton, B. R. S., Sobey, C. G., George, C. H., Stanford, S. C., Cirino, G., Docherty, J. R., Giembycz, M. A., Hoyer, D., Insel, P. A., Izzo, A. A., Ji, Y., MacEwan, D. J., Mangum, J., Wonnacott, S., & Ahluwalia, A. (2018). Goals and practicalities of immunoblotting and immunohistochemistry: A guide for submission to the British Journal of Pharmacology. British Journal of Pharmacology, 175, 407–411. https://doi.org/10.1111/bph.14112
    1. Bean, B. P. (1984). Nitrendipine block of cardiac calcium channels: High‐affinity binding to the inactivated state. Proceedings of the National Academy of Sciences of the United States of America, 81, 6388–6392. https://doi.org/10.1073/pnas.81.20.6388

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