A potent voltage-gated calcium channel inhibitor engineered from a nanobody targeted to auxiliary Ca<sub>V</sub>β subunits.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31403402.
- Also identified by DOI 10.7554/eLife.49253 and PMC identifier 6701945.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Inhibiting high-voltage-activated calcium channels (HVACCs; Ca<sub>V</sub>1/Ca<sub>V</sub>2) is therapeutic for myriad cardiovascular and neurological diseases. For particular applications, genetically-encoded HVACC blockers may enable channel inhibition with greater tissue-specificity and versatility than is achievable with small molecules. Here, we engineered a genetically-encoded HVACC inhibitor by first isolating an immunized llama nanobody (nb.F3) that binds auxiliary HVACC Ca<sub>V</sub>β subunits. Nb.F3 by itself is functionally inert, providing a convenient vehicle to target active moieties to Ca<sub>V</sub>β-associated channels. Nb.F3 fused to the catalytic HECT domain of Nedd4L (Ca<sub>V</sub>-aβlator), an E3 ubiquitin ligase, ablated currents from diverse HVACCs reconstituted in HEK293 cells, and from endogenous Ca<sub>V</sub>1/Ca<sub>V</sub>2 channels in mammalian cardiomyocytes, dorsal root ganglion neurons, and pancreatic β cells. In cardiomyocytes, Ca<sub>V</sub>-aβlator redistributed Ca<sub>V</sub>1.2 channels from dyads to Rab-7-positive late endosomes. This work introduces Ca<sub>V</sub>-aβlator as a potent genetically-encoded HVACC inhibitor, and describes a general approach that can be broadly adapted to generate versatile modulators for macro-molecular membrane protein complexes.
Medical subject headings
- Biological Products
- Calcium Channel Blockers
- Calcium Channels
- Single-Domain Antibodies