Download MendeleyA previously unrecognized superfamily of macro-conotoxins includes an inhibitor of the sensory neuron calcium channel Cav2.3.
Hackney, C.M., Florez Salcedo, P., Mueller, E., Koch, T.L., Kjelgaard, L.D., Watkins, M., Zachariassen, L., Tuelund, P.S., McArthur, J.R., Adams, D.J., Kristensen, A.S., Olivera, B., Finol-Urdaneta, R.K., Safavi-Hemami, H., Morth, J.P., Ellgaard, L.(2023) PLoS Biol 21: e3002217-e3002217
- PubMed: 37535677
- DOI: https://doi.org/10.1371/journal.pbio.3002217
- Primary Citation of Related Structures:
7PX1, 7PX2 - PubMed Abstract:
Animal venom peptides represent valuable compounds for biomedical exploration. The venoms of marine cone snails constitute a particularly rich source of peptide toxins, known as conotoxins. Here, we identify the sequence of an unusually large conotoxin, Mu8.1, which defines a new class of conotoxins evolutionarily related to the well-known con-ikot-ikots and 2 additional conotoxin classes not previously described. The crystal structure of recombinant Mu8.1 displays a saposin-like fold and shows structural similarity with con-ikot-ikot. Functional studies demonstrate that Mu8.1 curtails calcium influx in defined classes of murine somatosensory dorsal root ganglion (DRG) neurons. When tested on a variety of recombinantly expressed voltage-gated ion channels, Mu8.1 displayed the highest potency against the R-type (Cav2.3) calcium channel. Ca2+ signals from Mu8.1-sensitive DRG neurons were also inhibited by SNX-482, a known spider peptide modulator of Cav2.3 and voltage-gated K+ (Kv4) channels. Our findings highlight the potential of Mu8.1 as a molecular tool to identify and study neuronal subclasses expressing Cav2.3. Importantly, this multidisciplinary study showcases the potential of uncovering novel structures and bioactivities within the largely unexplored group of macro-conotoxins.
Organizational Affiliation:
Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark.
