Voltage-activated sodium (Nav) channels are found throughout the human body where they form the cornerstones of fast electrical signaling by regulating the Na+ permeability ofthe cell membrane. As such, Nav channels are among the most widely targeted ion channels by both drugs and toxins. Their medical relevance is underscored by mutations that underlie debilitating disorders such as epilepsy, muscle weakness, cardiac arrhythmias and pain syndromes. Despite their physiological importance, our understanding of thes;e channels is hampered by a lack of insight into their complex structures and working mechanisms. Rather than existing as independent units, Nav channels are part of a signaling complex that involves auxiliary proteins and membrane lipids. My goal is to address fundamental questions on the identities of the Nav channel signaling complex components and to resolve their mechanisms of action at the molecular level. In particular, I will examine to what extent and by what mechanism auxiliary 3-subunits shape Nav channel gating behavior and pharmacology. Furthermore, I intend to investigate how the surrounding membrane lipids influence Nav channel function and their interaction with (3-subunits. Successful completion of my aims will reveal key elements in the Nav channel signaling complex, help define Nav channel function in normal and pathological states, and may offer novel strategies for developing therapeutic drugs.

Public Health Relevance

Little is known about the interaction of Nav channels with auxiliary proteins that are also embedded in the membrane, and with lipid molecules forming the cell membrane, yet they have an enormous impact on channel function and pharmacology. Completion of my aims will help define the role of these components in the larger Nav channel complex, which is essential to our understanding of how we can target it with drugs.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
Research Transition Award (R00)
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Special Emphasis Panel (NSS)
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Stewart, Randall R
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Johns Hopkins University
Schools of Medicine
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Klint, Julie K; Smith, Jennifer J; Vetter, Irina et al. (2015) Seven novel modulators of the analgesic target NaV 1.7 uncovered using a high-throughput venom-based discovery approach. Br J Pharmacol 172:2445-58
Camargos, Thalita S; Bosmans, Frank; Rego, Solange C et al. (2015) The Scorpion Toxin Tf2 from Tityus fasciolatus Promotes Nav1.3 Opening. PLoS One 10:e0128578
Kalia, Jeet; Milescu, Mirela; Salvatierra, Juan et al. (2015) From foe to friend: using animal toxins to investigate ion channel function. J Mol Biol 427:158-175
Martin-Eauclaire, Marie-France; Ferracci, Géraldine; Bosmans, Frank et al. (2015) A surface plasmon resonance approach to monitor toxin interactions with an isolated voltage-gated sodium channel paddle motif. J Gen Physiol 145:155-62
Gilchrist, John; Dutton, Stacey; Diaz-Bustamante, Marcelo et al. (2014) Nav1.1 modulation by a novel triazole compound attenuates epileptic seizures in rodents. ACS Chem Biol 9:1204-12
Bende, Niraj S; Dziemborowicz, S?awomir; Mobli, Mehdi et al. (2014) A distinct sodium channel voltage-sensor locus determines insect selectivity of the spider toxin Dc1a. Nat Commun 5:4350
Martin-Eauclaire, Marie-France; Bosmans, Frank; Céard, Brigitte et al. (2014) A first exploration of the venom of the Buthus occitanus scorpion found in southern France. Toxicon 79:55-63
Gilchrist, John; Olivera, Baldomero M; Bosmans, Frank (2014) Animal toxins influence voltage-gated sodium channel function. Handb Exp Pharmacol 221:203-29
Bende, Niraj S; Kang, Eunji; Herzig, Volker et al. (2013) The insecticidal neurotoxin Aps III is an atypical knottin peptide that potently blocks insect voltage-gated sodium channels. Biochem Pharmacol 85:1542-54
Gilchrist, John; Das, Samir; Van Petegem, Filip et al. (2013) Crystallographic insights into sodium-channel modulation by the ?4 subunit. Proc Natl Acad Sci U S A 110:E5016-24

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