Determining the stoichiometry of endogenous voltage-gated potassium channels in the brain

The National Institute of Neurological Disorders and Stroke awarded Sanford Burnham Prebys Medical Discovery Institute $670,380 on September 4, 2026, under the Extramural Research Programs in the Neurosciences and Neurological Disorders program (CFDA 93.853) to determine the stoichiometry of endogenous voltage-gated potassium channels in the brain.

The research addresses fundamental gaps in understanding how ion channels are assembled and regulated in neurons. The work will elucidate the composition and arrangement of voltage-gated potassium (Kv) channel subunits in vivo under both physiological and pathological conditions, using a novel methodology developed by the principal investigator's laboratory. The research aims to identify how channel compositions are regulated by physiological stimuli or altered in disease states, and to determine whether disease-causing misassembled channels can be selectively targeted by therapeutics. The specific focus is on Kv1 family members, which control resting membrane potential and the firing pattern of action potentials in neurons.

Performance occurs in La Jolla, California, with a period of performance from September 4, 2026, through August 31, 2031. The assistance type is a Project Grant, an investigator-initiated award supporting basic research into the structure and function of the nervous system that aligns with NINDS's mission to reduce the burden of neurological disease.

Abstract

For neurons to act as the basic unit of information integration underlying all cognitive behaviors, ION channels are the essential molecules for electrical signaling, information integration, and cell-cell communication. To decode the brain, we must understand how channel properties are regulated. Because most ION channels are formed as assemblies of multiple proteins/subunits, achieving full understanding of native ION channels calls for a comprehensive blueprint of the types and arrangement of each subunit under physiological and pathological conditions. This important knowledge is lacking for nearly all types of native ION channels due to the limitation in technology. Many fundamental questions concerning endogenous ION channel assemblies remain unsolved. What are the compositions of endogenous ION channels in neurons in vivo? How are the compositions of the channels regulated by physiological stimuli or altered in pathological conditions? Can we find drugs that only target the misassembled channels that cause the disease? In this proposal, I plan to elucidate the stoichiometry of in vivo endogenous voltage-gated potassium (KV) channels using a novel strategy that has been developing in my lab. The activation of each neuron is under strict temporal control, which is primarily established by enabling action potentials to initiate at a specific threshold and fire with an adequate frequency and pattern. KV channels are hence a crucial group of channels to set and reset a neuron's electrical state. To establish this precise control of electrical state, KV channels form hetero-tetramers with multiple types and arrangements of subunits in a spatiotemporally dependent manner. As a major subfamily of KV channels, KV1 family members controls resting membrane potential and firing pattern of action potentials. Inherited and DE novo mutations of KV1 family members are directly linked to epilepsy and episodic ataxia type- 1. Whereas KV1 members can form homo-tetramers or hetero-tetramers in vitro, they mainly form hetero- tetramers in the brain. The composition and arrangement of KV1 channels control their voltage dependence of activation and inactivation as well as their ligand binding affinity. Determination of the stoichiometry of in vivo endogenous KV1 channels will provide a crucial foundation to understand the information processes among neuronal networks in health and diseases. To achieve these goals, we plan to investigate the range of stoichiometries of KV1 channels in mouse brains and to elucidate the stoichiometry of KV1 channels in mouse disease models. We will employ multidisciplinary approaches that combine single particle cryo-EM studies of KV1 channels from mouse brains with immunohistochemistry, patch-clamp electrophysiology and knock-in mouse lines. These investigations will shed light on the fundamental principles underlying how endogenous ION channels assemble and function in health and diseases. These studies may also make IT possible to design novel drugs that target disease-induced channel assemblies to treat patients with neurological or psychiatric disorders while limiting side-effects.