Ion channels underlie all electrical excitability in the brain and heart, and defects in ion channels are the cause of many human disorders. The KCNH family of channels, ERG, ELK, and EAG, are voltage-dependent potassium channels that are specialized for their role in shaping the electrical activity of neurons and cardiomyocytes. Defects in KCNH channels have been shown to be linked to cognitive defects, increased risk of schizophrenia, cardiac arrhythmias, and cancer. Recently it has become clear that the specialized gating of KCNH channels arises from their unique intracellular domains, the N-terminal eag domain, and the C-terminal C-linker/CNBHD. In this proposal, we will test the hypothesis that the C-linker/CNBHD of KCNH channels is a key regulatory domain that mediates the action of the eag domain and other intracellular regulators. We will build on three exciting new X-ray crystal structures we have solved of the intracellular domains of three different KCNH channels: 1) the C-linker/CNBHD of ELK, 2) the C-linker/CNBHD of ERG, and 3) a complex of the CNBHD and eag domain of EAG. These new structures reveal unexpected features like a direct interaction between the eag domain and the CNBHD, and an intrinsic ligand in the binding site of the CNBHD that regulates gating. They provide a framework to better understand the mechanisms of the gating and regulation of KCNH channels. Toward this goal, we will leverage the power of X-ray crystallography, electrophysiology, and fluorescence to study the structure and rearrangements of the eag domain and C-linker/CNBHD during gating of KCNH channels.

Public Health Relevance

The KCNH family of ion channels, including EAG, ERG, and ELK, control the electrical excitability in the brain and the heart, and defects in these channels cause mental illness, heart disease, and cancer. Our long term goal is to understand the molecular mechanisms for the specialized gating properties of KCNH channels to better design therapies for treatment of these diseases.

National Institute of Health (NIH)
National Institute of Mental Health (NIMH)
Research Project (R01)
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Biophysics of Neural Systems Study Section (BPNS)
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Asanuma, Chiiko
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University of Washington
Schools of Medicine
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Gordon, Sharona E; Munari, Mika; Zagotta, William N (2018) Visualizing conformational dynamics of proteins in solution and at the cell membrane. Elife 7:
Dai, Gucan; James, Zachary M; Zagotta, William N (2018) Dynamic rearrangement of the intrinsic ligand regulates KCNH potassium channels. J Gen Physiol 150:625-635
James, Zachary M; Zagotta, William N (2018) Structural insights into the mechanisms of CNBD channel function. J Gen Physiol 150:225-244
Flynn, Galen E; Zagotta, William N (2018) Insights into the molecular mechanism for hyperpolarization-dependent activation of HCN channels. Proc Natl Acad Sci U S A 115:E8086-E8095
James, Zachary M; Borst, Andrew J; Haitin, Yoni et al. (2017) CryoEM structure of a prokaryotic cyclic nucleotide-gated ion channel. Proc Natl Acad Sci U S A 114:4430-4435
Dai, Gucan; Zagotta, William N (2017) Molecular mechanism of voltage-dependent potentiation of KCNH potassium channels. Elife 6:
Aman, Teresa K; Gordon, Sharona E; Zagotta, William N (2016) Regulation of CNGA1 Channel Gating by Interactions with the Membrane. J Biol Chem 291:9939-47
Zagotta, William N; Gordon, Moshe T; Senning, Eric N et al. (2016) Measuring distances between TRPV1 and the plasma membrane using a noncanonical amino acid and transition metal ion FRET. J Gen Physiol 147:201-16
Gordon, Sharona E; Senning, Eric N; Aman, Teresa K et al. (2016) Transition metal ion FRET to measure short-range distances at the intracellular surface of the plasma membrane. J Gen Physiol 147:189-200