Journal Article

Progressive Myoclonic Epilepsy-Associated Gene KCTD7 is a Regulator of Potassium Conductance in Neurons

Bouschet, Tristan, Schiffmann, Serge N., Pirson, Isabelle, Orduz, David, Azizieh, Régis, Abramowicz, Marc J., Van Bogaert, Patrick, Rodriguez, Wendy

2011

Overview

The potassium channel tetramerization domain-containing protein 7 (KCTD7) was named after the structural homology of its predicted N-terminal broad complex, tramtrack and bric à brac/poxvirus and zinc finger domain with the T1 domain of the Kv potassium channel, but its expression profile and cellular function are still largely unknown. We have recently reported a homozygous nonsense mutation of KCTD7 in patients with a novel form of autosomal recessive progressive myoclonic epilepsy. Here, we show that KCTD7 expression hyperpolarizes the cell membrane and reduces the excitability of transfected neurons in patch clamp experiments. We found the expression of KCTD7 in the hippocampal and Purkinje cells of the murine brain, an expression profile consistent with our patients’ phenotype. The effect on the plasma membrane resting potential is possibly mediated by Cullin-3, as we demonstrated direct molecular interaction of KCTD7 with Cullin-3 in co-immunoprecipitation assays. Our data link progressive myoclonic epilepsy to an inherited defect of the neuron plasma membrane’s resting potential in the brain.

• Publisher: Humana Press Inc,Springer Nature B.V
• Subject: Action Potentials - physiology / Animals / Antibody Specificity / Biomedical and Life Sciences / Biomedicine / Cell Biology / Cell membranes / Cells, Cultured / Cercopithecus aethiops / COS Cells / Cullin / Cullin Proteins - metabolism / Epilepsy / Excitability / Gene Expression Regulation / Genes / Hippocampus / Hippocampus - metabolism / Hippocampus - pathology / Homology / Humans / Immunoprecipitation / Ion Channel Gating - genetics / Membrane potential / Mice / Myoclonic Epilepsies, Progressive - genetics / Neurobiology / Neurology / Neurons / Neurons - metabolism / Neurons - pathology / Neurosciences / Nonsense mutation / Olfactory Bulb - metabolism / Olfactory Bulb - pathology / Phenotypes / Potassium / Potassium Channels - genetics / Potassium Channels - metabolism / Potassium conductance / Poxvirus / Protein Binding / Protein Multimerization / Protein Transport / Purkinje cells / Purkinje Cells - metabolism / Purkinje Cells - pathology / RNA, Messenger - genetics / RNA, Messenger - metabolism / Zinc finger proteins