title: Progressive myoclonic epilepsy-associated gene KCTD7 is a regulator of potassium conductance in neurons.
abstract: 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.
authors.affiliation: Institute of Interdisciplinary Research (IRIBHM)-ULB, Brussels, Belgium. regismanga@gmail.com
authors.forename: Régis
authors.initials: R
authors.lastname: Azizieh
authors.forename: David
authors.initials: D
authors.lastname: Orduz
authors.forename: Patrick
authors.initials: P
authors.lastname: Van Bogaert
authors.forename: Tristan
authors.initials: T
authors.lastname: Bouschet
authors.forename: Wendy
authors.initials: W
authors.lastname: Rodriguez
authors.forename: Serge N
authors.initials: SN
authors.lastname: Schiffmann
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pirson
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Abramowicz
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D000918:Antibody Specificity; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D044842:Cullin Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D006801:Humans; D047468:Immunoprecipitation; D015640:Ion Channel Gating / Q000235:genetics*; D051379:Mice; D020191:Myoclonic Epilepsies, Progressive / Q000235:genetics*; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D009830:Olfactory Bulb / Q000378:metabolism / Q000473:pathology; D015221:Potassium Channels / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization; D021381:Protein Transport; D011689:Purkinje Cells / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: C503646:Cul3 protein, mouse; D044842:Cullin Proteins; C562164:KCTD7 protein, mouse; D015221:Potassium Channels; D012333:RNA, Messenger