Referenced in: none

Automatically associated channels: Kv3.3 , Slo1

Title: Mutations in voltage-gated potassium channel KCNC3 cause degenerative and developmental central nervous system phenotypes.

Authors: Michael F Waters, Natali A Minassian, Giovanni Stevanin, Karla P Figueroa, John P A Bannister, Dagmar Nolte, Allan F Mock, Virgilio Gerald H Evidente, Dominic B Fee, Ulrich Müller, Alexandra Durr, Alexis Brice, Diane M Papazian, Stefan M Pulst

Journal, date & volume: Nat. Genet., 2006 Apr , 38, 447-51

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/16501573

Abstract
Potassium channel mutations have been described in episodic neurological diseases. We report that K+ channel mutations cause disease phenotypes with neurodevelopmental and neurodegenerative features. In a Filipino adult-onset ataxia pedigree, the causative gene maps to 19q13, overlapping the SCA13 disease locus described in a French pedigree with childhood-onset ataxia and cognitive delay. This region contains KCNC3 (also known as Kv3.3), encoding a voltage-gated Shaw channel with enriched cerebellar expression. Sequencing revealed two missense mutations, both of which alter KCNC3 function in Xenopus laevis expression systems. KCNC3(R420H), located in the voltage-sensing domain, had no channel activity when expressed alone and had a dominant-negative effect when co-expressed with the wild-type channel. KCNC3(F448L) shifted the activation curve in the negative direction and slowed channel closing. Thus, KCNC3(R420H) and KCNC3(F448L) are expected to change the output characteristics of fast-spiking cerebellar neurons, in which KCNC channels confer capacity for high-frequency firing. Our results establish a role for KCNC3 in phenotypes ranging from developmental disorders to adult-onset neurodegeneration and suggest voltage-gated K+ channels as candidates for additional neurodegenerative diseases.