Referenced in: none

Automatically associated channels: Kv10.1

Title: 14-3-3θ is a binding partner of rat Eag1 potassium channels.

Authors: Po-Hao Hsu, Shi-Chuen Miaw, Chau-Ching Chuang, Pei-Yu Chang, Ssu-Ju Fu, Guey-Mei Jow, Mei-Miao Chiu, Chung-Jiuan Jeng

Journal, date & volume: PLoS ONE, 2012 , 7, e41203

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22911758

Abstract
The ether-à-go-go (Eag) potassium (K(+)) channel belongs to the superfamily of voltage-gated K(+) channel. In mammals, the expression of Eag channels is neuron-specific but their neurophysiological role remains obscure. We have applied the yeast two-hybrid screening system to identify rat Eag1 (rEag1)-interacting proteins from a rat brain cDNA library. One of the clones we identified was 14-3-3θ, which belongs to a family of small acidic protein abundantly expressed in the brain. Data from in vitro yeast two-hybrid and GST pull-down assays suggested that the direct association with 14-3-3θ was mediated by both the N- and the C-termini of rEag1. Co-precipitation of the two proteins was confirmed in both heterologous HEK293T cells and native hippocampal neurons. Electrophysiological studies showed that over-expression of 14-3-3θ led to a sizable suppression of rEag1 K(+) currents with no apparent alteration of the steady-state voltage dependence and gating kinetics. Furthermore, co-expression with 14-3-3θ failed to affect the total protein level, membrane trafficking, and single channel conductance of rEag1, implying that 14-3-3θ binding may render a fraction of the channel locked in a non-conducting state. Together these data suggest that 14-3-3θ is a binding partner of rEag1 and may modulate the functional expression of the K(+) channel in neurons.