Ca2+ binding protein centrin 4 is a novel binding partner of rat Eag1 K+ channels
Eag1 is neuron specific K+ channel abundantly expressed in the brain and retina. Subcellular localization and physiological analyses in neurons reveal that Eag1 may participate in Ca2+ signaling processes in the synapse. Here, we searched for rat Eag1 (rEag1) binding proteins that may contribute to Ca2+ regulation of the K+ channel. Yeast two hybrid screening identified centrin 4, a member of the centrin family of Ca2+ binding proteins. GST pull down and immunoprecipitation assays in brain and retina lysates confirm the interaction of centrin with rEag1 in neurons. Centrin 4 binds to rEag1 in the absence of Ca2+ Raising Ca2+ concentration enhances the association efficiency of centrin 4 and rEag1, and is required for the suppression of rEag1 currents by centrin 4. Altogether, our data suggest that centrin 4 is a novel binding partner that may contribute to Ca2+ regulation of rEag1 in neurons.
FEBS open bio