An Acidic Ring in the Palm Domain of ASIC1a Facilitates Pore opening

Abstract

Our previous FRET and functional studies suggest AKAP (A-kinase-anchoring-protein) 79/150 to be crucial in modulation of ion channel activity and neuronal function, by orchestrating important molecules such as protein kinases, phosphatases, G protein-coupled receptors and ion channels into signaling complexes in the plasma membrane. In this study, to directly visualize these AKAP79/150 signaling complexes and interactions between AKAP79/150, ion channels and receptors in sympathetic neurons, we utilized stochastic optical reconstruction microscopy (STORM) with sub-diffraction (~20 nm half width) resolution. STORM uses dyes that can cycle between a dark and a fluorescent state thousands of times, thus enabling detection of the precise localization of the center of these scattered spots given by cumulative integration of each cycle. Consistent with previous immunostaining/confocal studies, STORM imaging of fixed Chinese hamster ovary (CHO) cells using fluores