Shisa Homolog 9 (SHISA9)

Ckamp44 associated with AMPA receptors in mouse forebrain lysates. Ckamp44 fractionated with a detergent-insoluble postsynaptic density fraction together with Gria1, Psd95 (DLG4), and Tarp-gamma-2 (CACNG2). Cultured mouse hippocampal neurons showed relatively low Ckamp44 expression, and overexpression of Ckamp44 in these cells led to stronger and faster AMPA receptor desensitization, slower recovery from desensitization, and a reduction in the paired-pulse ratio of AMPA currents. By contrast, dentate gyrus granule cells showed relatively high Ckamp44 expression, and knockout of Ckamp44 in these cells increased the paired-pulse ratio of AMPA currents.The deduced 424-amino acid protein has an N-terminal signal sequence, followed by a cysteine-rich extracellular domain, a transmembrane domain, and a cytoplasmic segment that terminates in a PDZ type II ligand motif.