Involved in calcium homeostasis, growth and proliferation. Distributed throughout the cytoplasm and also localizes to the perinuclear region of both human erythroleukemia (HEL) cells and Jurkat cells. Colocalizes with ITPR1. Expressed in brain, placenta, lung, liver, kidney, pancreas, cardiac and skeletal muscle, and in cultured HEL and Dami cells. Truncated N-terminus. Truncated N-terminus. Extended N-terminus.