ITPR1 and GM1 gangliosidosis: In the GM1 gangliosidosis model, GM1 accumulates in the microstructure domain of the MAM, which increases ER Ca2+ depletion and Ca2+ flux to the mitochondria by interacting with phosphorylated IP3R, ultimately leading to mitochondrial Ca2+ overload-mediated apoptosis (Sano et al., 2009).