SIGMAR1 and amyotrophic lateral sclerosis: Furthermore, non-functional Sig1R variants responsible for the inherited juvenile ALS16 or Sig1R deficiency in transgenic SOD1-linked ALS mouse model were associated with impaired ultrastructure of the MAM, depletion of the Sig1R interacting partners at the MAM and deregulation of calcium homeostasis via mislocalization of the MAM-residing IP3R [112].