1.A.84.1.7
Calcium homeostasis modulators (CALHMs) are ATP release channels that play crucial roles in neurons including gustatory signaling and neuronal excitability. Pathologies of Alzheimer's disease and depression have been associated with the dysfunction of CALHMs (see TC# 1.A.84.1.1). CALHM5 structures, solved by cryoEM, showed an abnormally large pore channel structure assembled as an undecamer with four transmembrane helices (TMS1-TMS4), an N-terminal helix (NTH), an extracellular loop region and an intracellular C-terminal domain (CTD) that consists of three α-helices, CH1-3. The TMS1 and NTH were poorly defined among other CALHMs, but these regions were well defined in the CALHM5 channel structure (Bhat et al. 2021).