Calcium homeostasis modulator protein 2 (CALHM2)

Calcium homeostasis modulator protein 2 (CALHM2) is a membrane-bound, large-pore ion channel belonging to the CALHM family. It forms oligomeric assemblies, typically as an 11-mer, and is predicted to enable monoatomic cation channel activity. CALHM2 mediates ATP release from astrocytes and regulates ATP-induced Ca²⁺ influx in microglia, modulating neuronal ATP and calcium homeostasis, synaptic transmission, and neuroinflammatory responses. The protein may also form intercellular gap junction-like structures and is implicated in the regulation of apoptosis. CALHM2 is expressed in the central nervous system—especially in glial cells—and linked to the pathophysiology of depression and neurodegenerative diseases such as Alzheimer's disease, with emerging associations to medulloblastoma. Channel gating mechanisms remain incompletely understood, and aside from a report of inhibition by rubidium red, specific drugs targeting CALHM2 are lacking[1][2][3].

Other names

FAM26BProtein FAM26BCalcium homeostasis modulator 2Calcium homeostasis modulator family member 2Family with sequence similarity 26, member B

Channel inhibition (for rubidium red; other mechanisms currently unknown due to lack of further identified drugs)[1]