CALHM3
Function
Pore-forming subunit of gustatory voltage-gated ion channels required for sensory perception of sweet, bitter and umami tastes. With CALHM1 forms a fast-activating voltage-gated ATP-release channel in type II taste bud cells, ATP acting as a neurotransmitter to activate afferent neural gustatory pathways. Acts both as a voltage-gated and calcium-activated ion channel: mediates neuronal excitability in response to membrane depolarization and low extracellular Ca(2+) concentration. Has poor ion selectivity and forms a wide pore (around 14 Angstroms) that mediates permeation of small ions including Ca(2+), Na(+), K(+) and Cl(-), as well as larger ions such as ATP(4-).
Post-translational modifications
N-glycosylated.
Palmitoylated by ZDHHC3 and ZDHHC15. Palmitoylation positively regulates CALHM1:CALHM3 channel conductance.
Sequence Similarities
Belongs to the CALHM family.
Tissue Specificity
Specifically expressed in circumvallate taste bud cells.
Cellular localization
- Basolateral cell membrane
- Multi-pass membrane protein
Alternative names
FAM26A, CALHM3, Calcium homeostasis modulator protein 3, Protein A