Calcium release-activated calcium modulator 1 (ORAI1)

ORAI1 encodes an integral plasma membrane protein that assembles into hexameric complexes forming highly selective CRAC channels. These are activated by direct physical coupling with STIM proteins following endoplasmic reticulum store depletion—a process vital for sustained intracellular signaling events such as those required during immune responses. Structural studies reveal intricate arrangements among its four transmembrane domains per monomer within each hexameric assembly, providing both selectivity and regulatory mechanisms essential for precise cellular control over calcium influx.

Modulation of calcium influx through CRAC channels