Sterol hindrance of Orai activation.

Orai channels at the plasma membrane mediate store-operated Ca(2+) entry in response to Ca(2+) depletion of the endoplasmic reticulum. Orai channels are gated by stromal-interacting molecule proteins, which act as Ca(2+) sensors, and the association of these proteins is enhanced in cholesterol-rich lipid rafts. In research published in Science Signaling, Derler et al. report that cholesterol inhibits Orai function through direct association with the channel amino terminus.