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Updated: Oct 12, 2025

Single-Cell Calcium Imaging for Studying the Activation of Calcium Ion Channels
Published on: December 13, 2024
Structural Insights into Ca2+ Permeation through Orai Channels
Yang Li1, Xue Yang1, Yuequan Shen1
1State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China.
Abstract:
Orai channels belong to the calcium release-activated calcium (CRAC) channel family. Orai channels are responsible for the influx of extracellular Ca2+ that is triggered by Ca2+ depletion from the endoplasmic reticulum (ER); this function is essential for many types of non-excitable cells. Extensive structural and functional studies have advanced the knowledge of the molecular mechanism by which Orai channels are activated. However, the gating mechanism that allows Ca2+ permeation through Orai channels is less well explained. Here, we reviewed and summarized the existing structural studies of Orai channels. We detailed the structural features of Orai channels, described structural comparisons of their closed and open states, and finally proposed a "push-pull" model of Ca2+ permeation.
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