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Updated: Aug 8, 2026

Whole-Cell Recording of Calcium Release-Activated Calcium (CRAC) Currents in Human T Lymphocytes
Published on: December 21, 2010
Amplification of CRAC current by STIM1 and CRACM1 (Orai1)
Christine Peinelt1, Monika Vig, Dana L Koomoa
1Center for Biomedical Research at The Queen's Medical Center and John A. Burns School of Medicine at the University of Hawaii, Honolulu, HI 96813, USA.
Abstract:
Depletion of intracellular calcium stores activates store-operated calcium entry across the plasma membrane in many cells. STIM1, the putative calcium sensor in the endoplasmic reticulum, and the calcium release-activated calcium (CRAC) modulator CRACM1 (also known as Orai1) in the plasma membrane have recently been shown to be essential for controlling the store-operated CRAC current (I(CRAC)). However, individual overexpression of either protein fails to significantly amplify I(CRAC). Here, we show that STIM1 and CRACM1 interact functionally. Overexpression of both proteins greatly potentiates I(CRAC), suggesting that STIM1 and CRACM1 mutually limit store-operated currents and that CRACM1 may be the long-sought CRAC channel.
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