Induced by the depletion of ER calcium store, the calcium influx through calcium release-activated calcium (CRAC) channels is an ubiquitous way of Ca2+ influx for most cell types. This process is mediated by STIM protein, ER calcium sensor, and PM localized Orai calcium channels. Biophysical characterization of this STIM-Orai-mediated current, or ICRAC, with whole-cell patch-clamp technique is essential for revealing the molecular mechanisms underlying the process of STIM-Orai activation or modulation. Here we describe one commonly used procedure of monitoring CRAC activity with whole-cell patch-clamp technique.
Keywords: Calcium release-activated calcium (CRAC) channel; ICRAC; Store-operated Ca2+ entry (SOCE); Whole-cell patch clamp.