Stromal interaction molecule 1-dependent store-operated calcium entry complex (STIM1-SOCE complex)

The Stromal interaction molecule 1-dependent store-operated calcium entry (STIM1-SOCE) complex is a fundamental signaling unit composed primarily of the endoplasmic reticulum (ER) calcium sensor STIM1 and the plasma membrane calcium channel Orai1 (Prakriya & Lewis, 2015, Physiol Rev). When ER calcium levels drop, STIM1 senses the depletion and undergoes a conformational change that allows it to cluster and move toward the plasma membrane (Stathopulos et al., 2008, JBC). At ER-plasma membrane junctions, STIM1 directly interacts with and opens Orai1 channels, facilitating the influx of extracellular calcium into the cytoplasm (Feske et al., 2006, Nature). This influx, termed SOCE, is essential for refilling ER stores and triggering downstream signaling pathways, most notably the activation of the NFAT transcription factor in immune cells (Lacruz & Feske, 2015, Ann N Y Acad Sci). Dysregulation of this complex, through either loss-of-function or gain-of-function mutations, leads to severe clinical conditions such as immunodeficiency, myopathy, and Stormorken syndrome (Feske, 2010, Nat Rev Immunol). In oncology, the complex is often overexpressed or hyperactive, promoting cancer cell migration, invasion, and survival (Vashisht et al., 2015, Sci Rep). Pharmacological targeting of the STIM1-SOCE complex focuses on small-molecule inhibitors that block the Orai1 pore or disrupt the STIM1-Orai1 interaction (CalciMedica, 2024). These inhibitors, such as CM4620, are being investigated for treating acute pancreatitis, asthma, and various solid tumors (ClinicalTrials.gov, NCT04195347). Therapeutic challenges include maintaining a balance between efficacy and the risk of systemic immunosuppression or muscle-related side effects (Shaw & Feske, 2012, Front Biosci).

Other names

CRAC channel complexSTIM1-Orai1 complexStore-operated calcium entry complexCalcium release-activated calcium channel complex

Inhibition of the Calcium Release-Activated Calcium (CRAC) channel activity by blocking the Orai1 pore or interfering with the STIM1-Orai1 interaction, thereby preventing store-operated calcium entry.