The ORAI1 protein, a key component of the calcium release-activated calcium (CRAC) channel, plays a critical role in store-operated calcium entry (SOCE), a process essential for immune cell activation, gene transcription, and cellular homeostasis. ORAI1 interacts with stromal interaction molecule 1 (STIM1), which senses endoplasmic reticulum (ER) calcium depletion and activates ORAI1 to mediate extracellular calcium influx. Dysregulation of ORAI1 is linked to immune disorders, including severe combined immunodeficiency (SCID) and autoimmune diseases.
The ORAI1(L2) antibody specifically targets an extracellular epitope on the second loop (L2) of the ORAI1 protein. This region is critical for channel gating and STIM1-ORAI1 interaction, making the antibody a valuable tool for studying CRAC channel structure-function relationships. It is widely used in techniques like immunofluorescence, flow cytometry, and Western blot to detect ORAI1 expression in immune cells (e.g., T cells, mast cells) and other tissues. Additionally, ORAI1(L2) antibodies have been employed in functional studies to block CRAC channel activity, helping elucidate its role in calcium signaling pathways, immune responses, and diseases such as cancer or inflammation. Researchers also utilize these antibodies to explore therapeutic strategies targeting ORAI1 in autoimmune conditions or immunodeficiencies, underscoring their importance in both basic and translational research.