YM-58483 (CRAC Channel Inhibitor, BTP2), CRAC channel inhibitor

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

Orai1 also known as CRACM1 is an important protein that forms part of the calcium release-activated calcium (CRAC) channels. These channels are essential for calcium ion flow across cell membranes. Orai1 weighs about 33 kDa and plays an integral role in cellular calcium homeostasis. This protein is expressed ubiquitously but it is found in high levels in excitable cells like T-cells where calcium signaling is important for activation and function. The Orai1 channel structure includes six transmembrane segments and works specifically with calcium-specific pore formation.

Biological function summary

Orai1 is a critical component of the store-operated calcium entry (SOCE) mechanism which maintains cellular calcium levels after depletion. Orai1 partners with stromal interaction molecule 1 (STIM1) to form the functional CRAC channel complex. Upon calcium store depletion STIM1 senses this change and interacts with Orai1 triggering calcium influx. This process is important in activating various cellular responses and promoting the function of immune cells among others.

Pathways

Orai1 is a significant player in the calcium signaling pathway and the immune response pathway. Through its role in maintaining cellular calcium levels it influences the activation of various downstream signaling events including those involving calcineurin and nuclear factor of activated T-cells (NFAT). These interactions highlight the protein's importance in transcriptional regulation and immune cell activation highlighting its connection to proteins like STIM1 and NFAT.

Orai1 disruption relates to immune dysfunction and autoimmune diseases like severe combined immunodeficiency (SCID) and rheumatoid arthritis. Mutations in Orai1 lead to impaired CRAC channel function and compromised calcium homeostasis affecting immune cell function. Furthermore the aberrant expression or function of Orai1 and its partner STIM1 associates with these disorders providing potential targets for therapeutic CRAC channel inhibitors aimed to restore normal signaling and immune function.