Novel inositol 1,4,5-trisphosphate (IP3) receptor-binding protein and an IP3 indicator

摘要

The present invention provides a novel IP₃ receptor-binding protein that is used as an indicator effective for detecting and quantifying IP₃, and a method for detecting and/or quantifying IP₃ using the same. Determined is an IP₃ receptor-binding protein, particularly a novel IP₃ receptor-binding protein, IRBIT, which interacts with an IP₃ receptor, and whose interaction is regulated by IP₃. IRBIT has the characteristic that it can be dissociated from the IP₃ receptor by IP₃ at a physiological concentration. Because of this characteristic, IRBIT can be useful as an indicator for detecting IP₃ by the FRET method or the like.