Provided is a polypeptide for the optical control of calcium signaling, the polypeptide allowing for easy spatial control and manipulation of calcium signaling. This polypeptide is composed of an amino acid sequence including: an LOV2 domain composed of SEQ ID NO: 1 or an amino acid sequence having at least 80% sequence identity with SEQ ID NO: 1; a Ja domain composed of SEQ ID NO: 2, SEQ ID NO: 3, or an amino acid sequence maintaining a function as an LOV2-Ja optical switch and having a predetermined mutation in the amino acid sequence of SEQ ID NO: 2 or 3; and SEQ ID NO: 4 or a CAD domain which is able to activate the calcium channel Orai1 and has a predetermined mutation in the amino acid sequence of SEQ ID NO: 4; wherein the LOV2 domain, the Jadomain, and the CAD domain are arranged, from an N terminus to a C terminus, in the order of LOV2 domain, Ja domain, CAD domain, and wherein a polypeptide is used without an amino acid sequence interposed between the C terminus of the Ja domain and the N terminus of the CAD domain.
POLYPEPTIDE, ISOLATED NUCLEIC ACID, RECOMBINANT VECTOR, GENE TRANSFER KIT, TRANSFORMANT, AND METHOD FOR REGULATING INTRACELLULAR CALCIUM SIGNALING