UASp regulatory sequences drive expression of the N intracellular domain (amino acids 1790-2703) in which the two endogenous nuclear localization sequences have have been mutated (mutations are KRQR to AAAA and KKAK to AAAA respectively), tagged at the N-terminal end with the Tag:NES(Med) nuclear export signal (NES) followed by mCherry and at the C-terminal end with the Tag:AsLOV2(cNLS) light-regulated nuclear localization signal (NLS). The presence of the NES and the light-regulated NLS in the expressed protein allows reversible light-induced nuclear translocation of the N intracellular domain.