The viral genome delivered by Vector 1 encodes the fusion proteins FRB-p65 and FKBP-ZFHD1, which dimerize in the presence of rapamycin. ZFHD1 tethers the dimerized transcription factor to the ZFHD1 DNA binding domains (BD) in the viral genome of Vector 2, when p65 activates promoter and Epo expression.
CMV: Cytomegalovirus promoter; E: Epitope tag; FKBP: FK-binding protein; FRB: Rapamycin binding domain of FKBP-rapamycin associated protein; IRES: Internal ribosome entry site; minP IL-2: Minimal IL-2 promoter; N: Nuclear localization signal; pA: Polyadenylation signal; ZFHD1: Zinc finger homeodomain 1.