UASt regulatory sequences drive expression of the Hsap\SEM1 open reading frame, tagged at the C-terminal end with three copies of Tag:HA. The ORF was amplified from the hGUHO14903 clone. The human ORF is flanked by a pair of incompatible FRT sites (FRT5 and FRT2), which allows for future in vivo exchange of either the promoter or tag sequence.