lexAop (LexAop2) regulates expression of TEV\NIa in which all 3 potential glycosylation sites are mutated (and thus make TEV\NIa active) followed by the extracellular portion of a transmembrane protein (Tag:M(rCd2)). The N-terminus has the C. elegans PAT3 signal peptide sequence for endoplasmic reticulum targeting, while the C-terminus has the Kir2.1 ER export signal to improve trafficking to the plasma membrane, followed by the P10 3' UTR. Tag:MYC has been introduced in between the TEV\NIa and Tag:M(rCd2) sequence. A removable cassette is present prior to the signal peptide, comprising Scer\FLP1 and Hsp70b and SV40 3' UTRs surrounded by RSRT recombination sites. Thus, FLP activity can remove the cassette, placing TEV\NIa-Tag:M(rCd2) under control of lexAop. (GenBank MN658789.) Used in the first (release) step of the BacTrace system.