The Tag:FLAG tag present between hSNAP25 and Syx1A in PBac{LexAop2-QF2.V5.hSNAP25.Syx1A} has been replaced with a GlySer linker and Tag:NES(HIV-1-Rev) has been inserted in front of QF2. As a result lexAop regulates expression of a BacTrace sensor construct beginning with the Syn21 5' UTR and Tag:NES(HIV-1-Rev), followed by QF2 fused to amino acids 141-206 from human SNAP25 (flanked by Tag:V5 at the 5' end), followed by full length Syx1A (to target the inactive sensor to the synaptic membrane) and the SV40 3' UTR. (GenBank MN658783.)