Gt(ROSA)26Sor^{tm2(CAG-APX1*)Ddg}

A CAG promoter, FRT-flanked Stop cassette, loxP-flanked Stop cassette (in reverse transcriptional orientation), ER-dAPEX2, WPRE, bGHpA, attB, PGK-Neo, PGKpA, and attP were introduced to intron 1 via homologous recombination. APEX2 is an enhanced (K14D, W41F, E112K, A134P) soybean ascorbate peroxidase (APX1) that is less catalytically active than horseradish peroxidase (HRP), but is functional when expressed in cytosolic environments, unlike HRP. Dimeric APEX2 (dAPEX2) contains the reversion of K14 and E112 and is presumed to enhance heme affinity and thermal stability of the protein. Targeting of dAPEX2 to the endoplasmic reticulum to create ER-dAPEX2 (Addgene plasmid 117182) was accomplished by a an N-terminal Igk signal sequence and C-terminal KDEL retention sequence. (J:280094)