Tg(tetO-GCaMP2)12JRyu

This transgene contains an unspecified promoter followed by seven copies of the tetracycline responsive operator (tetO), cDNA encoding the Ca2+ reporter GCaMP2, and a polyadenylation signal. GCaMP2 is a circularly permuted enhanced green fluorescent protein (EGFP) interrupted at amino acid (aa) 145 so that the N-terminal 144 aa and the C-terminal 90 aa have exchanged places; calmodulin (CaM) and a 13 aa peptide of myosin light chain kinase (M13) have been appended to the new C- and N-termini, respectively. The 35-aa polyHis plasmid leader sequence RSET, found to be essential for thermal stability, resides N-terminal to M13, and mutations have been introduced to improve fluorescence (Asp180Tyr and Val93Ile) and thermal stability (Val163Aln and Ser175Gly) and to prevent GFP dimerization (Ala206Lys). Fluorescence of GCaMP2 is induced by interaction of the C-terminal calmodulin, in association with Ca2+, with the N-terminal M13. (J:107637, J:157448)