nSyb promoter sequences drive expression of a codon-optimized Ecol\lexA DNA-binding domain fused to a a calmodulin target peptide, which forms one half of a 'split driver' system that is designed to act as a transcriptional reporter of intracellular Ca[2+] (TRIC). The Tag:NLS(SV40-largeT) nuclear localisation signal is present at the N-terminal end of the fusion protein.