Construction of a rhythm transfer system that mimics the cellular clock.

Creation of an artificial oscillating gene expression system is one of the most challenging issues in synthetic biology. Here, we constructed a simple system to manipulate gene expression patterns to be circadian, reflecting the intrinsic cellular clock, by fusing a core clock protein, BMAL1 or CLOCK, with a zinc finger-type DNA binding domain. Circadian rhythmic gene expression was induced only when the target gene contained zinc finger-binding sequences. To our knowledge, this simple approach is the first to manipulate gene expression patterns into circadian rhythms and would be applicable to various endogenous genes.