RNA processing enables predictable programming of gene expression

Qi et al . control the expression levels of transgenes using bacterial CRISPR RNA-processing technology. Complex interactions among genetic components often result in variable systemic performance in designed multigene systems 1 , 2 . Using the bacterial clustered regularly interspaced short palindromic repeat (CRISPR) pathway 3 , 4 we develop a synthetic RNA-processing platform, and show that efficient and specific cleavage of precursor mRNA enables reliable and predictable regulation of multigene operons. Physical separation of linked genetic elements by CRISPR-mediated cleavage is an effective strategy to achieve assembly of promoters, ribosome binding sites, cis -regulatory elements, and riboregulators into single- and multigene operons with predictable functions in bacteria. We also demonstrate that CRISPR-based RNA cleavage is effective for regulation in bacteria, archaea and eukaryotes. Programmable RNA processing using CRISPR offers a general approach for creating context-free genetic elements and can be readily used in the bottom-up construction of increasingly complex biological systems in a plug-and-play manner.