RT Journal Article SR Electronic T1 Reprogrammed tracrRNAs enable repurposing RNAs as crRNAs and detecting RNAs JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.05.24.445356 DO 10.1101/2021.05.24.445356 A1 Yang Liu A1 Filipe Pinto A1 Xinyi Wan A1 Shuguang Peng A1 Mengxi Li A1 Zhen Xie A1 Christopher E. French A1 Baojun Wang YR 2021 UL http://biorxiv.org/content/early/2021/05/28/2021.05.24.445356.abstract AB In type II CRISPR systems, the guide RNA (gRNA) consists of a CRISPR RNA (crRNA) and a hybridized trans-acting CRISPR RNA (tracrRNA) which interacts directly with Cas9 and is essential to its guided DNA targeting function. Though tracrRNAs are diverse in sequences and structures across type II CRISPR systems, the programmability of crRNA-tracrRNA hybridization for particular Cas9 has not been studied adequately. Here, we revealed the high programmability of crRNA-tracrRNA hybridization for Streptococcus pyogenes Cas9. By reprogramming the crRNA-tracrRNA hybridized sequence, reprogrammed tracrRNAs can repurpose various RNAs as crRNAs to trigger CRISPR function. We showed that the engineered crRNA-tracrRNA pairs enable design of orthogonal cellular computing devices and hijacking of endogenous RNAs as crRNAs. We next designed novel RNA sensors that can monitor the transcriptional activity of specific genes on the host genome and detect SARS-CoV-2 RNA in vitro. The engineering potential of crRNA-tracrRNA interaction has therefore redefined the capabilities of CRISPR/Cas9 system.Competing Interest StatementThe authors have declared no competing interest.