摘要
While the human genome is pervasively transcribed,<2%of the human genome is transcribed into protein-coding mRNAs,leaving most of the transcripts as noncoding RNAs,such as microRNAs and long-noncoding RNAs(lncRNAs),which are critical components of epigenetic regulation.lncRNAs are emerging as critical regulators of gene expression and genomic stability.However,it remains largely unknown about how lncRNAs are regulated.Here,we develop a highly sensitive and dynamic reporter that allows us to identify and/or monitor negative modulators of lncRNA transcript levels in a high throughput fashion.Specifically,we engineer a fluorescent fusion protein by fusing three copies of the PEST destruction domain of mouse ornithine decarboxylase(MODC)to the C-terminal end of the codon-optimized bilirubin-inducible fluorescent protein,designated as dBiFP,and show that the dBiFP protein is highly destabilized,compared with the commonly-used eGFP protein.We further demonstrate that the dBiFP signal is effectively down-regulated when the dBiFP and mouse lncRNA H19 chimeric transcript is silenced by mouse H19-specific siRNAs.Therefore,our results strongly suggest that the dBiFP fusion protein may serve as a sensitive and dynamic transcript reporter to monitor the inhibition of lncRNAs by microRNAs,synthetic regulatory RNA molecules,RNA binding proteins,and/or small molecule inhibitors so that novel and efficacious inhibitors targeting the epigenetic circuit can be discovered to treat human diseases such as cancer and other chronic disorders.
基金
The reported work was supported in part by research grants from the National Institutes of Health(AT004418,DE020140 to TCH and RRR)
the US Department of Defense(OR130096 to JMW)
the Scoliosis Research Society(TCH and MJL)
the National Key Research and Development Program of China(2016YFC1000803 and 2011CB707906 to TCH)
the National Natural Science Foundation of China(#81201916 to XW)
ZZ was a recipient of protectorate fellowship from China Scholarship Council
This project was also supported in part by The University of Chicago Cancer Center Support Grant(P30CA014599)
the National Center for Advancing Translational Sciences of the National Institutes of Health through Grant Number UL1 TR000430.
