- Singha, Monika;
- Zimak, Jan;
- Levine, Samantha;
- Dai, Nan;
- Hong, Chan;
- Anaraki, Cecily;
- Gupta, Mrityunjay;
- Spitale, Robert;
- Atwood, Scott;
- Halbrook, Christopher
Current transcriptome-wide analyses have identified a growing number of regulatory RNA with expression that is characterized in a cell-type-specific manner. Herein, we describe RNA metabolic labeling with improved cell-specificity utilizing the in vivo expression of an optimized uracil phosphoribosyltransferase (UPRT) enzyme. We demonstrate improved selectivity for metabolic incorporation of a modified nucleobase (5-vinyuracil) into nascent RNA, using a battery of tests. The selective incorporation of vinyl-U residues was demonstrated in 3xUPRT LM2 cells through validation with dot blot, qPCR, LC-MS/MS and microscopy analysis. We also report using this approach in a metastatic human breast cancer mouse model for profiling cell-specific nascent RNA.