Live-cell imaging of Pol II promoter activity to monitor gene expression with RNA IMAGEtag reporters

SHIN, Ilchung
RAY, Judhajeet
Gupta, Vinayak
İlgü, Müslüm
Beasley, Jonathan
Kraus, George A.
Nilsen-Hamilton, Marit
We describe a ribonucleic acid (RNA) reporter system for live-cell imaging of gene expression to detect changes in polymerase II activity on individual promoters in individual cells. The reporters use strings of RNA aptamers that constitute IMAGEtags (Intracellular MultiAptamer GEnetic tags) that can be expressed from a promoter of choice. For imaging, the cells are incubated with their ligands that are separately conjugated with one of the FRET pair, Cy3 and Cy5. The IMAGEtags were expressed in yeast from the GAL1, ADH1 or ACT1 promoters. Transcription from all three promoters was imaged in live cells and transcriptional increases from the GAL1 promoter were observed with time after adding galactose. Expression of the IMAGEtags did not affect cell proliferation or endogenous gene expression. Advantages of this method are that no foreign proteins are produced in the cells that could be toxic or otherwise influence the cellular response as they accumulate, the IMAGEtags are short lived and oxygen is not required to generate their signals. The IMAGEtag RNA reporter system provides a means of tracking changes in transcriptional activity in live cells and in real time.


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Molecular dynamics simulations and coupled nucleotide substitution experiments indicate the nature of A center dot A base pairing and a putative structure of the coralyne-induced homo-adenine duplex
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Coralyne is an alkaloid drug that binds homo-adenine DNA (and RNA) oligonucleotides more tightly than it does Watson-Crick DNA. Hud's laboratory has shown that poly(dA) in the presence of coralyne forms an anti-parallel duplex, however attempts to determine the structure by NMR spectroscopy and X-ray crystallography have been unsuccessful. Assuming adenine-adenine hydrogen bonding between the two poly(dA) strands, we constructed 40 hypothetical homo-(dA) anti-parallel duplexes and docked coralyne into the s...
Citation Formats
I. SHIN et al., “Live-cell imaging of Pol II promoter activity to monitor gene expression with RNA IMAGEtag reporters,” NUCLEIC ACIDS RESEARCH, pp. 0–0, 2014, Accessed: 00, 2020. [Online]. Available: