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Abstract Guanosine tetra‐ and pentaphosphate, (p)ppGpp, are important alarmone nucleotides that regulate bacterial survival in stressful environment. A direct detection of (p)ppGpp in living cells is critical for our understanding of the mechanism of bacterial stringent response. However, it is still challenging to image cellular (p)ppGpp. Here, we report RNA‐based fluorescent sensors for the live‐cell imaging of (p)ppGpp. Our sensors are engineered by conjugating a recently identified (p)ppGpp‐specific riboswitch with a fluorogenic RNA aptamer, Broccoli. These sensors can be genetically encoded and enable direct monitoring of cellular (p)ppGpp accumulation. Unprecedented information on cell‐to‐cell variation and cellular dynamics of (p)ppGpp levels is now obtained under different nutritional conditions. These RNA‐based sensors can be broadly adapted to study bacterial stringent response.
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A Genetically Encoded RNA Photosensitizer for Targeted Cell Regulation
Abstract Genetically encoded RNA devices have emerged for various cellular applications in imaging and biosensing, but their functions as precise regulators in living systems are still limited. Inspired by protein photosensitizers, we propose here a genetically encoded RNA aptamer based photosensitizer (GRAP). Upon illumination, the RNA photosensitizer can controllably generate reactive oxygen species for targeted cell regulation. The GRAP system can be selectively activated by endogenous stimuli and light of different wavelengths. Compared with their protein analogues, GRAP is highly programmable and exhibits reduced off‐target effects. These results indicate that GRAP enables efficient noninvasive target cell ablation with high temporal and spatial precision. This new RNA regulator system will be widely used for optogenetics, targeted cell ablation, subcellular manipulation, and imaging.
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- Award ID(s):
- 1846152
- PAR ID:
- 10236005
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 59
- Issue:
- 49
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 21986-21990
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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