Chemogenetic Tags with Probe Exchange for Live-Cell Fluorescence Microscopy

Aditya Iyer*, Maxim Baranov, Alexander J Foster, Shreyans Chordia, Gerard Roelfes, Rifka Vlijm, Geert van den Bogaart, Bert Poolman*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

6 Downloads (Pure)


Fluorogenic protein tagging systems have been less developed for prokaryotes than for eukaryotic cell systems. Here, we extend the concept of noncovalent fluorogenic protein tags in bacteria by introducing transcription factor-based tags, namely, LmrR and RamR, for probe binding and fluorescence readout under aerobic and anaerobic conditions. We developed two chemogenetic protein tags that impart fluorogenicity and a longer fluorescence lifetime to reversibly bound organic fluorophores, hence the name Chemogenetic Tags with Probe Exchange (CTPEs). We present an extensive characterization of 30 fluorophores reversibly interacting with the two different CTPEs and conclude that aromatic planar structures bind with high specificity to the hydrophobic pockets of these tags. The reversible binding of organic fluorophores to the CTPEs and the superior photophysical properties of organic fluorophores enable long-term fluorescence microscopy of living bacterial cells. Our protein tags provide a general tool for investigating (sub)cellular protein localization and dynamics, protein-protein interactions, and prolonged live-cell microscopy, even under oxygen-free conditions.

Original languageEnglish
Article numberacschembio.1c00100
JournalACS chemical biology
Publication statusE-pub ahead of print - 29-Apr-2021

Cite this