De novo pan-rhodamine binders for fluorescence microscopy from mammalian cells to extremophiles
Fluorescent imaging in live cells is a cornerstone of life sciences. While natural fluorescent proteins have been engineered to enhance individual features, no existing tag combines ideal properties into a single system: high brightness, reversible binding, compact size, and stability across diverse conditions. Here, we achieve this through de novo design of rhodamine binders (Rhobin). To harness the broad repertoire of rhodamine fluorophores, we developed a generalizable design strategy for a pan-rhodamine binder compatible with diverse wavelengths and applications. Rhobin enables live- and fixed-cell imaging of various subcellular targets in mammalian cells, showing brightness surpassing existing tags. Its reversible fluorophore binding supports super-resolution stimulated emission depletion (STED) and live-cell single-molecule imaging for extended durations compared with HaloTag. Beyond conventional systems, Rhobin enables live imaging of the extremophile Sulfolobus acidocaldarius at 75°C, previously inaccessible with current tags. Together, these results establish Rhobin as a versatile platform for next-generation imaging and biosensor design.
Authors
- Bo Huang (ORCID: https://orcid.org/0000-0003-1704-4141)
- R. Dyche Mullins (ORCID: https://orcid.org/0000-0002-0871-5479)
- Kibeom Hong (ORCID: https://orcid.org/0000-0002-7648-3761)
- Klaus Yserentant (ORCID: https://orcid.org/0000-0001-9746-6912)
- Luke D. Lavis (ORCID: https://orcid.org/0000-0002-0789-6343)
- Sagar Bhattacharya (ORCID: https://orcid.org/0000-0002-8020-9255)
- Samuel J. Lord (ORCID: https://orcid.org/0000-0002-2785-989X)
- Samuel I. Mann (ORCID: https://orcid.org/0000-0003-3392-3170)
- Jonathan B. Grimm (ORCID: https://orcid.org/0000-0003-0331-4200)
- Arghya Bhowmick (ORCID: https://orcid.org/0000-0002-3755-8572)
- Kehan Chen (ORCID: https://orcid.org/0000-0003-0419-8360)
- Yuda Chen (ORCID: https://orcid.org/0000-0002-5399-1720)
- Kaipeng Hou
- Lei Lu
- William F. DeGrado
- Yiming Kuang
- Maggie Horst
- Robert S. Picardo
- Arthur Charles-Orszag
Institutions
- University of California, Riverside (US)
- Howard Hughes Medical Institute (US)
- University of California, San Francisco (US)
- Janelia Research Campus (US)
- Tohoku University (JP)
- Chan Zuckerberg Biohub San Francisco (US)
- University of San Francisco (US)
- University of California, Davis (US)
Publication Details
- Journal
- Cell
- Published
- 2026-09-01
- DOI
- https://doi.org/10.1016/j.cell.2026.08.007
- Primary Topic
- Click Chemistry and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- Howard Hughes Medical Institute
- Chan Zuckerberg Initiative
- National Institutes of Health
- University of California, San Francisco