FlAsH-ID enables live-cell photoproximity labeling with a short peptide tag.

FlAsH-ID enables green-light photoproximity labeling of proteins using a localized 6-aa Tsien tetracysteine peptide tag, including in primary CD8+ T cells.

• Why it matters: Existing proximity labeling relies on large fusion proteins that can perturb native biology or mask epitopes, limiting studies of small, sensitive proteins.
• What they did: The method combines the Tsien tetracysteine tag with the FlAsH dye to generate localized singlet oxygen under green light, and it is tested across cellular compartments and in primary CD8+ T cells.
• The result: FlAsH-ID is nontoxic and labels proteins in multiple compartments, and it can map the RUNX3 interactome in primary CD8+ T cells, supporting use with small proteins.

AI summary of the abstract · may contain errors · not medical advice · read the paper.