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bioRxiv · 10.64898/2026.01.22.700961

Programmable protein editing by split intein-mediated recombination

Somiya, M.·Yanase, T.
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Abstract

Biological regulation has long relied on modifying genes, transcripts, or protein abundance, yet direct rewriting of protein sequence after translation remains largely inaccessible. Here, we introduce a programmable protein editing platform based on split intein-mediated recombination, enabling precise excision and replacement of defined segments within mature proteins in living cells. By covalently exchanging a target segment with a donor-encoded sequence supplied in trans, this approach functions as a protein-level analogue of recombination, operating independently of transcription or translation. Using ultrafast and orthogonal split inteins, we demonstrate efficient protein recombination in mammalian cells, enabling single-amino acid substitutions, domain replacement, functional switching, and reprogramming of subcellular localization. This work establishes post-translational protein recombination as a general strategy for sequence-level control of protein function, expanding the conceptual and practical scope of biological editing beyond nucleic acids.

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Somiya, M., Yanase, T.. 2026-01-23. Programmable protein editing by split intein-mediated recombination. https://doi.org/10.64898/2026.01.22.700961

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