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Updated: May 16, 2026

Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells
Published on: February 24, 2026
[Co-delivery of exogenous protein and DNA into mammalian cells with Lactococcus lactis]
Yi-jie Li1, Huan-huan Liu, Fu-chun Zhang
1Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830046, China.
Aim:
To develop a co-delivery system of exogenous protein and DNA into mammalian cells using Lactococcus lactis (L. lactis).
Methods:
We constructed E.coli-L.lactis shuttle plasmid, pMG36e-RFP/eGFP, containing a L.lactis expression cassette with the cDNA of red fluorescent protein (RFP) gene and a eukaryotic expression cassette with the cDNA of enhanced green fluorescent protein (eGFP), then electrotransformated it into L.lactis cells, and co-cultured with 293T cells to evaluate the role of the system in the improvement of gene delivering efficiency after L.lactis cells were pretreated with glycine. RFP and GFP expressed in 293T cells was monitored by fluorescence microscopy.
Results:
Fluorescence microscopy revealed that the RFP and GFP was expressed in 293T cells.
Conclusion:
The co-delivery system of protein and DNA into mammalian cells using L.lactis was constructed successfully.
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