Comparison List


UnaG is a basic (constitutively fluorescent) green fluorescent protein published in 2013, derived from Anguilla japonica. It has low acid sensitivity. It requires the cofactor bilirubin for fluorescence.
Oligomerization Organism Molecular Weight Cofactor
? Anguilla japonica 15.6 kDa Bilirubin

FPbase ID: 5ULGG


Ex λ Em λ EC (M-1 cm-1) QY Brightness pKa Maturation (min) Lifetime (ns)
498 527 77,300 0.51 39.42 4.0    


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UnaG Sequence

GenBank: AB763906
UniProtKB: P0DM59
IPG: BAN57322.1


Deposited: ,


On heterologous expression in cell lines or mouse brain, UnaG produces oxygen-independent green fluorescence. Remarkably, UnaG fluorescence is triggered by an endogenous ligand, bilirubin, a membrane-permeable heme metabolite and clinical health biomarker... Therefore, unlike GFP, the green fluorescence of UnaG is not limited to aerobic conditions, suggesting that UnaG should have expansive utility in many important cell and animal systems in which anaerobic conditions prevail and GFP signals are not capable of being produced.

Kumagai et al. (2013)

Primary Reference

Additional References

  1. Two Distinct Fluorescence States of the Ligand-Induced Green Fluorescent Protein UnaG

    Shitashima Y, Shimozawa T, Kumagai A, Miyawaki A, Asahi T

    (2017). Biophysical Journal, 113(12) , 2805-2814. doi: 10.1016/j.bpj.2017.10.022. Article   Pubmed

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