Tibetan Firefly Luciferase with Low Temperature Adaptation

Area of Science:

• Biochemistry
• Molecular Biology
• Entomology

Background:

• Fireflies are known for their bioluminescence, produced by luciferase enzymes.
• Numerous luciferase genes have been identified, but diversity in extreme environments remains underexplored.

Purpose of the Study:

• To identify and characterize luciferase and luciferase-like genes from a Tibetan firefly species.
• To investigate the biochemical properties of the identified luciferase, particularly its function at low temperatures.

Main Methods:

• Transcriptome analysis of Tibetan firefly tissues (head, thorax, abdomen, light organ) using RNA sequencing.
• Recombinant expression and biochemical characterization of the identified luciferase.
• Analysis of a luciferase-like gene for sequence identity and expression patterns.

Main Results:

• One luciferase gene, highly similar to Pyrocoelia species luciferase, was identified and specifically expressed in the light organ.
• The recombinant Tibetan firefly luciferase exhibited optimal activity at 10°C, with specific K_m values for D-luciferin (23 μm) and ATP (154 μm).
• The enzyme showed optimal activity at pH 7.0-7.5, with emission peaks at 556 nm (pH 8.0) and 606 nm (pH 6.0). A luciferase-like gene was found with low expression and no detectable activity.

Conclusions:

• A novel cold-active luciferase from a high-altitude Tibetan firefly was identified and characterized.
• The findings highlight the adaptability of luciferase enzymes to extreme environmental conditions and expand the known diversity of firefly bioluminescence.