A coelenterazine-dependent luciferase from the deep-sea coral Anthoptilum murrayi Kölliker, 1880 (Cnidaria: Octocorallia: Pennatulacea)

Bioluminescence is the production of visible light by living organisms through biochemical reactions in which specialized enzymes known as luciferases catalyze the oxidation of light-emitting substrates (luciferins), producing photons. In the ocean, bioluminescence is widespread among anthozoans (corals and sea anemones), yet the molecular basis of their light emission remains poorly defined. To date, molecular characterization within Anthozoa has largely focused on the sea pansy Renilla reniformis (Octocorallia: Renillidae), leaving anthozoan luciferase diversity underexplored. Here, we report the identification and biochemical characterization of a coelenterazine-dependent luciferase from the deepsea sea pen Anthoptilum murrayi (AnmLuc). Transcriptome analysis identified a transcript encoding a [~]34-kDa protein bearing motifs characteristic of coelenterazine-dependent luciferases. The coding sequence was cloned and the recombinant protein was expressed in Escherichia coli. The purified enzyme produced intense blue emission ({lambda}max {approx} 495 nm) in the presence of coelenterazine and displayed an activity optimum near 5 {degrees}C. These findings provide the first molecular characterization of a luciferase from a deep-sea anthozoan, expand the known diversity of coelenterazine-dependent luciferases in Cnidaria, and offer new insights into the mechanism and evolution of light emission in Anthozoa.