Meeting Abstract

P3.24  Friday, Jan. 6  Cloning, expression, and characterization of a photoprotein from the luminescent ctenophore Bathocyroe fosteri POWERS, M.L.*; HADDOCK, S.H.D; Univ. of California, Santa Cruz; Monterey Bay Aquarium Research Institute

Calcium-binding photoproteins have been discovered in a variety of luminous marine organisms. Light emission occurs when calcium binds to a photoprotein-substrate-oxygen complex where the substrate, usually coelenterazine, is oxidized to produce blue light. This group of photoproteins has been widely studied in hydrozoans which use the same general mechanism and have similar spectral properties. However, to further understand the evolution of these proteins and their potentially unique properties, more primary sequence information is needed. Recent interest in this area has led to the identification of several ctenophore photoproteins. Here we report the cloning, expression, and purification of the photoprotein responsible for luminescence in the deep-sea ctenophore Bathocyroe fosteri. This animal was of particular interest due to its unique dual color spectrum observed in live specimens. Full-length sequences were identified using known photoprotein sequences to BLAST Bathocyroe expressed sequence tags (ESTs) obtained from 454 transcriptome sequencing. Primary structure alignment of the Bathoocyroe photoprotein with both mnemiopsin 1 and 2, berovin, and bolinopsin showed very strong sequence similarity and conservation of Ca2+ binding sites. Preliminary results from spectral characterization of regenerated photoprotein show a maximum emission wavelength at 489nm, and spectra do not indicate bimodal distribution as was previously observed.