Evidence that ferritin is associated with light production in the mucus of the marine worm Chaetopterus

TitleEvidence that ferritin is associated with light production in the mucus of the marine worm Chaetopterus
Publication TypeJournal Article
Year of Publication2016
AuthorsRawat R., Deheyn DD
JournalScientific Reports
Volume6
Date Published2016/11
Type of ArticleArticle
ISBN Number2045-2322
Accession NumberWOS:000387873800001
Keywordsbioluminescence; ceruloplasmin; ferroxidase activity; horse spleen ferritin; incorporation; Iron; oxidation; photoprotein; polychaete; protein-kinase-c; trace-elements
Abstract

The blue glow of the mucus from Chaetopterus involves a photoprotein, iron and flavins. Identity and respective role of these components remain, however, largely unresolved today, likely because of viscosity issues and inhibition of this system by oxidizers conventionally used to track bioluminescence activity. Here, we used gentle centrifugation to obtain a mucus supernatant showing no inhibition to oxidizers, allowing for further analysis. We applied conventional chromatographic techniques to isolate major proteins associated with light emission. Luminescence ability of elutriate fractions was tested with hydrogen peroxide to track photoprotein and/or protein-bound chromophore. Fractions producing light contained few major proteins, one with similarity to ferritin. Addition to the mucus of elements with inhibitory/potentiary effect on ferritin ferroxidase activity induced corresponding changes in light production, emphasizing the possible role of ferritin in the worm bioluminescence. DNA of the protein was cloned, sequenced, and expressed, confirming its identity to a Chaetopterus Ferritin (ChF). Both ferric and ferrous iron were found in the mucus, indicating the occurrence of both oxidase and reductase activity. Biochemical analysis showed ChF has strong ferroxidase activity, which could be a source of biological iron and catalytic energy for the worm bioluminescence when coupled to a reduction process with flavins.

DOI10.1038/srep36854
Short TitleSci Rep
Student Publication: 
No