title: It's cheap to be colorful. Anthozoans show a slow turnover of GFP-like proteins.
abstract: Pigments homologous to the green fluorescent protein (GFP) contribute up to approximately 14% of the soluble protein content of many anthozoans. Maintenance of such high tissue levels poses a severe energetic penalty to the animals if protein turnover is fast. To address this as yet unexplored issue, we established that the irreversible green-to-red conversion of the GFP-like pigments from the reef corals Montastrea cavernosa (mcavRFP) and Lobophyllia hemprichii (EosFP) is driven by violet-blue radiation in vivo and in situ. In the absence of photoconverting light, we subsequently tracked degradation of the red-converted forms of the two proteins in coral tissue using in vivo spectroscopy and immunochemical detection of the post-translational peptide backbone modification. The pigments displayed surprisingly slow decay rates, characterized by half-lives of approximately 20 days. The slow turnover of GFP-like proteins implies that the associated energetic costs for being colorful are comparatively low. Moreover, high in vivo stability makes GFP-like proteins suitable for functions requiring high pigment concentrations, such as photoprotection.
authors.affiliation: Institute of General Zoology and Endocrinology, University of Ulm, Ulm, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Leutenegger
authors.forename: Cecilia
authors.initials: C
authors.lastname: D'Angelo
authors.forename: Mikhail V
authors.initials: MV
authors.lastname: Matz
authors.forename: Andrea
authors.initials: A
authors.lastname: Denzel
authors.forename: Franz
authors.initials: F
authors.lastname: Oswald
authors.forename: Anya
authors.initials: A
authors.lastname: Salih
authors.forename: G Ulrich
authors.initials: GU
authors.lastname: Nienhaus
authors.forename: Jörg
authors.initials: J
authors.lastname: Wiedenmann
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry* / Q000528:radiation effects; D003116:Color; D003624:Darkness; D007700:Kinetics; D008027:Light; D008164:Luminescent Proteins / Q000378:metabolism* / Q000528:radiation effects; D010860:Pigments, Biological / Q000378:metabolism* / Q000528:radiation effects; D013050:Spectrometry, Fluorescence
chemical_list: D008164:Luminescent Proteins; D010860:Pigments, Biological