title: Characterization of a novel EF-hand homologue, CnidEF, in the sea anemone Anthopleura elegantissima.
abstract: The superfamily of EF-hand proteins is comprised of a large and diverse group of proteins that contain one or more characteristic EF-hand calcium-binding domains. This study describes and characterizes a novel EF-hand cDNA, CnidEF, from the sea anemone Anthopleura elegantissima (Phylum Cnidaria, Class Anthozoa). CnidEF was found to contain two EF-hand motifs near the C-terminus of the deduced amino acid sequence and two regions near the N-terminus that could represent degenerate EF-hand motifs. CnidEF homologues were also identified from two other sea anemone species. A combination of bioinformatic and molecular phylogenetic analyses was used to compare CnidEF to EF-hand proteins in other organisms. The closest homologues identified from these analyses were a luciferin binding protein (LBP) involved in the bioluminescence of the anthozoan Renilla reniformis, and a sarcoplasmic calcium-binding protein (SARC) involved in fluorescence of the annelid worm Nereis diversicolor. Predicted structure and folding analysis revealed a close association with bioluminescent aequorin (AEQ) proteins from the hydrozoan cnidarian Aequorea aequorea. Neighbor-joining analyses grouped CnidEF within the SARC lineage along with AEQ and other cnidarian bioluminescent proteins rather than in the lineage containing calmodulin (CAM) and troponin-C (TNC).
authors.affiliation: Department of Zoology, 3029 Cordley Hall, Oregon State University, Corvallis, Oregon 97331, USA. hauck1@science.oregonstate.edu
authors.forename: Laura L
authors.initials: LL
authors.lastname: Hauck
authors.forename: Wendy S
authors.initials: WS
authors.lastname: Phillips
authors.forename: Virginia M
authors.initials: VM
authors.lastname: Weis
mesh_terms: D000331:Aequorin / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000737:chemistry; D020832:EF Hand Motifs; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D010802:Phylogeny; D017433:Protein Structure, Secondary; D015800:Protozoan Proteins / Q000737:chemistry; D012615:Sea Anemones / Q000502:physiology*; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013559:Symbiosis
chemical_list: D002135:Calcium-Binding Proteins; D029721:Drosophila Proteins; D015800:Protozoan Proteins; C110573:Scp1 protein, Drosophila; C065397:luciferin-binding protein, dinoflagellate; D000331:Aequorin