title: Teleost fish osteocalcin 1 and 2 share the ability to bind the calcium mineral phase.
abstract: The occurrence of a second osteocalcin (OC2) has been reported in teleost fish, where it coexists with OC1 in some species. While it has been proposed that OC2 gene originated from OC1 through the fish whole-genome duplication event, little information is available on its molecular function and physiological role. The present study brings biological data supporting the presence of OC2 in the mineral phase of teleost fish bone and its association with the mineral phase together with OC1. The occurrence of OC2 forms with different levels of phosphorylation or γ-carboxylation, and with amino acid substitutions was observed. Comparative analysis of mature peptide sequences revealed the high conservation existing between OC1 and OC2, in particular within the core γ-carboxyglutamic acid domain, and suggests that both protein forms may have the same function, i.e., binding of calcium ions or hydroxyapatite crystals.
authors.affiliation: Centre of Marine Sciences (CCMAR/CIMAR-LA), University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Cavaco
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Williamson
authors.forename: Joana
authors.initials: J
authors.lastname: Rosa
authors.forename: Vânia
authors.initials: V
authors.lastname: Roberto
authors.forename: Odete
authors.initials: O
authors.lastname: Cordeiro
authors.forename: Paul A
authors.initials: PA
authors.lastname: Price
authors.forename: M
authors.initials: M
authors.lastname: Leonor Cancela
authors.forename: Vincent
authors.initials: V
authors.lastname: Laizé
authors.forename: Dina C
authors.initials: DC
authors.lastname: Simes
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D029941:Fish Proteins / Q000032:analysis / Q000378:metabolism*; D005399:Fishes / Q000378:metabolism*; D005412:Flatfishes; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss; D015675:Osteocalcin / Q000032:analysis / Q000378:metabolism*; D020033:Protein Isoforms / Q000737:chemistry; D021541:Sea Bream
chemical_list: D029941:Fish Proteins; D020033:Protein Isoforms; D015675:Osteocalcin; D002118:Calcium