1. Calcitonin-typical suppression of osteoclastic activity by amphioxus calcitonin superfamily peptides and insights into the evolutionary conservation and diversity of their structures.
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Sekiguchi, Toshio, Shiraishi, Akira, Satake, Honoo, Kuwasako, Kenji, Takahashi, Hiroki, Sato, Masayuki, Urata, Makoto, Wada, Shuichi, Endo, Masato, Ikari, Takahiro, Hattori, Atsuhiko, Srivastav, Ajai K., and Suzuki, Nobuo
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FISH endocrinology , *CALCITONIN , *AMINO acid sequence , *AMPHIOXUS , *STRUCTURE-activity relationships - Abstract
Calcitonin (CT) is a hormone that decreases serum calcium level by suppressing osteoclastic activity in the vertebrate bone. In vertebrates, the structure-function relationship of CTs has been studied extensively. We recently identified three CT superfamily peptides, Bf-CTFP1 to 3, and clarified the molecular and functional characteristics of their receptor and receptor activity-modifying protein in amphioxus, Branchiostoma floridae . However, the CT activity of Bf-CTFPs has yet to be investigated. In the present study, a functional analysis of Bf-CTFPs was performed using goldfish scales having both osteoclasts and osteoblasts. All Bf-CTFPs suppressed osteoclastic activity via a goldfish CT receptor. Although the primary amino acid sequences of the Bf-CTFPs showed low sequence similarity to vertebrate CTs, Bf-CTFP1 to 3 share three amino acids, Thr 25 , Thr 27 , and Pro 32 -NH 2 , that are required for receptor binding, with salmon CT. Moreover, homology model analysis revealed that the Bf-CTFPs form alpha-helical structures. The alpha-helical position and length of Bf-CTFP1 and 2 were conserved with those of a highly potent ligand, teleost CT. Interestingly, the composition of the alpha-helix of Bf-CTFP3 differed from those of teleost CT, despite that the action of Bf-CTFP3 on goldfish scales was the same as that of Bf-CTFP1 and 2. Collectively, the present study provides new insights into the structure-function relationship of CT and its functional evolution in chordates. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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