title: Identification and molecular cloning of a novel neuromedin U analog from the skin secretions of toad Bombina maxima.
abstract: Amphibian skin contains rich neuropeptides. In the present study, a novel neuromedin U (NmU) analog was isolated from skin secretions of Chinese red belly toad Bombina maxima. Being 17-amino acids long, its primary structure was established as DSSGIVGRPFFLFRPRN-NH2, in which the C-terminal 8-residue segment (FFLFRPRN) is the same as that of rat NmU, while the N-terminal part DSSGIVGRP shows a great sequence variation compared with those of NmU peptides from different resources. The peptide, named Bm-NmU-17, was found to elicit concentration-dependent contractile effects on smooth muscle of rat uterus horns. The cDNA structure of the peptide, as obtained by a 3'-RACE strategy and subsequently cloning from a skin cDNA library, was found to contain a coding region of 438 nucleotides. The encoded precursor is composed of 145 amino acids with a single copy of Bm-NmU-17 located towards the C-terminus. The sequence of the peptide is preceded by a dibasic site (Lys-Arg) and followed by the sequence of Gly-Arg-Lys, providing the sites of cleavage and releasing of the mature peptide.
authors.affiliation: Department of Animal Toxinology, Kunming Institute of Zoology, The Chinese Academy of Sciences, 32 East Jiao Chang Road, Kunming 650223, Yunnan, China.
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Lee
authors.forename: Shu-Bai
authors.initials: SB
authors.lastname: Liu
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Shen
authors.forename: Yang
authors.initials: Y
authors.lastname: Jin
authors.forename: Ren
authors.initials: R
authors.lastname: Lai
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001001:Anura / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000235:genetics* / Q000378:metabolism; D012867:Skin / Q000378:metabolism*
chemical_list: D009479:Neuropeptides; C056900:neuromedin U