title: Amphibian tachykinin precursor.
abstract: The precursor of amphibian tachykinin has not been found although more than 30 tachykinins have been isolated from amphibians since 1964. In this report, two tachykinin-like peptides are identified from the skin secretions of the frog, Odorrana grahami. Their amino acid sequences are DDTEDLANKFIGLM-NH(2) (named tachykinin OG1) and DDASDRAKKFYGLM-NH(2) that is the same with ranamargarin found in Rana margaretae, respectively, with a conserved FXGLM-NH(2) C-terminal consensus motif. By cDNA cloning, their precursors were screened from the skin cDNA library of O. grahami. The precursors are composed of 61 amino acid (aa) residues including a signal peptide followed by an acidic spacer peptide and one copy of mature tachykinin-like peptide. Their overall structure is different from structures of other tachykinin precursors such as human protachykinin 1 precursor containing 143 aa including one copy of substance P (SP) and neurokinin A (NKA), and ascidian tachykinin 1 precursor containing 164 aa including two copies of tachykinin-like peptides. The current results demonstrate that the biosynthesis mode of tachykinins in amphibians is different from other animals.
authors.affiliation: Biotoxin Units of Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China.
authors.forename: Jianxu
authors.initials: J
authors.lastname: Li
authors.forename: Tongguang
authors.initials: T
authors.lastname: Liu
authors.forename: Xueqing
authors.initials: X
authors.lastname: Xu
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Wu
authors.forename: Hailong
authors.initials: H
authors.lastname: Yang
authors.forename: Ren
authors.initials: R
authors.lastname: Lai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D011898:Ranidae / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D015320:Tachykinins / Q000737:chemistry* / Q000235:genetics*
chemical_list: D015320:Tachykinins