title: Identification and characterization of a motilin-like peptide and its receptor in teleost.
abstract: Although putative motilin receptor sequences have been reported in teleost, there is no proof for the existence of the motilin gene in teleost. In this study, we have identified a motilin-like gene in the genome of several fish species and cloned its cDNA sequence from zebrafish. The zebrafish motilin-like precursor shares very low amino acid (aa) identities with the previously reported motilin precursors. Processing of the zebrafish motilin-like precursor may generate a 17-aa C-terminal amidated mature peptide, the motilin-like peptide (motilin-LP). A putative zebrafish motilin receptor (MLNR) was also identified in zebrafish. In cultured eukaryotic cells transfected with the zebrafish MLNR, zebrafish motilin-LP could enhance both CRE-driven and SRE-driven promoter activities. Tissue distribution studies indicated that the zebrafish motilin-like gene is mainly expressed in the intestine and liver while the zebrafish MLNR gene is highly expressed in brain regions, suggesting that motilin-LP behaves like other gut hormones to regulate brain functions. These data suggest that the presence of a unique motilin/MNLR system in teleost.
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.forename: Shuisheng
authors.initials: S
authors.lastname: Li
authors.forename: Xigui
authors.initials: X
authors.lastname: Huang
authors.forename: Danqi
authors.initials: D
authors.lastname: Lu
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Liu
authors.forename: Wing-hung
authors.initials: WH
authors.lastname: Ko
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Christopher H K
authors.initials: CH
authors.lastname: Cheng
authors.forename: Haoran
authors.initials: H
authors.lastname: Lin
mesh_terms: D000818:Animals; D005399:Fishes / Q000235:genetics / Q000378:metabolism; D009037:Motilin / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D011964:Receptors, Gastrointestinal Hormone / Q000235:genetics / Q000378:metabolism*; D018013:Receptors, Neuropeptide / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism
chemical_list: D010455:Peptides; D011964:Receptors, Gastrointestinal Hormone; D018013:Receptors, Neuropeptide; C050802:motilin receptor; D009037:Motilin