title: Sturgeon proopiomelanocortin has a remnant of gamma-melanotropin.
abstract: For the investigation of the evolution of the proopiomelanocortin (POMC) gene in early ray-finned fishes, nucleotide sequence of POMC cDNA from a chondrostean fish, the sturgeon has been determined. POMC cDNA was amplified by PCR from double-strand cDNA prepared from sturgeon pituitary and ligated with lambdaZAP II. The POMC cDNA consists of 1079 bp without a poly-A. An open reading frame of the POMC cDNA encodes 263 amino acid residues. Sturgeon POMC contains ACTH, alpha-melanotropin (MSH), beta-MSH and beta-END at positions (115-153), (115-127), (186-202) and (205-238), respectively. Location of POMC(51-72) is homologous to gamma-MSH, whereas the third residue of MSH-core sequence, His-Phe-Arg-Trp, is changed to His. Moreover, there are no basic amino acids to serve as a processing signal on the N-terminal side of POMC(51-72). These structural characteristics suggest that an ancestor of the ray-finned fishes had gamma-MSH, whereas significant mutations occurred during the evolution of chondrostean fish.
authors.affiliation: Laboratory of Molecular Endocrinology, School of Fisheries Sciences, Kitasato University, Sanriku, Iwate, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Amemiya
authors.forename: A
authors.initials: A
authors.lastname: Takahashi
authors.forename: R M
authors.initials: RM
authors.lastname: Dores
authors.forename: H
authors.initials: H
authors.lastname: Kawauchi
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000096:biosynthesis / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D005260:Female; D005399:Fishes; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000096:biosynthesis / Q000737:chemistry*; D051379:Mice; D008969:Molecular Sequence Data; D010902:Pituitary Gland / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011333:Pro-Opiomelanocortin / Q000096:biosynthesis* / Q000737:chemistry*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D012474:Salmon; D017386:Sequence Homology, Amino Acid; D014981:Xenopus
chemical_list: D011994:Recombinant Proteins; D011333:Pro-Opiomelanocortin; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones