title: Promoter activity of sea lamprey proopiocortin and proopiomelanotropin genes in AtT-20/D16v cells.
abstract: Adrenocorticotropic hormone (ACTH) and melanophore-stimulating hormone (MSH) are produced in the pars distalis and pars intermedia, respectively, throughout vertebrates. These hormones together with beta-endorphin are encoded on a single gene proopiomelanocortin (POMC) in gnathostomes, but in the sea lamprey, an agnathan, ACTH and MSH are encoded on two separate genes, proopiocortin (POC) and proopiomelanotropin (POM), respectively. Moreover, the nucleotide sequences of 5'-flanking regions of the POC and POM genes are significantly different from each other. To investigate the potential promoter activities of the POC and POM genes, we constructed promoter reporter plasmids by fusing the 5' flanking sequences (nucleotides -1151 to +31 and -2510 to +51, respectively) to a firefly luciferase gene. Transient transfection studies in AtT-20/D16v cells, which derived from a mouse pituitary tumor cell line, revealed that the 5'-flanking sequence of the POC gene did not exhibit promoter activity, whereas that of the POM gene showed the activity at high levels nearly equivalent to SV40 promoter. Analysis of a series of the 5'-deleted reporter for the POM gene in the AtT-20/D16v cells demonstrated that the 422 bp 5'-flanking sequence was sufficient for promoter activity, while the sequence from -853 to -574 may contain negatively acting regulatory elements. Because the POC and POM genes are supposed to have differentiated from a common ancestor, during evolution, the POC gene may lack essential element(s) for expression in the AtT-20/D16v cells.
authors.affiliation: School of Fisheries Sciences, Kitasato University, Ofunato, Iwate, Japan. akiyoshi@kitasato-u.ac.jp
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Takahashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Nakata
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Kosugi
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kako
authors.forename: Takafumi
authors.initials: T
authors.lastname: Sakai
authors.forename: Michihiko
authors.initials: M
authors.lastname: Ito
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Takamatsu
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Shiba
authors.forename: Stacia A
authors.initials: SA
authors.lastname: Sower
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawauchi
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000235:genetics; D000818:Animals; D045744:Cell Line, Tumor; D007798:Lampreys / Q000235:genetics*; D008156:Luciferases / Q000235:genetics; D009074:Melanocyte-Stimulating Hormones / Q000235:genetics; D010911:Pituitary Neoplasms; D011333:Pro-Opiomelanocortin / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins; D014162:Transfection
chemical_list: D011993:Recombinant Fusion Proteins; D011333:Pro-Opiomelanocortin; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones; D008156:Luciferases