title: Role of chicken Pit-1 isoforms in activating growth hormone gene.
abstract: In the present study, we expressed chicken (ch) Pit-1α (chPit-1α) and chPit-1γin vitro to compare the roles of chPit-1s in the transcription of the chicken growth hormone (chGH) gene. Both green fluorescence protein (GFP)-fused chPit-1γ and GFP-fused chPit-1α were localized in the nuclei of COS-7 cells. In a luciferase reporter gene assay, both chPit-1α and chPit-1γ transactivated the chGH promoter, and chPit-1α showed a more potent effect than chPit-1γ. On the other hand, an increase of cellular cAMP induced by forskolin promoted transactivation of the chGH gene with chPit-1α and chPit-1γ to similar extents. These results suggest that chPit-1γ may modulate the basal promoter activity of the chGH gene to the same degree as chPit-1α; however, a structural difference observed at the N-terminus transactivation domains in chPit-1α and chPit-1γ could be associated with the efficiency of basal activation of the chGH promoter.
authors.affiliation: Graduate School of Agriculture, Kagawa University, Mikicho, Kagawa 761-0795, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Murase
authors.forename: Shusuke
authors.initials: S
authors.lastname: Taniuchi
authors.forename: Sakae
authors.initials: S
authors.lastname: Takeuchi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Adachi
authors.forename: Norio
authors.initials: N
authors.lastname: Kansaku
authors.forename: Katsuichiro
authors.initials: K
authors.lastname: Okazaki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohkubo
mesh_terms: D000818:Animals; D019556:COS Cells; D002467:Cell Nucleus / Q000378:metabolism; D002645:Chickens; D002522:Chlorocebus aethiops; D049452:Green Fluorescent Proteins; D013006:Growth Hormone / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D050817:Transcription Factor Pit-1 / Q000235:genetics / Q000378:metabolism*
chemical_list: D020033:Protein Isoforms; D050817:Transcription Factor Pit-1; D049452:Green Fluorescent Proteins; D013006:Growth Hormone