title: The role of pit-1 in the regulation of the rat growth hormone-releasing hormone receptor gene transcription by glucocorticoids.
abstract: Glucocorticoids are involved in the regulation of the rat growth hormone-releasing hormone (GHRH) receptor gene expression, but they act only in the presence of the pituitary specific transcription factor, pit-1. In this study, the role of pit-1 in the glucocorticoid stimulation of the GHRH-receptor gene transcription was examined. The results suggest the presence of a silencer element in the promoter and it is postulated that pit-1 permits glucocorticoid action through suppressing the inhibitory effect of an as yet unknown factor that binds to this element. The present results also suggest that the synergistic activation of the rat GHRH-receptor gene transcription depends on the proper distance between the proximal glucocorticoid response element and the pit-1 binding site.
authors.affiliation: Department of Neuroendocrinology, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki, Japan. hnogami@md.tsukuba.ac.jp
authors.forename: Haruo
authors.initials: H
authors.lastname: Nogami
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hiraoka
authors.forename: Kiyomoto
authors.initials: K
authors.lastname: Ogasawara
authors.forename: Sadakazu
authors.initials: S
authors.lastname: Aiso
authors.forename: Setsuji
authors.initials: S
authors.lastname: Hisano
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D004247:DNA / Q000235:genetics / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D017930:Genes, Reporter; D005938:Glucocorticoids / Q000494:pharmacology*; D008156:Luciferases / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000235:genetics / Q000378:metabolism; D018013:Receptors, Neuropeptide / Q000235:genetics*; D018017:Receptors, Pituitary Hormone-Regulating Hormone / Q000235:genetics*; D017384:Sequence Deletion; D037941:Silencer Elements, Transcriptional; D050817:Transcription Factor Pit-1 / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection
chemical_list: D005938:Glucocorticoids; D011965:Receptors, Glucocorticoid; D018013:Receptors, Neuropeptide; D018017:Receptors, Pituitary Hormone-Regulating Hormone; D050817:Transcription Factor Pit-1; D003907:Dexamethasone; D004247:DNA; D008156:Luciferases; C048250:somatotropin releasing hormone receptor