The role of pit-1 in the regulation of the rat growth hormone-releasing hormone receptor gene transcription by glucocorticoids.
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.
Nogami
Haruo
H
Department of Neuroendocrinology, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki, Japan. hnogami@md.tsukuba.ac.jp
Hiraoka
Yoshiki
Y
Ogasawara
Kiyomoto
K
Aiso
Sadakazu
S
Hisano
Setsuji
S
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
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