[en] Three DNA constructs, the natural human growth hormone gene (hGH-hGH) its 500 bp promoter linked to the chloramphenicol acetyl transferase reporter gene (hGH-CAT), and its structural part linked to the herpes virus thymidine kinase promoter (TK-hGH) were introduced into rat pituitary GC cells by DEAE-dextran transfection. Transient expression was followed as a function of triiodothyronine (T3) concentration. The hGH-CAT expression was specifically inhibited by T3 following a typical dose-response curve while hGH-GH gene expression was not significantly modified. The transient expression of TK-hGH increased as a function of T3 concentration. These results indicate that T3 exerts two opposite effects on hGH gene expression. First, it down-regulates expression by acting on the promoter; second, it up-regulates expression by acting on the structural part of the gene. These action could be due to regulation of transcription and mRNA stabilization, respectively.
Disciplines :
Biochemistry, biophysics & molecular biology
Author, co-author :
Morin, A.
Louette, J.
Voz, Marianne ; Université de Liège - ULiège > Département des sciences de la vie > GIGA-R : Biologie et génétique moléculaire
Tixier-Vidal, A.
Belayew, A.
Martial, Joseph ; Université de Liège - ULiège > Département des sciences de la vie > GIGA-R : Biologie et génétique moléculaire
Language :
English
Title :
Triiodothyronine inhibits transcription from the human growth hormone promoter
Publication date :
1990
Journal title :
Molecular and Cellular Endocrinology
ISSN :
0303-7207
eISSN :
1872-8057
Publisher :
North Holland Publishing Company, Amsterdam, Netherlands
Ackerblom, Slater, Beato, Baxter, Mellon (1988) Negative regulation by glucocorticoids through interference with a cAMP responsive enhancer. Science 241:350-353.