Down-regulation of glucocorticoid receptor mRNA by glucocorticoid hormones and recognition by the receptor of a specific binding sequence within a receptor cDNA clone.
A cDNA clone for the rat glucocorticoid receptor (GR) was used to study mechanisms of GR mRNA regulation. Treatment of rat hepatoma culture cells with 0.5 microM dexamethasone caused a small, initial increase in the GR mRNA level after 6 hr as well as a 50% to 95% reduction of the GR mRNA level after 24 hr of incubation when studied by RNA blot hybridization. After 72 hr, the initial GR mRNA level was restored. The down-regulation of GR mRNA levels appears to be independent of protein synthesis, since it also was observed in the presence of cycloheximide. However, cycloheximide caused a 4-fold increase in intracellular levels of GR mRNA. Using an immunoprecipitation assay, we could demonstrate that the GR specifically interacts with a GR cDNA clone, which represents a 2.6-kilobase fragment of the 3' nontranslated region of the GR mRNA. Nuclease protection experiments indicate the presence of several internal GR-binding regions in the above fragment.
D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D004262:DNA Restriction Enzymes; D003907:Dexamethasone / Q000494:pharmacology*; D006706:Homeostasis; D008114:Liver Neoplasms, Experimental / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*
D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; D003907:Dexamethasone; D004247:DNA; D004262:DNA Restriction Enzymes