Transcriptional control of the rat alpha 1-acid glycoprotein gene.
Dexamethasone strongly stimulates the production of alpha 1-acid glycoprotein (AGP) in rat liver. The regulated expression of AGP in cultured liver cells has been variably ascribed to the activation of AGP gene transcription, to change in the nuclear processing of AGP gene transcripts, or to both. Treatment of HTC cells with dexamethasone proportionally enhanced the rate of AGP gene transcription and the concentration of AGP mRNA. To assess whether hormone treatment is indeed capable of affecting posttranscriptionally the level of rat AGP mRNA, a hormone-independent expression vector containing the rat AGP gene was transiently introduced into HepG2 cells. None of the hormone combinations known to modulate expression of the endogenous AGP influenced the steady-state concentration of mature mRNA that was derived from the transgene. Hence, the existence of a hormone-sensitive posttranscriptional regulatory pathway for rat AGP gene expression could not be substantiated.
Baumann
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Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York 14263.
D000818:Animals; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006609:High Mobility Group Proteins / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D008099:Liver / Q000378:metabolism; D008114:Liver Neoplasms, Experimental; D009693:Nucleic Acid Hybridization; D009961:Orosomucoid / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection; D014407:Tumor Cells, Cultured
D006609:High Mobility Group Proteins; D009961:Orosomucoid; D012333:RNA, Messenger; D003907:Dexamethasone