Glucocorticoid-mediated induction of alpha 1-acid glycoprotein: evidence for hormone-regulated RNA processing.

Abstract

The glucocorticoid-mediated accumulation of .alpha.1-acid glycoprotein (AGP) mRNA was studied in HTC rat hepatoma cells. In contrast to the well-characterized primary response of mouse mammary tumor virus, in vitro transcription of the AGP gene is high even in the absence of hormone. Despite the constitutive transcription of the AGP gene, no detectable AGP RNA can be found in either the cytoplasm or the nuclei of untreated cells. The glucocorticoid induction of AGP RNA requires ongoing protein synthesis. Glucocorticoids may stimulate accumulation of AGP RNA by inducing an RNA processing factor that allows production of stable transcripts.