title: Expression of murine 21-hydroxylase in mouse adrenal glands and in transfected Y1 adrenocortical tumor cells.
abstract: The S region of the murine major histocompatibility complex contains two structurally related genes (21-OHase A and 21-OHase B) that encode 21-hydroxylase (21-OHase), an enzyme essential for the synthesis of adrenal steroids. Expression of these two genes has been analyzed by using oligonucleotide probes specific for the 21-OHase A and B genes and by DNA-mediated gene transfer. Hybridization of the oligonucleotides to blots of BALB/c adrenal RNA demonstrated that all 21-OHase mRNA is derived from the 21-OHase A gene. Cosmids bearing either the 21-OHase A or B gene were introduced into Y1 adrenocortical tumor cells by cotransfection with pSV2-neo. Cells transfected with the 21-OHase A gene expressed 21-OHase as determined by steroid metabolism and by RNA blot hybridization; 21-OHase transcripts were not detected in parent Y1 cells or in cells transfected with the 21-OHase B gene. Treatment of 21-OHase A transfectants with adrenocorticotropin increased 21-OHase mRNA levels by up to 10-fold, thus mimicking the observed effect of this hormone on 21-OHase levels in primary adrenal cultures. The regulated expression of the 21-OHase A gene in transfected Y1 cells should provide a useful system for the investigation of factors controlling the adrenal-specific regulation of 21-OHase activity.
mesh_terms: D000306:Adrenal Cortex Neoplasms / Q000235:genetics; D000311:Adrenal Glands / Q000502:physiology*; D000324:Adrenocorticotropic Hormone / Q000502:physiology; D000818:Animals; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D046911:Macromolecular Substances; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D013255:Steroid 21-Hydroxylase / Q000235:genetics*; D013250:Steroid Hydroxylases / Q000235:genetics*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D046911:Macromolecular Substances; D012333:RNA, Messenger; D000324:Adrenocorticotropic Hormone; D013250:Steroid Hydroxylases; D013255:Steroid 21-Hydroxylase