Multiple regulatory elements determine adrenocortical expression of steroid 21-hydroxylase.
Steroid 21-hydroxylase (21-OHase) is specifically expressed at high levels in the adrenal cortex, where it is required for the synthesis of mineralocorticoids and glucocorticoids. In this study, we have investigated the regulatory elements in the 21-OHase promoter region which contribute to the expression of this gene in Y1 adrenocortical cells. Eight potential regulatory elements in the 5'-flanking region of the 21-OHase gene were identified by DNase I footprinting and gel mobility shift experiments. Some of these footprints were produced by nuclear extracts from many cell lines, whereas other interactions were seen only when using nuclear extracts from Y1 adrenocortical and MA-10 Leydig tumor cells. Mutation of most of the elements markedly decreased the expression of a 21-OHase gene transfected into Y1 cells, thus documenting their functional importance for expression. Moreover, oligonucleotides containing the sequences of two related elements at -65 and -210, which share the heptamer AGGTCAG, increased the activity of a heterologous promoter in a Y1 cell-specific manner. Collectively, these results demonstrate that expression of 21-OHase in Y1 adrenocortical cells requires interactions among multiple cis-acting elements and regulatory proteins.
Rice
D A
DA
Department of Medicine, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710.
Kronenberg
M S
MS
Mouw
A R
AR
Aitken
L D
LD
Franklin
A
A
Schimmer
B P
BP
Parker
K L
KL
D000302:Adrenal Cortex / Q000201:enzymology*; D000306:Adrenal Cortex Neoplasms / Q000201:enzymology; D000310:Adrenal Gland Neoplasms / Q000201:enzymology; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000201:enzymology; D003850:Deoxyribonuclease I; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D007984:Leydig Cell Tumor / Q000201:enzymology; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010673:Pheochromocytoma / Q000201:enzymology; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D013255:Steroid 21-Hydroxylase / Q000235:genetics*; D013250:Steroid Hydroxylases / Q000235:genetics*; D013736:Testicular Neoplasms / Q000201:enzymology; D014162:Transfection; D014407:Tumor Cells, Cultured
D013250:Steroid Hydroxylases; D013255:Steroid 21-Hydroxylase; D003850:Deoxyribonuclease I