Isolation of a full-length cDNA insert encoding human aromatase system cytochrome P-450 and its expression in nonsteroidogenic cells.
The isolation and cloning of a full-length cDNA insert complementary to mRNA encoding human aromatase system cytochrome P-450 is reported. The insert contains an open reading frame encoding a protein of 503 amino acids. This gene is clearly a member of the cytochrome P-450 gene superfamily, because the sequence contains regions of marked homology to those of other members, notably a putative membrane-spanning region, I helix, Ozols, and heme-binding regions. The cDNA was inserted into a modified pCMV vector and expressed in COS-1 monkey kidney tumor cells. The expressed protein was similar in size to human placental aromatase system cytochrome P-450, as detected by immunoblot analysis, and catalyzed the aromatization of androstenedione, testosterone, and 16 alpha-hydroxyandrostenedione. This activity was inhibited by the known aromatase inhibitors, 4-hydroxyandrostenedione and econazole. Thus the several steps involved in the aromatization reaction appear to be catalyzed by a single polypeptide chain, which can metabolize the three major physiological substrates.
Corbin
C J
CJ
Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas 75235.
Graham-Lorence
S
S
McPhaul
M
M
Mason
J I
JI
Mendelson
C R
CR
Simpson
E R
ER
D000595:Amino Acid Sequence; D000818:Animals; D001141:Aromatase / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000302:isolation & purification*; D004251:DNA Transposable Elements; D005796:Genes; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012333:RNA, Messenger / Q000235:genetics; D014162:Transfection
D004251:DNA Transposable Elements; D012333:RNA, Messenger; D004247:DNA; D001141:Aromatase