Molecular characterization and expression of equine testicular cytochrome P450 aromatase.
We characterized testicular equine aromatase and its expression. A 2707 bp cDNA was isolated, it encoded a polypeptide of 503 residues with a deduced molecular mass of 57.8 kDa. The sequence features were those of a cytochrome P450 aromatase, with a 78% polypeptide identity with the human counterpart. The gene has a minimal length of 74 kb comprising at least 9 exons and expresses a 2.8 kb mRNA in the testis. Transient cDNA transfections in E293 cells and in vitro translations in a reticulocyte lysate system allowed aromatase protein and activity detections. The activity increased with androstenedione as substrate in a dose-dependent manner. The isolation of testicular aromatase by a new immunoaffinity method demonstrated that the protein could exist either glycosylated or not with a 2 kDa difference. All these results taken together allow new structural studies to progress in the understanding of this cytochrome P450.
Seralini
Gilles Eric
GE
Laboratory of Biochemistry and Molecular Biology, EA 2608, IBBA, University of Caen, Esplanade de la Paix, 14032 Caen Cedex, France. bioch.bio.mol@ibba.unicaen.fr
Tomilin
Alexey
A
Auvray
Pierrïck
P
Nativelle-Serpentini
Celine
C
Sourdaine
Pascal
P
Moslemi
Safa
S
D000595:Amino Acid Sequence; D000818:Animals; D001141:Aromatase / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D015139:Blotting, Southern; D002460:Cell Line; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D006736:Horses; D008297:Male; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D012333:RNA, Messenger / Q000032:analysis; D015183:Restriction Mapping; D013737:Testis / Q000201:enzymology*
D012333:RNA, Messenger; D001141:Aromatase