Figure 1

Schematic representation of pathway for the biosynthesis of sexual steroids. DAX1 regulates key steps for androgen production by repressing the transcriptional activation of SF-1 on the promoters of StAR [11], CYP11A [12] and CYP17 [13]. DAX1 binds directly to the CYP19 promoter to downregulate its transcription [14]. It also regulates estrogen [16] and androgen receptors [17] through protein-protein interactions. CYP11A, CYP17 and CYP19 are, respectively, genes that encode for the P450 enzymes cholesterol side chain cleavage, 17-hydroxylase and aromatase. StAR is the mitochondrial cholesterol transporter protein. AR and ER are respectively androgen and estrogen receptors (α and β). Supporting references for the scheme are indicated by numbers within [].