Adrenocortical pregnenolone binding activity resides with estrogen sulfotransferase.
Cytosol prepared from Chinese hamster ovary (CHO)-K1 cells transfected with guinea pig estrogen sulfotransferase (EST) cDNA demonstrated high affinity binding activity for pregnenolone as well as 17 beta-estradiol but failed to bind dehydroepiandrosterone or testosterone. In contrast, cytosol prepared from nontransfected CHO-K1 cells did not demonstrate steroid binding activity. Additionally, the binding activity for pregnenolone and 17 beta-estradiol was dependent on the presence of the cofactor adenosine-3',5'-diphosphate. Pregnenolone and 17 beta-estradiol effectively competed with each other for binding. On the other hand, pregnenolone, which was not sulfonated, did not inhibit the sulfonation of 17 beta-estradiol by expressed EST.
Lee
Y C
YC
Section on Steroid Regulation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-4510.
Park
C S
CS
Komatsu
K
K
Kwack
J
J
Strott
C A
CA
D000244:Adenosine Diphosphate / Q000378:metabolism; D000302:Adrenal Cortex / Q000378:metabolism*; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D018076:DNA, Complementary; D004958:Estradiol / Q000378:metabolism; D006168:Guinea Pigs; D011284:Pregnenolone / Q000378:metabolism*; D015238:Sulfotransferases / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
D018076:DNA, Complementary; D004958:Estradiol; D000244:Adenosine Diphosphate; D011284:Pregnenolone; C010840:adenosine 3'-phosphate-5'-phosphate; D015238:Sulfotransferases; C020122:estrone sulfotransferase