High impact information on STE

• A computer search of the protein data banks revealed significant homology with several sulfotransferases: 71% with bovine placental estrogen sulfotransferase, 52% with rat liver phenol sulfotransferase, 35% with rat liver hydroxysteroid sulfotransferase, and 36% with rat liver senescence marker protein 2 [1].
• Under high stringency hybridization conditions, EST mRNA was only detected in the adrenal gland, where two mRNA species of 1.4 and 1.8 kilobases were evident; when low stringency conditions were used, a faint 1.4-kilobase band was also detected in the liver [1].
• The EST cDNA was inserted into the pcDNA I eukaryotic expression vector and transfected into COS-7 cells [1].
• These isoforms were previously reported to be isomers of a pregnenolone-binding protein; however it is now evident that the isoforms and antibodies raised against them are EST specific [1].
• Estrogen sulfotransferase (EST) is responsible for the sulfoconjugation of estrogens, thereby changing their physical properties and preventing their action via the estrogen receptors [2].

Biological context of STE

• The objective of this study was to investigate the regulation of EST and ABCC1 during human chorionic gonadotropin (hCG)-induced ovulation/luteinization [2].
• It shares 88%, 77%, 75%, and 68% identity in amino acid sequence with the rat liver, human liver, guinea pig adrenal, and bovine placental estrogen sulfotransferase, respectively [3].
• The transcripts for EST and ABCC1 were cloned by RT-PCR, and the regulation of their mRNAs was studied in preovulatory follicles obtained during estrus at 0, 12, 24, 30, 33, 36, and 39 h after hCG [2].
• OST-activity did not change during pregnancy and parturition and was higher (p < 0.001) in cotyledonary than in caruncular tissue with mean conversions (median) of 61.8% and 41.6% after 30 min of homogenate incubation [4].

Anatomical context of STE

• In granulosa cells, a significant increase in EST transcript was observed 30-39 h after hCG [2].
• In contrast, no significant changes in either EST or ABCC1 were detected in theca interna samples after hCG [2].
• On a subcellular level OST-activity was clearly associated with the cytosol [4].
• To gain further information on the biological role of the high amounts of conjugated estrone (E1S) secreted by the bovine placenta, an in vitro assay system was developed to measure oestrogen sulfotransferase (OST) and oestrogen sulfatase (OS) activities in caruncular and cotyledonary homogenates and the respective subcellular fractions [4].

Associations of STE with chemical compounds

• 3H-E1 and 3H-E1S served as substrates and 4-nitrophenyl sulfate potassium salt was used as a competitive inhibitor to block OS when testing for OST activity [4].
• Studies on bovine adrenal estrogen sulfotransferase. V. Synthesis and assay of analogs of 3'-phosphoadenosine 5'-phosphosulfate as cosubstrates for estrogen sulfurylation [5].
• Analogs of adenosine 3',5'-diphosphate are described which aid in the characterization of the inhibition of estrone sulfurylation by 3'-phosphoadenosine 5'-phosphosulfate as mediated by bovine adrenal estrogen sulfotransferase (3'-5'-phosphosulfate:estrone 3-sulphotransferase, EC 2.8.2.4) [6].

Analytical, diagnostic and therapeutic context of STE

• Molecular cloning and expression of a full-length complementary DNA encoding the guinea pig adrenocortical estrogen sulfotransferase [1].
• Results obtained from RT-PCR/Southern blot analyses showed significant changes in steady-state levels of both EST and ABCC1 mRNA after hCG treatment (P < 0.05) [2].

References