High impact information on STE

• Proposed active site domain in estrogen sulfotransferase as determined by mutational analysis [1].
• An interesting finding was that, in addition to EST activity, gpEST bound estradiol with a high affinity [dissociation constant (Kd) 10 nM]; furthermore, the binding activity was absolutely dependent on the cofactor, adenosine-3',5'-diphosphate (3',5'-ADP) [2].
• Estrogen sulfotransferase (EST) purified from the guinea pig (gp) adrenal gland consists of multiple charge isoforms with isoelectric points (pls) ranging from 6.5 to 5 [2].
• Only after transfection with EST cDNA was there detectable estradiol sulfotransferase activity in COS-7 cell cytosol [3].
• The successful expression of EST cDNA in COS-7 cells was ascertained by Western blot analysis using antibody generated against the protein used to obtain the original amino acid sequence [3].

Biological context of STE

• The EST expressed by the stably transfected CHO-K1 cells was found to manifest Michaelis-Menten kinetics and would use only estrogenic steroids as substrates, whereas other forms of steroids, such as pregnenolone, dehydroepiandrosterone, cortisol, and testosterone, were not acted on [4].
• A 34-kilodalton EST and two HSTs with 3 alpha- and 3 beta-hydroxysteroid substrate specificities (32 and 33 kilodaltons, respectively) were previously purified from guinea pig adrenal cortex and characterized [5].
• CHO-K1 cells transfected with the same plasmid without the EST complementary DNA insert as well as untransfected CHO-K1 cells did not demonstrate either EST activity or the presence of an immunologically related protein [4].
• The high concentration of EST immunoreactivity in nuclei suggests that EST may play a role in modulating the ability of active estrogens to regulate gene expression in ACTH-responsive cells [5].
• The activities of estrogen sulfotransferase, estrogen sulfatase and estradiol 17beta-dehydrogenase change considerably in the guinea pig uterine compartment during gestation [6].

Anatomical context of STE

• In the European Reference Laboratory (EURL) a clone of this cell line, PK(15)A, and the STE (swine testicular epitheloid) cell line are in use for propagation of CSFV [7].
• Ovoid inclusions about 1-4 microns in diameter, with no limiting membrane, were observed in zona reticularis cells; these inclusions were strongly labeled for both EST and HSTs [5].
• EST was concentrated in cell nuclei; sparse labeling was distributed throughout the cytoplasm [5].
• Studies have been carried out which were designed to examine the hormonal requirement for the appearance of estrogen sulfotransferase activity in porcine uteri [8].
• Cytosolic estrogen sulfotransferase activity of chorion decreased 7-fold between stages 50 and -1 [9].

Associations of STE with chemical compounds

• Adrenocortical pregnenolone binding activity resides with estrogen sulfotransferase [10].
• 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 [10].
• The EST protein expressed by the CHO-K1 cell stable transfectants demonstrated a mol wt of 34 kilodaltons, as determined by sodium dodecyl sulfate-gel electrophoresis [4].
• Induction of porcine uterine estrogen sulfotransferase activity by progesterone [8].
• Cloning and sequence analysis of the 5'-flanking region of the estrogen sulfotransferase gene: steroid response elements and cell-specific nuclear DNA-binding proteins [11].

Other interactions of STE

• Compared with the control, PUFA were only slightly increased in backfat of pigs fed PF, OLE, STE or OO, although dietary PUFA intake was up to 70% higher [12].

Analytical, diagnostic and therapeutic context of STE

• Additionally, when the expressed EST protein was subjected to isoelectric focusing, it was found to consist of multiple charge isoforms [4].
• Guinea pig adrenal estrogen sulfotransferase from either sex was eluted as a single peak, irrespective of buffer salt concentration, when subjected to fast protein liquid chromatography on gel filtration columns [13].
• Each EST form exhibited an estimated molecular weight of 48-52 KDa by FPLC gel filtration and each acted upon both estrone (E1) and estradiol (E2) [14].

References