Enzymes
| UniProtKB help_outline | 4 proteins |
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- Name help_outline 16α-hydroxydehydroepiandrosterone 3-sulfate Identifier CHEBI:87538 Charge -1 Formula C19H27O6S InChIKeyhelp_outline ALBNSVAJDFJRKQ-DNKQKWOHSA-M SMILEShelp_outline C1[C@@]2([C@@]([C@@]3(C(C[C@@H](OS([O-])(=O)=O)CC3)=C1)C)(CC[C@]4([C@]2(C[C@H](C4=O)O)[H])C)[H])[H] 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline Na+ Identifier CHEBI:29101 (CAS: 17341-25-2) help_outline Charge 1 Formula Na InChIKeyhelp_outline FKNQFGJONOIPTF-UHFFFAOYSA-N SMILEShelp_outline [Na+] 2D coordinates Mol file for the small molecule Search links Involved in 259 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:71391 | RHEA:71392 | RHEA:71393 | RHEA:71394 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Transport of the placental estriol precursor 16alpha-hydroxy-dehydroepiandrosterone sulfate (16alpha-OH-DHEAS) by stably transfected OAT4-, SOAT-, and NTCP-HEK293 cells.
Schweigmann H., Sanchez-Guijo A., Ugele B., Hartmann K., Hartmann M.F., Bergmann M., Pfarrer C., Doering B., Wudy S.A., Petzinger E., Geyer J., Grosser G.
16α-Hydroxy-dehydroepiandrosterone sulfate (16α-OH-DHEAS) mainly originates from the fetus and serves as precursor for placental estriol biosynthesis. For conversion of 16α-OH-DHEAS to estriol several intracellular enzymes are required. However, prior to enzymatic conversion, 16α-OH-DHEAS must ent ... >> More
16α-Hydroxy-dehydroepiandrosterone sulfate (16α-OH-DHEAS) mainly originates from the fetus and serves as precursor for placental estriol biosynthesis. For conversion of 16α-OH-DHEAS to estriol several intracellular enzymes are required. However, prior to enzymatic conversion, 16α-OH-DHEAS must enter the cells by carrier mediated transport. To identify these carriers, uptake of 16α-OH-DHEAS by the candidate carriers organic anion transporter OAT4, sodium-dependent organic anion transporter SOAT, Na(+)-taurocholate cotransporting polypeptide NTCP, and organic anion transporting polypeptide OATP2B1 was measured in stably transfected HEK293 cells by LC-MS-MS. Furthermore, the study aimed to localize SOAT in the human placenta. Stably transfected OAT4-HEK293 cells revealed a partly sodium-dependent transport for 16α-OH-DHEAS with an apparent Km of 23.1 ± 5.1 μM and Vmax of 485.0 ± 39.1 pmol/mg protein/min, while stably transfected SOAT- and NTCP-HEK293 cells showed uptake only under sodium conditions with Km of 319.0 ± 59.5 μM and Vmax of 1465.8 ± 118.8 pmol/mg protein/min for SOAT and Km of 51.4 ± 9.9 μM and Vmax of 1423.3 ± 109.6 pmol/mg protein/min for NTCP. In contrast, stably transfected OATP2B1-HEK293 cells did not transport 16α-OH-DHEAS at all. Immunohistochemical studies and in situ hybridization of formalin fixed and paraffin embedded sections of human late term placenta showed expression of SOAT in syncytiotrophoblasts, predominantly at the apical membrane as well as in the vessel endothelium. In conclusion, OAT4, SOAT, and NTCP were identified as carriers for the estriol precursor 16α-OH-DHEAS. At least SOAT and OAT4 seem to play a functional role for the placental estriol synthesis as both are expressed in the syncytiotrophoblast of human placenta. << Less
J. Steroid Biochem. Mol. Biol. 143:259-265(2014) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.