Universität zu Köln

Mueller, Julian Peter, Keufgens, Lena and Gruendemann, Dirk (2021). Hyperosmolarity stimulates transporter-mediated insertion of estrone sulfate into the plasma membrane, but inhibits the uptake by SLC10A1 (NTCP). Biochem. Pharmacol., 186. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD. ISSN 1873-2968

Full text not available from this repository.

Abstract

Many drugs are largely hydrophobic molecules; a transporter might conceivably insert these into the plasma membrane. At least 18 transporters from diverse families have been reported to transport the model compound estrone sulfate alias estrone-3-sulfate (E3S). Out of these, we recently examined SLC22A11 (OAT4). We concluded from a comparison of E3S and uric acid transport that SLC22A11 does not translocate E3S into the cytosol, but into the plasma membrane. Here we present a hyperosmolarity alias hypertonicity assay to differentiate transport mechanisms. Human transporters were expressed heterologously in 293 cells. Solute uptake into intact cells was measured by LC-MS. Addition of mannitol or sucrose led to rapid cell shrinkage, but cell viability after 60 min in hyperosmolar buffer was not impaired. A decrease in substrate accumulation with increasing osmolarity as observed here for several substrates and the transporters SLC22A11, ETT (SLC22A4), OCT2 (SLC22A2), OAT3 (SLC22A8), and MATE1 (SLC47A1) suggests regular substrate translocation into the cytosol. An increase as observed for E3S transport by SLC22A11, OAT3, MATE1, SLC22A9, and SLC10A6 implies insertion into the membrane. In marked contrast to the other E3S transporters, the bile acid transporter SLC10A1 (NTCP, Na+ taurocholate co-transporting polypeptide) showed a decrease in the accumulation of E3S in hyperosmolar buffer; the same was observed with taurocholic acid. Indeed, our data from several functional assays strongly suggest that the transport mechanism is identical for both substrates. Apparently, a unique transport mechanism has been established for SLC10A1 by evolution that ensures the transport of amphipathic, detergent-like molecules into the cytosol.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Mueller, Julian Peter UNSPECIFIED UNSPECIFIED UNSPECIFIED Keufgens, Lena UNSPECIFIED UNSPECIFIED UNSPECIFIED Gruendemann, Dirk UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-569022
DOI:	10.1016/j.bcp.2021.114484
Journal or Publication Title:	Biochem. Pharmacol.
Volume:	186
Date:	2021
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Place of Publication:	OXFORD
ISSN:	1873-2968
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language COTRANSPORTING POLYPEPTIDE NTCP; HEPATITIS-B; MOLECULAR-CLONING; D VIRUSES; TAUROCHOLATE; ACID; PROTEIN; LOCALIZATION; ROSUVASTATIN; DEFORMATION Multiple languages Pharmacology & Pharmacy Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/56902