Related Experiment Video
Updated: Aug 18, 2026

High-Throughput Expression and Purification of Human Solute Carriers for Structural and Biochemical Studies
Published on: September 29, 2023
The rat Na+-sulfate cotransporter rNaS2: functional characterization, tissue distribution, and gene (slc13a4)
Paul A Dawson1, Katrina J Pirlo, Sarah E Steane
1School of Biomedical Sciences, University of Queensland, Brisbane, QLD, 4072, Australia.
Abstract:
Inorganic sulfate is essential for numerous functions in mammalian physiology. In the present study, we characterized the functional properties of the rat Na+-sulfate cotransporter NaS2 (rNaS2), determined its tissue distribution, and identified its gene (slc13a4) structure. Expression of rNaS2 protein in Xenopus oocytes led to a Na+-dependent transport of sulfate that was inhibited by phosphate, thiosulfate, tungstate, selenate, oxalate, and molybdate, but not by citrate, succinate, or DIDS. Transport kinetics of rNaS2 determined a K(M) for sulfate of 1.26 mM. Na+ kinetics determined a Hill coefficient of n=3.0+/-0.7, suggesting a Na+:SO4 (2-) stoichiometry of 3:1. rNaS2 mRNA was highly expressed in placenta, with lower levels found in the brain and liver. slc13a4 maps to rat chromosome 4 and contains 17 exons, spanning over 46 kb in length. This gene produces two alternatively spliced transcripts, of which the transcript lacking exon 2 is the most abundant form. Its 5' flanking region contains CAAT- and GC-box motifs and a number of putative transcription factor binding sites, including GATA-1, SP1, and AP-2 consensus sequences. This is the first study to characterize rNaS2 transport kinetics, define its tissue distribution, and resolve its gene (slc13a4) structure and 5' flanking region.
Related Concept Videos
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
Glucose Transporters
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
The Significance of Membrane Transport
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
The Ras Gene
Ras is a superfamily...
Membrane Transporters
Transporters are mainly composed of alpha-helices, built from bundles of ten or more helices traversing the plasma membrane. The solute-binding sites are located midway, where some of the helices are broken or distorted, making space for the binding site through...

