A family of mammalian na+-dependent l-ascorbic acid transporters

ABSTRACT Vitamin C (L-ascorbic acid) is essential for many enzymatic reactions, in which it serves to maintain prosthetic metal ions in their reduced forms (for example, Fe2+, Cu+)1,2, and

for scavenging free radicals in order to protect tissues from oxidative damage3. The facilitative sugar transporters of the GLUT type can transport the oxidized form of the vitamin,

dehydroascorbic acid4,5,6, but these transporters are unlikely to allow significant physiological amounts of vitamin C to be taken up in the presence of normal glucose concentrations,

because the vitamin is present in plasma essentially only in its reduced form7. Here we describe the isolation of two L-ascorbic acid transporters, SVCT1 and SVCT2, from rat complementary

DNA libraries, as the first step in investigating the importance of L-ascorbic acid transport in regulating the supply and metabolism of vitamin C. We find that SVCT1 and SVCT2 each mediate

concentrative, high-affinity L-ascorbic acid transport that is stereospecific and is driven by the Na+ electrochemical gradient. Despite their close sequence homology and similar functions,

the two isoforms of the transporter are discretely distributed: SVCT1 is mainly confined to epithelial systems (intestine, kidney, liver), whereas SVCT2 serves a host of metabolically active

cells and specialized tissues in the brain, eye and other organs. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution

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about institutional subscriptions * Read our FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS STRUCTURAL BASIS OF VITAMIN C RECOGNITION AND TRANSPORT BY MAMMALIAN SVCT1

TRANSPORTER Article Open access 13 March 2023 STRUCTURAL BASIS FOR METAL ION TRANSPORT BY THE HUMAN SLC11 PROTEINS DMT1 AND NRAMP1 Article Open access 17 January 2025 DIMERIC TRANSPORT

MECHANISM OF HUMAN VITAMIN C TRANSPORTER SVCT1 Article Open access 02 July 2024 REFERENCES * Englard, S. & Seifter, S. The biochemical functions of ascorbic acid. _Annu. Rev. Nutr._ 6,

365–406 (1986). Article  CAS  Google Scholar  * Padh, H. Vitamin C: newer insights into its biochemical functions. _Nutr. Rev._ 49, 65–70 (1991). Article  CAS  Google Scholar  * Rose, R. C.

& Bode, A. M. Biology of the free radical scavengers: an evaluation of ascorbate. _FASEB J._ 7, 1135–1142 (1993). Article  Google Scholar  * Vera, J. C., Rivas, C. I. & Fischbarg, J.

Mammalian facilitative hexose transporters mediate the transport of dehydroascorbic acid. _Nature_ 364, 79–82 (1993). Article  ADS  CAS  Google Scholar  * Rumsey, S. C. _et al_ . Glucose

transporter isoforms GLUT1 and GLUT3 transport dehydroascorbic acid. _J. Biol. Chem._ 272, 18982–18989 (1997). Article  Google Scholar  * Agus, D. B. _et al_ . Vitamin C crosses the

blood-brain barrier in the oxidized from through the glucose transporters. _J. Clin. Invest._ 100, 2842–2848 (1997). Article  Google Scholar  * Dhariwal, K. R., Hartzell, W. O. & Levine,

M. Ascorbic acid and dehydroascorbic acid measurements in human plasma and serum. _Am. J. Clin. Nutr._ 54, 712–716 (1991). Article  CAS  Google Scholar  * Nagase, T. _et al_ . Prediction of

the coding sequences of unidentified human genes. VI. The coding sequences of 80 new genes (_KIAA0201_ -_KIAA0280_ ) deduced by analysis of cDNA clones from cell line KG-1 and brain. _DNA

Res._ 3, 321–354 (1996). Article  ADS  CAS  Google Scholar  * Guimaraes, M. J. _et al_ . Anew approach to the study of haematopoietic development in the yolk sac and embryoid bodies.

_Development_ 121, 3335–3346 (1995). CAS  PubMed  Google Scholar  * Diallinas, G., Gorfinkiel, L., Arst, H. N., Cecchetto, G. & Scazzocchio, C. Genetic and molecular characterization of

a gene encoding a wide specificity purine permease of _Aspergillus nidulans_ reveals a novel family of transporters conserved in prokaryotes and eukaryotes. _J. Biol. Chem._ 270, 8610–8622

(1995). Article  CAS  Google Scholar  * Wright, E. M., Loo, D. D. F., Turk, E. & Hirayama, B. A. Sodium cotransporters. _Curr. Opin. Cell Biol._ 8, 468–473 (1996). Article  Google

Scholar  * Hazama, A., Loo, D. D. F. & Wright, E. M. Presteady-state currents of the rabbit Na+/glucose cotransporter (SGLT1). _J. Membr. Biol._ 155, 175–186 (1997). Article  Google

Scholar  * Mackenzie, B., Loo, D. D. F., Panayotova-Heiermann, M. & Wright, E. M. Biophysical characteristics of the pig kidney Na+/glucose cotransporter SGLT2 reveal a common mechanism

for SGLT1 and SGLT2. _J. Biol. Chem._ 271, 32678–32683 (1996). Article  CAS  Google Scholar  * Mackenzie, B., Loo, D. D. F. & Wright, E. M. Relationships between Na+/glucose

cotransporter currents and fluxes. _J. Membr. Biol._ 162, 101–106 (1998). Article  Google Scholar  * Gunshin, H. _et al_ . Cloning and characterization of a proton-coupled mammalian

metal-ion transporter. _Nature_ 388, 482–488 (1997). Article  Google Scholar  * Eskandari, S. _et al_ . Thyroid Na+/I symporter: mechanism, stoichiometry, and specificity. _J. Biol. Chem._

272, 27230–27238 (1997). Article  Google Scholar  * Segel, I. H. _Biochemical Calculations2nd edn_(Wiley, New York, (1976). Google Scholar  * Bowers-Komro, D. M. & McCormick, D. B.

Characterization of ascorbic acid uptake by isolated rat kidney cells. _J. Nutr._ 121, 57–64 (1991). Article  Google Scholar  * Toggenburger, G. _et al_ . Na+-dependent, potential-sensitive

L-ascorbate transport across brush border membrane vesicles from kidney cortex. _Biochim. Biophys. Acta_ 646, 433–443 (1981). Google Scholar  * Helbig, H. _et al_ . Electrogenic

Na+-ascorbate cotransport in cultured bovine pigmented ciliary epithelial cells. _Am. J. Physiol._ 256, C44–C49 (1989). Article  CAS  Google Scholar  * Rose, R. C. & Wilson, J. X. in

_Vitamin C in Health and Disease_(eds Packer, L. & Fuchs, J.) 143–161 (Dekker, New York, (1997). Google Scholar  * Franceschi, R. T., Wilson, J. X. & Dixon, S. J. Requirement for

Na+-dependent ascorbic acid transport in osteoblast function. _Am. J. Physiol._ 268, C1430–C1439 (1995). Article  CAS  Google Scholar  * Hammarström, L. Autoradiographic studies on the

distribution of C14-labelled ascorbic acid and dehydroascorbic acid. _Acta Physiol. Scand._ 70 (SUPPL.)289, 1–75 (1966). Article  Google Scholar  * Rose, R. C. & Bode, A. M.

Ocular ascorbate transport and metabolism. _Comp. Biochem. Physiol._ 100, 273–285 (1991). Article  Google Scholar  * Reiss, G. R., Werness, P. G., Zollman, P. E. & Brubaker, R. F.

Ascorbic acid levels in the aqueous humor of nocturnal and diurnal mammals. _Arch. Ophthalmol._ 104, 753–755 (1986). Article  CAS  Google Scholar  * Kodama, T., Kabasawa, I., Tamura, O.

& Reddy, V. N. Dynamics of ascorbate in the aqueous humor and tissues surrounding ocular chambers. _Ophthalmic Res._ 17, 331–337 (1985). Article  CAS  Google Scholar  * Romero, M. F.,

Kanai, Y., Gunshin, H. & Hediger, M. A. Expression cloning using _Xenopus laevis_ oocytes. _Methods Enzymol._ 296, 17–52 (1998). Google Scholar  * Mackenzie, B. in _Biomembrane

Transport_(ed. Van Winkle, L. J.) 327–342 (Academic, San Diego, (1999). Book  Google Scholar  * Schaeren-Wiemers, N. & Gerfin-Moser, A. Asingle protocol to detect transcripts of various

types and expression levels in neural tissue and cultured cells: _in situ_ hybridization using digoxigenin-labelled cRNA probes. _Histochemistry_ 100, 431–440 (1993). Article  Google Scholar

  Download references ACKNOWLEDGEMENTS We thank E. Brown for providing MC3T3-E1 cells and P. Fong for providing the pTLN2 vector. This research was supported by the NIH, the National Kidney

Foundation, the American Heart Association Massachusetts Affiliate, Cooley's Anemia Foundation, and the International Human Frontier Science Program. AUTHOR INFORMATION Author notes *

Taro Tokui Present address: Sankyo Company Ltd, Analytical and Metabolic Research Laboratories, 2-58 Hiromachi 1-Chome, Shinagawa-ku, Tokyo, 140, Japan * Hiroyasu Tsukaguchi, Taro Tokui and

Bryan Mackenzie: These authors contributed equally to this work. AUTHORS AND AFFILIATIONS * Membrane Biology Program and Renal Division, Department of Medicine, Brigham & Women's

Hospital and Harvard Medical School, 77 Avenu Louis Pasteur, Boston, 02115, Massachusetts, USA Hiroyasu Tsukaguchi, Taro Tokui, Bryan Mackenzie, Urs V. Berger, Xing-Zhen Chen, Yangxi Wang 

& Matthias A. Hediger * Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, 77 Avenu Louis Pasteur, Boston, 02115, Massachusetts, USA Matthias A.

Hediger * Department of Ophthalmology, Mayo Clinic, 200 First Street Southwest, Rochester, 55905, Minnesota, USA Richard F. Brubaker Authors * Hiroyasu Tsukaguchi View author publications

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B. _et al._ A family of mammalian Na+-dependent L-ascorbic acid transporters. _Nature_ 399, 70–75 (1999). https://doi.org/10.1038/19986 Download citation * Received: 08 February 1999 *

Accepted: 17 March 1999 * Issue Date: 06 May 1999 * DOI: https://doi.org/10.1038/19986 SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get

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