Cloning and functional characterization of the human sodium‐dependent vitamin C transporters hSVCT1 and hSVCT2

FEBS Letters

Daruwala, Rushad¹  Levine, Mark¹  Koh, Woo S.¹  Rumsey, Steve C.¹  Song, Jian¹ 

[1] Molecular and Clinical Nutrition Section, Bldg. 10, Rm. 4D52, MSC 1372, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1372, USA

关键词: Vitamin C;    Ascorbate;    Transport;    hSVCT1;    hSVCT2;    BLAST;    basic local alignment search tool;    GLUT;    glucose transporter;    hSVCT;    human sodium-dependent vitamin C transporter;    PCR;    polymerase chain reaction;    rSVCT;    rat sodium-dependent vitamin C transporter;    SMART;    simple modular architectural research tool;    YSPL;    yolk sac permease-like molecule or nucleobase transporter;   

DOI  :  10.1016/S0014-5793(99)01393-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Two sodium-dependent vitamin C transporters, hSVCT1 and hSVCT2, were cloned from a human kidney cDNA library. hSVCT1 had a 1797 bp open reading frame encoding a 598 amino acid polypeptide. The 1953 bp open reading frame of hSVCT2 encoded a 650 amino acid polypeptide. Using a Xenopus laevis oocyte expression system, both transporters were functionally expressed. By Eadie-Hofstee transformation the apparent K _m of hSVCT1 for ascorbate was 252.0 μM and of hSVCT2 for ascorbate was 21.3 μM. Both transporters were sodium-dependent and did not transport dehydroascorbic acid. Incubation of oocytes expressing either transporter with phorbol 12-myristate 13-acetate (PMA) inhibited ascorbate transport activity. Availability of the human transporter clones may facilitate new strategies for determining vitamin C intake.

【 授权许可】

Unknown