Oligomeric structure of a renal cystine transporter: implications in cystinuria

FEBS Letters

Tate, Suresh S.¹  Wang, Yan¹ 

[1] Department of Biochemistry, Cornell University Medical College, 1300 York Ave., New York, NY 10021, USA

关键词: Cystinuria;    Amino acid transport;    Kidney;    Oocyte;    Xenopus laevis;    NBAT;    neutral and basic amino acid transporter;    BBM;    brush border membrane;    MSD;    membrane-spanning domain;    IgG;    immunoglobulin;    SDS-PAGE;    sodium dodecylsulfate/polyacrylamide gel electrophoresis;    MSH;    2-mercaptoethanol;    NEM;    N-ethylmaleimide;    DMS;    dimethylsuberimidate;   

DOI  :  10.1016/0014-5793(95)00685-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Homologous proteins (NBAT) which mediate sodium-independent transport of neutral as well as basic amino acids and cystine when expressed in Xenopus oocytes were recently cloned from mammalian kidneys. Mutations in human NBAT have been implicated in cystinuria. Here, we show that rat kidney and jejunal brush border membrane NBAT (85 kDa) is found in association with a 50 kDa protein. The association involves one or more interprotein disulfide bonds. Rabbit kidney brush border membranes and membranes of NBAT cRNA-injected Xenopus oocytes also contain such heterodimers. Our data suggest that the heterodimer is the minimal functional unit of NBAT-mediated amino acid transport and that the NBAT-associated 50 kDa protein could play a role in cystinuria.

【 授权许可】

Unknown