In:
American Journal of Physiology-Renal Physiology, American Physiological Society, Vol. 275, No. 2 ( 1998-08-01), p. F298-F305
Abstract:
We report here the isolation, functional characterization, tissue distribution, and membrane localization of rat renal Na + -dicarboxylate transporter (rNaDC-1). rNaDC-1 consists of 2,245 nucleotides, and the deduced amino acid sequence showed 73% and 75% identity to rabbit and human NaDC-1, respectively. When expressed in Xenopus laevis oocytes, rNaDC-1 mediated sodium-dependent uptake of di- and tricarboxylates. Substrates of rNaDC-1 evoked inward currents in oocytes expressed with rNaDC-1; succinate, α-ketoglutarate, and glutarate were relatively high-affinity substrates, and citrate was a low-affinity substrate of rNaDC-1. The coupling ratio of citrate to charge was determined to be 1:1 at pH 7.4; influx of one positive charge per citrate molecule suggests a symport of three Na + with a divalent citrate. Expression of rNaDC-1 mRNA was detected in the kidney and the small and large intestines. Immunohistochemistry using polyclonal antibodies raised against the 14 amino acids at the COOH terminus of rNaDC-1 revealed that rNaDC-1 is localized exclusively in the luminal membrane of S2 and S3.
Type of Medium:
Online Resource
ISSN:
1931-857X
,
1522-1466
DOI:
10.1152/ajprenal.1998.275.2.F298
Language:
English
Publisher:
American Physiological Society
Publication Date:
1998
detail.hit.zdb_id:
1477287-5
Permalink