AJP - Renal Watch the video to learn how APS reaches out to developing nations.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Renal Physiol 290: F880-F887, 2006. First published October 18, 2005; doi:10.1152/ajprenal.00319.2005
0363-6127/06 $8.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
290/4/F880    most recent
00319.2005v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via ISI Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ristic, Z.
Right arrow Articles by Verrey, F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ristic, Z.
Right arrow Articles by Verrey, F.

Neutral amino acid transport mediated by ortholog of imino acid transporter SIT1/SLC6A20 in opossum kidney cells

Zorica Ristic,* Simone M. R. Camargo,* Elisa Romeo,1 Susana Bodoy,2 Joan Bertran,2 Manuel Palacin,2 Victoria Makrides,1 Esther M. Furrer,1 and François Verrey1

1Institute of Physiology and Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland; and 2Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain

Submitted 5 August 2005 ; accepted in final form 14 October 2005

Most neutral L-amino acid acids are transported actively across the luminal brush-border membrane of small intestine and kidney proximal tubule epithelial cells by a Na+ cotransport system named B0 that has been recently molecularly identified (B0AT1, SLC6A19). We show here that the opossum kidney-derived cell line OK also displays a Na+-dependent B0-type neutral L-amino acid transport, although with a slightly differing substrate selectivity. We tested the hypothesis that one of the two B0AT1-related transporters, SLC6A18 (ortholog of orphan transporter XT2) or SLC6A20 (ortholog of the recently identified mammalian imino acid transporter SIT1), mediates this transport. Anti-sense RNA to OK SIT1 (oSIT1) but not to OK XT2 (oXT2) inhibited Na+-dependent neutral amino acid transport induced by OK mRNA injected in Xenopus laevis oocytes. Furthermore, inhibition of oSIT1 gene expression in OK cells by transfection of siRNA and expression of shRNA selectively reduced the Na+-dependent uptake of neutral L-amino acids. Finally, expression of OK cell oSIT1 cRNA in X. laevis oocytes induced besides the transport of the L-imino acid L-Pro also that of neutral L-amino acids. Taken together, the data indicate that in OK cells SIT1 (SLC6A20) is not only an apical imino acid transporter but also plays a major role as Na+-dependent neutral L-amino acid transporter. A similar double role could be envisaged for SIT1 in mammalian kidney proximal tubule and small intestine.

Na+-dependent neurotransmitter transporter; B0AT1; Xenopus laevis oocytes; kidney proximal tubule; anti-sense; siRNA


Address for reprint requests and other correspondence: F. Verrey, Institute of Physiology, Univ. of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland (e-mail: verrey{at}access.unizh.ch)






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online
Copyright © 2006 by the American Physiological Society.