HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 287/2/C365    most recent 00502.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Regeer, R. R. Articles by Markovich, D. Search for Related Content PubMed PubMed Citation Articles by Regeer, R. R. Articles by Markovich, D.

PROTEIN AND VESICLE TRAFFICKING, CYTOSKELETON

A dileucine motif targets the sulfate anion transporter sat-1 to the basolateral membrane in renal cell lines

Department of Physiology and Pharmacology, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia

Submitted 14 November 2003 ; accepted in final form 2 April 2004

The sat-1 transporter mediates sulfate/bicarbonate/oxalate anion exchange in vivo at the basolateral membrane of the kidney proximal tubule. In the present study, we show two renal cell lines [Madin-Darby canine kidney (MDCK) and porcine proximal tubular kidney (LLC-PK1) cells] that similarly target sat-1 exclusively to the basolateral membrane. To identify possible sorting determinants, we generated truncations of the sat-1 cytoplasmic COOH terminus, fused to enhanced green fluorescence protein (EGFP) or the human IL-2 receptor -chain (Tac) protein, and both fusion constructs were transiently transfected into MDCK cells. Confocal microscopy revealed that removal of the last three residues on the sat-1 COOH terminus, a putative PDZ domain, had no effect on basolateral sorting in MDCK cells or on sulfate transport in Xenopus oocytes. Removal of the last 30 residues led to an intracellular expression for the GFP fusion protein and an apical expression for the Tac fusion protein, suggesting that a possible sorting motif lies between the last 3 and 30 residues of the sat-1 COOH terminus. Elimination of a dileucine motif at position 677/678 resulted in the loss of basolateral sorting, suggesting that this motif is required for sat-1 targeting to the basolateral membrane. This posttranslational mechanism may be important for the regulation of sulfate reabsorption and oxalate secretion by sat-1 in the kidney proximal tubule.

enhanced green fluorescence protein; Tac; polarized cells; sorting; transport

This article has been cited by other articles:

				M. Carmosino, I. Gimenez, M. Caplan, and B. Forbush Exon Loss Accounts for Differential Sorting of Na-K-Cl Cotransporters in Polarized Epithelial Cells Mol. Biol. Cell, October 1, 2008; 19(10): 4341 - 4351. [Abstract] [Full Text] [PDF]

				M. R. Dorwart, N. Shcheynikov, D. Yang, and S. Muallem The Solute Carrier 26 Family of Proteins in Epithelial Ion Transport Physiology, April 1, 2008; 23(2): 104 - 114. [Abstract] [Full Text] [PDF]

				J. Zheng, G.-G. Du, K. Matsuda, A. Orem, S. Aguinaga, L. Deak, E. Navarrete, L. D. Madison, and P. Dallos The C-terminus of prestin influences nonlinear capacitance and plasma membrane targeting J. Cell Sci., July 1, 2005; 118(13): 2987 - 2996. [Abstract] [Full Text] [PDF]