Synthesis, maturation, and trafficking of human Na+-dicarboxylate cotransporter NaDC1 requires the chaperone activity of cyclophilin B.
Renal excretion of citrate, an inhibitor of calcium stone formation, is controlled mainly by reabsorption via the apical Na(+)-dicarboxylate cotransporter NaDC1 (SLC13A2) in the proximal tubule. Recently, it has been shown that the protein phosphatase calcineurin inhibitors cyclosporin A (CsA) and FK-506 induce hypocitraturia, a risk factor for nephrolithiasis in kidney transplant patients, but apparently through urine acidification. This suggests that these agents up-regulate NaDC1 activity. Using the Xenopus lævis oocyte and HEK293 cell expression systems, we examined first the effect of both anti-calcineurins on NaDC1 activity and expression. While FK-506 had no effect, CsA reduced NaDC1-mediated citrate transport by lowering heterologous carrier expression (as well as endogenous carrier expression in HEK293 cells), indicating that calcineurin is not involved. Given that CsA also binds specifically to cyclophilins, we determined next whether such proteins could account for the observed changes by examining the effect of selected cyclophilin wild types and mutants on NaDC1 activity and cyclophilin-specific siRNA. Interestingly, our data show that the cyclophilin isoform B is likely responsible for down-regulation of carrier expression by CsA and that it does so via its chaperone activity on NaDC1 (by direct interaction) rather than its rotamase activity. We have thus identified for the first time a regulatory partner for NaDC1, and have gained novel mechanistic insight into the effect of CsA on renal citrate transport and kidney stone disease, as well as into the regulation of membrane transporters in general.
Unité de Neurobiologie Cellulaire, Centre de Recherche Université Laval Robert-Giffard, Québec, Canada. marc.bergeron.2@ulaval.ca
Marc J
MJ
Bergeron
Marc
M
Bürzle
Gergely
G
Kovacs
Alexandre
A
Simonin
Matthias A
MA
Hediger
D000818:Animals; D019703:Calcineurin / Q000235:genetics / Q000378:metabolism; D019343:Citric Acid / Q000378:metabolism; D021983:Cyclophilins / Q000235:genetics / Q000378:metabolism*; D016572:Cyclosporine / Q000494:pharmacology; D029382:Dicarboxylic Acid Transporters / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007668:Kidney / Q000378:metabolism; D007669:Kidney Calculi / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009865:Oocytes; D029363:Organic Anion Transporters, Sodium-Dependent / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects / Q000235:genetics; D027981:Symporters / Q000235:genetics / Q000378:metabolism*; D016559:Tacrolimus / Q000494:pharmacology; D014982:Xenopus laevis
D029382:Dicarboxylic Acid Transporters; D007166:Immunosuppressive Agents; D018832:Molecular Chaperones; D029363:Organic Anion Transporters, Sodium-Dependent; C092524:SLC13A2 protein, human; D027981:Symporters; C081786:cyclophilin B; D019343:Citric Acid; D016572:Cyclosporine; D019703:Calcineurin; D021983:Cyclophilins; D016559:Tacrolimus
J Biol Chem. 2002 Jan 25;277(4):2505-10
11700317
Kidney Int. 1990 Oct;38(4):728-35
2232510
J Biol Chem. 2000 Nov 17;275(46):35708-14
10964923
J Antibiot (Tokyo). 1987 Sep;40(9):1256-65
2445722
Kidney Int. 2000 Jul;58(1):206-15
10886565
Am J Physiol Renal Physiol. 2009 Jan;296(1):F160-9
18987109
Am J Physiol Renal Physiol. 2005 Jan;288(1):F40-7
15353404
Proc Natl Acad Sci U S A. 2002 May 14;99(10):6790-5
11997457
Int J Urol. 2007 Apr;14(4):344-9
17470169
Biochem Biophys Res Commun. 2004 Apr 16;316(4):1073-80
15044094
Clin Chem. 1990 Oct;36(10):1841-6
2208666
Pediatr Nephrol. 2005 May;20(5):652-6
15782300
PLoS One. 2010 Nov 10;5(11):e13930
21085665
Proc Natl Acad Sci U S A. 1997 May 13;94(10):5432-7
9144255
Proc Natl Acad Sci U S A. 1994 Apr 26;91(9):3931-5
7909608
Kidney Int. 2007 Jul;72(1):63-71
17410095
Am J Transplant. 2008 Nov;8(11):2283-96
18785955
FEBS Lett. 1998 Feb 6;422(3):307-10
9498805
Bioorg Med Chem Lett. 2005 Sep 1;15(17):3849-52
16002288
Am J Physiol. 1985 Oct;249(4 Pt 2):F590-5
2996368
Proc Natl Acad Sci U S A. 1991 Mar 1;88(5):1903-7
2000394
Antioxid Redox Signal. 2007 Dec;9(12):2357-71
17760508
J Biol Chem. 2008 Jun 27;283(26):18086-98
18445599
Methods Enzymol. 1998;296:17-52
9779438
PLoS One. 2010 Aug 05;5(8):e11925
20700529
Endocrinol Metab Clin North Am. 2002 Dec;31(4):885-93, viii
12474636
Transplant Proc. 1988 Jun;20(3 Suppl 3):530-3
3388497
EMBO J. 1994 Oct 17;13(20):4886-95
7957056
J Nephrol. 2004 Jan-Feb;17(1):34-42
15151257
Nephron. 1996;74(3):501-11
8938672
Neurosci Lett. 2000 Nov 3;293(3):211-5
11036198
Nature. 2007 Sep 20;449(7160):336-40
17882219
Nephrol Dial Transplant. 2007 Mar;22(3):906-10
17210594
J Biol Chem. 2005 Apr 29;280(17):17013-9
15671024
Adv Exp Med Biol. 2009;643:503-11
19239182
Transpl Int. 2003 Feb;16(2):108-14
12595972
Cell. 1991 Oct 18;67(2):255-63
1913822
Curr Top Med Chem. 2003;3(12):1315-47
12871165
Cell Physiol Biochem. 2000;10(1-2):1-12
10844393
Arterioscler Thromb Vasc Biol. 2010 Mar;30(3):419-25
20139366
Am J Physiol. 1996 Apr;270(4 Pt 2):F642-8
8967342
Mol Pharmacol. 2008 Apr;73(4):1254-63
18182482