Pendrin: an apical Cl-/OH-/HCO3- exchanger in the kidney cortex.
The identities of the apical Cl-/base exchangers in kidney proximal tubule and cortical collecting duct (CCD) cells remain unknown. Pendrin (PDS), which is expressed at high levels in the thyroid and its mutation causes Pendred's syndrome, is shown to be an anion exchanger. We investigated the renal distribution of PDS and its function. Our results demonstrate that pendrin mRNA expression in the rat kidney is abundant and limited to the cortex. Proximal tubule suspensions isolated from kidney cortex were highly enriched in pendrin mRNA. Immunoblot analysis studies localized pendrin to cortical brush-border membranes. Nephron segment RT-PCR localized pendrin mRNA to proximal tubule and CCD. Expression studies in HEK-293 cells demonstrated that pendrin functions in the Cl-/OH-, Cl-/HCO3-, and Cl-/formate exchange modes. The conclusion is that pendrin is an apical Cl-/base exchanger in the kidney proximal tubule and CCD and mediates Cl-/OH-, Cl-/HCO3-, and Cl-/formate exchange.
Soleimani
M
M
Department of Medicine, University of Cincinnati, Cincinnati, Ohio 45267-0585, USA manoocher.soleimani@uc.edu
Greeley
T
T
Petrovic
S
S
Wang
Z
Z
Amlal
H
H
Kopp
P
P
Burnham
C E
CE
D000704:Analysis of Variance; D017920:Antiporters / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D027963:Chloride-Bicarbonate Antiporters; D006801:Humans; D007672:Kidney Cortex / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism*; D007685:Kidney Tubules, Collecting / Q000378:metabolism*; D007687:Kidney Tubules, Proximal / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D000076988:Sulfate Transporters
D017920:Antiporters; D002352:Carrier Proteins; D027963:Chloride-Bicarbonate Antiporters; D026901:Membrane Transport Proteins; D012333:RNA, Messenger; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters