| Literature DB >> 12192091 |
Nati Hernando1, Nadine Déliot, Serge M Gisler, Eleanor Lederer, Edward J Weinman, Jürg Biber, Heini Murer.
Abstract
Type IIa Na/P(i) cotransporters are expressed in renal proximal brush border and are the major determinants of inorganic phosphate (P(i)) reabsorption. Their carboxyl-terminal tail contains information for apical expression, and interacts by means of its three terminal amino acids with several PSD95/DglA/ZO-1-like domain (PDZ)-containing proteins. Two of these proteins, NaPi-Cap1 and Na/H exchanger-regulatory factor 1 (NHERF1), colocalize with the cotransporter in the proximal brush border. We used opossum kidney cells to test the hypothesis of a potential role of PDZ-interactions on the apical expression of the cotransporter. We found that opossum kidney cells contain NaPi-Cap1 and NHERF1 mRNAs. For NHERF1, an apical location of the protein could be documented; this location probably reflects interaction with the cytoskeleton by means of the MERM-binding domain. Overexpression of PDZ domains involved in interaction with the cotransporter (PDZ-1/NHERF1 and PDZ-3/NaPi-Cap1) had a dominant-negative effect, disturbing the apical expression of the cotransporter without affecting the actin cytoskeleton or the basolateral expression of Na/K-ATPase. These data suggest an involvement of PDZ-interactions on the apical expression of type IIa cotransporters.Entities:
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Year: 2002 PMID： 12192091 PMCID： PMC129376 DOI： 10.1073/pnas.182412699
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205