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NHE3 Regulatory Factor 1 (NHERF1) Modulates Intestinal Sodium-dependent Phosphate Transporter (NaPi-2b) Expression in Apical Microvilli.
- Source :
-
Journal of Biological Chemistry . 10/12/2012, Vol. 287 Issue 41, p35047-35056. 10p. - Publication Year :
- 2012
-
Abstract
- Pi uptake in the small intestine occurs predominantly through the NaPi-2b (SLC34a2) co-transporter. NaPi-2b is regulated by changes in dietary Pi but the mechanisms underlying this regulation are largely undetermined. Sequence analyses show NaPi-2b has a PDZ binding motif at its C terminus. Immunofluorescence imaging shows NaPi-2b and two PDZ domain containing proteins, NHERF1 and PDZK1, are expressed in the apical microvillar domain of rat small intestine enterocytes. Co-immunoprecipitation studies in rat enterocytes show that NHERF1 associates with NaPi-2b but not PDZK1. In HEK coexpression studies, GFP-NaPi-2b co-precipitates with FLAGNHERF1. This interaction is markedly diminished when the C-terminal four amino acids are truncated from NaPi-2b. FLIMFRET analyses using tagged proteins in CACO-2BBE cells show a distinct phasor shift between NaPi-2b and NHERF1 but not between NaPi-2b and the PDZK1 pair. This shift demonstrates that NaPi-2b and NHERF1 reside within 10 nm of each other. NHERF1-/- mice, but not PDZK1-/- mice, had a diminished adaptation of NaPi-2b expression in response to a low Pi diet. Together these studies demonstrate that NHERF1 associates with NaPi-2b in enterocytes and regulates NaPi-2b adaptation [ABSTRACT FROM AUTHOR]
- Subjects :
- *MICROVILLI
*SODIUM
*IMMUNOFLUORESCENCE
*SMALL intestine
*IMMUNOGLOBULINS
Subjects
Details
- Language :
- English
- ISSN :
- 00219258
- Volume :
- 287
- Issue :
- 41
- Database :
- Academic Search Index
- Journal :
- Journal of Biological Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 82537849
- Full Text :
- https://doi.org/10.1074/jbc.M112.392415