| RRC ID |
38247
|
| Author |
Ito M, Sakurai A, Hayashi K, Ohi A, Kangawa N, Nishiyama T, Sugino S, Uehata Y, Kamahara A, Sakata M, Tatsumi S, Kuwahata M, Taketani Y, Segawa H, Miyamoto K.
|
| Title |
An apical expression signal of the renal type IIc Na+-dependent phosphate cotransporter in renal epithelial cells.
|
| Journal |
Am J Physiol Renal Physiol
|
| Abstract |
The type IIc Na(+)-dependent phosphate cotransporter (NaPi-IIc) is specifically targeted to, and expressed on, the apical membrane of renal proximal tubular cells and mediates phosphate transport. In the present study, we investigated the signals that determine apical expression of NaPi-IIc with a focus on the role of the N- and the C-terminal tails of mouse NaPi-IIc in renal epithelial cells [opossum kidney (OK) and Madin-Darby canine kidney cells]. Wild-type NaPi-IIc, the cotransporter NaPi-IIa, as well as several IIa-IIc chimeras and deletion mutants, were fused to enhanced green fluorescent protein (EGFP), and their cellular localization was analyzed in polarized renal epithelial cells by confocal microscopy and by cell-surface biotinylation. Fluorescent EGFP-fused NaPi-IIc transporter proteins are correctly expressed in the apical membrane of OK cells. The apical expression of N-terminal deletion mutants (deletion of N-terminal 25, 50, or 69 amino acids) was not affected by truncation. In contrast, C-terminal deletion mutants (deletion of C-terminal 45, 50, or 62 amino acids) did not have correct apical expression. A more detailed mutational analysis indicated that a domain (amino acids WLHSL) in the cytoplasmic C terminus is required for apical expression of NaPi-IIc in renal epithelial cells. We conclude that targeting of NaPi-IIc to the apical cell surface is regulated by a unique amino acid motif in the cytoplasmic C-terminal domain.
|
| Volume |
299(1)
|
| Pages |
F243-54
|
| Published |
2010-7-1
|
| DOI |
10.1152/ajprenal.00189.2009
|
| PII |
ajprenal.00189.2009
|
| PMID |
20410212
|
| MeSH |
Amino Acid Motifs
Amino Acid Sequence
Animals
Biotinylation
Caco-2 Cells
Cell Polarity*
Dogs
Epithelial Cells / metabolism*
Green Fluorescent Proteins / genetics
Green Fluorescent Proteins / metabolism
Humans
Kidney / cytology
Kidney / metabolism*
LLC-PK1 Cells
Mice
Microscopy, Confocal
Molecular Sequence Data
Mutation
Opossums
Protein Sorting Signals*
Protein Structure, Tertiary
Protein Transport
Recombinant Fusion Proteins / metabolism
Sodium-Phosphate Cotransporter Proteins, Type IIa / genetics
Sodium-Phosphate Cotransporter Proteins, Type IIa / metabolism
Sodium-Phosphate Cotransporter Proteins, Type IIb / genetics
Sodium-Phosphate Cotransporter Proteins, Type IIb / metabolism
Sodium-Phosphate Cotransporter Proteins, Type IIc / genetics
Sodium-Phosphate Cotransporter Proteins, Type IIc / metabolism*
Swine
Transfection
|
| IF |
3.191
|
| Times Cited |
8
|
|
WOS Category
|
UROLOGY & NEPHROLOGY
PHYSIOLOGY
|
| Resource |
| Human and Animal Cells |
MDCK(RCB0995) |
