RRC ID 38247
著者 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.
タイトル An apical expression signal of the renal type IIc Na+-dependent phosphate cotransporter in renal epithelial cells.
ジャーナル 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.
巻・号 299(1)
ページ F243-54
公開日 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
引用数 8
WOS 分野 UROLOGY & NEPHROLOGY PHYSIOLOGY
リソース情報
ヒト・動物細胞 MDCK(RCB0995)