Inorganic phosphate modulates the expression of the NaPi-2a transporter in the trans -golgi network and the interaction with PIST in the proximal tubule

Lanaspa, M.A. ; Caldas, Y.A. ; Breusegem, S.Y. ; Andrés-Hernando, A. ; Cicerchi, C. ; Levi, M. ; Sorribas, V. (Universidad de Zaragoza)

Resumen: Inorganic phosphate (Pi) homeostasis is maintained by the tight regulation of renal Pi excretion versus reabsorption rates that are in turn modulated by adjusting the number of Pi transporters (mainly NaPi-2a) in the proximal tubules. In response to some hormones and a high dietary Pi content, NaPi-2a is endocytosed and degraded in the lysosomes; however, we show here that some NaPi-2amolecules are targeted to the trans-Golgi network (TGN) during the endocytosis. In the TGN, NaPi-2a interacts with PIST (PDZ-domain protein interacting specifically with TC10), a TGN-resident PDZ-domain-containing protein. The extension of the interaction is proportional to the expression of NaPi-2a in the TGN, and, consistent with that, it is increased with a high Pi diet. When overexpressed in opossum kidney (OK) cells, PIST retains NaPi-2a in the TGN and inhibits Na-dependent Pi transport. Overexpression of PIST also prevents the adaptation of OK cells to a low Pi culture medium. Our data supports the view that NaPi-2a is subjected to retrograde trafficking from the plasma membrane to the TGN using one of the machineries involved in endosomal transport and explains the reported expression of NaPi-2a in the TGN.

Idioma: Inglés

DOI: 10.1155/2013/513932

Año: 2013

Publicado en: BioMed Research International 2013 (2013), 513932 [9 pp]
ISSN: 2314-6133

Factor impacto JCR: 0.0 (2013)

Categ. JCR: MEDICINE, RESEARCH & EXPERIMENTAL
Categ. JCR: BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Financiación: info:eu-repo/grantAgreement/ES/DGA/PI020-09
Financiación: info:eu-repo/grantAgreement/ES/MICINN/BFU2009-12763-BFI

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Toxicología (Departamento de Anatomía Patológica, Medicina Legal y Forense y Toxicología)