Previously, we isolated a cDNA (NaPi-1) related to a rabbit renal proximal tubular Na-Pi cotransporter (A. Werner, M. L. Moore, N. Mantei, J. Biber, G. Semenza, and H. Murer, Proc. Natl. Acad. Sci. USA 88: 9608-9612, 1991.). In this study, we isolated an additional (rabbit renal) cDNA (NaPi-6), which induces Na-dependent Pi uptake in Xenopus laevis oocytes. Substrate specificity and kinetic properties corresponded to those known for rabbit renal brush-border membrane (BBM) Na-Pi cotransport. NaPi-6 was cloned by homology using NaPi-2 cDNA, a rat renal BBM Na-Pi cotransporter (S. Magagnin, A. Werner, D. Markovich, V. Sorribas, G. Stange, J. Biber, and H. Murer. Proc. Natl. Acad. Sci. USA 90: 5979-5983, 1993.). NaPi-6 encodes a protein of 642 amino acids, exhibiting at least eight transmembrane domains. NaPi-6 mRNA and protein in kidneys of rabbits fed a low-P(i) diet (LPD; 0.11% P(i)) for 1 wk were increased by 1.5- and 4-fold, respectively, compared with those of rabbits fed a high-P(i) diet (HPD; 1.20% P(i)). This effect was correlated with an increase in Na-P(i) cotransport of BBM vesicles isolated from animals adapted to LPD (2.5-fold with respect to HPD). In contrast, NaPi-1 mRNA and protein were not altered in response to LPD. Thus rabbit proximal tubular BBMs contain two different Na-P(i) cotransport systems: NaPi-1 (type I) and NaPi-6 (type II). Only the type II transport system seems to be under regulatory control in response to low-P(i) dietary intake.
Cloning of a rabbit renal Na-P(i) cotransporter, which is regulated by dietary phosphate / T. Verri, D. Markovich, C. Perego, F. Norbis, G. Stange, V. Sorribas, J. Biber, H. Murer. - In: AMERICAN JOURNAL OF PHYSIOLOGY. RENAL, FLUID AND ELECTROLYTE PHYSIOLOGY. - ISSN 0363-6127. - 268:4(1995), pp. F626-F633.
|Titolo:||Cloning of a rabbit renal Na-P(i) cotransporter, which is regulated by dietary phosphate|
|Parole Chiave:||Sodium posphate cotransport; xenopus laevis oocyte expression; sodium deprivation|
|Settore Scientifico Disciplinare:||Settore BIO/09 - Fisiologia|
|Data di pubblicazione:||1995|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1152/ajprenal.1995.268.4.f626|
|Appare nelle tipologie:||01 - Articolo su periodico|