| First Author | Bai L | Year | 2000 |
| Journal | Am J Physiol Cell Physiol | Volume | 279 |
| Issue | 4 | Pages | C1135-43 |
| PubMed ID | 11003594 | Mgi Jnum | J:65169 |
| Mgi Id | MGI:1913157 | Doi | 10.1152/ajpcell.2000.279.4.C1135 |
| Citation | Bai L, et al. (2000) Cloning and characterization of a type III Na-dependent phosphate cotransporter from mouse intestine. Am J Physiol Cell Physiol 279(4):C1135-43 |
| abstractText | Intestinal and renal absorption of inorganic phosphate (P(i)) is critical for phosphate homeostasis in mammals. We have isolated a cDNA that encodes a type III Na-dependent phosphate cotransporter from mouse small intestine (mPit-2). The nucleotide sequence of mPit-2 predicts a protein of 653 amino acids with at least 10 putative transmembrane domains. Kinetic studies, carried out in Xenopus oocytes, showed that mPit-2 cRNA induces significant Na-dependent P(i) uptake with an apparent Michaelis constant (K(m)) for phosphate of 38 &mgr;M. The transport of phosphate by mPit-2 is inhibited at high pH. Northern blot analysis demonstrated the presence of mPit-2 mRNA in various tissues, including intestine, kidney, heart, liver, brain, testis, and skin. The highest expression of mPit-2 in the intestine was found in the jejunum. In situ hybridization revealed that mPit-2 mRNA is expressed throughout the vertical crypt-villus axis of the intestinal epithelium. The presence of mPit-2 in the mouse intestine and its unique transport characteristics suggest that multiple Na-dependent cotransporters may contribute to phosphate absorption in the mammalian small intestine. |
