| First Author | Ohkido I | Year | 2003 |
| Journal | Pflugers Arch | Volume | 446 |
| Issue | 1 | Pages | 106-15 |
| PubMed ID | 12690469 | Mgi Jnum | J:73893 |
| Mgi Id | MGI:2157079 | Doi | 10.1007/s00424-003-1010-6 |
| Citation | Ohkido I, et al. (2003) Cloning, gene structure and dietary regulation of the type-IIc Na/Pi cotransporter in the mouse kidney. Pflugers Arch 446(1):106-15 |
| abstractText | We have demonstrated previously that the type-IIc Na/Pi cotransporter is a growth-related renal Na/Pi cotransporter that is highly expressed in kidney of the weaning rat. In the present study, we investigated type-IIc Na/Pi cotransporter function further by cloning the mouse gene and characterizing the corresponding protein. The mouse type-IIc transporter amino acid sequence shows a high degree of similarity to the human (86%) and rat (95%) type-IIc Na/Pi-cotransporters. The mouse gene contained 14 exons and mapped to chromosome 2. The DNA sequence upstream from exon 1 is GC rich. The upstream region does not contain an apparent TATA box, but does contain two dietary Pi-responsive elements, which are potential binding sites for the transcription factor micro E3 (TFE3). Microinjection of mouse type-IIc cRNA into Xenopus oocytes demonstrated sodium-dependent Pi cotransport activity. The affinity for Pi was about 200 micro M in 100 mM Na. Feeding adult mice fed a low-Pi diet increased the expression of type-IIc protein in the apical membrane of renal proximal tubular cells. Hybrid depletion studies suggested that the type-IIc transporter contributes to about 30% of Na/Pi cotransport in the kidney of adult mice fed a low-Pi diet. The present study suggests that the type-IIc Na/Pi cotransporter is a functional of renal Pi transporter in adult mice fed a low-Pi diet. |
