CHARACTERIZATION OF THE 5'-FLANKING REGION OF THE HUMAN NPT-1 NA+ PHOSPHATE COTRANSPORTER GENE/

To elucidate the expression and regulation of the human type I Na+/pho sphate transporter gene (NPT-I), the 5' flanking region of the NPT-1 g ene was cloned, and its nucleotide sequence and function were determin ed. A genomic clone that contained approximately 14.0 kb of the 5'-fla nking region of the NPT-1 gene was isolated. A single transcription st art site was located 104 base pairs (bp) upstream of the 3' end of exo n 1. In addition to the sequence of the S-flanking region contained a sequence weakly homologous to a TATA box at position -41 to -36 and ma ny transcriptional regulatory elements.' Transient expression revealed that a 45-bp region of proximal to exon 1, which contained TATA-like sequence, was sufficient for promoting luciferase expression in OK-cel ls derived from opossum kidney proximal tubule. (C) 1998 Elsevier Scie nce B.V.