Renal Tubule-specific Transcription and Chromosomal Localization of Rat Thiazide-sensitive Na-Cl Cotransporter Gene

• Published in: The Journal of biological chemistry 2001-07, Vol.276 (28), p.26260-26268
• Main Authors: Taniyama, Yoshihiro, Sato, Kazunori, Sugawara, Akira, Uruno, Akira, Ikeda, Yukio, Kudo, Masataka, Ito, Sadayoshi, Takeuchi, Kazuhisa
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; Carrier Proteins - genetics; Carrier Proteins - metabolism; chromosome 19; Chromosome Mapping; Gene Expression Regulation; HFH-3 protein; Kidney Tubules - metabolism; Molecular Sequence Data; Rats; Receptors, Drug - genetics; Receptors, Drug - metabolism; Sequence Alignment; Sodium Chloride Symporters; sodium/chloride cotransporter; Solute Carrier Family 12, Member 3; Symporters; Thiazide; Transcription, Genetic; TSC gene
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M101614200

The molecular mechanism underlying the renal expression localization of the thiazide-sensitive Na-Cl cotransporter (TSC) gene was studied. TheTSC gene was localized to chromosome 19p12–14. In cultured cells, tissue-specific transcription activity of the 5′-flanking region of the rat rTSC gene (5′FL/rTSC) was demonstrated, and the major promoter region was located between position −580 and −141. To further examine the tissue-specific transcription, transgenic rats harboring the 5′FL/rTSC fused upstream of the LacZ gene were generated. Immunohistochemical analysis clearly showed that LacZ gene expression was co-localized to distal convoluted tubules (DCT) with TSC, indicating that the 5′FL/rTSC regulates the renal tubule-specific TSC expression. Because a transcription factor, HFH-3 (hepatocyte nuclear factor-3/folk head homologue-3), had also been localized to DCT, a possible role of the putative cis-acting element (HFH-3/rTSC, −400/−387 position) for HFH-3 binding in the tissue-specific transcription was examined. Deletion and mutation analyses suggested that transcription of the HFH-3/rTSC was actually responsive to HFH-3, and electrophoretic mobility shift assay showed a direct binding of in vitrosynthesized HFH-3 to the HFH-3/rTSC. In conclusion, therTSC gene is localized to rat chromosome 19p12–24. The transcription regulatory region of the TSC gene confers DCT-specific gene expression. DCT-specific transcription factor HFH-3 may be involved in the renal tubule-specific transcription ofTSC gene.