Data/hora: 09/06/2024 00:33:07

Provedor de dados: 	Brazilian Journal of Medical and Biological Research	
País: 	Brazil	
Título: 	Essential regulatory elements for NHE3 gene transcription in renal proximal tubule cells	
Autores: 	Neri,E.A.; Bezerra,C.N.A.; Rebouças,N.A.	
Data: 	2011-06-01	
Ano: 	2011	
Palavras-chave: 	Na+/H+ exchanger isoform 3; Gene promoter; Specificity protein 1; Early growth response factor 1; Proximal tubules.	
Resumo: 	The objectives of the present study were to identify the cis-elements of the promoter absolutely required for the efficient rat NHE3 gene transcription and to locate positive and negative regulatory elements in the 5’-flanking sequence (5’FS), which might modulate the gene expression in proximal tubules, and to compare this result to those reported for intestinal cell lines. We analyzed the promoter activity of different 5’FS segments of the rat NHE3 gene, in the OKP renal proximal tubule cell line by measuring the activity of the reporter gene luciferase. Because the segment spanning the first 157 bp of 5’FS was the most active it was studied in more detail by sequential deletions, point mutations, and gel shift assays. The essential elements for gene transcription are in the region -85 to -33, where we can identify consensual binding sites for Sp1 and EGR-1, which are relevant to NHE3 gene basal transcription. Although a low level of transcription is still possible when the first 25 bp of the 5’FS are used as promoter, efficient transcription only occurs with 44 bp of 5’FS. There are negative regulatory elements in the segments spanning -1196 to -889 and -467 to -152, and positive enhancers between -889 and -479 bp of 5’FS. Transcription factors in the OKP cell nuclear extract efficiently bound to DNA elements of rat NHE3 promoter as demonstrated by gel shift assays, suggesting a high level of similarity between transcription factors of both species, including Sp1 and EGR-1.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000600004	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2011007500054	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.44 n.6 2011	
Fonte: 	info:eu-repo/semantics/openAccess