Data/hora: 09/06/2024 17:18:46

Provedor de dados: | 56
País: | Brazil
Título: | Influence of the polymorphisms of the α-major regulatory element HS-40 on in vitro gene expression
Autores: | Ribeiro,D.M.; Zaccariotto,T.R.; Santos,M.N.N.; Costa,F.F.; Sonati,M.F.
Data: | 2009-09-01
Ano: | 2009
Palavras-chave: | Alpha-major regulatory element; HS-40; Alpha-globin genes; Genetic polymorphisms; Gene expression.
Resumo: | The α-MRE is the major regulatory element responsible for the expression of human α-like globin genes. It is genetically polymorphic, and six different haplotypes, named A to F, have been identified in some population groups from Europe, Africa and Asia and in native Indians from two Brazilian Indian tribes. Most of the mutations that constitute the α-MRE haplotypes are located in flanking sequences of binding sites for nuclear factors. To our knowledge, there are no experimental studies evaluating whether such variability may influence the α-MRE enhancer activity. We analyzed and compared the expression of luciferase of nine constructs containing different α-MRE elements as enhancers. Genomic DNA samples from controls with A (wild-type α-MRE) and B haplotypes were used to generate C-F haplotypes by site-directed mutagenesis. In addition, three other elements containing only the G→A polymorphism at positions +130, +199, and +209, separately, were also tested. The different α-MRE elements were amplified and cloned into a plasmid containing the luciferase reporter gene and the SV40 promoter and used to transiently transfect K562 cells. A noticeable reduction in luciferase expression was observed with all constructs compared with the A haplotype. The greatest reductions occurred with the F haplotype (+96, C→A) and the isolated polymorphism +209, both located near the SP1 protein-binding sites believed not to be active in vivo. These are the first analyses of α-MRE polymorphisms on gene expression and demonstrate that these single nucleotide polymorphisms, although outside the binding sites for nuclear factors, are able to influence in vitro gene expression.
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000900002
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2009005000014
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.42 n.9 2009
Fonte: | info:eu-repo/semantics/openAccess