Influence of the polymorphisms of the alpha-major regulatory element HS-40 on in vitro gene expression
Rev. bras. pesqui. méd. biol
; Braz. j. med. biol. res;42(9): 783-786, Sept. 2009. graf, tab
Article
em En
| LILACS
| ID: lil-524320
Biblioteca responsável:
BR1.1
ABSTRACT
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.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Polimorfismo Genético
/
Haplótipos
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Globinas
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Regulação da Expressão Gênica
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Elementos Reguladores de Transcrição
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Mutação
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Braz. j. med. biol. res
/
Rev. bras. pesqui. méd. biol
Assunto da revista:
BIOLOGIA
/
MEDICINA
Ano de publicação:
2009
Tipo de documento:
Article
/
Project document
País de afiliação:
Brasil
País de publicação:
Brasil