Two non-homologous brain diseases-related genes, SERPINI1 and PDCD10, are tightly linked by an asymmetric bidirectional promoter in an evolutionarily conserved manner.
BMC Mol Biol
; 8: 2, 2007 Jan 09.
Article
em En
| MEDLINE
| ID: mdl-17212813
ABSTRACT
BACKGROUND:
Despite of the fact that mammalian genomes are far more spacious than prokaryotic genomes, recent nucleotide sequencing data have revealed that many mammalian genes are arranged in a head-to-head orientation and separated by a small intergenic sequence. Extensive studies on some of these neighboring genes, in particular homologous gene pairs, have shown that these genes are often co-expressed in a symmetric manner and regulated by a shared promoter region. Here we report the identification of two non-homologous brain disease-related genes, with one coding for a serine protease inhibitor (SERPINI1) and the other for a programmed cell death-related gene (PDCD10), being tightly linked together by an asymmetric bidirectional promoter in an evolutionarily conserved fashion. This asymmetric bidirectional promoter, in cooperation with some cis-acting elements, is responsible for the co-regulation of the gene expression pattern as well as the tissue specificity of SERPINI1 and PDCD10.RESULTS:
While SERPINI1 is predominantly expressed in normal brain and down-regulated in brain tumors, PDCD10 is ubiquitously expressed in all normal tissues but its gene transcription becomes aberrant in different types of cancers. By measuring the luciferase activity in various cell lysates, their 851-bp intergenic sequence was shown to be capable of driving the reporter gene expression in either direction. A 175-bp fragment from nt 1 to 175 in the vicinity of PDCD10 was further determined to function as a minimal bidirectional promoter. A critical regulatory fragment, from nt 176-473 outside the minimal promoter in the intergenic region, was identified to contain a strong repressive element for SERPINI1 and an enhancer for PDCD10. These cis-acting elements may exist to help coordinate the expression and regulation of the two flanking genes.CONCLUSION:
For all non-homologous genes that have been described to be closely adjacent in the mammalian genomes, the intergenic region of the head-to-head PDCD10-SERPINI1 gene pair provides an interesting and informative example of a complex regulatory system that governs the expression of both genes not only through an asymmetric bidirectional promoter, but also through fine-tuned regulations with some cis-acting elements.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Neuropeptídeos
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Encefalopatias
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Serpinas
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Regulação da Expressão Gênica
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Proteínas Proto-Oncogênicas
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Regiões Promotoras Genéticas
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Sequência Conservada
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Evolução Molecular
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Proteínas Reguladoras de Apoptose
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Proteínas de Membrana
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article