Insulin gene expression in nonexpressing cells appears to be regulated by multiple distinct negative-acting control elements.
AUTOR(ES)
Cordle, S R
RESUMO
Selective transcription of the insulin gene in pancreatic beta cells is regulated by its enhancer, located between nucleotides -340 and -91 relative to the transcription start site. Transcription from the enhancer is controlled by both positive- and negative-acting cellular factors. Cell-type-specific expression is mediated principally by a single cis-acting enhancer element located between -100 and -91 in the rat insulin II gene (referred to as the insulin control element [ICE]), which is acted upon by both of these cellular activities. Analysis of the effect of 5' deletions within the insulin enhancer has identified a region between nucleotides -217 and -197 that is also a site of negative control. Deletion of these sequences from the 5' end of the enhancer leads to transcription of the enhancer in non-insulin-producing cells, even though the ICE is intact. Derepression of this ICE-mediated effect was shown to be due to the binding of a ubiquitously distributed cellular factor to a sequence element which resides just upstream of the ICE (i.e., between nucleotides -110 and -100). We discuss the possible relationship of these results to cell-type-specific regulation of the insulin gene.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=360077Documentos Relacionados
- Negative-acting factor and superantigen are separable activities of the mouse mammary tumor virus long terminal repeat.
- Activation of skeletal alpha-actin gene transcription: the cooperative formation of serum response factor-binding complexes over positive cis-acting promoter serum response elements displaces a negative-acting nuclear factor enriched in replicating myoblasts and nonmyogenic cells.
- naf, a trans-regulating negative-acting factor encoded within the mouse mammary tumor virus open reading frame region.
- Human erythropoietin gene expression in transgenic mice: multiple transcription initiation sites and cis-acting regulatory elements.
- Cell cycle-dependent transcription of CLN2 is conferred by multiple distinct cis-acting regulatory elements.