Sequencing and Functional Analysis of the SNRPN Promoter: In Vitro Methylation Abolishes Promoter Activity

AUTOR(ES)

Huq, A.H.M. Mahbubul

FONTE

Cold Spring Harbor Laboratory Press

RESUMO

The gene encoding the small nuclear ribonucleoprotein-associated polypeptide N (SNRPN) maps to the Prader–Willi syndrome critical region on chromosome 15 and is expressed preferentially from the paternal allele. A CpG island encompassing the first exon of SNRPN is methylated on the inactive maternal allele. DNA sequence was determined for a cosmid containing the first three exons of SNRPN and extending 20 kb upstream and 15 kb downstream from the CpG island. This region is extremely rich in Alu elements and other repetitive sequences and contains a single CpG island, which includes numerous short direct repeat sequences. Functional analysis of the first exon revealed strong promoter activity for a 260-bp fragment extending 207 bp upstream from the exon. In vitro methylation of this 260-bp fragment abolished promoter activity completely, suggesting that the silencing of the maternal SNRPN allele may be a direct consequence of methylation of the promoter region.

Documentos Relacionados

• Silencing of the Escherichia coli bgl promoter: effects of template supercoiling and cell extracts on promoter activity in vitro.
• Molecular and functional analysis of the XPBC/ERCC-3 promoter: transcription activity is dependent on the integrity of an Sp1-binding site.
• Cytosine methylation in CTF and Sp1 recognition sites of an HSV tk promoter: effects on transcription in vivo and on factor binding in vitro.
• The tac promoter: a functional hybrid derived from the trp and lac promoters.
• The E-cadherin promoter: functional analysis of a G.C-rich region and an epithelial cell-specific palindromic regulatory element.