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TATA box binding protein (TBP) recruitment to the U1 gene promoter is disrupted by substituting a U6 proximal sequence element (PSEA) for the U1 PSEA
Author(s) -
Barakat Nermeen,
Stumph William E.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.782.25
Subject(s) - transcription (linguistics) , small nuclear rna , biology , rna , gene , microbiology and biotechnology , rna polymerase ii , chromatin immunoprecipitation , genetics , gene expression , promoter , rna dependent rna polymerase , philosophy , linguistics
Most of the spliceosomal small nuclear RNAs (U1, U2, U4, and U5) are synthesized by RNA polymerase II, but U6 snRNA is synthesized by RNA polymerase III. In Drosophila melanogaster. transcription of all snRNA genes requires a unique proximal promoter element, the PSEA. Surprisingly, the RNA polymerase specificity of the snRNA genes is determined by a few nucleotide differences between the PSEAs in the two classes of genes. In both classes, the PSEA is recognized by the small nuclear RNA activating protein complex (DmSNAPc). Previous transfection assays demonstrated that Pol II was unable to initiate transcription from a U1 promoter that contained the U6 PSEA. We have now used chromatin immunoprecipitation assays to determine at which step Pol II pre‐initiation complex assembly is disrupted when the U1 promoter contains a U6 PSEA. Interestingly, we found that DmSNAPc stably assembled on a U1 promoter that contained either the U1 or the U6 PSEA. However, although TBP was recruited to the wild type U1 promoter, TBP failed to assemble in vivo on the U1 promoter that contained the U6 PSEA. These results indicate that changing the U1 PSEA to a U6 PSEA had no effect on the binding of DmSNAPc, but it instead suggests that DmSNAPc is in the wrong conformation when bound to a U6 PSEA to recruit TBP to the U1 promoter. N.B. is a recipient of the Arne N. Wick Predoctoral Research Fellowship from the California Metabolic Research Foundation.