Open AccessThe New Core Promoter Element XCPE1 (X Core Promoter Element 1) Directs Activator-, Mediator-, and TATA-Binding Protein-Dependent but TFIID-Independent RNA Polymerase II Transcription from TATA-Less Promoters
Author(s) -
Yumiko Tokusumi,
Ying Ma,
Xianzhou Song,
Raymond H. Jacobson,
Shinako Takada
Publication year - 2007
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.01363-06
Subject(s) - transcription factor ii d , taf1 , transcription factor ii a , tata box , promoter , biology , rna polymerase ii , general transcription factor , response element , transcription (linguistics) , transcription factor ii b , taf2 , microbiology and biotechnology , rna polymerase ii holoenzyme , transcription preinitiation complex , tata box binding protein , genetics , gene , gene expression , linguistics , philosophy
The core promoter is a critical DNA element required for accurate transcription and regulation of transcription. Several core promoter elements have been previously identified in eukaryotes, but those cannot account for transcription from most RNA polymerase II-transcribed genes. Additional, as-yet-unidentified core promoter elements must be present in eukaryotic genomes. From extensive analyses of the hepatitis B virus X gene promoter, here we identify a new core promoter element, XCPE1 (theX genec orep romotere lement1 ), that drives RNA polymerase II transcription. XCPE1 is located between nucleotides −8 and +2 relative to the transcriptional start site (+1) and has a consensus sequence of G/A/T-G/C-G-T/C-G-G-G/A-A-G/C+1 -A/C. XCPE1 shows fairly weak transcriptional activity alone but exerts significant, specific promoter activity when accompanied by activator-binding sites. XCPE1 is also found in the core promoter regions of about 1% of human genes, particularly in poorly characterized TATA-less genes. Our in vitro transcription studies suggest that the XCPE1-driven transcription can be highly active in the absence of TFIID because it can utilize either free TBP or the complete TFIID complex. Our findings suggest the possibility of the existence of a TAF1 (TFIID)-independent transcriptional initiation mechanism that may be used by a category of TATA-less promoters in higher eukaryotes.