Targeting TBP to a non-TATA box cis-regulatory element: a TBP-containing complex activates transcription from snRNA promoters through the PSE.
In the human small nuclear RNA (snRNA) promoters, the presence of a TATA box recognized by the TATA box-binding protein (TBP) determines the selection of RNA polymerase III over RNA polymerase II. The RNA polymerase II snRNA promoters are, therefore, good candidates for TBP-independent promoters. We show here, however, that TBP activates transcription from RNA polymerase II snRNA promoters through a non-TATA box element, the snRNA proximal sequence element (PSE), as part of a new snRNA-activating protein complex (SNAPc). In contrast to the previously identified TBP-containing complexes SL1, TFIID, and TFIIIB, which appear dedicated to transcription by a single RNA polymerase, SNAPc is also essential for RNA polymerase III transcription from the U6 snRNA promoter. The U6 initiation complex appears to contain two forms of TBP, one bound to the TATA box and one bound to the PSE as a part of SNAPc, suggesting that multiple TBP molecules can have different functions within a single promoter.
Sadowski
C L
CL
Cold Spring Harbor Laboratory, New York 11724.
Henry
R W
RW
Lobo
S M
SM
Hernandez
N
N
D000818:Animals; D001483:Base Sequence; D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000096:biosynthesis*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011506:Proteins; D012319:RNA Polymerase II / Q000096:biosynthesis; D012320:RNA Polymerase III / Q000096:biosynthesis; D017414:Ribonucleoprotein, U4-U6 Small Nuclear / Q000235:genetics*; D013329:Structure-Activity Relationship; D016385:TATA Box; D035181:TATA-Box Binding Protein; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D011506:Proteins; D017414:Ribonucleoprotein, U4-U6 Small Nuclear; D035181:TATA-Box Binding Protein; D015534:Trans-Activators; D014157:Transcription Factors; D012319:RNA Polymerase II; D012321:DNA-Directed RNA Polymerases; D012320:RNA Polymerase III