|
KMID : 0624219980060000057
|
|
Focus on Genetic Science
1998 Volume.6 No. 0 p.57 ~ p.65
|
|
|
Sp1 Plays a Role Similar to TBP to Initiate Transcription by Binding to the Core GC-Box Elements
|
|
Kwon Hye-Sook
Hur Man-Wook
|
|
|
Abstract
|
|
|
TBP is the most well characterized protein known to initiate the formation of general transcription complex at 20-30 bp downstream of the TATA box. However, little is known on the mechanism of transcriptional initiation on the GC-rich promoter with no apparent TATA box. We investigated the transcriptional initiation on the ADH5/FDH minimal promoter, which is GC-rich with no TATA box. A minimal promoter extending from -34 bp to +61bp directs high levels of transcription in several different cells, consistent with the ubiquitous expression of the gene. Interestingly, nearly the entire minimal promoter can be bound by Sp1. Two core cis-elements (-22 bp to +22 bp) had the highest affinity for Sp1. Mutagenesis revealed that the core-elements are critical for transcription. In Drosophila SL2 cells, which lack endogenous Sp1, the minimal promoter cannot drive transcription. introduction of Sp1 activated transcription potently, suggesting that Sp1 is critical in the initiation of transcription. The pCAT Sp1-core constructs was also able to drive transcription in the presence of Sp1 but not in the absence of Sp1, suggesting the importance of Sp1 in the transcriptional activation. These data clearly suggest that Sp1 initiates transcription by binding to the core cis-elements.
Abbreviations: ADH5/FDH, alcohol dehydrogenase 5/formaldehyde dehydrogenase; bp, base pairs; CAT, chloramphenicol acetyltransferas; CMV, cytomegarovirus; DTT, dithiothreitol; EMSA, electrophoretic mobility sheft assay; fpu, footprinting unit; kb, kilobase pair(s); PBS, phosphate-buffered saline; PCR, polymerase chain reaction; SL2, Drosophila Schneider line 2 cells; TBP, TATA-box binding protein, TRF, TBP-related factor)
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|