Related Experiment Videos
Structure and function of the zeta-globin upstream regulatory element
D E Sabath1, K M Koehler, W Q Yang
1Department of Laboratory Medicine, University of Washington School of Medicine, Seattle 98195-7110, USA. dsabath@u.washington.edu
Nucleic Acids Research
|December 15, 1996
Summary
Researchers identified a 60 bp zeta-globin upstream regulatory element (URE) crucial for gene expression. This URE involves binding sites for GATA-1, Sp1, and a novel factor (URE-BF), highlighting complex protein-DNA interactions in globin gene regulation.
Area of Science:
- Molecular Biology
- Genetics
- Gene Regulation
Background:
- The human zeta-globin gene promoter contains a regulatory element (URE) in its 5' flanking region.
- Understanding the precise sequences and protein interactions within the URE is key to deciphering zeta-globin gene expression.
Purpose of the Study:
- To define the minimal sequences of the zeta-globin URE essential for its function.
- To characterize the specific protein-DNA interactions occurring at the URE.
Main Methods:
- Deletion analysis to map the functional boundaries of the URE.
- Electrophoretic mobility shift assays (EMSA) to identify protein binding to specific DNA sequences within the URE.
Main Results:
- The URE spans a 60 bp region (-220 to -279 bp) upstream of the transcription start site.
- GATA-1 binds at -230, Sp1 and an unknown factor bind a CCACC site at -240, and a novel factor (URE-BF) binds at -269 to -255.
- URE-BF is present in zeta-globin expressing cells (K562) but absent in non-expressing cells (OCIM1), and its binding is influenced by GATA sites.
Conclusions:
- Zeta-globin promoter activity is critically dependent on a 60 bp region with at least three distinct binding factors.
- Two identified factors, including URE-BF, may be novel DNA-binding proteins important for globin gene regulation.
- These factors likely interact to form a functional regulatory unit, influencing zeta-globin gene expression.