Related Experiment Videos
Characterization of an antisense Inr element in the eIF-2 alpha gene
M Noguchi1, S Miyamoto, T A Silverman
1Molecular Hematology Branch, NHLBI, National Institutes of Health, Bethesda, Maryland 20892.
The Journal of Biological Chemistry
|November 18, 1994
Summary
Researchers identified overlapping sense and antisense transcripts for the eIF-2 alpha gene, regulated by an opposing initiator promoter (Inr) and a 43-kDa protein, impacting gene expression.
Area of Science:
- Molecular Biology
- Gene Regulation
- RNA Biology
Background:
- The eukaryotic translation initiation factor 2 alpha (eIF-2 alpha) gene plays a crucial role in protein synthesis.
- Previous studies identified an initiator promoter (Inr) downstream of the sense promoter for the eIF-2 alpha gene.
Purpose of the Study:
- To investigate the functional significance of the opposing initiator promoter (Inr) and its associated binding proteins in eIF-2 alpha gene regulation.
- To elucidate the mechanism of sense and antisense transcript generation and their interplay in T-lymphocytes.
Main Methods:
- Reverse transcriptase/polymerase chain reaction (RT-PCR) to analyze T-lymphocyte RNA.
- DNase I footprinting and electrophoretic mobility shift assay (EMSA) to identify protein-DNA interactions.
- Luciferase reporter gene assays to assess promoter activity and the role of regulatory elements.
Main Results:
- Overlapping sense and antisense transcripts for the eIF-2 alpha gene were identified in T-lymphocytes.
- A 43-kDa protein was found to bind a cis-regulatory sequence upstream of the Inr, influencing DNase I hypersensitivity.
- Insertion of the Inr footprint region significantly increased reporter gene expression, while mutations altered activity, indicating functional roles for the Inr and binding protein.
Conclusions:
- The opposing Inr and its associated 43-kDa binding protein are critical for regulating eIF-2 alpha gene expression, potentially by facilitating RNA polymerase II access.
- A model is proposed where the differential activity of sense and antisense promoters leads to double-stranded RNA (dsRNA) formation and rapid degradation, contributing to gene expression control.