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pBR322 contains glucocorticoid regulatory element DNA consensus sequences
Biochemical and Biophysical Research Communications
|April 14, 1987
Summary
Glucocorticoid regulatory elements (GREs) in pBR322 DNA bind glucocorticoid receptors, explaining high background in experiments. This research highlights GREs' crucial role in DNA-protein interactions.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- pBR322 DNA is frequently used as a negative control in studies of glucocorticoid receptor-DNA interactions.
- High background binding has been observed, necessitating an explanation for this phenomenon.
Purpose of the Study:
- To investigate the presence and significance of glucocorticoid regulatory elements (GREs) within the pBR322 DNA sequence.
- To elucidate the role of identified GREs in the interaction between pBR322 DNA and the glucocorticoid receptor.
Main Methods:
- Bioinformatic analysis of the pBR322 DNA sequence to identify potential GRE consensus sequences.
- Experimental validation using DNA fragments containing and lacking GRE sites, employing immobilized receptor binding and competitive binding assays.
Main Results:
- Five sites matching reported GRE DNA consensus sequences and three related sites were identified in pBR322 DNA.
- A pBR322 DNA fragment with a GRE site demonstrated significant binding to the glucocorticoid receptor.
- A pBR322 DNA fragment lacking GRE sites showed minimal interaction with the glucocorticoid receptor.
Conclusions:
- GRE consensus sequences are critical for glucocorticoid receptor interactions with DNA.
- The identified GRE sites in pBR322 DNA explain the high background binding observed in experimental assays, clarifying its utility as a negative control.