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Distance constraints and stereospecific alignment requirements characteristic of p53 DNA-binding consensus sequence
J L Cook1, R N Ré, J F Giardina
1Division of Research, Alton Ochsner Medical Foundation, New Orleans, Louisiana, USA 70121.
Oncogene
|August 17, 1995
Summary
Some mutant p53 proteins can still activate genes via DNA binding sites. The spacing and sequence of these sites significantly influence mutant p53 activity and DNA binding, impacting gene regulation.
Area of Science:
- Molecular Biology
- Genetics
- Cancer Research
Background:
- Mutant p53 proteins are frequently found in human cancers.
- The role of mutant p53 in gene trans-activation remains incompletely understood.
Purpose of the Study:
- To investigate the DNA-binding and trans-activation capabilities of mutant p53 proteins.
- To determine the influence of consensus sequence (CS) homology, inter-motif distance, and flanking DNA on p53 activity.
Main Methods:
- Assessed trans-activation activity of mutant p53 in cell lines with high mutant p53 levels.
- Analyzed the impact of varying inter-motif distances (N) in p53 DNA-binding CS homologies.
- Examined the effect of DNA flanking sequences on p53-mediated trans-activation.
Main Results:
- Mutant p53 demonstrated differential activity in trans-activating various CS homologies.
- Inter-motif distance is critical for determining binding affinity for both wild-type and mutant p53.
- Stereospecific alignment of DNA-binding motifs influences p53 binding preference.
- Functional activity of CS homologies is distance-dependent, with significant loss of trans-activation upon introduction of ~200 bp.
Conclusions:
- Certain mutant p53 proteins retain trans-activation function through specific DNA-binding consensus sequences.
- DNA sequence, motif spacing, and flanking DNA composition are key modulators of mutant p53 activity and DNA binding.