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CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
STAT1:DNA sequence-dependent binding modulation by phosphorylation, protein:protein interactions and small-molecule
Andrew J Bonham1, Nikola Wenta, Leah M Osslund
1Department of Chemistry & Biochemistry, University of California, Santa Barbara, CA 93106, USA.
Nucleic Acids Research
|November 28, 2012
Summary
Investigating the transcription factor STAT1 revealed that phosphorylation alters its DNA binding. Small-molecule inhibitors can disrupt STAT1 binding in a sequence-dependent manner, offering potential for targeted drug design.
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- Transcription factors (TFs) regulate gene expression.
- STAT1 is a dimeric human TF involved in cellular signaling.
- Protein phosphorylation significantly impacts TF activity and DNA binding.
Purpose of the Study:
- To assess the DNA-binding specificity and affinity of STAT1.
- To evaluate the effects of phosphorylation, polymerization, and small-molecule inhibition on STAT1.
- To determine the sequence-dependence of STAT1 inhibition by small molecules.
Main Methods:
- Total internal reflectance fluorescence protein-binding microarrays (TIRF-PBM) were employed.
- STAT1 and Myc/Max TFs were analyzed.
- Inhibitors LLL3 and Mycro3 were used to test TF inhibition.
Main Results:
- Phosphorylated STAT1 exhibited known binding preferences.
- Unphosphorylated STAT1 showed altered DNA binding to the GAS consensus site.
- Inhibitor LLL3 disrupted STAT1 binding in a sequence-dependent manner.
- Inhibitor Mycro3 showed sequence-independent inhibition of Myc/Max.
Conclusions:
- STAT1 phosphorylation influences its DNA-binding characteristics.
- STAT1 inhibition by LLL3 is sequence-dependent, unlike Myc/Max inhibition.
- Sequence-dependent inhibition of STAT1 presents a promising avenue for future drug development targeting this TF.
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