Mutation analysis of the Pip interaction domain reveals critical residues for protein–protein interactions
AUTOR(ES)
Ortiz, Maria Antonia
FONTE
The National Academy of Sciences
RESUMO
The PU.1 interaction partner (Pip) is a member of the interferon regulatory factor family that regulates gene expression through heterodimerization with the ETS transcription factor PU.1. Binding of Pip alone to DNA is weak, and usually it is recruited by phosphorylated PU.1 to form a strong ternary complex with specific DNA sequences. An approach combining sequence homology analysis, secondary structure predictions, and a precise mutational strategy has been used to determine critical residues within the Pip heterodimerization domain that contribute to ternary complex formation. We have delimited the Pip interaction domain to residues 245–422 by using deletion analysis. Site-directed mutagenesis of conserved polar amino acids within two predicted α-helices contained in this region, and which are highly conserved in the IRF family, confirmed the importance of these residues for Pip–PU.1 interaction with DNA as well as for trans-activation activity. Our results suggest the existence of a functional epitope essential for heterodimerization between Pip and PU.1 and possibly, in general, between interferon regulatory factor family members and their partners.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=15839Documentos Relacionados
- Anchor residues in protein–protein interactions
- Inferring Domain–Domain Interactions From Protein–Protein Interactions
- Protein-protein interactions: methods for detection and analysis.
- Implications for domain fusion protein-protein interactions based on structural information
- A novel in vivo assay for the analysis of protein-protein interaction.