TATA binding protein associated factor 3 (TAF3) interacts with p53 and inhibits its function

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• The tumor suppressor protein p53 regulates crucial cellular processes like genome protection and apoptosis by controlling gene expression.
• Understanding the regulation of p53's transcription function is key to comprehending its multifaceted roles.

Purpose of the Study:

• To investigate the regulatory mechanisms governing p53 transcription function.
• To identify novel interacting partners of p53.

Main Methods:

• Yeast two-hybrid assays to detect protein-protein interactions.
• In vitro binding assays to confirm physical interactions.
• Functional assays in human cell lines to assess the impact of TAF3 on p53 activity.

Main Results:

• Identified BIP2 (Bric-à-brac interacting protein 2), the fly homolog of TAF3, as a binding partner of Drosophila melanogaster p53 (Dmp53).
• Confirmed physical interaction between the C terminus of Dmp53 and the central region of TAF3.
• Demonstrated that TAF3 interacts with both Dmp53 and human p53, indicating evolutionary conservation.
• Showed that elevated TAF3 expression inhibits p53-mediated transcription activation and reduces p53 protein levels in human cells.

Conclusions:

• TAF3 is identified as an evolutionarily conserved protein that negatively regulates the transcription activation function of p53.
• This interaction between TAF3 and p53 has functional significance in controlling p53 activity and protein stability.