Related Experiment Videos
TAF7 (TAFII55) plays a role in the transcription activation by c-Jun
Christine Munz1, Eleni Psichari, Dimitris Mandilis
1Division of Signal Transduction and Growth Control, Deutsches Krebforschungszentrum, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany.
Abstract:
c-Jun is a member of the AP-1 family of transcription factors regulating expression of specific target genes in a variety of cellular processes including proliferation, stress response, and tumorigenicity. In the present study we have analyzed the mechanism of c-Jun function as a transactivator with respect to members of the basal transcription machinery, TATA-binding protein-associated factors (TAFs). We show that one member of the family, human TAF7 (formerly TAFII55), physically interacts with c-Jun through two independent interaction domains, within the N- and C-terminal part of c-Jun. Interaction in vitro correlates with enhanced transactivation function of c-Jun in HEK293 and COS cells in the presence of increasing amounts of TAF7. TAF7 interacts preferentially with DNA-bound phosphorylated c-Jun, suggesting that TAF7 represents a novel c-Jun co-activator mediating activation of AP-1 target genes in response to extracellular signals.
Insights
The transcription factor c-Jun interacts with TAF7, a component of the basal transcription machinery. This interaction enhances c-Jun
Area of Science:
- Molecular Biology
- Gene Regulation
- Transcription Factors
Background:
- c-Jun is a key transcription factor in the AP-1 family, regulating cellular processes like proliferation and stress response.
- Understanding c-Jun's transactivation mechanism involves its interaction with basal transcription machinery components, such as TATA-binding protein-associated factors (TAFs).
Purpose of the Study:
- To investigate the mechanism of c-Jun's transactivator function in relation to TAFs.
- To identify specific interactions between c-Jun and TAF7 and their functional consequences.
Main Methods:
- In vitro interaction assays to analyze physical binding between c-Jun and TAF7.
- Cell-based transactivation assays using HEK293 and COS cells to measure functional enhancement.
- Analysis of c-Jun phosphorylation status and its effect on TAF7 interaction.
Main Results:
- Human TAF7 (TAFII55) physically interacts with c-Jun via two independent domains located in the N- and C-termini of c-Jun.
- TAF7 enhances the transactivation function of c-Jun in a dose-dependent manner in HEK293 and COS cells.
- TAF7 preferentially binds to phosphorylated, DNA-bound c-Jun.
Conclusions:
- TAF7 acts as a novel co-activator for c-Jun.
- The interaction between TAF7 and phosphorylated c-Jun mediates the activation of AP-1 target genes in response to extracellular signals.
- This finding provides new insights into the regulation of gene expression by the AP-1 transcription factor family.