Journal
GENE
Volume 320, Issue -, Pages 155-164Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S0378-1119(03)00823-0
Keywords
AP-2; transcription self-interference; transcriptional cofactors
Categories
Funding
- NCI NIH HHS [R01-CA53475, P30-CA22453] Funding Source: Medline
Ask authors/readers for more resources
The transcriptional positive cofactor 4 (PC4) physically interacts with the transcription factor, activator protein-2 (AP-2) 0, and overexpression of PC4 results in a relief of the AP-2 transcriptional self-interference, which is induced by high levels of AP-2alpha expression. PC4 was initially described as a DNA-binding protein that enhances the activator-dependent transcription of class 11 genes in vitro, but it was later shown that PC4 could also act as a potent repressor of transcription on specific DNA structures such as single-stranded (ss) DNA, DNA ends and heteroduplex DNA. To further explore the functional domains of PC4 and its ssDNA-binding effect in the interaction with AP-2alpha and on AP-2 transcriptional activity, we investigated the C-terminal domain of PC4 (PC4-CTD) and several PC4 mutants in which the ssDNA binding function was interrupted. We found that the C-terminal domain of PC4 physically interacts with AP-2alpha and retains the function of full-length protein in relieving transcription self-interference of AP-2. A point-mutated form of PC4 within the C-terminal domain beta-ridge, PC4 W89A, or a triple mutant in the beta2-beta3 loop of PC4, F77A/K78G/K80G, inactivate the ability of PC4 to bind AP-2alpha and to relieve the transcription self-interference of AP-2alpha. In addition, point-mutated forms of AP-2alpha within the activation domain (AD) that inactivate AP-2 transcription activity also lose their self-interference function. Our data suggest that the C-terminal domain of the transcription cofactor PC4 is critical for AP-2alpha transcriptional interference that is mediated by the activation domain of AP-2alpha. (C) 2003 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available