Format

Send to

Choose Destination
J Biol Chem. 2006 Feb 10;281(6):3389-97. Epub 2005 Dec 12.

Differential use of functional domains by coiled-coil coactivator in its synergistic coactivator function with beta-catenin or GRIP1.

Author information

1
Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, California 90089, USA.

Abstract

beta-Catenin, a pivotal component of the Wnt-signaling pathway, binds to and serves as a transcriptional coactivator for the T-cell factor/lymphoid enhancer factor (TCF/LEF) family of transcriptional activator proteins and for the androgen receptor (AR), a nuclear receptor. Three components of the p160 nuclear receptor coactivator complex, including CARM1, p300/CBP, and GRIP1 (one of the p160 coactivators), bind to and cooperate with beta-catenin to enhance transcriptional activation by TCF/LEF and AR. Here we report that another component of the p160 nuclear receptor coactivator complex, the coiled-coil coactivator (CoCoA), directly binds to and cooperates synergistically with beta-catenin as a coactivator for AR and TCF/LEF. CoCoA uses different domains to bind GRIP1 and beta-catenin, and it uses different domains to transmit the activating signal to the transcription machinery, depending on whether it is bound to GRIP1 or beta-catenin. CoCoA associated specifically with the promoters of transiently transfected and endogenous target genes of TCF/LEF, and reduction of the endogenous CoCoA level decreased the ability of TCF/LEF and beta-catenin to activate transcription of transient and endogenous target genes. Thus, CoCoA uses different combinations of functional domains to serve as a physiologically relevant component of the Wnt/beta-catenin signaling pathway and the androgen signaling pathway.

PMID:
16344550
PMCID:
PMC1626527
DOI:
10.1074/jbc.M510403200
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center