title: Ankyrin repeats-containing cofactors interact with ADA3 and modulate its co-activator function.
abstract: ANCO (ankyrin repeats-containing cofactor)-1 and ANCO-2 are a family of unique transcriptional co-regulators with dual properties: they interact with both the co-activators and the co-repressors [Zhang, Yeung, Li, Tsai, Dinh, Wu, Li and Chen (2004) J. Biol. Chem. 279, 33799-33805]. Specifically, ANCO-1 is thought to recruit HDACs (histone deacetylases) to the p160 co-activator to repress transcriptional activation by nuclear receptors. In the present study, we provide new evidence to suggest further that ANCO-1 and ANCO-2 also interact with the co-activator ADA3 (alteration/deficiency in activation 3). The interaction occurs between the conserved C-terminal domain of ANCO-1 and the N-terminal transactivation domain of ADA3. Several subunits of the P/CAF {p300/CBP [CREB (cAMP-response-element-binding protein)-binding protein]-associated factor} complex, including ADA3, ADA2alpha/beta and P/CAF, showed co-localization with ANCO-1 nuclear dots, indicating an in vivo association of ANCO-1 with the P/CAF complex. Furthermore, a transient reporter assay revealed that both ANCO-1 and ANCO-2 repress ADA3-mediated transcriptional co-activation on nuclear receptors, whereas ANCO-1 stimulated p53-mediated transactivation. These data suggest that ADA3 is a newly identified target of the ANCO proteins, which may modulate co-activator function in a transcription-factor-specific manner.
authors: Department of Pharmacology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
authors: Chia-Wei
authors: CW
authors: Li
authors: Gia Khanh
authors: GK
authors: Dinh
authors: Aihua
authors: A
authors: Zhang
authors: J Don
authors: JD
authors: Chen
mesh_terms: D000818:Animals; D017089:Ankyrin Repeat; D017487:Ankyrins / Q000737:chemistry*; D019556:COS Cells; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002522:Chlorocebus aethiops; D005786:Gene Expression Regulation; D006801:Humans; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques
chemical_list: C492515:ANKRD11 protein, human; D017487:Ankyrins; D012097:Repressor Proteins; C444103:TADA3 protein, human; D014157:Transcription Factors