Activating Signal Cointegrator 2 Belongs to a Novel Steady-State Complex That Contains a Subset of Trithorax Group Proteins
| Autor: | Eunyee Kwak, Kang Min Jung, Jae Woon Lee, Young Chang Sohn, David O. Azorsa, Young Chul Lee, Seung-Whan Kim, Kong-Joo Lee, Shelley L. Berger, Pan Gil Suh, Robert G. Roeder, Young-Hwa Goo, Eun Joo Song, Nickolai A. Barlev, Paul S. Meltzer, Dae-Hwan Kim, Vincent T. K. Chow, Dong Ju Jung |
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| Jazyk: | angličtina |
| Rok vydání: | 2003 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Macromolecular Substances Receptors Retinoic Acid Amino Acid Motifs Molecular Sequence Data Nuclear Receptor Coactivators Biology DNA-binding protein Methylation Histones Transactivation Tubulin Coactivator Animals Drosophila Proteins Humans Amino Acid Sequence Nuclear protein Molecular Biology Transcription factor Cell Growth and Development Cation Transport Proteins Cell Nucleus Sequence Homology Amino Acid Lysine Intracellular Signaling Peptides and Proteins Nuclear Proteins Promoter Cell Biology DNA-Binding Proteins Retinoic acid receptor Biochemistry Nuclear receptor Carrier Proteins HeLa Cells Transcription Factors |
| Popis: | Many transcription coactivators interact with nuclear receptors in a ligand- and C-terminal transactivation function (AF2)-dependent manner. These include activating signal cointegrator 2 (ASC-2), a recently isolated transcriptional coactivator molecule, which is amplified in human cancers and stimulates transactivation by nuclear receptors and numerous other transcription factors. In this report, we show that ASC-2 belongs to a steady-state complex of approximately 2 MDa (ASC-2 complex [ASCOM]) in HeLa nuclei. ASCOM contains retinoblastoma-binding protein RBQ-3, alpha/beta-tubulins, and trithorax group proteins ALR-1, ALR-2, HALR, and ASH2. In particular, ALR-1/2 and HALR contain a highly conserved 130- to 140-amino-acid motif termed the SET domain, which was recently implicated in histone H3 lysine-specific methylation activities. Indeed, recombinant ALR-1, HALR, and immunopurified ASCOM exhibit very weak but specific H3-lysine 4 methylation activities in vitro, and transactivation by retinoic acid receptor appears to involve ligand-dependent recruitment of ASCOM and subsequent transient H3-lysine 4 methylation of the promoter region in vivo. Thus, ASCOM may represent a distinct coactivator complex of nuclear receptors. Further characterization of ASCOM will lead to a better understanding of how nuclear receptors and other transcription factors mediate transcriptional activation. |
| Databáze: | OpenAIRE |
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