Purification and Identification of p68 RNA Helicase Acting as a Transcriptional Coactivator Specific for the Activation Function 1 of Human Estrogen Receptor α

Autor: Daniel Metzger, Hitoshi Tai, Yoko Kobayashi, Masahide Goto, Shigeaki Kato, Junn Yanagisawa, Yoshikazu Masuhiro, Seiichi Hashimoto, Kazunori Maruyama, Hideki Endoh
Rok vydání: 1999
Předmět:
Transcription
Genetic
Recombinant Fusion Proteins
Activation function
Molecular Sequence Data
Estrogen receptor
Breast Neoplasms
Adenocarcinoma
Biology
Bioinformatics
DEAD-box RNA Helicases
chemistry.chemical_compound
Coactivator
Tumor Cells
Cultured
Animals
Humans
Amino Acid Sequence
Retractions
P68 RNA Helicase
Phosphorylation
Protein kinase A
Molecular Biology
Transcriptional Regulation
DDX5
Estrogen Receptor alpha
Cell Biology
Molecular biology
Cell biology
Neoplasm Proteins
Protein Structure
Tertiary
Androgen receptor
Gene Expression Regulation
Receptors
Estrogen
chemistry
Retinoic acid receptor alpha
Transcriptional Coactivator
Calcium-Calmodulin-Dependent Protein Kinases
Identification (biology)
Female
Rabbits
Protein Kinases
Protein Processing
Post-Translational
Sequence Analysis
Estrogen receptor alpha
RNA Helicases
Protein Binding
Zdroj: Molecular and Cellular Biology. 19:5363-5372
ISSN: 1098-5549
DOI: 10.1128/mcb.19.8.5363
Popis: The estrogen receptor (ER) regulates the expression of target genes in a ligand-dependent manner. The ligand-dependent activation function AF-2 of the ER is located in the ligand binding domain (LBD), while the N-terminal A/B domain (AF-1) functions in a ligand-independent manner when isolated from the LBD. AF-1 and AF-2 exhibit cell type and promoter context specificity. Furthermore, the AF-1 activity of the human ERalpha (hERalpha) is enhanced through phosphorylation of the Ser(118) residue by mitogen-activated protein kinase (MAPK). From MCF-7 cells, we purified and cloned a 68-kDa protein (p68) which interacted with the A/B domain but not with the LBD of hERalpha. Phosphorylation of hERalpha Ser(118) potentiated the interaction with p68. We demonstrate that p68 enhanced the activity of AF-1 but not AF-2 and the estrogen-induced as well as the anti-estrogen-induced transcriptional activity of the full-length ERalpha in a cell-type-specific manner. However, it did not potentiate AF-1 or AF-2 of ERbeta, androgen receptor, retinoic acid receptor alpha, or mineralocorticoid receptor. We also show that the RNA helicase activity previously ascribed to p68 is dispensable for the ERalpha AF-1 coactivator activity and that p68 binds to CBP in vitro. Furthermore, the interaction region for p68 in the ERalpha A/B domain was essential for the full activity of hERalpha AF-1. Taken together, these findings show that p68 acts as a coactivator specific for the ERalpha AF-1 and strongly suggest that the interaction between p68 and the hERalpha A/B domain is regulated by MAPK-induced phosphorylation of Ser(118).
Databáze: OpenAIRE
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