Identity between TRAP and SMCC complexes indicates novel pathways for the function of nuclear receptors and diverse mammalian activators.
The human thyroid hormone receptor-associated protein (TRAP) complex, an earlier described coactivator for nuclear receptors, and an SRB- and MED-containing cofactor complex (SMCC) that mediates activation by Gal4-p53 are shown to be virtually the same with respect to specific polypeptide subunits, coactivator functions, and mechanisms of action (activator interactions). In parallel with ligand-dependent interactions of nuclear receptors with the TRAP220 subunit, p53 and VP16 activation domains interact directly with a newly cloned TRAP80 subunit. These results indicate novel pathways for the function of nuclear receptors and other activators (p53 and VP16) through a common coactivator complex that is likely to target RNA polymerase II. Identification of the TRAP230 subunit as a previously predicted gene product also suggests a coactivator-related transcription defect in certain disease states.
Pubmed ID: 10198638 RIS Download
Amino Acid Sequence | Blotting, Northern | Blotting, Western | Carrier Proteins | Cloning, Molecular | Fungal Proteins | Gene Expression Regulation | HeLa Cells | Herpes Simplex Virus Protein Vmw65 | Humans | Mediator Complex | Mediator Complex Subunit 1 | Molecular Sequence Data | Protein Binding | RNA Polymerase II | Receptors, Calcitriol | Receptors, Thyroid Hormone | Response Elements | Saccharomyces cerevisiae Proteins | Trans-Activators | Transcription Factors | Tumor Suppressor Protein p53