Sequence-specific recruitment of transcriptional co-repressor Cabin1 by myocyte enhancer factor-2.
The myocyte enhancer factor-2 (MEF2) family of transcription factors has important roles in the development and function of T cells, neuronal cells and muscle cells. MEF2 is capable of repressing or activating transcription by association with a variety of co-repressors or co-activators in a calcium-dependent manner. Transcriptional repression by MEF2 has attracted particular attention because of its potential role in hypertrophic responses of cardiomyocytes. Several MEF2 co-repressors, such as Cabin1/Cain and class II histone deacetylases (HDACs), have been identified. However, the molecular mechanism of their recruitment to specific promoters by MEF2 remains largely unknown. Here we report a crystal structure of the MADS-box/MEF2S domain of human MEF2B bound to a motif of the transcriptional co-repressor Cabin1 and DNA at 2.2 A resolution. The crystal structure reveals a stably folded MEF2S domain on the surface of the MADS box. Cabin1 adopts an amphipathic alpha-helix to bind a hydrophobic groove on the MEF2S domain, forming a triple-helical interaction. Our studies of the ternary Cabin1/MEF2/DNA complex show a general mechanism by which MEF2 recruits transcriptional co-repressor Cabin1 and class II HDACs to specific DNA sites.
Pubmed ID: 12700764 RIS Download
Adaptor Proteins, Signal Transducing | Amino Acid Sequence | Base Sequence | Binding Sites | Calcineurin | Crystallography, X-Ray | DNA | DNA-Binding Proteins | Humans | Hydrophobic and Hydrophilic Interactions | MADS Domain Proteins | MEF2 Transcription Factors | Models, Molecular | Molecular Sequence Data | Mutation | Myogenic Regulatory Factors | Phosphoproteins | Protein Binding | Protein Structure, Tertiary | Repressor Proteins | Substrate Specificity | Transcription Factors | Transcription, Genetic