title: Sequence-specific recruitment of transcriptional co-repressor Cabin1 by myocyte enhancer factor-2.
abstract: 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.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado 80309-0215, USA.
authors.forename: Aidong
authors.initials: A
authors.lastname: Han
authors.forename: Fan
authors.initials: F
authors.lastname: Pan
authors.forename: James C
authors.initials: JC
authors.lastname: Stroud
authors.forename: Hong-Duk
authors.initials: HD
authors.lastname: Youn
authors.forename: Jun O
authors.initials: JO
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D019703:Calcineurin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D026161:MADS Domain Proteins; D064326:MEF2 Transcription Factors; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D018006:Myogenic Regulatory Factors; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C491861:CABIN1 protein, human; D004268:DNA-Binding Proteins; D026161:MADS Domain Proteins; D064326:MEF2 Transcription Factors; C578038:MEF2B protein, human; D018006:Myogenic Regulatory Factors; D010750:Phosphoproteins; D012097:Repressor Proteins; D014157:Transcription Factors; D004247:DNA; D019703:Calcineurin