A Drosophila MBD family member is a transcriptional corepressor associated with specific genes.
DNA methylation in Drosophila melanogaster is restricted temporally during development and occurs at a significantly lower frequency than in mammals. Thus, the regulatory functions, if any, of this form of DNA modification in Drosophila are unclear. However, the presence of homologs of vertebrate methyl-CpG-binding proteins implies functional consequences for DNA methylation in flies. This work describes the properties of dMBD-like, a Drosophila homolog of vertebrate MBD2 and MBD3. dMBD-like and dMBD-likeDelta (a splice variant) failed to bind model methylated DNA probes, inconsistent with their function as mediators of methyl CpG-directed transcriptional repression. However, the MBD-like proteins exhibit transcriptional and biochemical properties consistent with roles as components of a histone deacetylase-dependent corepressor complex similar to the vertebrate Mi-2 complex. The two proteins are differentially expressed during development, suggesting functional specialization. dMBD-like and/or dMBD-likeDelta is present at the chromocenter on larval polytene chromosomes as well as at discrete bands interspersed along the euchromatic chromosome arms, many of which are coincident with known ecdysone-induced loci. This banding pattern suggests gene-specific regulatory functions for dMBD-like and the Drosophila Mi-2 complex.
Ballestar
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Laboratory of Molecular Embryology, National Institute of Child Health and Human Development, Bethesda, MD, USA. Esteban.Ballestar@uv.es
Pile
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Wassarman
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Wolffe
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Wade
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D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002875:Chromosomes / Q000737:chemistry / Q000235:genetics; D003001:Cloning, Molecular; D018899:CpG Islands / Q000235:genetics*; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006570:Heterochromatin / Q000737:chemistry / Q000378:metabolism; D006655:Histone Deacetylases / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009707:Nucleosomes / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014158:Transcription, Genetic / Q000235:genetics*
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D006570:Heterochromatin; D009707:Nucleosomes; D012333:RNA, Messenger; D011994:Recombinant Proteins; D012097:Repressor Proteins; D004247:DNA; D006655:Histone Deacetylases; D000251:Adenosine Triphosphatases