MBD1
Domain
The methyl-CpG-binding domain (MBD) functions both in binding to methylated DNA and in protein interactions.
The third CXXC-type zinc finger mediates binding to DNA containing unmethylated CpG dinucleotides.
The transcriptional repression domain (TRD) is involved in transcription repression and in protein interactions.
Function
Transcriptional repressor that binds CpG islands in promoters where the DNA is methylated at position 5 of cytosine within CpG dinucleotides. Binding is abolished by the presence of 7-mG that is produced by DNA damage by methylmethanesulfonate (MMS). Acts as transcriptional repressor and plays a role in gene silencing by recruiting ATF7IP, which in turn recruits factors such as the histone methyltransferase SETDB1. Probably forms a complex with SETDB1 and ATF7IP that represses transcription and couples DNA methylation and histone 'Lys-9' trimethylation. Isoform 1 and isoform 2 can also repress transcription from unmethylated promoters.
Post-translational modifications
Sumoylated, sumoylation may increase interaction with ATF7IP.
Tissue Specificity
Widely expressed.
Cellular localization
- Nucleus
- Nucleus matrix
- Nucleus speckle
- Chromosome
- Nuclear, in a punctate pattern (PubMed:12711603). Associated with euchromatic regions of the chromosomes, with pericentromeric regions on chromosome 1 and with telomeric regions from several chromosomes (PubMed:10454587, PubMed:10648624).
Alternative names
CXXC3, PCM1, MBD1, Methyl-CpG-binding domain protein 1, CXXC-type zinc finger protein 3, Methyl-CpG-binding protein MBD1, Protein containing methyl-CpG-binding domain 1