MBD5 Background Information Methylation of DNA contributes to the regulation of gene transcription in both mammalian and invertebrate systems. DNA methylation predominates on cytosine residues that are present in dinucleotide motifs consisting of a 5’ cytosine followed by guanosine (CpG), and it requires the enzymatic activity of DNA methyltransferase, which results in transcriptional repression of the methylated gene. Several proteins have been identified that associate with the methyl-CpG sites, and they include methyl-CpG binding protein-1 (MBD1), MBD2, MBD3, MBD4, MBD5 and MeCP2. MBD5 is a 1494 amino acid protein containing one MBD domain and one PWWP domain. Localized to the nucleus, MBD5 is expressed in skeletal muscle, kidney, heart, kidney, liver, pancreas and placenta. Mutations in the gene that encodes MBD5 have been found to cause mental retardation autosomal dominant type 1 (MRD1), which is characterized by sub-average general intellectual functioning manifested during the developmental period.
