Dnmt3b

Dnmt3b (DNA methyltransferase 3 beta) is an enzyme that plays a crucial role in the process of DNA methylation, which is a key epigenetic mechanism involved in regulating gene expression. Dnmt3b is part of the DNA methyltransferase family, which also includes Dnmt1 and Dnmt3a.

Function

Dnmt3b is responsible for the de novo methylation of cytosine residues in CpG dinucleotides, which is essential for the establishment of DNA methylation patterns during embryogenesis. This enzyme is particularly important in the early stages of development, where it helps in the formation of imprinted genes and the X-chromosome inactivation in females.

Structure

The Dnmt3b protein consists of several domains, including a PWWP domain, a CXXC domain, and a catalytic domain. The PWWP domain is involved in binding to histones, while the CXXC domain binds to unmethylated CpG sites. The catalytic domain is responsible for the transfer of a methyl group from S-adenosyl methionine (SAM) to the cytosine residue.

Clinical Significance

Mutations in the Dnmt3b gene are associated with Immunodeficiency, Centromeric instability, and Facial anomalies syndrome (ICF syndrome), a rare autosomal recessive disorder. Patients with ICF syndrome exhibit a range of symptoms, including immunodeficiency, facial anomalies, and developmental delays. The role of Dnmt3b in cancer has also been studied extensively, as abnormal DNA methylation patterns are a hallmark of many types of cancer.

Research

Research on Dnmt3b has provided significant insights into the mechanisms of epigenetic regulation and its implications in various diseases. Studies have shown that Dnmt3b interacts with other proteins involved in chromatin remodeling and gene regulation, highlighting its importance in maintaining genomic stability.

Related Pages

• DNA methylation
• DNA methyltransferase
• Dnmt1
• Dnmt3a
• CpG dinucleotide
• Epigenetics
• Immunodeficiency, Centromeric instability, and Facial anomalies syndrome
• Cancer