DNA (cytosine-5)-methyltransferase 3 beta, is an
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
that in humans in encoded by the DNMT3B
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Mutation in this gene are associated with
immunodeficiency, centromere instability and facial anomalies syndrome.
Function
CpG methylation is an
epigenetic
In biology, epigenetics is the study of changes in gene expression that happen without changes to the DNA sequence. The Greek prefix ''epi-'' (ἐπι- "over, outside of, around") in ''epigenetics'' implies features that are "on top of" or "in ...
modification that is important for
embryonic development
In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm, sperm cell (spermat ...
,
imprinting, and X-chromosome inactivation. Studies in mice have demonstrated that DNA methylation is required for mammalian development. This gene encodes a
DNA methyltransferase
In biochemistry, the DNA methyltransferase (DNA MTase, DNMT) family of enzymes catalyze the transfer of a methyl group to DNA. DNA methylation serves a wide variety of biological functions. All the known DNA methyltransferases use S-adenosyl ...
which is thought to function in ''de novo'' methylation, rather than maintenance methylation. The protein localizes primarily to the nucleus and its expression is developmentally regulated. Eight alternatively spliced transcript variants have been described. The full length sequences of variants 4 and 5 have not been determined.
Clinical significance
Immunodeficiency-centromeric instability-facial anomalies (ICF) syndrome is a result of defects in
lymphocyte
A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include T cells (for cell-mediated and cytotoxic adaptive immunity), B cells (for humoral, antibody-driven adaptive immunity), an ...
maturation resulting from aberrant DNA methylation caused by mutations in the DNMT3B gene.
Variants of the gene can also contribute to
nicotine dependency.
Interactions
DNMT3B has been shown to
interact with:
*
CBX5,
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DNMT1,
NCAPG
Condensin complex subunit 3 also known as condensin subunit CAP-G (CAP-G) or non-SMC condensin I complex subunit G (NCAPG) is a protein that in humans is encoded by the ''NCAPG'' gene
In biology, the word gene has two meanings. The Mendelia ...
,[
* SMC2,][
* ]SUMO1
Small ubiquitin-related modifier 1 is a protein that in humans is encoded by the ''SUMO1'' gene.
Function
This gene encodes a protein that is a member of the SUMO (small ubiquitin-like modifier) protein family. It is a ubiquitin-like protein a ...
UBE2I
SUMO-conjugating enzyme UBC9 is an enzyme that in humans is encoded by the ''UBE2I'' gene. It is also sometimes referred to as "ubiquitin conjugating enzyme E2I" or "ubiquitin carrier protein 9", even though these names do not accurately describe ...
.[
]
References
Further reading
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External links
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{{One carbon transferases