Histone-lysine N-methyltransferase SETDB1 is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...
that in humans is encoded by the ''SETDB1''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
SETDB1 is also known as KMT1E or H3K9 methyltransferase ESET.
Function
The
SET domain is a highly conserved, approximately 150-amino acid motif implicated in the modulation of
chromatin
Chromatin is a complex of DNA and protein found in eukaryote, eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important ...
structure. It was originally identified as part of a larger conserved region present in the ''
Drosophila
''Drosophila'' () is a genus of flies, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or (less frequently) pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many s ...
'' Trithorax protein and was subsequently identified in the ''Drosophila'' Su(var)3-9 and 'Enhancer of zeste' proteins, from which the acronym SET is derived. Studies have suggested that the SET domain may be a signature of proteins that modulate transcriptionally active or repressed chromatin states through chromatin remodeling activities.
Model organisms
Model organisms have been used in the study of SETDB1 function. A conditional
knockout mouse
A knockout mouse, or knock-out mouse, is a genetically modified mouse (''Mus musculus'') in which researchers have inactivated, or " knocked out", an existing gene by replacing it or disrupting it with an artificial piece of DNA. They are importa ...
line, called ''Setdb1
tm1a(EUCOMM)Wtsi''
was generated as part of the
International Knockout Mouse Consortium
The International Knockout Mouse Consortium (IKMC) is a scientific endeavour to produce a collection of mouse embryonic stem cell lines that together lack every gene in the genome, and then to distribute the cells to scientific researchers to cr ...
program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.
Male and female animals underwent a standardized
phenotypic screen
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological prop ...
to determine the effects of deletion.
Twenty seven tests were carried out on
mutant
In biology, and especially in genetics, a mutant is an organism or a new genetic character arising or resulting from an instance of mutation, which is generally an alteration of the DNA sequence of the genome or chromosome of an organism. It ...
mice and four significant abnormalities were observed.
No
homozygous
Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism.
Mo ...
mutant
In biology, and especially in genetics, a mutant is an organism or a new genetic character arising or resulting from an instance of mutation, which is generally an alteration of the DNA sequence of the genome or chromosome of an organism. It ...
embryos were identified during gestation, and therefore none survived until
weaning
Weaning is the process of gradually introducing an infant human or another mammal to what will be its adult diet while withdrawing the supply of its mother's milk.
The process takes place only in mammals, as only mammals produce milk. The infa ...
. The remaining tests were carried out on
heterozygous
Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism.
Mo ...
mutant adult mice and two significant abnormalities were observed. Females had abnormal peripheral blood lymphocytes data and both sexes displayed increased bone strength and mineral content.
Zebrafish are an important model organism to study developmental biology and have been used to study cancer genetics. A screen to identify new oncogenes in melanoma performed in zebrafish identified SETDB1 as an oncogene that cooperates with another cancer gene, BRAF, to accelerate melanoma onset.
Subsequent reports have linked SETDB1 to hepatocellular carcinoma
Interactions
SETDB1 has been shown to
interact with
TRIM28.
>
See also
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SETD1A, a protein that is highly homologous to SETDB1
References
Further reading
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External links
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{{NLM content
Genes mutated in mice