Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
2010-11-5
pubmed:abstractText
Fragile X syndrome (FXS) is the most common heritable cause of intellectual disability and the most common known cause of autism. Most cases of FXS result from the expansion of a CGG·CCG repeat in the 5' UTR of the FMR1 gene that leads to gene silencing. It has previously been shown that silenced alleles are associated with histone H3 dimethylated at lysine 9 (H3K9Me2) and H3 trimethylated at lysine 27 (H3K27Me3), modified histones typical of developmentally repressed genes. We show here that these alleles are also associated with elevated levels of histone H3 trimethylated at lysine 9 (H3K9Me3) and histone H4 trimethylated at lysine 20 (H4K20Me3). All four of these modified histones are present on exon 1 of silenced alleles at levels comparable to that seen on pericentric heterochromatin. The two groups of histone modifications show a different distribution on fragile X alleles: H3K9Me2 and H3K27Me3 have a broad distribution, whereas H3K9Me3 and H4K20Me3 have a more focal distribution with the highest level of these marks being present in the vicinity of the repeat. This suggests that the trigger for gene silencing may be local to the repeat itself and perhaps involves a mechanism similar to that involved in the formation of pericentric heterochromatin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1460-2083
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4634-42
pubmed:meshHeading
pubmed-meshheading:20843831-Alleles, pubmed-meshheading:20843831-Blotting, Northern, pubmed-meshheading:20843831-Cell Line, pubmed-meshheading:20843831-Chromatin Immunoprecipitation, pubmed-meshheading:20843831-Chromosomes, Human, X, pubmed-meshheading:20843831-DNA Methylation, pubmed-meshheading:20843831-Fragile X Mental Retardation Protein, pubmed-meshheading:20843831-Fragile X Syndrome, pubmed-meshheading:20843831-Gene Silencing, pubmed-meshheading:20843831-Heterochromatin, pubmed-meshheading:20843831-Histones, pubmed-meshheading:20843831-Humans, pubmed-meshheading:20843831-Methylation, pubmed-meshheading:20843831-Polymerase Chain Reaction, pubmed-meshheading:20843831-Protein Processing, Post-Translational, pubmed-meshheading:20843831-RNA, pubmed-meshheading:20843831-RNA Interference, pubmed-meshheading:20843831-Trinucleotide Repeats
pubmed:year
2010
pubmed:articleTitle
The distribution of repressive histone modifications on silenced FMR1 alleles provides clues to the mechanism of gene silencing in fragile X syndrome.
pubmed:affiliation
Section on Gene Structure and Disease, Laboratory of Molecular and Cellular Biology, National Institute of Diabetes and Digestive and Kidney Disease/NIH, Bethesda, MD 20892-0830, USA. ku@helix.nih.gov
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural, Research Support, N.I.H., Intramural