NoRC:HDAC:DNMT deacetylates histone H4 and methylates histone H3

Stable Identifier
R-HSA-433672
Type
Reaction [omitted]
Species
Homo sapiens
Compartment
Synonyms
Deacetylation of Histone H4 and Dimethylation of Lysine-9 of Histone H3 in Promoter of rRNA Gene
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As inferred from mouse cell models, histones in silenced rRNA gene copies are deacetylated by HDAC1 (and possibly HDAC2), which is part of the SIN3-HDAC complex bound to NoRC. The PHD domain of the TIP5 (BAZ2A) component of NoRC binds acetylated lysine-16 of histone H4. The residues of histone H4 that are deacetylatd are lysine-5, lysine-8, and lysine-12.
In the main promoters of silenced rRNA gene copies, histone H3 is methylated on lysine-9 (H3K9) by an unknown histone methyltransferase. H3K9 methylation is still observed when deacetylation is inhibited, therefore histone methylation does not depend on deacetylation. However histone deacetylation is required for DNA methylation. Significantly more dimethylation than trimethylation is observed.

Participants
Participant Of
Catalyst Activity
Catalyst Activity
Title
histone deacetylase activity of NoRC:pRNA:HDAC:DNMT [nucleoplasm]
Physical Entity
Activity
Inferred From
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Reviewed
Created