Epigenetics Library
Recommended Post: 【Bioinformatics】 Bioinformatics Analysis Index
2. CNV
1.Histone Modification
○ Overview
○ Among histones, H3 is most frequently modified: H2A and H2B are much less frequently modified
○ Histone modification occurs on histone tails
Figure 1. Locations of Histone Modifications
○ Epigenetics Map (feat. abcam): File
○ Combinations of histone modifications according to gene expression regulatory elements
Figure 2. Combinations of histone modifications according to gene expression regulatory elements
○ H2AK119Ub
○ Related to DDR (DNA damage response)
○ H2BK5me1
○ Activates gene transcription
○ H2BK5me3
○ Represses gene transcription
○ H3K4me1
○ Enhancer and promoter: Activates gene transcription
○ H3K4me3
○ A modification where three methyl groups (me3) are attached to the 4th lysine (K) residue of the histone protein
○ Active promoter: Activates gene transcription
○ Particularly in the brain, positively correlated with H3K27ac and negatively correlated with H3K27me3
○ Example 1. Gpr88 shows high H3K4me3 modification in the striatum → Increased expression
○ H3K9ac
○ Active promoter: Activates gene transcription
○ Associated with faster PolI elongation rate, promoting exon skipping and intron inclusion.
○ H3K9me1
○ Activates gene transcription
○ H3K9me2
○ Represses gene transcription
○ H3K9me3
○ Heterochromatin silencing: Represses gene transcription
○ Shown to slow PolI elongation rate, promoting exon inclusion.
○ H3K14ac
○ Activates gene transcription
○ H3K27ac
○ A modification where an acetyl group (ac) is attached to the 27th lysine (K) residue of histone H3
○ Enhancer and promoter: Activates gene transcription
○ Particularly in the brain, positively correlated with H3K4me3 and negatively correlated with H3K27me3
○ Example 1. Gpr88 shows high H3K27ac modification in the striatum → Increased expression
○ H3K27me1
○ Activates gene transcription
○ H3K27me2
○ Represses gene transcription
○ H3K27me3
○ A modification where three methyl groups (me3) are attached to the 27th lysine (K) residue of histone H3
○ Polycomb repression: Represses gene transcription
○ Particularly in the brain, negatively correlated with H3K4me3 and H3K27ac
○ Example 1. Genes involved in GABAergic regulation during synaptic signaling show high H3K27me3 modification
○ Example 2. Genes involved in glutamatergic regulation during synaptic signaling show low H3K27me3 modification
○ Example 3. The Car2 gene shows high H3K27me3 modification in the cerebral cortex compared to the corpus callosum and striatum
○ Example 4. Related to DDR (DNA damage response)
○ H3K27me1
○ Activates gene transcription
○ H3K27me3
○ Polycomb silenced promoter: Represses gene transcription
○ H3K36me3
○ Transcribed gene body, transcription elongation: Activates gene transcription
○ Recruits splicing factors via chromatin-binding proteins.
○ H3K79me1
○ Activates gene transcription
○ H3K79me2
○ Promoter activity: Activates gene transcription
○ H3K79me3
○ Activates or represses gene transcription
○ H4K20me1
○ Activates gene transcription
○ Mecp2
○ Exclusive reader of non-CpG methylation
2. CNV (Copy Number Variation)
○ 12q13 deletion: Chromosomal deletion anomaly of the tumor suppressor gene TP53
Input: 2024.01.07 01:24