Histone modifications code

Modification Gene silencing Gene activation Correlation with TSS Function
H3K9ac NO NO NO Mark of active regulatory elements with preference for promoters
H3K27ac NO NO NO Mark of active regulatory elements; may distinguish active enhancers and promoters from their inactive counterparts
H2A.Z NO NO NO Histone protein variant (H2A.Z) associated with regulatory elements with dynamic chromatin
H3K4me1 NO YES NO Mark of regulatory elements associated with enhancers and other distal elements but also enriched downstream of transcription starts
H3K4me2 NO YES NO Mark of regulatory elements associated with promoters and enhancers
H3K4me3 NO YES NO Mark of regulatory elements primarily associated with promoters/transcription starts. Correlates positivily with transcription
H3K9me1 NO YES YES Preference for the 5′ end of genes. Detected in more active promoters surrounding the TSS
H3K9me3 YES NO NO Repressive mark associated with constitutive heterochromatin and repetitive elements
H3K27me1 NO YES YES
H3K27me3 YES NO NO Correlates with gene repression
H3K36me3 NO YES NO Elongation mark associated with transcribed portions of genes with preference for 3′ regions after intron 1
H3K79me2 YES NO NO Transcription-associated mark with preference for 5′ end of genes. Preference for active promoters.
H4K20me1 NO YES YES Preference for 5′ end of genes. Repressive chromatine.
H3R2 YES NO NO May be involved in transcriptional activation but not enriched in TSS
H2BK5 NO YES YES Active promoters downstream of the TSS