Histone modifications code

[table]
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
[/table]