Table 1.
Summary of epigenetic histone modifications and their effect on gene expression [118,119,120,121,122].
| Histone/Position/Modification | Location | Effect | Enzyme |
|---|---|---|---|
| H3K4me2 | Gene activation | Set1, MLL, Set7/9, SMYD3, LSD1, JAR1D1A | |
| H3K4me3 | 5′ End of transcriptionally active genes | Gene activation | Set1, MLL, Set7/9, SMYD3, JAR1D1A |
| H3K9me | Euchromatin | Gene silencing | G9a; Suv91, StB1, PRD14, CLL8, GLP, Suv39h1, Suv39h2 |
| H3K9me2 | Euchromatin | Gene silencing | G9a; Suv91, StB1, PRD14, CLL8, GLP, Suv39h1, Suv39h2, JMJD2A |
| H3K9me3 | Promoters and heterochromatin, Gene coding region | Gene silencing Gene activation |
G9a; Suv91, StB1, PRD14, CLL8, GLP, Suv39h1, Suv39h2, JMJD2A |
| H3K27me1 | Heterochromatin | Gene activation | |
| H3K27me2/3 | Inactive-X chromosome, homeotic genes | Gene silencing | EZH2 |
| H3K36me | Promoter | Not well characterized | JHDM1A |
| H3K36me2 | Near double strand breaks, for repair | Gene silencing | NSD1, JMJD2A, JHDM1A |
| H3K36me3 | 3′ End of active genes. Marks exons. | Gene activation | JMJD2A |
| H3K79me2 | Gene activation | Dot1L | |
| H3K79me3 | Gene activation | Dot1L | |
| H4K20me1 | Cell cycle regulation, present at active promoters | Gene activation | SET8/PR-Set7 |
| H4K20me2 | Heterochromatin, marks origin for replication, DNA damage response | Gene silencing | NSD1, Suv4-20h1, Suv4-20H2, Set8/PR-SET7 |
| H4K20me3 | Heterochromatin, at promoters | Gene silencing | NSD1, Suv4-20h1, Suv4-20H2, Set8/PR-SET7 |