Ubiquitination
This large modification is found on H2A and H2B histones. How Ubiquitylation functions is unclear; it is likely to recruit additional factors to chromatin and may function to physically keep the chromatin open by a wedging process, given its large size.
| Variant | Site of modification |
Enzymes |
Role |
|
H2A,H2A1A,H2A1B,H2A1C,H2A1D,H2A1E, H2A1H,H2A1J,H2A.1,H2A.3,H2A2A,H2A2C, H2B1N |
K119 | Ring1A/Bmi |
Transcriptional repression, X chromosome inactivation
|
| MacroH2A.1 | K115 | CUL3/SPOP E3 complex | Enrichment of inactive X chromosome |
|
H2B,H2B1B,H2B1C/E/F/G/I,H2B1D, H2B1H,H2B1J,H2B1L,H2B1M,H2B1N, H2B1O,H2B2E,H2B2F,H2B3B,Testis specific histone H2B |
K120 | RNF 20/40 complex, UbcH6 |
Induce HOX gene expression,Transcription activation,stimulate elongation process
|