| Histone subunit |
Residue |
Modification |
Consequence |
| H2A |
Serine 1 |
Phosphorylation |
Mitosis, transcriptional repression |
| |
Lysine 4 |
Acetylation |
Transcriptional activation |
| H2B |
Lysine 119
Serine 14 |
Ubiquitylation
Phosphorylation |
Spermatogenesis
Apoptosis |
| H3 |
Lysine 120
Lysine 4 |
Ubiquitylation
Acetylation |
Meiosis
Transcriptional activation |
| |
|
Methylation |
Active euchromatin |
| |
Lysine 9 |
Acetylation |
Transcriptional activation |
| |
|
Methylation |
Transcriptional repression |
| H4 |
Threonine 11
Arginine 3 |
Phosphorylation
Methylation |
Mitosis
Transcriptional activation |
| |
Lysine 16 |
Acetylation |
Transcriptional activation |
| |
|
|
DNA repair |
| |
Lysine 59 |
Methylation |
Transcriptional silencing |
Adapted from Watson et al. [32], Epigenetic modification can occur through acetylaion, methylation, phosphorylation and ubiquitylation of histone subunits with different
consequences to the cells through transcriptional activation or repression. The effects of such epigenetic modification of genomes may in some occasions exhibit themselves
as genetic disorders. We postulate, within credence, that the above epigenetic modifications, if occurred on DR and DQ molecules, would alter the charge distributions
on these molecules and consequentially derail co-operativity thereby obviating haplotypic potentials to predispose T1D: such genetically primed individuals escape this
autoimmune calamity.