PARP1 orchestrates epigenetic events setting up chromatin domains

- PARP1 modulates chromatin architecture in a context-dependent manner.
- PARP1 controls epigenetic modifications of both histones and DNA.
- PARP1 maintains the integrity of constitutive and facultative heterochromatin.
- PARP1 controls heterochromatin to euchromatin transitions.
- PARP1 promotes and maintains euchromatin.

Epigenetic events include reversible modifications of DNA and histone tails driving chromatin organization and thus transcription. The epigenetic regulation is a highly integrated process underlying the plasticity of the genomic information both in the context of complex physiological and pathological processes. The global regulatory aspects of epigenetic events are largely unknown. PARylation and PARP1 are recently emerging as multi-level regulatory effectors that modulate the topology of chromatin by orchestrating very different processes. This review focuses in particular on the role of PARP1 in epigenetics, trying to build a comprehensive perspective of its involvement in the regulation of epigenetic modifications of histones and DNA, contextualizing it in the global organization of chromatin domains in the nucleus.

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