A phylogenetic and proteomic reconstruction of eukaryotic chromatin evolution
Résumé
Histones and associated chromatin proteins have essential functions in eukaryotic genome
organization and regulation. Despite this fundamental role in eukaryotic cell biology, we lack a
phylogenetically comprehensive understanding of chromatin evolution. Here, we combine
comparative proteomics and genomics analysis of chromatin in eukaryotes and archaea.
Proteomics uncovers the existence of histone post-translational modifications in archaea.
However, archaeal histone modifications are scarce, in contrast with the highly conserved and
abundant marks we identify across eukaryotes. Phylogenetic analysis reveals that chromatin-
associated catalytic functions (for example, methyltransferases) have pre-eukaryotic origins,
whereas histone mark readers and chaperones are eukaryotic innovations. We show that further
chromatin evolution is characterized by expansion of readers, including capture by transposable
elements and viruses. Overall, our study infers detailed evolutionary history of eukaryotic
chromatin: from its archaeal roots, through the emergence of nucleosome-based regulation in the
eukaryotic ancestor, to the diversification of chromatin regulators and their hijacking by genomic
parasites.
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers produits par l'(les) auteur(s) |
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