Apicomplexan and histone variants: What's new?

LAURA VANAGAS; SUSANA MARISOL CONTRERAS; SERGIO O. ANGEL

Chromatin

IntechOpen

Año: 2018;

Plasmodium spp and Toxoplasma gondii present a conservednucleosome composition, based on canonical H3 and variants, H4, canonical H2Aand variants and H2B. One-off, the phylum has also a H2B variant, named H2B.Z,which was shown to form a double variant nucleosome H2A.Z/H2B.Z. These histonesalso present conserved and unique postranslational modifications (PTMs).Histone variants have shown particular genomic localization and PTMs along theeuchromatin and heterochromatin, including telomere associated sequences (TAS),suggesting fine-grained chromatin structure modulation. Several othernon-histone proteins presented remarkable participation in controllingchromatin state, especially at TAS. Based on that, we will discuss the role ofepigenetics (PTMs and histone variants) in Plasmodiumand Toxoplasma gene expression,replication and DNA repair. We will also discuss TAS structures and chromatincomposition and its impact on antigenic variant expression in Plasmodium.