Plasmodium falciparum acetylated variant histones

Variant histones play important roles in regulating gene expression and chromatin structure in diverse eukaryotes. Acetylation of histones often affects their function. This study aimed to investigate the roles of acetylated Plasmodium falciparum variant histones Pf H2A.Z and Pf H2B.Z in regulating gene expression and in maintaining heterochromatin structure. Maintenance of facultative heterochromatin is required for variegated expression of P. falciparum genes and this enables rapid adaptation and survival in diverse host environments and results in pathogenesis in humans. In P. falciparum Pf H2A.Z and Pf H2B.Z are enriched in intergenic euchromatin but depleted from heterochromatin. They occupy most promoters and acetylated Pf H2A.Z and Pf H2B.Z are dynamically associated with gene expression at promoters, and with lifecycle stage at splice sites. Acetylated Pf H2A.Z and Pf H2B.Z are antagonised by the sirtuin class III histone deacetylase (HDAC) PfSir2A at heterochromatin boundaries and encroach upon heterochromatin in parasites lacking PfSir2A.