Gene transcription across the life cycle in the human malaria parasite Plasmodium falciparum is highly ordered and stage-specific. Post-translational modification of histones is one of the key gene regulatory mechanisms during the intraerythrocytic development cycle which can influence gene expression, either by directly affecting chromatin structure or by recruiting regulatory proteins. Histone acetylation is particularly abundant in P. falciparum; it is associated with active genes and is essential for parasite growth. Bromodomains interact with acetylated lysine residues on histone tails. In P. falciparum, there are eight putative bromodomain proteins. Bromodomain protein 1 (PfBDP1) is critical for the coordinated regulation of invasion genes and is essential for parasite survival.
We used chromatin immunoprecipitation sequencing (ChIP-seq) analysis to identify genomic sites of bromodomain protein 3 (PfBDP3) enrichment to understand its potential role in P. falciparum gene regulation. PfBDP3 was successfully immunoprecipitated from ring and schizont stage nuclei. During schizont stage, PfBDP3 is located upstream of schizont specific genes as well as adjacent and downstream to genes involved in DNA modulation/repair and biosynthesis pathways. In addition, BDP3 is also located near genes that are implicated in gametocyte commitment or expressed specifically in the gametocyte stage. Overall, these data provide a first insight into the role of PfBDP3 in gene regulation.