Transcriptional control and gene silencing in Plasmodium falciparum.

Infection with the apicomplexan parasite Plasmodium falciparum is associated with a high burden of morbidity and mortality across the developing world, yet the mechanisms of transcriptional control in this organism are poorly understood. While P. falciparum possesses many of the characteristics common to eukaryotic transcription, including much of the canonical machinery, it also demonstrates unique patterns of gene expression and possesses unusually AT-rich intergenic sequences. Importantly, several biological processes that are critical to parasite virulence involve highly regulated patterns of gene expression and silencing. The relative scarcity of transcription-associated proteins and specific cis-regulatory motifs recognized in the P. falciparum genome have been thought to reflect a reduced role for transcription factors in transcriptional control in these parasites. New approaches and technologies, however, have led to the discovery of many more of these elements, including an expanded family of DNA-binding proteins, and a re-assessment of this hypothesis is required. We review the current understanding of transcriptional control in P. falciparum, specifically highlighting promoter-driven and epigenetic mechanisms involved in the control of transcription initiation.