The effects of glucose concentration on the reciprocal regulation of rRNA promoters in Plasmodium falciparum.

The developmental progression of Plasmodium falciparum is remarkably sensitive to glucose concentration. We have investigated the effects of glucose concentration on the parasite development cycle as reflected by changes of ribosomal RNA (rRNA) transcription. We showed that glucose starvation differentially affects transcriptional control of the rRNA genes by sharply repressing transcription from those loci involved with asexual development of the parasite while up-regulating transcription at those loci involved with sexual development of the parasite. Temperature change also effects regulation of transcription. We found that the effects of temperature and glucose were synergistic. We identified and compared the upstream region of the transcription start sites of each gene. These putative promoter structures are considerably different from one another and contain structures remarkably similar to rRNA control elements in other organisms.