PHYSICAL AND FUNCTIONAL MAPPING OF THE TRANSCRIPTIONAL START SITES OFPLASMODIUM-FALCIPARUM PROLIFERATING CELL NUCLEAR ANTIGEN

RNase protection assays and primer extension analysis have been used t o locate a major transcription start site 960 bp upstream from the tra nslational start of the PfPCNA coding sequence. A second, minor, site is situated a further 40 bp upstream. Intraerythrocytic parasite stage s were transiently transfected with constructs containing a firefly lu ciferase reporter gene under the transcriptional control of variously modified elements of the PfPCNA 5' flanking sequence. These experiment s identified a 470 bp region essential for promoter activity, which co ntains the physically mapped transcriptional start sites. In addition, a region between 290 and 620 bp upstream of the transcriptional start sites is required for efficient promoter activity.