Transcription & post-transcriptional processing in the Plasmodium chloroplast (360G-Wellcome-094249_Z_10_Z)

It is now recognized that Plasmodium has photosynthetic ancestry, being closely related to dinoflagellate algae. It has a remnant chloroplast, including a 35kbp genome, expression of which is essential for Plasmodium viability. The chloroplast is recognised as a target for new antimalarials. Very little is known about transcription and post-transcriptional processing in the Plasmodium chloroplast, although by analogy with other chloroplasts they are expected to be important determinants of gene expression. Although the Plasmodium chloroplast genome encodes some of the subunits of a bacterial-type RNA polymerase, we have identified a nuclear gene for a phage-type RNA polymerase, which algorithms predict is chloroplast targeted (probably in addition to the mitochondrion, and similar to what may be the case for dinoflagellates). Using our experience of chloroplast molecular biology, we have also identified putative genes for other important proteins, including a sigma factor for the bacte rial-type polymerase, an RNA processing enzyme and two RNA binding proteins. All of these are predicted in silico located in the Plasmodium chloroplast, with varying degrees of confidence. We wish to confirm the chloroplast location of these five proteins, and test their function. This will provide a basis for developing a detailed understanding of Plasmodium chloroplast gene expression.