RRC ID 58351
Author Dorrell RG, Drew J, Nisbet RE, Howe CJ.
Title Evolution of chloroplast transcript processing in Plasmodium and its chromerid algal relatives.
Journal PLoS Genet
Abstract It is well understood that apicomplexan parasites, such as the malaria pathogen Plasmodium, are descended from free-living algae, and maintain a vestigial chloroplast that has secondarily lost all genes of photosynthetic function. Recently, two fully photosynthetic relatives of parasitic apicomplexans have been identified, the 'chromerid' algae Chromera velia and Vitrella brassicaformis, which retain photosynthesis genes within their chloroplasts. Elucidating the processes governing gene expression in chromerid chloroplasts might provide valuable insights into the origins of parasitism in the apicomplexans. We have characterised chloroplast transcript processing pathways in C. velia, V. brassicaformis and P. falciparum with a focus on the addition of an unusual, 3' poly(U) tail. We demonstrate that poly(U) tails in chromerids are preferentially added to transcripts that encode proteins that are directly involved in photosynthetic electron transfer, over transcripts for proteins that are not involved in photosynthesis. To our knowledge, this represents the first chloroplast transcript processing pathway to be associated with a particular functional category of genes. In contrast, Plasmodium chloroplast transcripts are not polyuridylylated. We additionally present evidence that poly(U) tail addition in chromerids is involved in the alternative processing of polycistronic precursors covering multiple photosynthesis genes, and appears to be associated with high levels of transcript abundance. We propose that changes to the chloroplast transcript processing machinery were an important step in the loss of photosynthesis in ancestors of parasitic apicomplexans.
Volume 10(1)
Pages e1004008
Published 2014-1-1
DOI 10.1371/journal.pgen.1004008
PMID 24453981
PMC PMC3894158
MeSH 3' Untranslated Regions Alveolata / genetics Chloroplasts / genetics* Evolution, Molecular* Humans Malaria, Falciparum / genetics Malaria, Falciparum / parasitology Molecular Sequence Data Photosynthesis / genetics Phylogeny Plasmodium falciparum / genetics* Plasmodium falciparum / growth & development Plasmodium falciparum / pathogenicity Plastids / genetics Poly U / genetics* RNA Precursors / genetics* Transcription, Genetic
IF 5.175
Times Cited 14
Algae NIES-4391