title: Polysome profiling reveals translational control of gene expression in the human malaria parasite Plasmodium falciparum.
abstract: BACKGROUND
  In eukaryotic organisms, gene expression is regulated at multiple levels during the processes of transcription and translation. The absence of a tight regulatory network for transcription in the human malaria parasite suggests that gene expression may largely be controlled at post-transcriptional and translational levels.
  
  
  RESULTS
  In this study, we compare steady-state mRNA and polysome-associated mRNA levels of Plasmodium falciparum at different time points during its asexual cell cycle. For more than 30% of its genes, we observe a delay in peak transcript abundance in the polysomal fraction as compared to the steady-state mRNA fraction, suggestive of strong translational control. Our data show that key regulatory mechanisms could include inhibitory activity of upstream open reading frames and translational repression of the major virulence gene family by intronic transcripts. In addition, we observe polysomal mRNA-specific alternative splicing events and widespread transcription of non-coding transcripts.
  
  
  CONCLUSIONS
  These different layers of translational regulation are likely to contribute to a complex network that controls gene expression in this eukaryotic pathogen. Disrupting the mechanisms involved in such translational control could provide novel anti-malarial strategies.
authors.forename: Evelien M
authors.initials: EM
authors.lastname: Bunnik
authors.forename: Duk-Won Doug
authors.initials: DW
authors.lastname: Chung
authors.forename: Michael
authors.initials: M
authors.lastname: Hamilton
authors.forename: Nadia
authors.initials: N
authors.lastname: Ponts
authors.forename: Anita
authors.initials: A
authors.lastname: Saraf
authors.forename: Jacques
authors.initials: J
authors.lastname: Prudhomme
authors.forename: Laurence
authors.initials: L
authors.lastname: Florens
authors.forename: Karine G
authors.initials: KG
authors.lastname: Le Roch
mesh_terms: D016000:Cluster Analysis; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D018503:Genome, Protozoan; D006801:Humans; D007438:Introns; D016778:Malaria, Falciparum / Q000469:parasitology; D016366:Open Reading Frames; D010963:Plasmodium falciparum / Q000235:genetics*; D011132:Polyribosomes / Q000737:chemistry / Q000235:genetics*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016053:RNA, Protozoan / Q000235:genetics; D017423:Sequence Analysis, RNA; D059467:Transcriptome
chemical_list: D012333:RNA, Messenger; D016053:RNA, Protozoan