Polysome profiling reveals translational control of gene expression in the human malaria parasite Plasmodium falciparum
1 Department of Cell Biology and Neuroscience, University of California Riverside, 900 University Ave, Riverside, CA 92521, USA
2 Current address: INRA Centre de Bordeaux Aquitaine, 33883 Villenave d’Ornon, Cedex, France
3 Stowers Institute for Medical Research, Kansas City, MO 64110, USA
4 Institute for Integrative Genome Biology, Center for Disease Vector Research, Department of Cell Biology and Neuroscience, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
Genome Biology 2013, 14:R128 doi:10.1186/gb-2013-14-11-r128Published: 22 November 2013
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.
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.
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.