title: Transcriptional responses of Plasmodium falciparum to alpha-difluoromethylornithine-induced polyamine depletion.
abstract: Abstract Polyamines are essential polycationic molecules involved in multiple cellular events, including cell differentiation, division and death. Inhibition of polyamine biosynthesis has been considered in diverse therapeutic strategies ranging from tumour suppressors to anti-parasitic agents. In the human malaria parasite, Plasmodium falciparum, inhibition of ornithine decarboxylase (ODC) results in the arrest of schizogony due to polyamine depletion. However, the exact physiological role of the polyamines in the parasite is unknown. Here, we present results of the depletion of polyamines in the malaria parasite by alpha-difluoromethylornithine inhibition of ODC, as observed with differential transcriptome profiling. Upon depletion of their endogenous polyamines, the up- and downregulated parasite transcripts were selected with suppression subtractive hybridisation and differences were detected using blots or DNA microarrays. A direct linkage between polyamine depletion and the differential expression of two distinct transcripts was observed, indicating the existence of a transcriptional feedback response in the P. falciparum transcriptome upon drug challenge. The data presented provide input into the role of the polyamines in the cellular biology of P. falciparum and contribute towards the validation of polyamine biosynthesis as an antimalarial target.
authors.affiliation: Department of Biochemistry, School of Biological Sciences, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa.
authors.forename: Katherine
authors.initials: K
authors.lastname: Clark
authors.forename: Minishca
authors.initials: M
authors.lastname: Dhoogra
authors.forename: Abraham I
authors.initials: AI
authors.lastname: Louw
authors.forename: Lyn-Marié
authors.initials: LM
authors.lastname: Birkholtz
mesh_terms: D000818:Animals; D000518:Eflornithine / Q000494:pharmacology; D025461:Feedback, Physiological; D020869:Gene Expression Profiling / Q000379:methods*; D005786:Gene Expression Regulation; D006801:Humans; D065108:Ornithine Decarboxylase Inhibitors; D010963:Plasmodium falciparum / Q000235:genetics*; D011073:Polyamines; D014158:Transcription, Genetic
chemical_list: D065108:Ornithine Decarboxylase Inhibitors; D011073:Polyamines; D000518:Eflornithine