Temporal evaluation of commitment to sexual development in Plasmodium falciparum

Malaria Journal

Research

Matthew WA Dixon¹  Donald L Gardiner²  Katharine R Trenholme³  Christopher L Peatey⁴ 

[1] Malaria Biology Laboratory, Queensland Institute of Medical Research, 300 Herston Rd, 4006, Herston, QLD, Australia;Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, and ARC Centre of Excellence for Coherent X-ray Science, University of Melbourne, 3010, Parkville, VIC, Australia;Malaria Biology Laboratory, Queensland Institute of Medical Research, 300 Herston Rd, 4006, Herston, QLD, Australia;School of Biomolecular and Physical Sciences, Griffith University, Queensland, Australia;School of Medicine, University of Queensland, Queensland, Australia;Malaria Biology Laboratory, Queensland Institute of Medical Research, 300 Herston Rd, 4006, Herston, QLD, Australia;School of Medicine, University of Queensland, Queensland, Australia;Malaria Biology Laboratory, Queensland Institute of Medical Research, 300 Herston Rd, 4006, Herston, QLD, Australia;School of Molecular and Microbial Sciences, University of Queensland, Queensland, Australia;

关键词: Plasmodium falciparum;    Malaria;    Gametocyte;   

DOI  :  10.1186/1475-2875-12-134

 received in 2012-12-11, accepted in 2013-04-12,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundThe production of gametocytes is essential for transmission of malaria parasites from the mammalian host to the mosquito vector. However the process by which the asexual blood-stage parasite undergoes commitment to sexual development is not well understood. This process is known to be sensitive to environmental stimuli and it has been suggested that a G protein dependent system may mediate the switch, but there is little evidence that the Plasmodium falciparum genome encodes heterotrimeric G proteins. Previous studies have indicated that the malaria parasite can interact with endogenous erythrocyte G proteins, and other components of the cyclic nucleotide pathway have been identified in P. falciparum. Also, the polypeptide cholera toxin, which induces commitment to gametocytogenesis is known to catalyze the ADP-ribosylation of the αs class of heterotrimeric G protein α subunits in mammalian systems has been reported to detect a number of Gα subunits in P. falciparum- infected red cells.MethodsCholera toxin and Mas 7 (a structural analogue of Mastoparan) were used to assess the role played by putative G protein signalling in the commitment process, both are reported to interact with different components of classical Gαs and Gαi/o signalling pathways. Their ability to induce gametocyte production in the transgenic P. falciparum line Pfs16-GFP was determined and downstream effects on the secondary messenger cAMP measured.ResultsTreatment of parasite cultures with either cholera toxin or MAS 7 resulted in increased gametocyte production, but only treatment with MAS 7 resulted in a significant increase in cAMP levels. This indicates that MAS 7 acts either directly or indirectly on the P. falciparum adenylyl cyclase.ConclusionThe observation that cholera toxin treatment did not affect cAMP levels indicates that while addition of cholera toxin does increase gametocytogenesis the method by which it induces increased commitment is not immediately obvious, except that is unlikely to be via heterotrimeric G proteins.

【 授权许可】

Unknown   
© Peatey et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.