title: Comparative Plasmodium gene overexpression reveals distinct perturbation of sporozoite transmission by profilin.
abstract: Plasmodium relies on actin-based motility to migrate from the site of infection and invade target cells. Using a substrate-dependent gliding locomotion, sporozoites are able to move at fast speed (1-3 μm/s). This motility relies on a minimal set of actin regulatory proteins and occurs in the absence of detectable filamentous actin (F-actin). Here we report an overexpression strategy to investigate whether perturbations of F-actin steady-state levels affect gliding locomotion and host invasion. We selected two vital Plasmodium berghei G-actin-binding proteins, C-CAP and profilin, in combination with three stage-specific promoters and mapped the phenotypes afforded by overexpression in all three extracellular motile stages. We show that in merozoites and ookinetes, additional expression does not impair life cycle progression. In marked contrast, overexpression of C-CAP and profilin in sporozoites impairs circular gliding motility and salivary gland invasion. The propensity for productive motility correlates with actin accumulation at the parasite tip, as revealed by combinations of an actin-stabilizing drug and transgenic parasites. Strong expression of profilin, but not C-CAP, resulted in complete life cycle arrest. Comparative overexpression is an alternative experimental genetic strategy to study essential genes and reveals effects of regulatory imbalances that are not uncovered from deletion-mutant phenotyping.
authors.affiliation: Parasitology Unit, Max Planck Institute for Infection Biology, 10117 Berlin, Germany Infectious Diseases Interdisciplinary Research Group, Singapore-Massachusetts Institute of Technology Alliance for Research and Technology, 138602 Singapore yuko@smart.mit.edu.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Parasitology Unit, Max Planck Institute for Infection Biology, 10117 Berlin, Germany School of BioSciences, University of Melbourne, Parkville, 3010 Victoria, Australia.
authors.forename: Marion
authors.initials: M
authors.lastname: Hliscs
authors.affiliation: Parasitology Unit, Max Planck Institute for Infection Biology, 10117 Berlin, Germany Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: Josefine
authors.initials: J
authors.lastname: Dunst
authors.affiliation: Imaging Unit, Max Planck Institute for Infection Biology, 10117 Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Goosmann
authors.affiliation: Imaging Unit, Max Planck Institute for Infection Biology, 10117 Berlin, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Brinkmann
authors.affiliation: Parasitology Unit, Max Planck Institute for Infection Biology, 10117 Berlin, Germany Departamento de Microbiologia, Immunologia e Parasitologia, Universidade Federal de São Paulo, 04039-032 São Paulo, Brazil.
authors.forename: Georgina N
authors.initials: GN
authors.lastname: Montagna
authors.affiliation: Parasitology Unit, Max Planck Institute for Infection Biology, 10117 Berlin, Germany Institute of Biology, Humboldt University, 10117 Berlin, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Matuschewski
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000818:Animals; D000852:Anopheles / Q000469:parasitology; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation; D051379:Mice; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins / Q000378:metabolism; D010961:Plasmodium / Q000235:genetics* / Q000378:metabolism*; D010962:Plasmodium berghei / Q000235:genetics / Q000378:metabolism; D051304:Profilins / Q000378:metabolism*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D034101:Sporozoites / Q000378:metabolism / Q000502:physiology
chemical_list: D000199:Actins; D008840:Microfilament Proteins; D051304:Profilins; D015800:Protozoan Proteins