title: The Flagellar Arginine Kinase in Trypanosoma brucei Is Important for Infection in Tsetse Flies.
abstract: African trypanosomes are flagellated parasites that cause sleeping sickness. Parasites are transmitted from one mammalian host to another by the bite of a tsetse fly. Trypanosoma brucei possesses three different genes for arginine kinase (AK) including one (AK3) that encodes a protein localised to the flagellum. AK3 is characterised by the presence of a unique amino-terminal insertion that specifies flagellar targeting. We show here a phylogenetic analysis revealing that flagellar AK arose in two independent duplication events in T. brucei and T. congolense, the two species of African trypanosomes that infect the tsetse midgut. In T. brucei, AK3 is detected in all stages of parasite development in the fly (in the midgut and in the salivary glands) as well as in bloodstream cells, but with predominance at insect stages. Genetic knockout leads to a slight reduction in motility and impairs parasite infectivity towards tsetse flies in single and competition experiments, both phenotypes being reverted upon expression of an epitope-tagged version of AK3. We speculate that this flagellar arginine kinase is important for T. brucei infection of tsetse, especially in the context of mixed infections and that its flagellar targeting relies on a system equivalent to that discovered for calflagins, a family of trypanosome flagellum calcium binding proteins.
authors.affiliation: Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, 25 Rue du Docteur Roux, 75015, Paris, France.
authors.forename: Cher-Pheng
authors.initials: CP
authors.lastname: Ooi
authors.affiliation: Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, 25 Rue du Docteur Roux, 75015, Paris, France.
authors.forename: Brice
authors.initials: B
authors.lastname: Rotureau
authors.affiliation: Molecular Biology of Gene in Extremophiles Unit, Department of Microbiology, Institut Pasteur, 25 rue du Docteur Roux, 75015, Paris, France.
authors.forename: Simonetta
authors.initials: S
authors.lastname: Gribaldo
authors.affiliation: Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, 25 Rue du Docteur Roux, 75015, Paris, France.
authors.forename: Christina
authors.initials: C
authors.lastname: Georgikou
authors.affiliation: Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, 25 Rue du Docteur Roux, 75015, Paris, France.
authors.forename: Daria
authors.initials: D
authors.lastname: Julkowska
authors.affiliation: Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, 25 Rue du Docteur Roux, 75015, Paris, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Blisnick
authors.affiliation: Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, 25 Rue du Docteur Roux, 75015, Paris, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Perrot
authors.affiliation: Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, 25 Rue du Docteur Roux, 75015, Paris, France.
authors.forename: Ines
authors.initials: I
authors.lastname: Subota
authors.affiliation: Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, 25 Rue du Docteur Roux, 75015, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Bastin
mesh_terms: D000818:Animals; D001122:Arginine Kinase / Q000235:genetics / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005407:Flagella / Q000235:genetics / Q000378:metabolism; D008018:Life Cycle Stages / Q000502:physiology*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000201:enzymology*; D014370:Tsetse Flies / Q000469:parasitology*
chemical_list: D002135:Calcium-Binding Proteins; D015800:Protozoan Proteins; D001122:Arginine Kinase