title: Actin dynamics is controlled by a casein kinase II and phosphatase 2C interplay on Toxoplasma gondii Toxofilin.
abstract: Actin polymerization in Apicomplexa protozoa is central to parasite motility and host cell invasion. Toxofilin has been characterized as a protein that sequesters actin monomers and caps actin filaments in Toxoplasma gondii. Herein, we show that Toxofilin properties in vivo as in vitro depend on its phosphorylation. We identify a novel parasitic type 2C phosphatase that binds the Toxofilin/G-actin complex and a casein kinase II-like activity in the cytosol, both of which modulate the phosphorylation status of Toxofilin serine53. The interplay of these two molecules controls Toxofilin binding of G-actin as well as actin dynamics in vivo. Such functional interactions should play a major role in actin sequestration, a central feature of actin dynamics in Apicomplexa that underlies the spectacular speed and nature of parasite gliding motility.
authors.affiliation: Departement des Maladies Infectieuses, Centre National de la Recherche Scientifique Unité Mixte Recherche 8104, Institut Cochin, 75014 Paris, France.
authors.forename: Violaine
authors.initials: V
authors.lastname: Delorme
authors.forename: Xavier
authors.initials: X
authors.lastname: Cayla
authors.forename: Grazyna
authors.initials: G
authors.lastname: Faure
authors.forename: Alphonse
authors.initials: A
authors.lastname: Garcia
authors.forename: Isabelle
authors.initials: I
authors.lastname: Tardieux
mesh_terms: D051344:Actin Capping Proteins; D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D047390:Casein Kinase II; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008840:Microfilament Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015800:Protozoan Proteins; D016415:Sequence Alignment; D012694:Serine / Q000378:metabolism; D014122:Toxoplasma / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism
chemical_list: D051344:Actin Capping Proteins; D000199:Actins; D004791:Enzyme Inhibitors; D008840:Microfilament Proteins; D015800:Protozoan Proteins; C406004:toxofilin protein, Toxoplasma gondii; D012694:Serine; D004004:Dichlororibofuranosylbenzimidazole; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D010749:Phosphoprotein Phosphatases