scholarly journals Three F-actin assembly centers regulate organelle inheritance, cell-cell communication and motility in Toxoplasma gondii

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Nicolò Tosetti ◽  
Nicolas Dos Santos Pacheco ◽  
Dominique Soldati-Favre ◽  
Damien Jacot
Keyword(s):  
Protein Kinase ◽  
Toxoplasma Gondii ◽  
Actin Polymerization ◽  
Cell Communication ◽  
Residual Body ◽  
Filamentous Actin ◽  
Calcium Dependent ◽  
Actin Regulatory Proteins ◽  
Parasite Motility ◽  
Cell Cell

Toxoplasma gondii possesses a limited set of actin-regulatory proteins and relies on only three formins (FRMs) to nucleate and polymerize actin. We combined filamentous actin (F-actin) chromobodies with gene disruption to assign specific populations of actin filaments to individual formins. FRM2 localizes to the apical juxtanuclear region and participates in apicoplast inheritance. Restricted to the residual body, FRM3 maintains the intravacuolar cell-cell communication. Conoidal FRM1 initiates a flux of F-actin crucial for motility, invasion and egress. This flux depends on myosins A and H and is controlled by phosphorylation via PKG (protein kinase G) and CDPK1 (calcium-dependent protein kinase 1) and by methylation via AKMT (apical lysine methyltransferase). This flux is independent of microneme secretion and persists in the absence of the glideosome-associated connector (GAC). This study offers a coherent model of the key players controlling actin polymerization, stressing the importance of well-timed post-translational modifications to power parasite motility.

scholarly journals A Novel Calcium-Dependent Protein Kinase 1 Inhibitor Potently Prevents Toxoplasma gondii Transmission to Foetuses in Mouse

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4203
Author(s):  
Héloïse Débare ◽  
Nathalie Moiré ◽  
Firmin Baron ◽  
Louis Lantier ◽  
Bruno Héraut ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Toxoplasma Gondii ◽  
Intraperitoneal Administration ◽  
Congenital Toxoplasmosis ◽  
Parasite Burden ◽  
Oral Route ◽  
Dependent Protein Kinase ◽  
Calcium Dependent ◽  
Dependent Protein ◽  
Calcium Dependent Protein Kinase

Treatments currently used to prevent congenital toxoplasmosis are non-specific of Toxoplasma gondii and have grievous side effects. To develop a more specific and less toxic drug, we have designed SP230, an imidazo[1,2-b]pyridazine salt targeting the Toxoplasma gondii calcium-dependent protein kinase 1 (TgCDPK1) and active against acute toxoplasmosis in mice. Efficiency of SP230 to inhibit foetal transmission of the parasite was evaluated in a mouse model of congenital toxoplasmosis. Swiss mice were infected at mid-pregnancy with tachyzoites or cysts of the ME49 strain of T. gondii by intraperitoneal and oral route, respectively, and treated with SP230 at 50 mg/kg for 5 days by the same routes. Parasite burden in organs of dams and in foetuses was measured by quantitative PCR. Intraperitoneal administration of SP230 drastically reduced the number of parasites (more than 97% of reduction) in the brain and lungs of dams, and led to a reduction of 66% of parasite burden in foetuses. Oral administration of SP230 was particularly efficient with 97% of reduction of parasite burdens in foetuses. SP230 did not impact number and weight of offspring in our conditions. This inhibitor of TgCDPK1 is a promising candidate for the development of alternative therapeutics to treat infected pregnant women.

scholarly journals Optimizing Small Molecule Inhibitors of Calcium-Dependent Protein Kinase 1 to Prevent Infection by Toxoplasma gondii

2013 ◽  
Vol 56 (7) ◽  
pp. 3068-3077 ◽  
Author(s):  
Sebastian Lourido ◽  
Chao Zhang ◽  
Michael S. Lopez ◽  
Keliang Tang ◽  
Jennifer Barks ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Toxoplasma Gondii ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Dependent Protein Kinase ◽  
Calcium Dependent ◽  
Dependent Protein ◽  
Calcium Dependent Protein Kinase

Correction of cell–cell communication defect by introduction of a protein kinase into mutant cells

Nature ◽  
1983 ◽  
Vol 305 (5933) ◽  
pp. 433-435 ◽  
Author(s):  
Erik C. Wiener ◽  
Werner R. Loewenstein
Keyword(s):  
Protein Kinase ◽  
Cell Communication ◽  
Mutant Cells ◽  
Cell Cell

scholarly journals Myosin-dependent cell-cell communication controls synchronicity of division in acute and chronic stages of Toxoplasma gondii

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Karine Frénal ◽  
Damien Jacot ◽  
Pierre-Mehdi Hammoudi ◽  
Arnault Graindorge ◽  
Bohumil Maco ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Cell Communication ◽  
Dependent Cell ◽  
Cell Cell

scholarly journals Actin Dynamics Is Controlled by a Casein Kinase II and Phosphatase 2C Interplay on Toxoplasma gondii Toxofilin

2003 ◽  
Vol 14 (5) ◽  
pp. 1900-1912 ◽  
Author(s):  
Violaine Delorme ◽  
Xavier Cayla ◽  
Grazyna Faure ◽  
Alphonse Garcia ◽  
Isabelle Tardieux
Keyword(s):  
Toxoplasma Gondii ◽  
Actin Polymerization ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Gliding Motility ◽  
Actin Dynamics ◽  
Central Feature ◽  
Parasite Motility

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.

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