Plasticity between MyoC- and MyoA-glideosomes: an example of functional compensation in Toxoplasma gondii invasion.
The glideosome is an actomyosin-based machinery that powers motility in Apicomplexa and participates in host cell invasion and egress from infected cells. The central component of the glideosome, myosin A (MyoA), is a motor recruited at the pellicle by the acylated gliding-associated protein GAP45. In Toxoplasma gondii, GAP45 also contributes to the cohesion of the pellicle, composed of the inner membrane complex (IMC) and the plasma membrane, during motor traction. GAP70 was previously identified as a paralog of GAP45 that is tailored to recruit MyoA at the apical cap in the coccidian subgroup of the Apicomplexa. A third member of this family, GAP80, is demonstrated here to assemble a new glideosome, which recruits the class XIV myosin C (MyoC) at the basal polar ring. MyoC shares the same myosin light chains as MyoA and also interacts with the integral IMC proteins GAP50 and GAP40. Moreover, a central component of this complex, the IMC-associated protein 1 (IAP1), acts as the key determinant for the restricted localization of MyoC to the posterior pole. Deletion of specific components of the MyoC-glideosome underscores the installation of compensatory mechanisms with components of the MyoA-glideosome. Conversely, removal of MyoA leads to the relocalization of MyoC along the pellicle and at the apical cap that accounts for residual invasion. The two glideosomes exhibit a considerable level of plasticity to ensure parasite survival.
Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland.
Karine
K
Frénal
Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland.
Jean-Baptiste
JB
Marq
Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland.
Damien
D
Jacot
Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland.
Valérie
V
Polonais
Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland.
Dominique
D
Soldati-Favre
D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement; D017930:Genes, Reporter; D006790:Host-Parasite Interactions; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000378:metabolism; D018994:Myosin Light Chains / Q000378:metabolism; D009218:Myosins / Q000235:genetics / Q000378:metabolism*; D024507:Nonmuscle Myosin Type IIA / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D014122:Toxoplasma / Q000235:genetics / Q000378:metabolism*; D014123:Toxoplasmosis / Q000469:parasitology*
D008565:Membrane Proteins; D046912:Multiprotein Complexes; D018994:Myosin Light Chains; D015800:Protozoan Proteins; C509918:glideosome-associated protein 45, Plasmodium falciparum; D024507:Nonmuscle Myosin Type IIA; D009218:Myosins