A Toxoplasma type 2C serine-threonine phosphatase is involved in parasite growth in the mammalian host cell.
Toxoplasma gondii is a human protozoan parasite that belongs to the phylum of Apicomplexa and causes toxoplasmosis. As the other members of this phylum, T. gondii obligatory multiplies within a host cell by a peculiar type of mitosis that leads to daughter cell assembly within a mother cell. Although parasite growth and virulence have been linked for years, few molecules controlling mitosis have been yet identified and they include a couple of kinases but not the counteracting phosphatases. Here, we report that in contrast to other animal cells, type 2C is by far the major type of serine threonine phosphatase activity both in extracellular and in intracellular dividing parasites. Using wild type and transgenic parasites, we characterized the 37kDa TgPP2C molecule as an abundant cytoplasmic and nuclear enzyme with activity being under tight regulation. In addition, we showed that the increase in TgPP2C activity significantly affected parasite growth by impairing cytokinesis while nuclear division still occurred. This study supports for the first time that type 2C protein phosphatase is an important regulator of cell growth in T. gondii.
Jan
Gaelle
G
Institut Cochin, Université Paris Descartes, CNRS UMR 8104, Paris, France.
Delorme
Violaine
V
Saksouk
Nehmé
N
Abrivard
Marie
M
Gonzalez
Virginie
V
Cayla
Xavier
X
Hakimi
Mohamed-Ali
MA
Tardieux
Isabelle
I
D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000737:chemistry; D006801:Humans; D010749:Phosphoprotein Phosphatases / Q000032:analysis / Q000502:physiology*; D000071636:Protein Phosphatase 2C; D051381:Rats; D014122:Toxoplasma / Q000502:physiology*
D010749:Phosphoprotein Phosphatases; D000071636:Protein Phosphatase 2C