Disruption of Toxoplasma hsp20 gene alters invasion, gliding motility and replication

COCERES VM,CORVI M,GARRISON , ARRIZABALAGA , AND ANGEL

Otawa

Congreso; International Congress on Toxoplasmosis 2011; 2011

Toxoplasma gondii Hsp20 is an inner membrane complex (IMC) functional chaperone, facing the plasma membrane as any other protein belonging to the glideosome.  Hsp20 is incorporated late in the IMC of budding cells during parasite replication. In order to determine the biological role of Hsp20, the hsp20 gene was replaced by thehxgprt gene in RH∆Ku80 parental cells generating Hsp20KO parasites.The Hsp20KO parasitespresented an alteration of the gliding trace, presenting a predominant circular motion in comparison to parental cells.Also the knock out presented a delay in host cell invasion and a lower invasion rate when compared to both the parental cell and a complemented null mutant expressing Hsp20 fused to YFP (Hsp20YFP). During replication, near 25% of parasites presented defects in nucleus segregation andthe Hsp20KO growth rate was significantly lower than parental parasites.In concordance with these alterations thirty two percent of extracellular Hsp20KO parasites showed inconclusive replication process too in comparison with parental cells. In conclusion, Hsp20 is not essential for tissue culture growth but it rather could be modulating some process during parasite gliding, invasion and replication.