Wednesday, September 11, 2013

The Toxoplasma gondii calcium-dependent protein kinase 7 is involved in early steps of parasite division and is crucial for parasite survival

2013 Aug 23. doi: 10.1111/cmi.12186. [Epub ahead of print]

The Toxoplasma gondii calcium-dependent protein kinase 7 is involved in early steps of parasite division and is crucial for parasite survival

Source

Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS, Université de Montpellier I et II, Montpellier, France.

Abstract

Apicomplexan parasites express various calcium-dependent protein kinases (CDPKs), and some of them play essential roles in invasion and egress. Five of the six CDPKs conserved in most Apicomplexa have been studied at the molecular and cellular levels in Plasmodium species and/or in Toxoplasma gondii parasites, but the function of CDPK7 was so far uncharacterized. In T. gondii, during intracellular replication, two parasites are formed within a mother cell through a unique process called endodyogeny. Here we demonstrate that the knock-down of CDPK7 protein in T. gondii results in pronounced defects in parasite division and a major growth deficiency, while it is dispensable for motility, egress and microneme exocytosis. In cdpk7-depleted parasites, the overall DNA content was not impaired, but the polarity of daughter cells budding and the fate of several subcellular structures or proteins involved in cell division were affected, such as the centrosomes and the kinetochore. Overall, our data suggest that CDPK7 is crucial for proper maintenance of centrosome integrity required for the initiation of endodyogeny. Our findings provide a first insight into the probable role of calcium-dependent signalling in parasite multiplication, in addition to its more widely explored role in invasion and egress.
© 2013 John Wiley & Sons Ltd.
PMID:
24011186
[PubMed - as supplied by publisher]

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