Tzen M, Benarous R, Dupouy-Camet J, Roisin M P
Institut Cochin, Département des Maladies infectieuses, Paris, France.
Parasite. 2007 Jun;14(2):141-7. doi: 10.1051/parasite/2007142141.
Toxoplasma gondii is an obligate intracellular parasite that infects all types of cells in humans. A family of calcium-dependent protein kinases (CDPKs), previously identified as important in the development of plants and protists, was recently shown to play a role in the infectivity of apicomplexans, and in motility and host cell invasion in particular. We report here the isolation of a new calcium-dependent protein kinase gene from the human toxoplasmosis parasite, Toxoplasma gondii. The gene consists of 12 exons. The encoded protein, TgCDPK4, consists of the four characteristic domains of members of the CDPK family and is most similar to PfCDPK2 from Plasmodium falciparum. We measured TgCDPK4 activity, induced by calcium influx, using a kinase assay. A calcium chelator (EGTA) inhibited this activity. These findings provide evidence of signal transduction involving members of the CDPK family in T. gondii.
刚地弓形虫是一种专性细胞内寄生虫，可感染人类的所有类型细胞。一个钙依赖性蛋白激酶（CDPK）家族，先前被确定在植物和原生生物的发育中很重要，最近被证明在顶复门寄生虫的感染性中起作用，特别是在运动性和宿主细胞入侵方面。我们在此报告从人类弓形虫病寄生虫刚地弓形虫中分离出一个新的钙依赖性蛋白激酶基因。该基因由12个外显子组成。编码的蛋白TgCDPK4由CDPK家族成员的四个特征结构域组成，与恶性疟原虫的PfCDPK2最为相似。我们使用激酶测定法测量了钙内流诱导的TgCDPK4活性。一种钙螯合剂（乙二醇双乙醚二胺四乙酸）抑制了这种活性。这些发现提供了刚地弓形虫中涉及CDPK家族成员的信号转导的证据。
