Analysis of the phosphatydilinositol mediated lipid signal which involved in phagocytosis of the enteric protozoan parasite Entamoeba histolytica

在我们之前的研究中，我们发现磷脂酰肌醇3-磷酸在肠道原虫组织溶解内阿米巴的吞噬和吞噬小体成熟过程中起着重要的作用。在本研究中，我们试图弄清脂质介质对吞噬小体成熟的信号转导作用。因此，我们发现了一种新的受体分子，它参与了水解酶从内质网到溶酶体或吞噬体的运输，并对其功能进行了表征。半胱氨酸蛋白酶结合蛋白家族1(CPBF1)是一种半胱氨酸蛋白酶结合蛋白，在溶组乳杆菌基因组中有11个家族基因。其中至少有4个与溶酶体水解酶结合，我们在本研究中对CPBF8进行了鉴定。这表明这些家族分子共享它们的配体，并参与溶酶体的运输。在酵母或哺乳动物中，存在参与内质网向溶酶体转运的受体，即MPR、VPS10p/sortilin。CPBF是这些分子的功能同系物，但这是参与这一过程的家族分子的第一个例子。

In our previous study, we found the important role of phosphatidylinositol 3-phosphate during phagocytosis and phagosome maturation in enteric protozoan parasite Entamoeba histolytica. In this study we try to figure out the signaling from lipid mediator on phagosome maturation. As a result, we found a novel receptor molecule which involved in transport hydrolytic enzymes from endoplasmic reticulum to lysosomes or phagosomes and characterize their function. Cystene protease binding protein family 1(CPBF1) is identified as a binding protein of cysteine protease and there are 11 familial genes encorded in E. histolytica genome. At least 4 of them are bind to lysosomal hydrolase and we characterize CPBF8 in this study. It is suggests that these family molecules share their ligands and involved in lysosomal trafficking. In yeast or mammals there are receptors involved in ER to lysosome transport, i. e. MPR, VPS10p/Sortilin. CPBFs are functional homologue of these molecules but this is the first example the familial molecules involved in this process.