Identification of proteases that regulate erythrocyte rupture by the malaria parasite Plasmodium falciparum
Identification of proteases that regulate erythrocyte rupture by the malaria parasite Plasmodium falciparum
复制标题
DOI：
10.1038/nchembio.70
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发表时间：
2008-03-01
影响因子：
14.8
通讯作者：
Bogyo, Matthew
中科院分区：
文献类型：
--
作者：
Arastu-Kapur, Shirin;Ponder, Elizabeth L.;Bogyo, Matthew
新复制的恶性疟原虫通过多种蛋白水解酶介导的严格调控过程从宿主红细胞中逃逸。然而，特异性蛋白酶的鉴定一直具有挑战性。我们在这里描述了一种正向化学遗传筛选，使用高度集中的1200多种共价丝氨酸和半胱氨酸蛋白酶抑制剂文库来鉴定阻断恶性疟原虫宿主细胞破裂的化合物。通过文库筛选，我们确定枯草杆菌家族丝氨酸蛋白酶PfSUB1和半胱氨酸蛋白酶二肽基肽酶3 （DPAP3）是这一过程的主要调节因子。抑制DPAP3和PfSUB1导致丝氨酸重复抗原（SERA）蛋白SERA5的蛋白水解过程阻滞，这与观察到的破裂阻滞有关。此外，DPAP3抑制降低了成熟PfSUB1的水平。这些结果表明，两种机制不同的蛋白酶调节下游底物的加工，这些底物是寄生虫从宿主红细胞有效释放所必需的。
Newly replicated Plasmodium falciparum parasites escape from host erythrocytes through a tightly regulated process that is mediated by multiple classes of proteolytic enzymes. However, the identification of specific proteases has been challenging. We describe here a forward chemical genetic screen using a highly focused library of more than 1,200 covalent serine and cysteine protease inhibitors to identify compounds that block host cell rupture by P. falciparum. Using hits from the library screen, we identified the subtilisin-family serine protease PfSUB1 and the cysteine protease dipeptidyl peptidase 3 (DPAP3) as primary regulators of this process. inhibition of both DPAP3 and PfSUB1 caused a block in proteolytic processing of the serine repeat antigen (SERA) protein SERA5 that correlated with the observed block in rupture. Furthermore, DPAP3 inhibition reduced the levels of mature PfSUB1. These results suggest that two mechanistically distinct proteases function to regulate processing of downstream substrates required for efficient release of parasites from host red blood cells.