Secretion of a malarial histidine-rich protein (Pf HRP II) from Plasmodium falciparum-infected erythrocytes.
Secretion of a malarial histidine-rich protein (Pf HRP II) from Plasmodium falciparum-infected erythrocytes.
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DOI：
10.1083/jcb.103.4.1269
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发表时间：
1986-10
期刊：
影响因子：
--
通讯作者：
Taylor DW
中科院分区：
文献类型：
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作者：
Howard RJ;Uni S;Aikawa M;Aley SB;Leech JH;Lew AM;Wellems TE;Rener J;Taylor DW
恶性疟原虫感染的红细胞（IRBC）合成几种富含组氨酸的蛋白质（HRP），这些蛋白质积累高水平的[3H]组氨酸，但积累极低水平的氨基酸，如[3H]异亮氨酸或[35S]甲硫氨酸。我们制备了一种单克隆抗体，该抗体与这些HRP（PfHRP II）之一发生特异性反应，并研究了寄生虫细胞内生长过程中这种蛋白质的定位和合成。对于结节阳性的马来亚恶性疟原虫坎普株，单克隆抗体鉴定出多条蛋白条带，主要种类为Mr 72，000和69，000。Pf HRP II的合成始于未成熟的寄生虫（环），并持续通过滋养体阶段。从完整IRBC的培养上清液中回收作为水溶性蛋白的Pf HRP II的Mr 72，000条带，但不是多重峰的快速移动条带。约50%的总[3H]组氨酸放射性纳入Mr 72，000带之间的2和24小时的培养是细胞外。免疫荧光和cryothin切片免疫电子显微镜定位PF HRP II的几个细胞室，包括寄生虫的细胞质，作为集中的“包”在宿主红细胞的细胞质和IRBC膜。我们的研究结果提供了证据的一个分泌的疟疾蛋白从寄生虫通过几个膜和宿主细胞质的细胞内运输路线。
Plasmodium falciparum-infected erythrocytes (IRBCs) synthesize several histidine-rich proteins (HRPs) that accumulate high levels of [3H]histidine but very low levels of amino acids such as [3H]isoleucine or [35S]methionine. We prepared a monoclonal antibody which reacts specifically with one of these HRPs (Pf HRP II) and studied the location and synthesis of this protein during the parasite's intracellular growth. With the knob-positive Malayan Camp strain of P. falciparum, the monoclonal antibody identified a multiplet of protein bands with major species at Mr 72,000 and 69,000. Pf HRP II synthesis began with immature parasites (rings) and continued through the trophozoite stage. The Mr 72,000 band of Pf HRP II, but not the faster moving bands of the multiplet, was recovered as a water-soluble protein from the culture supernatant of intact IRBCs. Approximately 50% of the total [3H]histidine radioactivity incorporated into the Mr 72,000 band was extracellular between 2 and 24 h of culture. Immunofluorescence and cryothin-section immunoelectron microscopy localized Pf HRP II to several cell compartments including the parasite cytoplasm, as concentrated "packets" in the host erythrocyte cytoplasm and at the IRBC membrane. Our results provide evidence for an intracellular route of transport for a secreted malarial protein from the parasite through several membranes and the host cell cytoplasm.