Erythrocytic Stage-dependent Regulation of Oligomerization of Plasmodium Ribosomal Protein P2
Erythrocytic Stage-dependent Regulation of Oligomerization of Plasmodium Ribosomal Protein P2
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DOI：
10.1074/jbc.m112.384388
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发表时间：
2012-11-30
影响因子：
4.8
通讯作者：
Sharma, Shobhona
中科院分区：
文献类型：
--
作者：
Das, Sudipta;Sudarsan, Rajagopal;Sharma, Shobhona
真核60 S-核糖体柄由P0、P1和P2蛋白组成，它们以五聚体结构（P1（2）-P0-P2（2））缔合。恶性疟原虫蛋白P2（PfP 2）似乎发挥非核糖体的作用。在裂殖子侵入（PMI）后30 h，它被输出到感染的红细胞（IE）表面，伴随着广泛的寡聚化。在这里，我们提出了PfP 2的某些生物物理特性。重组P2（rPfP 2）蛋白显示SDS抗性寡聚化，这可以显着消除还原条件下。然而，即使当两个半胱氨酸残基都发生突变时，蛋白质也会继续寡聚化，并且从C-末端缺失多达40个氨基酸（aa）。P2的CD分析显示主要是α-螺旋和无规卷曲结构域。进一步研究了抗SDS和DTT的寡聚化，因为它在疟原虫中以发育特异性方式发生。在恶性疟原虫的同步红细胞培养物中，PfP 2蛋白在18和30 h PMI时作为核糖体复合物的一部分（类似于96 kDa）被检测到，并且是SDS敏感的。然而，在30小时时，还观察到大量>600 kDa的SDS敏感性聚集体。在30小时PMI，每种寄生虫，IE胞质溶胶和IE鬼含有60-80-kDa PfP 2复合物，其在SDS-PAGE上解析为单个65-kDa种类。四甲基罗丹明标记的rPfP 2蛋白表现出DTT-和SDS-抗性寡聚化时，与恶性疟原虫提取物处理，只有从24至36小时PMI，和多个蛋白质似乎需要这种寡聚化。了解PfP 2寡聚化的调节可能有助于阐明PfP 2向红细胞表面输出的新型结构-功能关系。
The eukaryotic 60 S-ribosomal stalk consists of P0, P1, and P2 proteins, which associate in a pentameric structure (P1(2)-P0-P2(2)). The Plasmodium falciparum protein P2 (PfP2) appears to play nonribosomal roles. It gets exported to the infected erythrocyte (IE) surface at 30 h post-merozoite invasion (PMI), concomitant with extensive oligomerization. Here we present certain biophysical properties of PfP2. Recombinant P2 (rPfP2) protein showed SDS-resistant oligomerization, which could be significantly abolished under reducing conditions. However, the protein continued to oligomerize even when both cysteine residues were mutated, and with up to 40 amino acids (aa) deleted from the C-terminal end. CD analysis of P2 showed largely alpha-helical and random coil domains. The SDS- and DTT-resistant oligomerization was studied further as it occurred in a development-specific manner in Plasmodium. In a synchronized erythrocytic culture of P. falciparum, the PfP2 protein was detected as part of the ribosomal complex (similar to 96 kDa) at 18 and 30 h PMI, and was SDS sensitive. However, at 30 h, large amounts of SDS-sensitive aggregates of >600 kDa were also seen. At 30 h PMI, each of the parasites, IE cytosol and IE ghost contained 60-80-kDa PfP2 complexes, which resolved to a single 65-kDa species on SDS-PAGE. Tetramethylrhodamine-labeled rPfP2 protein exhibited DTT- and SDS-resistant oligomerization when treated with P. falciparum parasite extracts only from 24 to 36 h PMI, and multiple proteins appeared to be required for this oligomerization. Understanding the regulation of oligomerization of PfP2 may help in the elucidation of the novel structure-function relationship in the export of PfP2 to the red cell surface.