Expression of a Malarial Hsp70 Improves Defects in Chaperone-Dependent Activities in ssa1 Mutant Yeast
Expression of a Malarial Hsp70 Improves Defects in Chaperone-Dependent Activities in ssa1 Mutant Yeast
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DOI：
10.1371/journal.pone.0020047
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发表时间：
2011-05-19
期刊：
影响因子：
3.7
通讯作者：
Brodsky, Jeffrey L.
中科院分区：
文献类型：
--
作者：
Bell, Samantha L.;Chiang, Annette N.;Brodsky, Jeffrey L.
恶性疟原虫引起最致命的疟疾形式，并编码大量的分子伴侣。由于寄生虫在其生命周期中遇到完全不同的环境，因此这种伴侣蛋白集合的许多成员可能对恶性疟原虫的生存至关重要。因此，疟原虫分子伴侣代表了新的治疗靶点，但为了建立任何开发的治疗剂的作用机制，确定这些分子伴侣的功能至关重要。为此，我们报告了恶性疟原虫胞质伴侣PfHsp 70 -1的酵母表达系统的开发。我们发现，PfHsp 70 -1修复酵母菌株缺乏两个主要的胞质Hsp 70，SSA 1和SSA 2，并在菌株窝藏温度敏感的SSA 1等位基因的突变生长表型。PfHsp 70 -1还支持分子伴侣依赖的过程，如蛋白质易位和ER相关的降解，并改善氧化应激的毒性作用。通过将工程形式的PfHsp 70 -1引入突变菌株中，我们发现拯救需要PfHsp 70 -1 ATP酶活性。总之，我们得出结论，酵母可以增选迅速发现疟疾分子伴侣介导的特定细胞活动。
Plasmodium falciparum causes the most virulent form of malaria and encodes a large number of molecular chaperones. Because the parasite encounters radically different environments during its lifecycle, many members of this chaperone ensemble may be essential for P. falciparum survival. Therefore, Plasmodium chaperones represent novel therapeutic targets, but to establish the mechanism of action of any developed therapeutics, it is critical to ascertain the functions of these chaperones. To this end, we report the development of a yeast expression system for PfHsp70-1, a P. falciparum cytoplasmic chaperone. We found that PfHsp70-1 repairs mutant growth phenotypes in yeast strains lacking the two primary cytosolic Hsp70s, SSA1 and SSA2, and in strains harboring a temperature sensitive SSA1 allele. PfHsp70-1 also supported chaperone-dependent processes such as protein translocation and ER associated degradation, and ameliorated the toxic effects of oxidative stress. By introducing engineered forms of PfHsp70-1 into the mutant strains, we discovered that rescue requires PfHsp70-1 ATPase activity. Together, we conclude that yeast can be co-opted to rapidly uncover specific cellular activities mediated by malarial chaperones.