Saccharomyces cerevisiae Fpr1 functions as a chaperone to inhibit protein aggregation
Saccharomyces cerevisiae Fpr1 functions as a chaperone to inhibit protein aggregation
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DOI：
10.1016/j.ijbiomac.2021.09.046
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发表时间：
2021-09-17
影响因子：
8.2
通讯作者：
Roy, Ipsita
中科院分区：
文献类型：
--
作者：
Das, Eshita;Prasad, Shivcharan;Roy, Ipsita
肽基脯氨酰异构酶 (PPIase) 通过催化肽基脯氨酰键的顺式/反式异构化来加速蛋白质折叠的限速步骤。较大的 PPI 酶已被证明是多结构域蛋白质，具有除含脯氨酸肽键异构化以外的功能。最近，一些较小的 PPI 酶也因其稳定折叠中间体的能力而被描述。酵母 Fpr1（FK506 敏感脯氨酸旋转异构酶）是哺乳动物脯氨酰异构酶 FKBP12（12 kDa 的 FK506 结合蛋白）的同源物。其稳定应激细胞蛋白的能力尚未被报道。我们之前曾报道过暴露于蛋白毒性应激条件下的酵母细胞中 Fpr1 的上调。在这项工作中，我们证明酵母 Fpr1 表现出蛋白质稳态网络一般伴侣的典型特征。与亲本酵母细胞相比，Fpr1 缺失的突变亨廷顿片段的聚集更高。 Fpr1 的过度表达通过减少寡聚体的数量并将聚集途径转向形成洗涤剂可溶性物质来减少蛋白质聚集。这与这些细胞的较高存活率密切相关。纯化的具有酶活性的酵母Fpr1能够在体外以浓度依赖性方式抑制突变亨廷顿片段和荧光素酶的聚集；表明 Fpr1 具有直接的聚集抑制作用。酵母 Fpr1 的过度表达能够保护大肠杆菌细胞免受热冲击。这项工作确立了 Fpr1 在蛋白质折叠网络中的作用，并将用于鉴定疾病条件下的新型药理学先导化合物。
Peptidyl prolyl isomerases (PPIases) accelerate the rate limiting step of protein folding by catalyzing cis/trans isomerization of peptidyl prolyl bonds. The larger PPIases have been shown to be multi-domain proteins, with functions other than isomerization of the proline-containing peptide bond. Recently, a few smaller PPIases have also been described for their ability to stabilize folding intermediates. The yeast Fpr1 (FK506-sensitive proline rotamase) is a homologue of the mammalian prolyl isomerase FKBP12 (FK506-binding protein of 12 kDa). Its ability to stabilize stressed cellular proteins has not been reported yet. We had earlier reported upregulation of Fpr1 in yeast cells exposed to proteotoxic stress conditions. In this work, we show that yeast Fpr1 exhibits characteristics typical of a general chaperone of the proteostasis network. Aggregation of mutant huntingtin fragment was higher in Fpr1-deleted as compared to parental yeast cells. Overexpression of Fpr1 led to reduced protein aggregation by decreasing the amount of oligomers and diverting the aggregation pathway towards the formation of detergent-soluble species. This correlated well with higher survival of these cells. Purified and enzymatically active yeast Fpr1 was able to inhibit aggregation of mutant huntingtin fragment and luciferase in vitro in a concentration-dependent manner; suggesting a direct action for aggregation inhibitory action of Fpr1. Overexpression of yeast Fpr1 was able to protect E. coli cells against thermal shock. This work establishes the role of Fpr1 in the protein folding network and will be used for the identification of novel pharmacological leads in disease conditions.