Abstract The peptidyl-prolyl cis/trans isomerases (PPIases) Parvulin 14 (Par14) and Parvulin 17 (Par17) result from alternative transcription initiation of the PIN4 gene. Whereas Par14 is present in all metazoan, Par17 is only expressed in Hominidae. Par14 resides mainly within the cellular nucleus, while Par17 is translocated into mitochondria. Using photo-affinity labeling, cross-linking and mass spectrometry (MS) we identified binding partners for both enzymes from HeLa lysates and disentangled their cellular roles. Par14 is involved in biogenesis of ribonucleoprotein (RNP)-complexes, RNA processing and DNA repair. Its elongated isoform Par17 participates in protein transport/translocation and in cytoskeleton organization. Nuclear magnetic resonance (NMR) spectroscopy reveals that Par17 binds to β-actin with its N-terminal region, while both parvulins initiate actin polymerization depending on their PPIase activity as monitored by fluorescence spectroscopy. The knockdown (KD) of Par17 in HCT116 cells results in a defect in cell motility and migration.

中文翻译：

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通过二氮嗪介导的交联靶向 parvulin 相互作用物揭示了人 Par14/17 在肌动蛋白聚合中的细胞作用

摘要 肽基脯氨酰顺式/反式异构酶 (PPIases) Parvulin 14 (Par14) 和 Parvulin 17 (Par17) 由 PIN4 基因的选择性转录起始产生。Par14 存在于所有后生动物中，而 Par17 仅在人科中表达。Par14 主要位于细胞核内，而 Par17 易位到线粒体中。使用光亲和标记、交联和质谱 (MS)，我们从 HeLa 裂解物中鉴定了两种酶的结合伙伴，并解开了它们的细胞作用。Par14 参与核糖核蛋白 (RNP) 复合物的生物发生、RNA 加工和 DNA 修复。其延长的同种型 Par17 参与蛋白质转运/易位和细胞骨架组织。核磁共振 (NMR) 光谱显示 Par17 与 β-肌动蛋白的 N 端区域结合，而两种 parvulins 都根据荧光光谱监测的 PPIase 活性启动肌动蛋白聚合。HCT116 细胞中 Par17 的敲低 (KD) 导致细胞运动和迁移缺陷。