PC12细胞的PSI诱导性包含体富集了真核细胞翻译因子

路易小体(Lewy body, LB)，位于神经细胞核周(perikaryon)的嗜酸性包含体(eosinophilic inclusion)，含有广泛的蛋白质组分，其中一部分是组成型蛋白质(consistent organization)，另外一部分则是选择型蛋白质(selective composition).为了在体外获得LB中未知蛋白质的新线索，通过人工合成蛋白酶体抑制剂PSI（proteasomal inhibitor, 10 μmol/L）作用PC 12细胞48 h,使其产生嗜酸性（staining for eosin）和抗α-synuclein阳性（immunostaining for α- synuclein）的PSI诱导性包含体（PSI-induced inclusion），通过成功的分级分离（fractionation）纯化了完整、纯净的包含体，通过有效的双向电泳（two-dimensional electrophoresis,2-DE）分离了包含体蛋白质，通过无偏差的基质辅助激光解析 离子化飞行时间质谱（matrix- assisted laser desorption/ionization time-of-flight massspectrometry,MALDI-TOF MS）鉴定了真核细胞翻译起始因子-3亚单位5（eukaryotic translation initiation factor 3 subunit 5, eIF-3ε）、真核细胞延伸因子-2（eukaryotic elongation factor 2, eEF-2）和线粒体延伸因子-Tu（mitochondrial elongation factor Tu, EF-Tumt）等真核细胞翻译因子(eukaryotic translation factors).这一结果提示,当蛋白酶体受到抑制时真核细胞翻译因子被富集到PSI诱导性包含体中，并且可能影响其形成过程.

Eukaryotic Translation Factors Resided in PSI-induced Inclusions in PC12

Lewy body (LB), an eosinophilic inclusion localized in the neuronal perikaryon, consists of a wide range of proteins, including the consistent organization and the selective composition. Treatment of PC12 cells with synthetic proteasome inhibitor (PSI) at 10 μmol/L for 48 hours induced the formation of inclusions, which were detected by eosin staining and immunostaining for α-synuclein. To investigate the potential new components of PSI-induced inclusions in vitro, pure intact inclusions were successfully obtained by fractionation and subjected to two-dimensional electrophoresis (2-DE) then analyzed with unequivocal matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Eukaryotic translation initiation factor 3 subunit 5 (eIF-3ε), eukaryotic elongation factor 2 (eEF-2) and mitochondrial elongation factor Tu (EF-Tumt) were identified. The results suggest that 3 eukaryotic translation factors recruited in PSI-induced inclusions may influence formation of the intermediate organelles following the inhibition of proteasomes.