Eukaryotic Translation Factors Resided in PSI-induced Inclusions in PC12 / 中国生物化学与分子生物学报

ABSTRACT

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.