FIGURE 4.

Western blot verification of proteomics results and evaluation of aggregation-induced eIF2 pathway activation. (a) During integrated stress response (ISR), eIF2 pathway kinases phosphorylate the alpha subunit which halts protein synthetize and leads to increased autophagy. HRI: the eIF2α kinase heme-regulated inhibitor; PKR: the IFN-induced double-stranded RNA-dependent protein kinase; PERK: protein kinase RNA-like endoplasmic reticulum kinase; GCN2: general control nonderepressible 2, a serine/threonine-protein kinase that senses amino acid deficiency through binding to uncharged transfer RNA. GADD34: the growth arrest and DNA-damaged protein 34, a stress-induced regulatory subunit of the serine/threonine-protein phosphatase 1. (b) Western blot images of PERK, an eIF2 kinase, and the ratio of activation. (c) Western blot readings for activated and total eIF2α along with the ratio of which reflects ISR-based activity. (d) Western blot and densitometry readings of downstream transcription targets of p-eIF2α. Data represent the mean of at least three independent determinations; errors represent the standard error in the mean. eIF2, eukaryotic initiation factor 2. *p < .05