Project description:Intracellular ATP is mainly produced by the glycolysis pathway in culture cells incubated with high-glucose medium, whereas ATP production is switched to the OXPHOS pathway by culturing with the no-glucose medium. To elucidate the potential function of PERK during activation of OXPHOS pathway, we perfomed RNA-sequencing analayais using wild-type and PERK-deficient HEK293 cells.
Project description:The area of mitochondria in differentiated brown adipocytes is dramatically increased compared with that in brown pre-adipocytes. The ATP production is switched from the glycolysis pathway to the OXPHOS pathway during brown adipocyte differentiation. Endoplasmic reticulum (ER) is surrounded by mitochondria and the area of contact sites between mitochondria and the ER is increased. ER stress sensor PERK was phosphorylated during differentiation. To elucidate the mitochondria-ER crosstalk signaling mediated by PERK, RNA-sequencing analysis was performed using control siRNA- or PERK siRNA-transfected brown adipocytes.
Project description:In response to different cellular stressors, the ISR kinases, PERK, PKR, HRI and GCN2, activate downstream transcriptional programs. While the core ISR transcription program is well characterized, markers that are specific to each individual ISR kinase activation pathway are not known. To identify markers that are induced by PERK or GCN2, but not the other ISR kinases, we subjected WT, GCN2-/-, and PERK-/- MEFs to amino acid starvation (RPMI 1640 SILAC -Lys -Arg) or Thapsigargin (200nM) treatment for 6 hours to activate the GCN2 and PERK pathways, respectively and performed RNA sequencing.
Project description:Disruptions of the endoplasmic reticulum (ER) that perturb protein folding cause ER stress and elicit an unfolded protein response (UPR) that involves translational and transcriptional changes in gene expression aimed at expanding the ER processing capacity and alleviating cellular injury. Three ER stress sensors PERK, ATF6, and IRE1 implement the UPR. PERK phosphorylation of eIF2 during ER stress represses protein synthesis, which prevents further influx of ER client proteins, along with preferential translation of ATF4, a transcription activator of the integrated stress response. In this study we show that the PERK/eIF2α~P/ATF4 pathway is required not only for translational control, but also activation of ATF6 and its target genes. The PERK pathway facilitates both the synthesis of ATF6 and trafficking of ATF6 from the ER to the Golgi for intramembrane proteolysis and activation of ATF6. As a consequence, liver-specific depletion of PERK significantly reduces both the translational and transcriptional phases of the UPR, leading to reduced protein chaperone expression, disruptions of lipid metabolism, and enhanced apoptosis. These findings show that the regulatory networks of the UPR are fully integrated, and helps explain the diverse pathologies associated with loss of PERK. 14 gene expression arrays, 3 WT control arrays; 3 lsPERK control arrays; 4 WT Treated arrays; 4 lsPERK treated arrays. Comparison of gene expression profiles for treated vs control in wildtype and knock-out.
Project description:Disruptions of the endoplasmic reticulum (ER) that perturb protein folding cause ER stress and elicit an unfolded protein response (UPR) that involves translational and transcriptional changes in gene expression aimed at expanding the ER processing capacity and alleviating cellular injury. Three ER stress sensors PERK, ATF6, and IRE1 implement the UPR. PERK phosphorylation of eIF2 during ER stress represses protein synthesis, which prevents further influx of ER client proteins, along with preferential translation of ATF4, a transcription activator of the integrated stress response. In this study we show that the PERK/eIF2α~P/ATF4 pathway is required not only for translational control, but also activation of ATF6 and its target genes. The PERK pathway facilitates both the synthesis of ATF6 and trafficking of ATF6 from the ER to the Golgi for intramembrane proteolysis and activation of ATF6. As a consequence, liver-specific depletion of PERK significantly reduces both the translational and transcriptional phases of the UPR, leading to reduced protein chaperone expression, disruptions of lipid metabolism, and enhanced apoptosis. These findings show that the regulatory networks of the UPR are fully integrated, and helps explain the diverse pathologies associated with loss of PERK.
Project description:Here we report that the Th2 cytokine IL-4 and the tumor microenvironment activated protein kinase RNA-like ER kinase (PERK) ER stress signaling cascade to promote immunosuppressive M2 activation and proliferation. Lacking PERK signaling impeded mitochondrial respiration and lipid oxidation critical for M2 macrophages. In addition, PERK activation mediated the upregulation of PSAT1 and serine biosynthesis via the downstream transcription factor ATF4.
Project description:Recently, it is reported that multiple signaling pathways are involved with the pathogenesis of PPCM. Here, we show that PERK kockout affect these pathways in postpartum period.