PERK-dependent regulation of IAP translation during ER stress

• Published in: Oncogene Vol. 28; no. 6; pp. 910 - 920
• Main Authors: Hamanaka, R B, Bobrovnikova-Marjon, E, Ji, X, Liebhaber, S A, Diehl, J A
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.02.2009; Nature Publishing Group
• Subjects: 1-Phosphatidylinositol 3-kinase; Ageing, cell death; AKT protein; Animals; Apoptosis; Baculoviral IAP Repeat-Containing 3 Protein; Biological and medical sciences; Caspase; Cell Biology; Cell physiology; Cell transformation and carcinogenesis. Action of oncogenes and antioncogenes; Cellular stress response; Complications and side effects; eIF-2 Kinase - metabolism; Embryo fibroblasts; Endoplasmic reticulum; Endoplasmic Reticulum - metabolism; Fibroblasts - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Enzymologic; Genetic aspects; Genetics; Health aspects; Human Genetics; Humans; Inhibitor of Apoptosis Proteins - metabolism; Internal Medicine; Kinases; Medicine; Medicine & Public Health; Mice; Models, Biological; Molecular and cellular biology; NIH 3T3 Cells; Oncology; original-article; Polyribosomes - metabolism; Protein Biosynthesis; Protein kinases; Signal transduction; Stress; Stress (Physiology); Transcription; Transcription, Genetic; Ubiquitin-Protein Ligases; Canada; ER stress; apoptosis; IAP; PERK; Regulation(control); Carcinogenesis; Stress; Apoptosis
• ISSN: 0950-9232; 1476-5594
• DOI: 10.1038/onc.2008.428

Exposure of cells to endoplasmic reticulum (ER) stress leads to activation of phosphatidylinositol 3-kinase (PI3K)–Akt signaling pathway and transcriptional induction of the inhibitor of apoptosis family of proteins. One of the proximal effectors of the ER stress response, the PKR-like ER kinase (PERK), leads to cellular adaptation to stress by multiple mechanisms, including attenuation of protein synthesis and transcriptional induction of pro-survival genes. Although PERK activity leads to cellular adaptation to ER stress, we now demonstrate that PERK activity also inhibits the ER stress-induced apoptotic program through the induction of cellular inhibitor of apoptosis (cIAP1 and cIAP2) proteins. This induction of IAPs occurs through both transcriptional and translational responses that are PERK dependent. Reintroduction of cIAP1 or cIAP2 expression into PERK-/- murine embryonic fibroblasts during ER stress delays the early onset of ER stress-induced caspase activation and apoptosis observed in these cells. Furthermore, we demonstrate that the activation of the PI3K–Akt pathway by ER stress is dependent on PERK, suggesting additional ways in which PERK activity protects cells from ER stress-induced apoptosis.