Evidence for eIF2α phosphorylation-independent effects of GSK2656157, a novel catalytic inhibitor of PERK with clinical implications
| Autor: | Jothilatha Krishnamoorthy, Polixenia Kesoglidou, Kamindla Rajesh, Antonis E. Koromilas, Andreas I. Papadakis, Farzaneh Mirzajani |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
endocrine system
Indoles mRNA translation Eukaryotic Initiation Factor-2 Antineoplastic Agents translation initiation factor eIF2 Biology Cell Line Serine 03 medical and health sciences Mice eIF-2 Kinase 0302 clinical medicine Report Glucose homeostasis Animals Humans Protein phosphorylation PERK/PEK kinase Phosphorylation Protein kinase A Molecular Biology Protein Kinase Inhibitors 030304 developmental biology 0303 health sciences eIF2 Cell Death Endoplasmic reticulum Adenine Cell Biology unfolded protein response Endoplasmic Reticulum Stress pharmacological inhibitors 3. Good health Cell biology protein phosphorylation tumorigenesis 030220 oncology & carcinogenesis Unfolded protein response Developmental Biology |
| Zdroj: | Cell Cycle |
| ISSN: | 1551-4005 |
| Popis: | The endoplasmic reticulum (ER)-resident protein kinase PERK is a major component of the unfolded protein response (UPR), which promotes the adaptation of cells to various forms of stress. PERK phosphorylates the α subunit of the translation initiation factor eIF2 at serine 51, a modification that plays a key role in the regulation of mRNA translation in stressed cells. Several studies have demonstrated that the PERK-eIF2α phosphorylation pathway maintains insulin biosynthesis and glucose homeostasis, facilitates tumor formation and decreases the efficacy of tumor treatment with chemotherapeutic drugs. Recently, a selective catalytic PERK inhibitor termed GSK2656157 has been developed with anti-tumor properties in mice. Herein, we provide evidence that inhibition of PERK activity by GSK2656157 does not always correlate with inhibition of eIF2α phosphorylation. Also, GSK2656157 does not always mimic the biological effects of the genetic inactivation of PERK. Furthermore, cells treated with GSK2656157 increase eIF2α phosphorylation as a means to compensate for the loss of PERK. Using human tumor cells impaired in eIF2α phosphorylation, we demonstrate that GSK2656157 induces ER stress-mediated death suggesting that the drug acts independent of the inhibition of eIF2α phosphorylation. We conclude that GSK2656157 might be a useful compound to dissect pathways that compensate for the loss of PERK and/or identify PERK pathways that are independent of eIF2α phosphorylation. |
| Databáze: | OpenAIRE |
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