1. The hnRNP-Htt axis regulates necrotic cell death induced by transcriptional repression through impaired RNA splicing.
- Author
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Mao Y, Tamura T, Yuki Y, Abe D, Tamada Y, Imoto S, Tanaka H, Homma H, Tagawa K, Miyano S, and Okazawa H
- Subjects
- Amanitins pharmacology, Animals, Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Cells, Cultured, Drosophila growth & development, Drosophila metabolism, Drosophila Proteins genetics, Embryo, Mammalian cytology, Heterogeneous-Nuclear Ribonucleoprotein Group A-B genetics, Heterogeneous-Nuclear Ribonucleoprotein Group A-B metabolism, Heterogeneous-Nuclear Ribonucleoproteins genetics, Huntingtin Protein antagonists & inhibitors, Huntingtin Protein genetics, Larva metabolism, Neurons cytology, Neurons metabolism, Protein Serine-Threonine Kinases genetics, Protein Serine-Threonine Kinases metabolism, Proto-Oncogene Proteins genetics, Proto-Oncogene Proteins metabolism, Pupa metabolism, RNA Splicing drug effects, Rats, Rats, Wistar, Ribonucleoproteins genetics, Ribonucleoproteins metabolism, Transcription Factors genetics, Transcription Factors metabolism, Transcription, Genetic drug effects, beta-Transducin Repeat-Containing Proteins genetics, beta-Transducin Repeat-Containing Proteins metabolism, Polo-Like Kinase 1, Apoptosis drug effects, Drosophila Proteins metabolism, Heterogeneous-Nuclear Ribonucleoproteins metabolism, Huntingtin Protein metabolism
- Abstract
In this study, we identify signaling network of necrotic cell death induced by transcriptional repression (TRIAD) by α-amanitin (AMA), the selective RNA polymerase II inhibitor, as a model of neurodegenerative cell death. We performed genetic screen of a knockdown (KD) fly library by measuring the ratio of transformation from pupa to larva (PL ratio) under TRIAD, and selected the cell death-promoting genes. Systems biology analysis of the positive genes mapped on protein-protein interaction databases predicted the signaling network of TRIAD and the core pathway including heterogeneous nuclear ribonucleoproteins (hnRNPs) and huntingtin (Htt). RNA sequencing revealed that AMA impaired transcription and RNA splicing of Htt, which is known as an endoplasmic reticulum (ER)-stabilizing molecule. The impairment in RNA splicing and PL ratio was rescued by overexpresion of hnRNP that had been also affected by transcriptional repression. Fly genetics with suppressor or expresser of Htt and hnRNP worsened or ameliorated the decreased PL ratio by AMA, respectively. Collectively, these results suggested involvement of RNA splicing and a regulatory role of the hnRNP-Htt axis in the process of the transcriptional repression-induced necrosis.
- Published
- 2016
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