title: Cold-inducible RBM3 inhibits PERK phosphorylation through cooperation with NF90 to protect cells from endoplasmic reticulum stress.
abstract: The cold-inducible RNA-binding motif protein 3 (RBM3) is involved in the protection of neurons in hypoxic-ischemic and neurodegenerative disorders. RBM3 belongs to a small group of proteins whose synthesis increases during hypothermia while global protein production is slowed down. To investigate the molecular mechanisms underlying RBM3 action, we subjected hippocampal organotypic slice cultures from RBM3 knockout mice to various stressors and found exuberant signaling of the endoplasmic reticulum (ER) stress pathway PRKR-like ER kinase (PERK)-eukaryotic translation initiation factor 2α (eIF2α)-CCAAT/enhancer-binding protein homologous protein (CHOP) as compared with wild-type mice. Further, blocking RBM3 expression in human embryonic kidney HEK293 cells by specific small interfering RNAs increased phosphorylation of PERK and eIF2α, whereas overexpression of RBM3 prevented PERK-eIF2α-CHOP signaling during ER stress induced by thapsigargin or tunicamycin. RBM3 did not affect expression of the ER stress sensor immunoglobulin binding protein/GRP78. However, based on affinity purification coupled with mass spectrometry, coimmunoprecipitation, and proximity ligation assay, we revealed that nuclear factor 90 (NF90) is a novel protein interactor of PERK and that this interaction is essential for RBM3-mediated regulation of PERK activity, which requires an RNA-dependent interaction. In conclusion, our data provide evidence for a central role of RBM3 in preventing cell death by inhibiting the PERK-eIF2α-CHOP ER stress pathway through cooperation with NF90.
authors.affiliation: *University of Basel Children's Hospital (UKBB), Basel, Switzerland; and Anatomical Institute, Department of Biomedicine, University of Basel, Basel, Switzerland.
authors.forename: Xinzhou
authors.initials: X
authors.lastname: Zhu
authors.affiliation: *University of Basel Children's Hospital (UKBB), Basel, Switzerland; and Anatomical Institute, Department of Biomedicine, University of Basel, Basel, Switzerland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Zelmer
authors.affiliation: *University of Basel Children's Hospital (UKBB), Basel, Switzerland; and Anatomical Institute, Department of Biomedicine, University of Basel, Basel, Switzerland.
authors.forename: Josef P
authors.initials: JP
authors.lastname: Kapfhammer
authors.affiliation: *University of Basel Children's Hospital (UKBB), Basel, Switzerland; and Anatomical Institute, Department of Biomedicine, University of Basel, Basel, Switzerland sven.wellmann@ukbb.ch.
authors.forename: Sven
authors.initials: S
authors.lastname: Wellmann
mesh_terms: D000818:Animals; D002470:Cell Survival; D003080:Cold Temperature; D004721:Endoplasmic Reticulum / Q000502:physiology; D000091342:Endoplasmic Reticulum Chaperone BiP; D015852:Eukaryotic Initiation Factor-2 / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D051379:Mice; D050779:Nuclear Factor 90 Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological / Q000502:physiology; D019284:Thapsigargin / Q000494:pharmacology; D046509:Tissue Culture Techniques; D051742:Transcription Factor CHOP / Q000235:genetics / Q000378:metabolism; D019892:eIF-2 Kinase / Q000235:genetics / Q000378:metabolism*
chemical_list: D000091342:Endoplasmic Reticulum Chaperone BiP; D015852:Eukaryotic Initiation Factor-2; D050779:Nuclear Factor 90 Proteins; D016601:RNA-Binding Proteins; D019284:Thapsigargin; D051742:Transcription Factor CHOP; D019892:eIF-2 Kinase; C497250:Ddit3 protein, mouse; C000717247:HSPA5 protein, human; C000717248:Hspa5 protein, mouse; C099506:RBM3 protein, human; C484384:Rbm3 protein, mouse; C460640:EIF2AK3 protein, human
keywords: RNA-binding protein; apoptosis; hypothermia; unfolded protein response