title: Intracellular calcium regulates nonsense-mediated mRNA decay.
abstract: The nonsense-mediated mRNA decay (NMD) pathway selectively eliminates aberrant transcripts containing premature translation termination codons and regulates the levels of a number of physiological mRNAs. NMD modulates the clinical outcome of a variety of human diseases, including cancer and many genetic disorders, and may represent a target for therapeutic intervention. Here, we have developed a new multicolored bioluminescence-based reporter system that can specifically and effectively assay NMD in live human cells. Using this reporter system, we conducted a robust high-throughput small-molecule screen in human cells and, unpredictably, identified a group of cardiac glycosides, including ouabain and digoxin, as potent inhibitors of NMD. Cardiac glycoside-mediated effects on NMD are dependent on binding and inhibiting the sodium-potassium ATPase on the plasma membrane and subsequent elevation of intracellular calcium levels. Induction of calcium release from the endoplasmic reticulum also leads to inhibition of NMD. Thus, this study reveals intracellular calcium as a key regulator of NMD and has implications for exploiting NMD in the treatment of disease.
authors: Department of Cell Biology &Physiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors: Andrew
authors: A
authors: Nickless
authors: BRIGHT Institute, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors: Erin
authors: E
authors: Jackson
authors: BRIGHT Institute, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors: Jayne
authors: J
authors: Marasa
authors: Department of Cell Biology &Physiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors: Patrick
authors: P
authors: Nugent
authors: Department of Cell Biology &Physiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors: Robert W
authors: RW
authors: Mercer
authors: 1] Department of Cell Biology &Physiology, Washington University School of Medicine, St. Louis, Missouri, USA. [2] BRIGHT Institute, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA. [3] Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors: David
authors: D
authors: Piwnica-Worms
authors: Department of Cell Biology &Physiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors: Zhongsheng
authors: Z
authors: You
mesh_terms: D002118:Calcium / Q000378:metabolism*; D002301:Cardiac Glycosides / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D004077:Digoxin / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D017930:Genes, Reporter; D057166:High-Throughput Screening Assays / Q000379:methods; D006801:Humans; D008163:Luminescent Measurements; D059365:Nonsense Mediated mRNA Decay / Q000235:genetics*; D010042:Ouabain / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
chemical_list: D002301:Cardiac Glycosides; D012333:RNA, Messenger; D010042:Ouabain; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium