DEDD, a novel death effector domain-containing protein, targeted to the nucleolus

• Published in: The EMBO journal Vol. 17; no. 20; pp. 5974 - 5986
• Main Authors: Stegh, Alexander H., Schickling, Olaf, Ehret, Andreas, Scaffidi, Carsten, Peterhänsel, Christoph, Hofmann, Thomas G., Grummt, Ingrid, Krammer, Peter H., Peter, Marcus E.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 15-10-1998
• Subjects: Amino Acid Sequence; Animals; Apoptosis; Arabidopsis Proteins; Base Sequence; Cell Nucleolus - metabolism; Cloning, Molecular; Conserved Sequence; Death Domain Receptor Signaling Adaptor Proteins; death effector domain (DED); DNA-Binding Proteins - analysis; DNA-Binding Proteins - genetics; DNA-Binding Proteins - physiology; Fatty Acid Desaturases - metabolism; Humans; Intracellular Signaling Peptides and Proteins; Jurkat Cells; Lymphoma; Mice; Molecular Sequence Data; mononucleosome; nucleolus; Peptide Fragments - metabolism; Plant Proteins - metabolism; Protein Binding; transcriptional inhibition; Tumor Cells, Cultured
• ISSN: 0261-4189; 1460-2075; 1460-2075
• DOI: 10.1093/emboj/17.20.5974

The CD95 signaling pathway comprises proteins that contain one or two death effector domains (DED), such as FADD/Mort1 or caspase‐8. Here we describe a novel 37 kDa protein, DEDD, that contains an N‐terminal DED. DEDD is highly conserved between human and mouse (98.7% identity) and is ubiquitously expressed. Overexpression of DEDD in 293T cells induced weak apoptosis, mainly through its DED by which it interacts with FADD and caspase‐8. Endogenous DEDD was found in the cytoplasm and translocated into the nucleus upon stimulation of CD95. Immunocytological studies revealed that overexpressed DEDD directly translocated into the nucleus, where it co‐localizes in the nucleolus with UBF, a basal factor required for RNA polymerase I transcription. Consistent with its nuclear localization, DEDD contains two nuclear localization signals and the C‐terminal part shares sequence homology with histones. Recombinant DEDD binds to both DNA and reconstituted mononucleosomes and inhibits transcription in a reconstituted in vitro system. The results suggest that DEDD is a final target of a chain of events by which the CD95‐induced apoptotic signal is transferred into the nucleolus to shut off cellular biosynthetic activities.