1 Original Research Article Identification of the PKR Nuclear Interactome Reveals Roles in Ribosome Biogenesis, mRNA Processing and Cell Division † William L. Blalock 1,3*, Manuela Piazzi 2 , Alberto Bavelloni 3,4 , Mirco Raffini 4 , Irene Faenza 2 , Antonietta D’Angelo 4 and Lucio Cocco 2 1 CNR-National Research Council of Italy, Institute of Molecular Genetics, Bologna, Italy; 2 Cell Signalling Laboratory, Department of Biomedical Sciences, University of Bologna, Bologna Italy; 3 SC Laboratory of Musculoskeletal Cell Biology, Rizzoli Orthopedic Institute, Bologna, Italy; 4 Laboratory RAMSES, Rizzoli Orthopedic Institute, Bologna, Italy WLB and MP contributed equally to this manuscript. * Address correspondence to: William L. Blalock, PhD IGM-CNR, Bologna c/o Rizzoli Orthopedic Institute via di Barbiano, 1/10 40136 Bologna, Italy Tele: +39 0516366770 E-mail: william.blalock@cnr.it Running Title: The Nuclear PKR Interactome. Key words:  PKR  nucleus  acute leukemia  mass spectrometry  interactome † This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: [10.1002/jcp.24529] Additional Supporting Information may be found in the online version of this article. Received 27 November 2013; Revised 3 December 2013; Accepted 5 December 2013 Journal of Cellular Physiology © 2013 Wiley Periodicals, Inc. DOI 10.1002/jcp.24529