Analysis of epitope-tagged forms of the dyskeratosis congenital protein (dyskerin): identification of a nuclear localization signal

Blood Cells Mol Dis. 1999 Oct-Dec;25(5-6):305-9. doi: 10.1006/bcmd.1999.0258.

Abstract

The X-linked form of the bone marrow failure syndrome Dyskeratosis congenital is caused by mutations in dyskerin, a 514 amino acid protein that is presumed to play a role in ribosome biogenesis. Here we report that dyskerin tagged with the human immunoglobulin epitope localizes to nuclei of transfected HeLa and COS-1 cells. A carboxyl-terminal domain consisting of amino acids 467-475 and encoding KKEKKKSKK is both necessary and sufficient to mediate nuclear entry. Immunoglobulin-tagged dyskerin did not interact with the Fanconi anemia group A protein, FANCA. These results suggest a nuclear role for dyskerin. Moreover, hematopoietic failure observed in both Dyskeratosis congenital and the most common type of Fanconi anemia is unlikely to have a common mechanism resulting from abnormal physical interactions between the respective gene products of these disorders.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Affinity Labels*
  • Animals
  • COS Cells / ultrastructure
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / immunology*
  • Cell Cycle Proteins / metabolism*
  • DNA-Binding Proteins*
  • Dyskeratosis Congenita / genetics
  • Dyskeratosis Congenita / immunology
  • Dyskeratosis Congenita / metabolism
  • Epitopes / immunology
  • Epitopes / metabolism*
  • Fanconi Anemia Complementation Group A Protein
  • HeLa Cells / ultrastructure
  • Humans
  • Immunoglobulin G / immunology
  • Immunoglobulin G / metabolism
  • Microscopy, Fluorescence
  • Mutation
  • Nuclear Localization Signals
  • Nuclear Proteins / genetics
  • Nuclear Proteins / immunology*
  • Nuclear Proteins / metabolism*
  • Protein Binding
  • Proteins / metabolism
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / immunology
  • Recombinant Fusion Proteins / metabolism
  • Subcellular Fractions / chemistry
  • Transfection

Substances

  • Affinity Labels
  • Cell Cycle Proteins
  • DKC1 protein, human
  • DNA-Binding Proteins
  • Epitopes
  • FANCA protein, human
  • Fanconi Anemia Complementation Group A Protein
  • Immunoglobulin G
  • Nuclear Localization Signals
  • Nuclear Proteins
  • Proteins
  • Recombinant Fusion Proteins