Characterization of the structures involved in localization of the SUN proteins to the nuclear envelope and the centrosome

DNA Cell Biol. 2006 Oct;25(10):554-62. doi: 10.1089/dna.2006.25.554.


The nuclear envelope forms a selective barrier that separates the cytoplasm from the nucleus. During mitosis the nuclear envelope breaks down so that the microtubule network can form contacts with the kinetochore and guide chromosome segregation. Previous studies have suggested a model in which the centrosome and the microtubule network may play a role in nuclear envelope breakdown through as yet unidentified interactions with proteins localized to the nuclear envelope. In the current study we characterized a nuclear envelope protein SUN2 and identified a substructure involved in its localization to the nuclear envelope. We found that a structurally related protein, SUN1, may be localized to the nuclear envelope through a different mechanism. Furthermore, the SUN2 protein can form different assemblies, including homodimers and heterodimers with SUN1. Finally, we provide evidence indicating that SUN1 and SUN2 may form a physical interaction between the nuclear envelope and the centrosome.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans
  • Cell Line, Tumor
  • Cell Nucleus / metabolism
  • Centrosome / chemistry*
  • Centrosome / metabolism
  • Centrosome / ultrastructure
  • Cloning, Molecular
  • Cytoplasm / metabolism
  • HeLa Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Membrane Proteins / metabolism*
  • Mice
  • Microtubule-Associated Proteins / metabolism*
  • Nuclear Envelope / metabolism*
  • Nuclear Proteins
  • Protein Binding


  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Microtubule-Associated Proteins
  • Nuclear Proteins
  • SUN1 protein, human
  • SUN1 protein, mouse
  • SUN2 protein, human