Journal Article

Protein Tpr is required for establishing nuclear pore-associated zones of heterochromatin exclusion

Norder, Helene, Cordes, Volker C, Dörries, Julia, Krull, Sandra, Reidenbach, Sonja, Magnius, Lars, Thyberg, Johan, Boysen, Björn

2010

Overview

Amassments of heterochromatin in somatic cells occur in close contact with the nuclear envelope (NE) but are gapped by channel‐ and cone‐like zones that appear largely free of heterochromatin and associated with the nuclear pore complexes (NPCs). To identify proteins involved in forming such heterochromatin exclusion zones (HEZs), we used a cell culture model in which chromatin condensation induced by poliovirus (PV) infection revealed HEZs resembling those in normal tissue cells. HEZ occurrence depended on the NPC‐associated protein Tpr and its large coiled coil‐forming domain. RNAi‐mediated loss of Tpr allowed condensing chromatin to occur all along the NE's nuclear surface, resulting in HEZs no longer being established and NPCs covered by heterochromatin. These results assign a central function to Tpr as a determinant of perinuclear organization, with a direct role in forming a morphologically distinct nuclear sub‐compartment and delimiting heterochromatin distribution.

• Publisher: John Wiley & Sons, Ltd,Nature Publishing Group UK,Springer Nature B.V,Nature Publishing Group
• Subject: Animals / Cell culture / Cell Nucleus - metabolism / Cellular biology / Chromatin / Chromatin - chemistry / Chromatin - metabolism / EMBO09 / Gene Silencing / HeLa Cells / heterochromatin / Heterochromatin - chemistry / Humans / Mice / Microscopy, Confocal - methods / Microscopy, Electron, Transmission - methods / Microscopy, Fluorescence - methods / Models, Biological / Molecular biology / nuclear compartmentalization / nuclear pore complex / Nuclear Pore Complex Proteins - chemistry / Poliovirus / Poliovirus - metabolism / Proteins / Proto-Oncogene Proteins - chemistry / RNA Interference / Tpr