View the Current Issue

Article

  • The EMBO Journal (2007) 26, 132 - 143
  • doi:10.1038/sj.emboj.7601470

Published online: 14 December 2006

Caenorhabditis elegans BAF-1 and its kinase VRK-1 participate directly in post-mitotic nuclear envelope assembly

Mátyás Gorjánácz1,b, Elke PF Klerkx2,b, Vincent Galy1,a, Rachel Santarella1, Carmen López-Iglesias3, Peter Askjaer1,2 and Iain W Mattaj1

  1. European Molecular Biology Laboratory, Heidelberg, Germany
  2. Institute for Research in Biomedicine, Barcelona Science Park IRB-PCB, Barcelona, Spain
  3. University of Barcelona, Barcelona Science Park SCT-UB, Barcelona, Spain

Correspondence to:

Peter Askjaer, Cell Division Group, Institute for Research in Biomedicine, Parc Cientific de Barcelona, C/Josep Samitier 1-5, Barcelona 08028, Spain. Tel.: +34 93 403 70 18; Fax: +34 93 403 71 09; E-mail: paskjaer@pcb.ub.es

Iain W Mattaj, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany; E-mail: mattaj@embl.de

aPresent address: Institut Pasteur, 25 rue du Docteur Roux 75724, Paris cedex 15, France

bThese authors contributed equally to this work

Received 25 July 2006; Accepted 6 November 2006

Barrier-to-autointegration factor (BAF) is an essential, highly conserved, metazoan protein. BAF interacts with LEM (LAP2, emerin, MAN1) domain-carrying proteins of the inner nuclear membrane. We analyzed the in vivo function of BAF in Caenorhabditis elegans embryos using both RNA interference and a temperature-sensitive baf-1 gene mutation and found that BAF is directly involved in nuclear envelope (NE) formation. NE defects were observed independent of and before the chromatin organization phenotype previously reported in BAF-depleted worms and flies. We identified vaccinia-related kinase (VRK) as a regulator of BAF phosphorylation and localization. VRK localizes both to the NE and chromatin in a cell-cycle-dependent manner. Depletion of VRK results in several mitotic defects, including impaired NE formation and BAF delocalization. We propose that phosphorylation of BAF by VRK plays an essential regulatory role in the association of BAF with chromatin and nuclear membrane proteins during NE formation.

  • Keywords:

    • chromosome segregation,
    • LEM proteins,
    • mitosis,
    • nuclear envelope,
    • nuclear pore complex