VRK2A is an A-type lamin-dependent nuclear envelope kinase that phosphorylates BAF

Mol Biol Cell. 2017 Aug 15;28(17):2241-2250. doi: 10.1091/mbc.E17-03-0138. Epub 2017 Jun 21.


The nuclear envelope (NE) is critical for numerous fundamental cellular functions, and mutations in several NE constituents can lead to a heterogeneous spectrum of diseases. We used proximity biotinylation to uncover new constituents of the inner nuclear membrane (INM) by comparative BioID analysis of lamin A, Sun2 and a minimal INM-targeting motif. These studies identify vaccinia-related kinase-2 (VRK2) as a candidate constituent of the INM. The transmembrane VRK2A isoform is retained at the NE by association with A-type lamins. Furthermore, VRK2A physically interacts with A-type, but not B-type, lamins. Finally, we show that VRK2 phosphorylates barrier to autointegration factor (BAF), a small and highly dynamic chromatin-binding protein, which has roles including NE reassembly, cell cycle, and chromatin organization in cells, and subtly alters its nuclear mobility. Together these findings support the value of using BioID to identify unrecognized constituents of distinct subcellular compartments refractory to biochemical isolation and reveal VRK2A as a transmembrane kinase in the NE that regulates BAF.

MeSH terms

  • Biotinylation
  • DNA-Binding Proteins / metabolism*
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Lamin Type A / genetics
  • Lamin Type A / metabolism
  • Lamin Type B / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Nuclear Envelope / metabolism
  • Nuclear Proteins / metabolism*
  • Phosphorylation
  • Protein Isoforms
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*


  • BANF1 protein, human
  • DNA-Binding Proteins
  • Intracellular Signaling Peptides and Proteins
  • Lamin Type A
  • Lamin Type B
  • Membrane Proteins
  • Nuclear Proteins
  • Protein Isoforms
  • SUN2 protein, human
  • Protein Serine-Threonine Kinases
  • VRK2 protein, human