The vaccinia-related kinases phosphorylate the N' terminus of BAF, regulating its interaction with DNA and its retention in the nucleus. Mol Biol Cell 2006 May;17(5):2451-64
Date
02/24/2006Pubmed ID
16495336Pubmed Central ID
PMC1446082DOI
10.1091/mbc.e05-12-1179Scopus ID
2-s2.0-33745450085 (requires institutional sign-in at Scopus site) 207 CitationsAbstract
The vaccinia-related kinases (VRKs) comprise a branch of the casein kinase family whose members are characterized by homology to the vaccinia virus B1 kinase. The VRK orthologues encoded by Caenorhabditis elegans and Drosophila melanogaster play an essential role in cell division; however, substrates that mediate this role have yet to be elucidated. VRK1 can complement the temperature sensitivity of a vaccinia B1 mutant, implying that VRK1 and B1 have overlapping substrate specificity. Herein, we demonstrate that B1, VRK1, and VRK2 efficiently phosphorylate the extreme N' terminus of the BAF protein (Barrier to Autointegration Factor). BAF binds to both DNA and LEM domain-containing proteins of the inner nuclear membrane; in lower eukaryotes, BAF has been shown to play an important role during the reassembly of the nuclear envelope at the end of mitosis. We demonstrate that phosphorylation of ser4 and/or thr2/thr3 abrogates the interaction of BAF with DNA and reduces its interaction with the LEM domain. Coexpression of VRK1 and GFP-BAF greatly diminishes the association of BAF with the nuclear chromatin/matrix and leads to its dispersal throughout the cell. Cumulatively, our data suggest that the VRKs may modulate the association of BAF with nuclear components and hence play a role in maintaining appropriate nuclear architecture.
Author List
Nichols RJ, Wiebe MS, Traktman PMESH terms used to index this publication - Major topics in bold
Amino Acid SequenceAnimals
Cell Nucleus
Cells, Cultured
DNA
DNA-Binding Proteins
Humans
Intracellular Signaling Peptides and Proteins
Molecular Sequence Data
Mutation
Nuclear Proteins
Phosphoamino Acids
Phosphorylation
Protein Structure, Tertiary
Proteins
Serine
Threonine
Viral Proteins
