tailieunhanh - Báo cáo Y học: The binding of lamin B receptor to chromatin is regulated by phosphorylation in the RS region

Binding of lamin B receptor (LBR) to chromatin was studied by means of an in vitro assay system involving recombinant fragments of human LBR and Xenopus sperm chromatin. Glutathione-S-transferase (GST)-fused proteins including LBR fragments containing the N-terminal region (residues 1–53) and arginine-serine repeat-containing region (residues 54–89) bound to chromatin. The binding of GST-fusion proteins incorporating the N-terminal and arginine-serine repeat-containing regions to chromatin was suppressed by mild trypsinization of the chromatin and by pretreatment with a DNA solution | Eur. J. Biochem. 269 943-953 2002 FEBS 2002 The binding of lamin B receptor to chromatin is regulated by phosphorylation in the RS region Makoto Takano1 Masaki Takeuchi1 Hiromi Ito2. Kazuhiro Furukawa1 2 3 Kenji Suaimoto4 Saburo Omata1 2 3 and Tsuneyoshi Horigome1 5 1 Courses of Biosphere Science and 2Functional Biology Graduate School of Science and Technology Niigata University Japan 3Department of Biochemistry Faculty of Science Niigata University Japan 4Laboratory of Applied Molecular Biology Department of Applied Biochemistry University of Osaka Prefecture Osaka Japan 5 Center for Instrumental Analysis Niigata University Japan Binding of lamin B receptor LBR to chromatin was studied by means of an in vitro assay system involving recombinant fragments of human LBR and Xenopus sperm chromatin. Glutathione-S-transferase GST -fused proteins including LBR fragments containing the N-terminal region residues 1-53 and arginine-serine repeat-containing region residues 54-89 bound to chromatin. The binding of GST-fusion proteins incorporating the N-terminal and arginine-serine repeat-containing regions to chromatin was suppressed by mild trypsinization of the chromatin and by pretreatment with a DNA solution. A new cell-free system for analyzing the cell cycle-dependent binding of a protein to chromatin was developed from recombinant proteins a Xenopus egg cytosol fraction and sperm chromatin. The system was applied to analyse the binding of LBR to chromatin. It was shown that the binding of LBR fragments to chromatin was stimulated by phosphorylation in the arginine-serine repeatcontaining region by a protein kinase s in a synthetic phase egg cytosol. However the binding of LBR fragments was suppressed by phosphorylation at different residues in the same region by a kinase s in a mitotic phase cytosol. These results suggested that the cell cycle-dependent binding of LBR to chromatin is regulated by phosphorylation in the arginine-serine repeat-containing region by .