Regulation of binding of lamin B receptor to chromatin by SR protein kinase and cdc2 kinase in Xenopus egg extracts.
Participation of multiple kinases in regulation of the binding of lamin B receptor (LBR) to chromatin was suggested previously (Takano, M., Takeuchi, M., Ito, H., Furukawa, K., Sugimoto, K., Omata, S., and Horigome, T. (2002) Eur. J. Biochem. 269, 943-953). To identify these kinases, regulation of the binding of the nucleoplasmic region (NK, amino acid residues 1-211) of LBR to sperm chromatin was studied using a cell cycle-dependent Xenopus egg extract in vitro. The binding was stimulated on specific phosphorylation of the NK fragment by an S-phase egg extract. Protein depletion with beads bearing SF2/ASF, which binds SR protein kinases, abolished this stimulation, suggesting that an SR protein kinase(s) is responsible for the activation of LBR. This was confirmed by direct phosphorylation and activation with recombinant SR protein-specific kinase 1. The binding of the NK fragment to chromatin pretreated with an S-phase extract was suppressed by incubation with an M-phase extract. Enzyme inhibitor experiments revealed that multiple kinases participate in the suppression. One of these kinases was shown to be cdc2 kinase using a specific inhibitor, roscovitine, and protein depletion with beads bearing p13, which specifically binds cdc2 kinase. Experiments involving a mutant NK fragment showed that the phosphorylation of serine 71 by cdc2 kinase is responsible for the suppression.
Takano
Makoto
M
Course of Biosphere Science, Graduate School of Science and Technology, Faculty of Science, Niigata University, Igarashi-2, Niigata 950-2181, Japan.
Koyama
Yuhei
Y
Ito
Hiromi
H
Hoshino
Satomi
S
Onogi
Hiroshi
H
Hagiwara
Masatoshi
M
Furukawa
Kazuhiro
K
Horigome
Tsuneyoshi
T
D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D002482:Cellulose / Q000737:chemistry; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000737:chemistry; D015971:Gene Expression Regulation, Enzymologic; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008938:Mitosis; D009154:Mutation; D009865:Oocytes / Q000201:enzymology* / Q000378:metabolism; D010449:Peptide Mapping; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011687:Purines / Q000494:pharmacology; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D000077546:Roscovitine; D016196:S Phase; D012694:Serine / Q000737:chemistry; D014357:Trypsin / Q000494:pharmacology; D014981:Xenopus; D000097682:Lamin B Receptor
D016203:CDC2 Protein Kinase; D002482:Cellulose; D002843:Chromatin; D004247:DNA; D005982:Glutathione Transferase; D017346:Protein Serine-Threonine Kinases; D011687:Purines; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins; D000077546:Roscovitine; D012694:Serine; D014357:Trypsin; D000097682:Lamin B Receptor; C087728:SRPK1 protein, human