Discovery - University of Dundee - Online Publications

Library & Learning Centre

Chromatin-associated Protein Phosphatase I Regulates Aurora-B and Histone H3 Phosphorylation

Chromatin-associated Protein Phosphatase I Regulates Aurora-B and Histone H3 Phosphorylation

Research output: Contribution to journalArticle

View graph of relations

Authors

  • Mairead E. Murnion
  • R.R. Adams
  • Deborah M. Callister
  • C.D. Allis
  • W.C. Earnshaw
  • Jason R. Swedlow

Research units

Info

Original languageEnglish
Pages26656-26665
Number of pages10
JournalJournal of Biological Chemistry
Journal publication date13 Jul 2001
Journal number28
Volume276
DOIs
StatePublished

Abstract

Proper chromosome condensation requires the phosphorylation of histone and nonhistone chromatin proteins. We have used an in vitro chromosome assembly system based on Xenopus egg cytoplasmic extracts to study mitotic histone H3 phosphorylation. We identified a histone H3 Ser kinase activity associated with isolated mitotic chromosomes. The histone H3 kinase was not affected by inhibitors of cyclin-dependent kinases, DNA-dependent protein kinase, p90, or cAMP-dependent protein kinase. The activity could be selectively eluted from mitotic chromosomes and immunoprecipitated by specific anti-X aurora-B/AIRK2 antibodies. This activity was regulated by phosphorylation. Treatment of X aurora-B immunoprecipitates with recombinant protein phosphatase 1 (PP1) inhibited kinase activity. The presence of PP1 on chromatin suggested that PP1 might directly regulate the X aurora-B associated kinase activity. Indeed, incubation of isolated interphase chromatin with the PPI-specific inhibitor 12 and ATP generated an H3 kinase activity that was also specifically immunoprecipitated by anti-X aurora-B antibodies. Nonetheless, we found that stimulation of histone H3 phosphorylation in interphase cytosol does not drive chromosome condensation or targeting of 13 S condensin to chromatin. In summary, the chromosome-associated mitotic histone H3 Ser kinase is associated with X aurora-B and is inhibited directly in interphase chromatin by PPI.

Documents

Library & Learning Centre

Contact | Accessibility | Policy