Aurora-A and an interacting activator, the LIM protein Ajuba, are required for mitotic commitment in human cells

Cell. 2003 Sep 5;114(5):585-98. doi: 10.1016/s0092-8674(03)00642-1.

Abstract

Aurora family kinases contribute to regulation of mitosis. Using RNA interference in synchronized HeLa cells, we now show that Aurora-A is required for mitotic entry. We found that initial activation of Aurora-A in late G2 phase of the cell cycle is essential for recruitment of the cyclin B1-Cdk1 complex to centrosomes, where it becomes activated and commits cells to mitosis. A two-hybrid screen identified the LIM protein Ajuba as an Aurora-A binding protein. Ajuba and Aurora-A interact in mitotic cells and become phosphorylated as they do so. In vitro analyses revealed that Ajuba induces the autophosphorylation and consequent activation of Aurora-A. Depletion of Ajuba prevented activation of Aurora-A at centrosomes in late G2 phase and inhibited mitotic entry. Overall, our data suggest that Ajuba is an essential activator of Aurora-A in mitotic commitment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aurora Kinase A
  • Aurora Kinases
  • CDC2 Protein Kinase / metabolism
  • COS Cells
  • Cell Cycle
  • Cell Cycle Proteins
  • Cell Line
  • Centrosome / ultrastructure
  • Cyclin B / metabolism
  • Cyclin B1
  • G2 Phase
  • Gene Deletion
  • Glutathione Transferase / metabolism
  • HeLa Cells
  • Homeodomain Proteins / metabolism
  • Homeodomain Proteins / physiology*
  • Humans
  • LIM Domain Proteins
  • Microscopy, Fluorescence
  • Mitosis*
  • Models, Biological
  • Molecular Sequence Data
  • Phosphorylation
  • Precipitin Tests
  • Protein Binding
  • Protein Kinases / metabolism
  • Protein Kinases / physiology*
  • Protein-Serine-Threonine Kinases
  • RNA Interference
  • Recombinant Proteins / metabolism
  • Temperature
  • Time Factors
  • Two-Hybrid System Techniques
  • Xenopus Proteins

Substances

  • AJUBA protein, human
  • Ajuba protein, rat
  • CCNB1 protein, human
  • Ccnb1 protein, rat
  • Cell Cycle Proteins
  • Cyclin B
  • Cyclin B1
  • Homeodomain Proteins
  • LIM Domain Proteins
  • Recombinant Proteins
  • Xenopus Proteins
  • Glutathione Transferase
  • Protein Kinases
  • AURKA protein, Xenopus
  • Aurka protein, rat
  • Aurora Kinase A
  • Aurora Kinases
  • Protein-Serine-Threonine Kinases
  • CDC2 Protein Kinase

Associated data

  • GENBANK/AY169959