A functional interplay between Aurora-A, Plk1 and TPX2 at spindle poles: Plk1 controls centrosomal localization of Aurora-A and TPX2 spindle association

Cell Cycle. 2006 Feb;5(3):296-303. doi: 10.4161/cc.5.3.2392. Epub 2006 Feb 7.


Aurora-A and Plk1 are centrosomal kinases involved in centrosome maturation and spindle assembly. The microtubule-binding protein TPX2 interacts with, and activates, Aurora-A. Here we have used RNA interference-mediated inactivation to investigate whether Aurora-A, Plk1 and TPX2 act independently or are part of one signaling cascade in spindle formation in mammalian cells. We have identified both specific, and over- lapping, roles of each single regulator in centrosome maturation and spindle formation: (1) Aurora-A and TPX2 are required for centriole cohesion and spindle bipolarity; (2) TPX2, besides its known role in microtubule organization, is also involved in centrosome maturation; (3) finally, Plk1 controls the localization of Aurora-A to centrosomes, as well as TPX2 recruitment to microtubules. Based on these results therefore a hierarchical functional relation between Plk1 and the Aurora-A/TPX2 pathway emerges.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aurora Kinases
  • Base Sequence
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Line, Tumor
  • Humans
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Mitosis / physiology*
  • Molecular Sequence Data
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism*
  • RNA Interference
  • Signal Transduction
  • Spindle Apparatus / metabolism*
  • Spindle Apparatus / ultrastructure


  • Cell Cycle Proteins
  • Microtubule-Associated Proteins
  • Neoplasm Proteins
  • Nuclear Proteins
  • Phosphoproteins
  • Proto-Oncogene Proteins
  • TPX2 protein, human
  • Aurora Kinases
  • Protein-Serine-Threonine Kinases
  • polo-like kinase 1