Mitotic activation of the kinase Aurora-A requires its binding partner Bora.
The protein kinase Aurora-A is required for centrosome maturation, spindle assembly, and asymmetric protein localization during mitosis. Here, we describe the identification of Bora, a conserved protein that is required for the activation of Aurora-A at the onset of mitosis. In the Drosophila peripheral nervous system, bora mutants have defects during asymmetric cell division identical to those observed in aurora-A. Furthermore, overexpression of bora can rescue defects caused by mutations in aurora-A. Bora is conserved in vertebrates, and both Drosophila and human Bora can bind to Aurora-A and activate the kinase in vitro. In interphase cells, Bora is a nuclear protein, but upon entry into mitosis, Bora is excluded from the nucleus and translocates into the cytoplasm in a Cdc2-dependent manner. We propose a model in which activation of Cdc2 initiates the release of Bora into the cytoplasm where it can bind and activate Aurora-A.
Hutterer
Andrea
A
Institute of Molecular Biotechnology (IMBA), Dr Bohr Gasse 3-5, 1030 Vienna, Austria.
Berdnik
Daniela
D
Wirtz-Peitz
Frederik
F
Zigman
Mihaela
M
Schleiffer
Alexander
A
Knoblich
Juergen A
JA
D000818:Animals; D064127:Aurora Kinases; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D002478:Cells, Cultured; D004330:Drosophila; D029721:Drosophila Proteins / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008938:Mitosis / Q000502:physiology*; D009154:Mutation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*
C514197:Bora protein, Drosophila; D029721:Drosophila Proteins; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase