Premium
Ajuba: a new microtubule‐associated protein that interacts with BUBR1 and Aurora B at kinetochores in metaphase
Author(s) -
Ferrand Alexia,
Chevrier Véronique,
Chauvin JeanPaul,
Birnbaum Daniel
Publication year - 2009
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1042/bc20080060
Subject(s) - biology , kinetochore , microbiology and biotechnology , metaphase , microtubule , aurora b kinase , genetics , chromosome , gene
Background information . The role of the LIM‐domain‐containing protein Ajuba was initially described in cell adhesion and migration processes and recently in mitosis as an activator of the Aurora A kinase. Results . In the present study, we show that Ajuba localizes to centrosomes and kinetochores during mitosis. This localization is microtubule‐dependent and Ajuba binds microtubules in vitro . A microtubule regrowth assay showed that Ajuba follows nascent microtubules from centrosomes to kinetochores. Owing to its contribution to mitotic commitment and its microtubule‐dependent localization, Ajuba could also play a role during the metaphase—anaphase transition. We show that Ajuba interacts with Aurora B and BUBR1 [BUB (budding uninhibited by benomyl)‐related 1], two major components of the mitotic checkpoint. Inhibition of BUBR1 by siRNA (small interfering RNA) disrupts chromosome alignment at the metaphase plate and modifies Ajuba localization due to premature mitotic exit. Conclusions . Ajuba is a microtubule‐associated protein that collaborates with Aurora B and BUBR1 at the metaphase—anaphase transition and this may be important to ensure proper chromosome segregation.