Centromeric Aurora-B activation requires TD-60, microtubules, and substrate priming phosphorylation.
The chromosome passenger complex (CPC) controls chromosome congression, kinetochore-microtubule attachments, and spindle checkpoint signaling during mitosis. Aurora-B kinase is the catalytic subunit of the CPC. To understand how a single kinase can regulate such diverse events, we have investigated the activation of Aurora-B and describe two distinct activation mechanisms. First, Aurora-B activation in vitro requires two cofactors, telophase disc-60kD (TD-60) and microtubules. TD-60 is critical to localize both the CPC and Haspin kinase activity to centromeres and thus regulates Aurora-B at several levels. Second, Aurora-B substrates can inhibit kinase activation, and this is relieved by phosphorylation of these substrates by the centromeric kinases Plk1 and Haspin. These regulatory mechanisms suggest models for phosphorylation by Aurora-B of centromeric substrates at unaligned chromosomes and merotelic attachments.
PubMed ID: 18218899
Article link: Science.
Grant support: R01GM063045-06 NIGMS NIH HHS
Genes referenced: plk1 rcc2
Antibodies referenced: Aurkb Ab2 H3f3a Ab8 Incenp Ab1 Kif2c Ab1 Kif2c Ab2