title: Cenp-meta is required for sustained spindle checkpoint.
abstract: Cenp-E is a kinesin-like motor protein required for efficient end-on attachment of kinetochores to the spindle microtubules. Cenp-E immunodepletion in Xenopus mitotic extracts results in the loss of mitotic arrest and massive chromosome missegregation, whereas its depletion in mammalian cells leads to chromosome segregation defects despite the presence of a functional spindle assembly checkpoint (SAC). Cenp-meta has previously been reported to be the Drosophila homolog of vertebrate Cenp-E. In this study, we show that cenp-metaΔ mutant neuroblasts arrest in mitosis when treated with colchicine. cenp-metaΔ mutant cells display a mitotic delay. Yet, despite the persistence of the two checkpoint proteins Mad2 and BubR1 on unattached kinetochores, these cells eventually enter anaphase and give rise to highly aneuploid daughter cells. Indeed, we find that cenp-metaΔ mutant cells display a slow but continuous degradation of cyclin B, which eventually triggers the mitotic exit observed. Thus, our data provide evidence for a role of Cenp-meta in sustaining the SAC response.
authors.affiliation: Present address: Department of Genetics and Developmental Biology, Institut Curie, 75248 Paris Cedex 05, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rubin
authors.affiliation: CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, 75205 Paris Cedex 13, France Present address: Department of Genetics and Developmental Biology, Institut Curie, 75248 Paris Cedex 05, France.
authors.forename: Roger E
authors.initials: RE
authors.lastname: Karess
authors.affiliation: CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, 75205 Paris Cedex 13, France Present address: Department of Genetics and Developmental Biology, Institut Curie, 75248 Paris Cedex 05, France. rahmani.zohra@ijm.univ-paris-diderot.fr.
authors.forename: Zohra
authors.initials: Z
authors.lastname: Rahmani
keywords: APC/C; BubR1; Cenp-E; Kinetochore; Metaphase; Mitosis; Spindle assembly checkpoint