BUB-1 promotes amphitelic chromosome biorientation via multiple activities at the kinetochore.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30547880.
- Also identified by DOI 10.7554/eLife.40690 and PMC identifier 6303103.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Accurate chromosome segregation relies on bioriented amphitelic attachments of chromosomes to microtubules of the mitotic spindle, in which sister chromatids are connected to opposite spindle poles. BUB-1 is a protein of the Spindle Assembly Checkpoint (SAC) that coordinates chromosome attachment with anaphase onset. BUB-1 is also required for accurate sister chromatid segregation independently of its SAC function, but the underlying mechanism remains unclear. Here we show that, in <i>Caenorhabditis elegans</i> embryos, BUB-1 accelerates the establishment of non-merotelic end-on kinetochore-microtubule attachments by recruiting the RZZ complex and its downstream partner dynein-dynactin at the kinetochore. In parallel, BUB-1 limits attachment maturation by the SKA complex. This activity opposes kinetochore-microtubule attachment stabilisation promoted by CLS-2<sup>CLASP</sup>-dependent kinetochore-microtubule assembly. BUB-1 is therefore a SAC component that coordinates the function of multiple downstream kinetochore-associated proteins to ensure accurate chromosome segregation.
Medical subject headings
- Anaphase
- Caenorhabditis elegans Proteins
- Chromosome Segregation
- Kinetochores
- M Phase Cell Cycle Checkpoints
- Protein Serine-Threonine Kinases
- Spindle Apparatus