Mitotic chromosome condensation requires phosphorylation of the centromeric protein KNL-2 inC. elegans
| Autor: | Reinier F Prosée, Joanna M. Wenda, Caroline Gabus, Florian A. Steiner |
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| Rok vydání: | 2021 |
| Předmět: |
0303 health sciences
Kinetochore macromolecular substances Biology Cell biology Chromosome segregation Mitotic chromosome condensation 03 medical and health sciences 0302 clinical medicine Histone Microtubule Premature chromosome condensation Centromere biology.protein Mitosis 030217 neurology & neurosurgery 030304 developmental biology |
| Popis: | Centromeres are chromosomal regions that serve as sites for kinetochore formation and microtubule attachment, processes that are essential for chromosome segregation during mitosis. Centromeres are almost universally defined by the histone variant CENP-A. In the holocentric nematodeC. elegans, CENP-A deposition depends on the loading factor KNL-2. Depletion of either CENP-A or KNL-2 results in defects in centromere maintenance, chromosome condensation and kinetochore formation, leading to chromosome segregation failure. Here, we show that KNL-2 is phosphorylated by CDK-1, and that mutation of three C-terminal phosphorylation sites causes chromosome segregation defects and an increase in embryonic lethality. In strains expressing phosphodeficient KNL-2, CENP-A and kinetochore proteins are properly localised, indicating that the role of KNL-2 in centromere maintenance is not affected. Instead, the mutant embryos exhibit reduced mitotic levels of condensin II on chromosomes and significant chromosome condensation impairment. Our findings separate the functions of KNL-2 in CENP-A loading and chromosome condensation and demonstrate that KNL-2 phosphorylation regulates the cooperation between centromeric regions and the condensation machinery inC. elegans.SUMMARY STATEMENTPhosphorylation of the essential centromere protein KNL-2 is required for mitotic chromosome condensation, but not for the role of KNL-2 in centromere maintenance and kinetochore formation. |
| Databáze: | OpenAIRE |
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