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Cdc4 phospho-degrons allow differential regulation of Ame1CENP-U protein stability across the cell cycle
- Source :
- eLife, Vol 10 (2021)
- Publication Year :
- 2021
- Publisher :
- eLife Sciences Publications Ltd, 2021.
-
Abstract
- Kinetochores are multi-subunit protein assemblies that link chromosomes to microtubules of the mitotic and meiotic spindle. It is still poorly understood how efficient, centromere-dependent kinetochore assembly is accomplished from hundreds of individual protein building blocks in a cell cycle-dependent manner. Here, by combining comprehensive phosphorylation analysis of native Ctf19CCAN subunits with biochemical and functional assays in the model system budding yeast, we demonstrate that Cdk1 phosphorylation activates phospho-degrons on the essential subunit Ame1CENP-U, which are recognized by the E3 ubiquitin ligase complex SCF-Cdc4. Gradual phosphorylation of degron motifs culminates in M-phase and targets the protein for degradation. Binding of the Mtw1Mis12 complex shields the proximal phospho-degron, protecting kinetochore-bound Ame1 from the degradation machinery. Artificially increasing degron strength partially suppresses the temperature sensitivity of a cdc4 mutant, while overexpression of Ame1-Okp1 is toxic in SCF mutants, demonstrating the physiological importance of this mechanism. We propose that phospho-regulated clearance of excess CCAN subunits facilitates efficient centromere-dependent kinetochore assembly. Our results suggest a novel strategy for how phospho-degrons can be used to regulate the assembly of multi-subunit complexes.
- Subjects :
- cell cycle
kinetochore
SCF
Medicine
Science
Biology (General)
QH301-705.5
Subjects
Details
- Language :
- English
- ISSN :
- 2050084X
- Volume :
- 10
- Database :
- Directory of Open Access Journals
- Journal :
- eLife
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.170bac9637e4eb3923e585b0ad9662b
- Document Type :
- article
- Full Text :
- https://doi.org/10.7554/eLife.67390