Regulation of a Spindle Positioning Factor at Kinetochores by SUMO-Targeted Ubiquitin Ligases.
Dev Cell
; 36(4): 415-27, 2016 Feb 22.
Article
em En
| MEDLINE
| ID: mdl-26906737
ABSTRACT
Correct function of the mitotic spindle requires balanced interplay of kinetochore and astral microtubules that mediate chromosome segregation and spindle positioning, respectively. Errors therein can cause severe defects ranging from aneuploidy to developmental disorders. Here, we describe a protein degradation pathway that functionally links astral microtubules to kinetochores via regulation of a microtubule-associated factor. We show that the yeast spindle positioning protein Kar9 localizes not only to astral but also to kinetochore microtubules, where it becomes targeted for proteasomal degradation by the SUMO-targeted ubiquitin ligases (STUbLs) Slx5-Slx8. Intriguingly, this process does not depend on preceding sumoylation of Kar9 but rather requires SUMO-dependent recruitment of STUbLs to kinetochores. Failure to degrade Kar9 leads to defects in both chromosome segregation and spindle positioning. We propose that kinetochores serve as platforms to recruit STUbLs in a SUMO-dependent manner in order to ensure correct spindle function by regulating levels of microtubule-associated proteins.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Cinetocoros
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Ubiquitina-Proteína Ligases
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Proteínas Associadas aos Microtúbulos
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Microtúbulos
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Fuso Acromático
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article