Protein phosphatase 1 inactivates Mps1 to ensure efficient spindle assembly checkpoint silencing
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal
Abstract
Faithfull genome partitioning during cell division relies on the Spindle Assembly Checkpoint (SAC), a conserved signaling pathway that delays anaphase onset until all chromosomes are attached to spindle microtubules. Mps1 kinase is an upstream SAC regulator that promotes the assembly of an anaphase inhibitor through a sequential multi-target phosphorylation cascade. Thus, the SAC is highly responsive to Mps1, whose activity peaks in early mitosis as a result of its T-loop autophosphorylation. However, the mechanism controlling Mps1 inactivation once kinetochores attach to microtubules and the SAC is satisfied remains unknown. Here we show in vitro and in Drosophila that Protein Phosphatase 1 (PP1) inactivates Mps1 by dephosphorylating its T-loop. PP1-mediated dephosphorylation of Mps1 occurs at kinetochores and in the cytosol, and inactivation of both pools of Mps1 during metaphase is essential to ensure prompt and efficient SAC silencing. Overall, our findings uncover a mechanism of SAC inactivation required for timely mitotic exit.
Article and author information
Author details
Funding
FEDER-Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 (Norte-01-0145-FEDER-000029)
- Margarida Moura
- Claudio E Sunkel
- Carlos Conde
Fundação para a Ciência e a Tecnologia (PTDC7BEX-BCM/1921/2014-PR041602)
- Claudio E Sunkel
Fundação para a Ciência e a Tecnologia (PEst-C/SAU/LA0002/2013-Incentivo2014-BGCT)
- Claudio E Sunkel
Fundação para a Ciência e a Tecnologia (FCT Investigator grant IF/01755/2014)
- Carlos Conde
Fundação para a Ciência e a Tecnologia (GABBA PhD Program grant PD/BD/105746/2014)
- Mariana Osswald
Fundação para a Ciência e a Tecnologia (FCT PhD grant SFRH/BD/87871/2012)
- João Barbosa
European Research Council (PRECISE)
- Helder Maiato
European Research Council (CODECHECK)
- Helder Maiato
FLAD Life Science
- Helder Maiato
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2017, Moura et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 10,534
- views
-
- 735
- downloads
-
- 54
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Further reading
-
- Cell Biology
Distal appendages are ninefold symmetric blade-like structures attached to the distal end of the mother centriole. These structures are critical for the formation of the primary cilium, by regulating at least four critical steps: preciliary vesicle recruitment, recruitment and initiation of intraflagellar transport (IFT), and removal of CP110. While specific proteins that localize to the distal appendages have been identified, how exactly each protein functions to achieve the multiple roles of the distal appendages is poorly understood. Here, we comprehensively analyze known and newly discovered distal appendage proteins (CEP83, SCLT1, CEP164, TTBK2, FBF1, CEP89, KIZ, ANKRD26, PIDD1, LRRC45, NCS1, CEP15) for their precise localization, order of recruitment, and their roles in each step of cilia formation. Using CRISPR-Cas9 knockouts, we show that the order of the recruitment of the distal appendage proteins is highly interconnected and a more complex hierarchy. Our analysis highlights two protein modules, CEP83-SCLT1 and CEP164-TTBK2, as critical for structural assembly of distal appendages. Functional assays revealed that CEP89 selectively functions in the RAB34+ vesicle recruitment, while deletion of the integral components, CEP83-SCLT1-CEP164-TTBK2, severely compromised all four steps of cilium formation. Collectively, our analyses provide a more comprehensive view of the organization and the function of the distal appendage, paving the way for molecular understanding of ciliary assembly.
-
- Cell Biology
- Medicine
In pulmonary hypertension, a combination of metabolic and mechanical dysfunction leads to irreversible vascular damage.
