APC/CCdc20 dependent degradation of Clb4 is all there is to astral microtubule stabilization
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion Lumos
ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)
SUBMITTER: 
Jiaming Li
LAB HEAD: Steven P. Gygi
PROVIDER: PXD028828 | Pride | 2022-10-19
REPOSITORIES: Pride
Similar Datasets
Project description:The spindle checkpoint is a mitotic surveillance system which ensures equal segregation of sister chromatids. It delays anaphase onset by inhibiting the action of the E3 ubiquitin ligase known as the anaphase promoting complex or cyclosome (APC/C). Mads/BubR1 is a key component of the mitotic checkpoint complex (MCC) which binds and inhibits the APC/C early in mitosis. Mps1Mph1 kinase is critical for checkpoint signalling and MCC-APC/C inhibition, yet few substrates have been identified. Here we identify Mad3 as a substrate of fission yeast Mps1Mph1 kinase. We map and mutate phosphorylation sites in Mad3, producing mutants that are targeted to kinetochores and assembled into MCC, yet display reduced APC/C binding and are unable to maintain checkpoint arrests. We chow biochemically that Mad3 phospho-mimics are potent APC/C inhibitors in vitro, demonstrating that Mad3p modification can directly influence Cdc20Slp1-APC/C activity. This genetic dissection of APC/C inhibition demonstrates that Mps1Mph1 kinase-dependant modification of Mad3 and Mad2 act in a concerted manner to maintain spindle checkpoint arrests.
2016-03-31 | PXD003806 | Pride
Project description:Most human tumors have abnormal numbers of chromosomes, a condition known as aneuploidy. The mitotic checkpoint is an important mechanism that prevents aneuploidy through restraining the activity of the anaphase-promoting complex (APC). USP44 was identified as a key regulator of APC activation that maintains the association of MAD2 with the APC co-activator Cdc20. However, the physiological importance of USP44 and its impact on cancer biology are unknown. Here, we show that USP44 is required to prevent tumors in mice and is frequently down-regulated in human lung cancer. USP44 inhibits chromosome segregation errors independently of its role in the mitotic checkpoint by regulating proper centrosome separation, positioning, and mitotic spindle geometry, functions that require direct binding to the centriole protein, centrin. These data reveal a new role for the ubiquitin system in mitotic spindle regulation and underscore the importance of USP44 in the pathogenesis of human cancer.
2013-09-01 | GSE40791 | GEO
Project description:Most human tumors have abnormal numbers of chromosomes, a condition known as aneuploidy. The mitotic checkpoint is an important mechanism that prevents aneuploidy through restraining the activity of the anaphase-promoting complex (APC). USP44 was identified as a key regulator of APC activation that maintains the association of MAD2 with the APC co-activator Cdc20. However, the physiological importance of USP44 and its impact on cancer biology are unknown. Here, we show that USP44 is required to prevent tumors in mice and is frequently down-regulated in human lung cancer. USP44 inhibits chromosome segregation errors independently of its role in the mitotic checkpoint by regulating proper centrosome separation, positioning, and mitotic spindle geometry, functions that require direct binding to the centriole protein, centrin. These data reveal a new role for the ubiquitin system in mitotic spindle regulation and underscore the importance of USP44 in the pathogenesis of human cancer. Study included 100 non-neoplastic (N) lung samples, and 69, 12, and 13 stage I, II, and II lung adenocarcinoma (AD) frozen tissues, respectively. Expression levels of Usp44 in different stages of AD was compared against N.
2013-09-01 | E-GEOD-40791 | biostudies-arrayexpress
Project description:The Anaphase Promoting Complex/Cyclosome (APC/C) is a mega-dalton ubiquitin ligase that initiates mitotic exit by targeting substrates for degradation. The APC/C is activated by Cdc20, which acts as a substrate receptor, and is inhibited by the mitotic checkpoint complex (MCC), which delays mitotic exit when the spindle assembly checkpoint (SAC) is activated. We previously identified apcin, a small molecule ligand of Cdc20, as an inhibitor of APC/CCdc20. Surprisingly, we found that apcin paradoxically accelerates substrate degradation and promotes mitotic exit in cells with high SAC activity. Biochemical studies indicate that apcin cooperates with p31comet to relieve MCC-dependent inhibition of APC/C. Apcin’s behavior as an antagonist of Cdc20 can thus result in either net inhibition of APC/C, delaying mitotic exit when SAC activity is slow, or net activation of APC/C, promoting mitotic exit when SAC activity is high. Genetic experiments suggest that the dual behaviors of apcin arise from targeting a common binding site in Cdc20 that is required for both substrate ubiquitination as well as efficient APC/C inhibition by MCC. We therefore establish a new mechanism through which a small molecule, by targeting a single site on a dynamic protein interface, can lead to opposing biological effects depending on the regulatory context.
2020-01-07 | PXD013786 | Pride
Project description:The cell division cycle culminates in mitosis when two daughter cells are born. As cyclin-dependent kinase (Cdk) activity reaches its peak, the Anaphase Promoting Complex (APC) is activated to trigger sister chromatid separation and mitotic spindle elongation, followed by spindle disassembly and cytokinesis. Degradation of mitotic cyclins and activation of Cdk-counteracting phosphatases are thought to cause protein dephosphorylation to control these sequential events. Here, we use budding yeast to analyze phosphorylation dynamics of 3456 phosphosites on 1101 proteins with high temporal resolution as cells progress synchronously through mitosis. This illustrates sequential protein dephosphorylation and reveals that the order arises from successive inactivation of S and M phase Cdks and of the mitotic kinase Polo. Unexpectedly, we detect as many new phosphorylation events as there are dephosphorylation events. These correlate with late mitotic kinase activation and identify numerous candidate targets of these kinases. Our findings revise our view of mitotic exit and portray it as a dynamic process in which a range of mitotic kinases instruct the order of both protein dephosphorylation as well as phosphorylation.
2018-10-15 | PXD008327 | Pride
Project description:Ibrahim2008 - Mitotic Spindle Assembly Checkpoint - Convey variant
The Mitotic Spindle Assembly Checkpoint ((M)SAC) is an evolutionary conserved mechanism. This model incorporates the perspectives of three central control pathways, namely Mad1/Mad2 induced Cdc20 sequestering based on the Template Model, MCC formation, and APC inhibition. MCC:APC dissociation is described by two alternatives models, namely the "Dissociation" and the "Convey" model variants. Both these model are available in BioModels Database. This model corresponds to the "Convey" variant.
This model is described in the article:
In-silico modeling of the mitotic spindle assembly checkpoint.
Ibrahim B, Diekmann S, Schmitt E, Dittrich P
PLoS One. 2008 Feb 6;3(2):e1555.
Abstract:
BACKGROUND: The Mitotic Spindle Assembly Checkpoint ((M)SAC) is an evolutionary conserved mechanism that ensures the correct segregation of chromosomes by restraining cell cycle progression from entering anaphase until all chromosomes have made proper bipolar attachments to the mitotic spindle. Its malfunction can lead to cancer.
PRINCIPLE FINDINGS: We have constructed and validated for the human (M)SAC mechanism an in silico dynamical model, integrating 11 proteins and complexes. The model incorporates the perspectives of three central control pathways, namely Mad1/Mad2 induced Cdc20 sequestering based on the Template Model, MCC formation, and APC inhibition. Originating from the biochemical reactions for the underlying molecular processes, non-linear ordinary differential equations for the concentrations of 11 proteins and complexes of the (M)SAC are derived. Most of the kinetic constants are taken from literature, the remaining four unknown parameters are derived by an evolutionary optimization procedure for an objective function describing the dynamics of the APC:Cdc20 complex. MCC:APC dissociation is described by two alternatives, namely the "Dissociation" and the "Convey" model variants. The attachment of the kinetochore to microtubuli is simulated by a switching parameter silencing those reactions which are stopped by the attachment. For both, the Dissociation and the Convey variants, we compare two different scenarios concerning the microtubule attachment dependent control of the dissociation reaction. Our model is validated by simulation of ten perturbation experiments.
CONCLUSION: Only in the controlled case, our models show (M)SAC behaviour at meta- to anaphase transition in agreement with experimental observations. Our simulations revealed that for (M)SAC activation, Cdc20 is not fully sequestered; instead APC is inhibited by MCC binding.
This model describes the controlled dissociation variant of the mitotic spindle assembly checkpoint. If the tool you use has problems with events, you can uncomment the assignment rules for u and u_prime and comment out the list of events.
In accordance with the authors due to typos in the original publication some initial conditions and parameters were slightly changed in the model:
article
model
[O-Mad2]
1.5e-7 M
1.3e-7 M
[BubR1:Bub3]
1.30e-7 M
1.27e-7 M
k -4
0.01 M -1
s -1
0.02 M -1
s -1
k -5
0.1 M -1
s -1
0.2 M -1
s -1
This model is hosted on BioModels Database
and identified by: MODEL6655578762
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication
for more information.
2008-09-01 | BIOMD0000000187 | BioModels
Project description:Ibrahim2008 - Mitotic Spindle Assembly Checkpoint - Dissociation variant
The Mitotic Spindle Assembly Checkpoint ((M)SAC) is an evolutionary conserved mechanism. This model incorporates the perspectives of three central control pathways, namely Mad1/Mad2 induced Cdc20 sequestering based on the Template Model, MCC formation, and APC inhibition. MCC:APC dissociation is described by two alternatives models, namely the "Dissociation" and the "Convey" model variants. Both these model are available in BioModels Database. This model corresponds to the "Dissociation" variant.
This model is described in the article:
In-silico modeling of the mitotic spindle assembly checkpoint.
Ibrahim B, Diekmann S, Schmitt E, Dittrich P
PLoS One. 2008 Feb 6;3(2):e1555.
Abstract:
BACKGROUND: The Mitotic Spindle Assembly Checkpoint ((M)SAC) is an evolutionary conserved mechanism that ensures the correct segregation of chromosomes by restraining cell cycle progression from entering anaphase until all chromosomes have made proper bipolar attachments to the mitotic spindle. Its malfunction can lead to cancer.
PRINCIPLE FINDINGS: We have constructed and validated for the human (M)SAC mechanism an in silico dynamical model, integrating 11 proteins and complexes. The model incorporates the perspectives of three central control pathways, namely Mad1/Mad2 induced Cdc20 sequestering based on the Template Model, MCC formation, and APC inhibition. Originating from the biochemical reactions for the underlying molecular processes, non-linear ordinary differential equations for the concentrations of 11 proteins and complexes of the (M)SAC are derived. Most of the kinetic constants are taken from literature, the remaining four unknown parameters are derived by an evolutionary optimization procedure for an objective function describing the dynamics of the APC:Cdc20 complex. MCC:APC dissociation is described by two alternatives, namely the "Dissociation" and the "Convey" model variants. The attachment of the kinetochore to microtubuli is simulated by a switching parameter silencing those reactions which are stopped by the attachment. For both, the Dissociation and the Convey variants, we compare two different scenarios concerning the microtubule attachment dependent control of the dissociation reaction. Our model is validated by simulation of ten perturbation experiments.
CONCLUSION: Only in the controlled case, our models show (M)SAC behaviour at meta- to anaphase transition in agreement with experimental observations. Our simulations revealed that for (M)SAC activation, Cdc20 is not fully sequestered; instead APC is inhibited by MCC binding.
This model describes the controlled dissociation variant of the mitotic spindle assembly checkpoint. If the tool you use has problems with events, you can uncomment the assignment rules for u and u_prime and comment out the list of events.
In accordance with the authors due to typos in the original publication some initial conditions and parameters were slightly changed in the model:
article
model
[O-Mad2]
1.5e-7 M
1.3e-7 M
[BubR1:Bub3]
1.30e-7 M
1.27e-7 M
k -4
0.01 M -1
s -1
0.02 M -1
s -1
k -5
0.1 M -1
s -1
0.2 M -1
s -1
This model is hosted on BioModels Database
and identified by: MODEL6655615431
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication
for more information.
2008-09-02 | BIOMD0000000186 | BioModels
Project description:Accurate chromosome segregation is coordinated by the spindle assembly checkpoint (SAC) through its effector the mitotic checkpoint complex (MCC), to inhibit the anaphase-promoting complex or cyclosome (APC/C). Cdc20 is an essential mitotic regulator since it promotes mitotic exit through activating the APC/C and monitors kinetochore-microtubule attachment through activating the SAC. The proper functioning of Cdc20 requires multiple interactions with APC/C and MCC subunits. To functionally assess each of these interactions within cells requires efficient depletion of endogenous Cdc20, which is highly difficult to achieve by RNAi. Here we generated Cdc20 RNAi sensitive cell lines by CRISPR/Cas9 which display a penetrant metaphase arrest phenotype by a single RNAi treatment. In this null background, we accurately measured the contribution of each known motif of Cdc20 on APC/C and SAC activation. The CRY box, a previously identified degron was found to be critical for the SAC by promoting theMCC formation and stabilizing the interaction between the MCC and APC/C. These data reveal additionalregulatory components within the SAC and establish a novel method to interrogate Cdc20 function.
2023-12-06 | PXD045411 | Pride
Project description:In budding yeast, the Mitotic Exit Network (MEN), a GTPase signaling cascade integrates spatial and temporal signals to promote exit from mitosis. This signal integration requires transmission of a signal created on the cytoplasmic face of the spindle pole bodies (SPBs, functional equivalent of the centrosome in yeast) to the nucleolus, where the MEN effector protein Cdc14 resides. In this study, we show that the MEN activating signal at SPBs is relayed to Cdc14 in the nucleolus through the dynamic localization of its terminal kinase complex Dbf2-Mob1. Cdc15, the protein kinase that activates Dbf2-Mob1 at SPBs, also regulates its nuclear access. Once in the nucleus, priming phosphorylation by the Polo kinase Cdc5 targets Dbf2-Mob1 to the nucleolus. Cdc5 phosphorylates the Cdc14 nucleolar anchor Cfi1/Net1 creating a phospho-binding site for Dbf2-Mob1 which allows Dbf2-Mob1 to phosphorylate Cfi1/Net1 and Cdc14, which activates Cdc14. The mechanisms governing intracellular signal transmission that we uncovered in the MEN – regulated nuclear access and effector activation through priming kinases - may well serve as paradigms for intracellular signal transmission in general. As for phosphoproteomics, our analyses suggest a simple model where Cdc5 and Dbf2-Mob1 phosphorylate Cfi1/Net1 to bring about the release of Cdc14 from its inhibitor. Previous studies have shown that Cfi1/Net1 is a highly phosphorylated protein. To map sites in Cfi1/Net1 that are phosphorylated in a CDC5 or MEN-dependent manner, we performed phosphoproteomics analyses on wild-type anaphase cells and cells in which Cdc5 or Cdc15 were inhibited. We synchronized wild-type, cdc5-as1 and cdc15-as1 cells in G1 with α-factor pheromone and released them into the cell cycle with the corresponding inhibitors. Cultures enriched in anaphase cells as judged by anaphase spindle formation (~70% for wild-type cells and ~95% for cdc5-as1 and cdc15-as1 cells) were collected and processed for a reproducible data-independent acquisition mass spectrometry (DIA-MS) analysis with 7 technical replicates for each sample. Also, 10 out of 12 CDC5-only sites identified in anaphase cells are already phosphorylated in cells arrested in metaphase using the microtubule depolymerizing drug nocodazole with 6 of them were also determined to be CDC5-dependent in metaphase, which is consistent with the finding that Cdc5 is already active in metaphase.
2021-01-14 | PXD020369 | Pride
Project description:The spindle assembly checkpoint (SAC) is an evolutionarily conserved mechanism, exclusively sensitive to the states of kinetochores attached to microtubules. During metaphase, the anaphase-promoting complex/cyclosome (APC/C) is inhibited by the SAC but it rapidly switches to its active form following proper attachment of the final spindle. It had been thought that APC/C activity is an all-or-nothing response, but recent findings have demonstrated that it switches steadily. In this study, we develop a detailed mathematical model that considers all 92 human kinetochores and all major proteins involved in SAC activation and silencing. We perform deterministic and spatially-stochastic simulations and find that certain spatial properties do not play significant roles. Furthermore, we show that our model is consistent with in-vitro mutation experiments of crucial proteins as well as the recently-suggested rheostat switch behavior, measured by Securin or CyclinB concentration. Considering an autocatalytic feedback loop leads to an all-or-nothing toggle switch in the underlying core components, while the output signal of the SAC still behaves like a rheostat switch. The results of this study support the hypothesis that the SAC signal varies with increasing number of attached kinetochores, even though it might still contain toggle switches in some of its components.
2024-01-24 | MODEL1812210002 | BioModels