Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Cyclin A triggers Mitosis either via Greatwall or Cyclin B

ABSTRACT: Two mitotic Cyclins, A and B, exist in higher eukaryotes, but their specialised functions in mitosis are poorly understood. Using degron tags we analyse how acute depletion of these proteins affects mitosis. Loss of Cyclin A in G2-phase prevents the initial activation of Cdk1. Cells lacking Cyclin B can enter mitosis and phosphorylate most mitotic proteins, because of parallel PP2A:B55 phosphatase inactivation by Greatwall kinase. The final barrier to mitotic establishment corresponds to nuclear envelope breakdown that requires a decisive shift in the balance of Cdk1 and PP2A:B55 activity. Beyond this point Cyclin B/Cdk1 is essential to phosphorylate a distinct subset mitotic Cdk1 substrates that are essential to complete cell division. Our results identify how Cyclin A, B and Greatwall coordinate mitotic progression by increasing levels of Cdk1-dependent substrate phosphorylation. The phosphoproteomics dataset aims to identify substrates that are affected specifically by acute depletion of Cyclin Bprotein.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Epithelial Cell

DISEASE(S): Disease Free

SUBMITTER: Tony Ly

LAB HEAD: Tony Ly

PROVIDER: PXD012100 | Pride | 2020-05-21

REPOSITORIES: Pride

ACCESS DATA

Json Xml

Similar Datasets

Cyclin A/Cdk1 modulates Plk1 activity in prometaphase to regulate k-MT attachment stability

Project description:The fidelity of chromosome segregation in mitosis is safeguarded by the precise regulation of kinetochore microtubule (k-MT) attachment stability. Previously, we demonstrated that Cyclin A/Cdk1 destabilizes k-MT attachments to promote faithful chromosome segregation. Here, we use quantitative phosphoproteomics to identify 156 Cyclin A/Cdk1 substrates in prometaphase. One Cyclin A/Cdk1 substrate is myosin phosphatase targeting subunit 1 (MYPT1), and we show that MYPT1 localization to kinetochores depends on Cyclin A/Cdk1 activity and that MYPT1 destabilizes k-MT attachments by negatively regulating Plk1 at kinetochores. Thus, Cyclin A/Cdk1 phosphorylation primes MYPT1 for Plk1 binding. Interestingly, priming of PBIP1 by Plk1 itself (self-priming) increased in MYPT1-depleted cells showing that MYPT1 provides a molecular link between the processes of Cdk1-dependent priming and self-priming of Plk1 substrates. These data demonstrate cross-regulation between Cyclin A/Cdk1-dependent and Plk1-dependent phosphorylation of substrates during mitosis to ensure efficient correction of k-MT attachment errors necessary for high mitotic fidelity.

2017-12-01 | PXD008316 | Pride

Ordered dephosphorylation initiated by the selective proteolysis of cyclin B drives mitotic exit

Project description:APC/C-mediated proteolysis of cyclin B and securin promotes entry into anaphase, inactivating CDK1 and permitting chromosome segregation, respectively. Reduction of CDK1 activity relieves inhibition of the CDK1-opposing phosphatases PP1 and PP2A-B55 leading to dephosphorylation of substrates crucial for mitotic exit. Meanwhile, continued APC/C activity is required to target various proteins, including Aurora and Polo kinases, for degradation. Together, these activities orchestrate a complex series of events during mitotic exit. However, the relative importance of regulated proteolysis and dephosphorylation in dictating the order and timing of these events remains unclear. Using high temporal-resolution mass spectrometry, we compare the relative extent of proteolysis and protein dephosphorylation. This reveals highly-selective rapid (~5min half-life) proteolysis of cyclin B, securin and geminin at the metaphase to anaphase transition, followed by slow proteolysis (>60 min half-life) of other mitotic regulators. Protein dephosphorylation requires APC/C-dependent destruction of cyclin B and was resolved into PP1-dependent fast, intermediate and slow categories with unique sequence motifs. We conclude that dephosphorylation initiated by the selective proteolysis of cyclin B drives the bulk of changes observed during mitotic exit.

2020-09-04 | PXD019788 | Pride

Ordered dephosphorylation initiated by the selective proteolysis of cyclin B drives mitotic exit

2020-09-04 | PXD019795 | Pride

Ordered dephosphorylation initiated by the selective proteolysis of cyclin B drives mitotic exit

2020-09-04 | PXD019786 | Pride

Ordered dephosphorylation initiated by the selective proteolysis of cyclin B drives mitotic exit

2020-09-04 | PXD019787 | Pride

Ordered dephosphorylation initiated by the selective proteolysis of cyclin B drives mitotic exit

2020-09-04 | PXD019791 | Pride

Identification of CDK1 substrates in mitosis by quantitative phosphoproteomics

Project description:Cyclin-dependent kinase 1 (Cdk1) is an essential regulator of many mitotic processes including the reorganization of the cytoskeleton, chromosome segregation, and formation and separation of daughter cells. Deregulation of Cdk1 activity results in defects in these processes. Although the role of Cdk1 in mitosis is well established, only a limited number of Cdk1 substrates have been identified in mammalian cells. Thus to increase our understanding of Cdk1-dependent phosphorylation pathways in mitosis, we conducted a quantitative phosphoproteomics analysis in mitotic HeLa cells using two small molecule inhibitors of Cdk1, Flavopiridol and RO-3306. In these analyses we identified a total of 24,900 phosphopeptides on 4,274 proteins of which 1215 phosphopeptides on 551 proteins that were significantly reduced by 2.5-fold or more upon Cdk1 inhibitor addition. Comparison of phosphopeptide quantification upon either inhibitor treatment revealed a high degree of correlation (R2 value of 0.87) between the different inhibitor datasets. Motif enrichment analysis of significantly regulated phosphopeptides revealed enrichment of canonical Cdk1 kinase motifs. Interestingly, the majority of proteins identified in this analysis contained 2 or more Cdk1 inhibitor-sensitive phosphorylation sites, are highly connected with other candidate Cdk1 substrates as determined by protein-protein network analysis, are enriched at specific subcellular structures, or are part of protein complexes as identified by the CORUM database. Furthermore, candidate Cdk1 substrates were enriched in G2 and M phase-specific genes. Finally, we validated a subset of candidate Cdk1 substrates by in vitro kinase assays. Our findings provide a valuable resource for the cell signaling and mitosis research community and greatly increase our knowledge of Cdk1 substrates and Cdk1-dependent signaling pathways.

2016-02-24 | MSV000079528 | MassIVE

The Greatwall-Endosulfine switch accelerates autophagic flux during the cell divisions leading to G1 arrest and quiescence in fission yeast

Project description:In fission yeast cell cycle exit, autophagy, G1 arrest and entry into quiescence are coordinated by the activity of the protein phosphatase PP2A/B55 through the Greatwall-Endosulfine switch. In order to study the role of this pathway in the transcriptional changes that occur during entry into quiescence, RNA was extracted from wild-type cells and from four mutant strains at three time points.

2022-11-09 | GSE217398 | GEO

Human Cdc14A is phosphorylated by Cdk1 at early mitosis

Project description:Cdc14 enzymes compose a family of highly conserved phosphatases that are present in a wide range of organisms, including yeast and humans, and that preferentially reverse the phosphorylation of Cyclin-Dependent Kinase (Cdk) substrates. The budding yeast Cdc14 orthologue has essential functions in the control of late mitosis and cytokinesis. In mammals, however, the two Cdc14 homologues, Cdc14A and Cdc14B, do not play a prominent role in controlling late mitotic events, suggesting that some Cdc14 functions are not conserved across species. Moreover, in yeast, Cdc14 is regulated by changes in its subcellular location and by phosphorylation events. In contrast, little is known about the regulation of human Cdc14 phosphatases. Here, we have studied how the human Cdc14A orthologue is regulated during the cell cycle. We found that Cdc14A is phosphorylated on Ser411, Ser453 and Ser549 by Cdk1 early in mitosis and becomes dephosphorylated during late mitotic stages. Interestingly, in vivo and in vitro experiments revealed that, unlike in yeast, Cdk1-mediated phosphorylation of human Cdc14A did not control its catalytic activity but likely modulated its interaction with other proteins in early mitosis. These findings point to differences in Cdk1-mediated mechanisms of regulation between human and yeast Cdc14 orthologues.

2018-08-13 | PXD009481 | Pride

CEP55 is a determinant of cell fate during perturbed mitosis in breast cancer

Project description:The centrosomal protein, CEP55 is a key regulator of cytokinesis and its overexpression is linked to genomic instability, a hallmark of cancer. However, the mechanism by which it mediates genomic instability remains elusive. Here, we showed that CEP55 overexpression/knockdown impacts survival of aneuploid cells. Loss of CEP55 sensitizes breast cancer cells to anti-mitotic agents through premature CDK1/Cyclin B activation and CDK1-Caspase-dependent mitotic cell death. Further, we showed that CEP55 is a downstream effector of the MEK1/2-MYC axis. Blocking MEK1/2-PLK1 signaling therefore reduced outgrowth of basal-like syngeneic and human breast tumors in in-vivo models. In conclusion, high CEP55 levels dictate cell fate during perturbed mitosis. Forced mitotic cell death by blocking MEK1/2-PLK1 represents a potential therapeutic strategy for MYC-CEP55-dependent basal-like, triple-negative breast cancers.

2018-07-14 | GSE117058 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data