Characterization of the pocket mutant of cyclin B1
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Q Exactive HF-X, Orbitrap Exploris 480
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Permanent Cell Line Cell, Cell Culture
SUBMITTER: 
Tanja Bange
LAB HEAD: Tanja Bange
PROVIDER: PXD047204 | Pride | 2025-04-03
REPOSITORIES: Pride
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| 20220411_TB_SA_TM_HeLa_M_1.raw | Raw | |||
| 20220411_TB_SA_TM_HeLa_M_2.raw | Raw | |||
| 20220411_TB_SA_TM_HeLa_M_3.raw | Raw | |||
| 20220411_TB_SA_TM_HeLa_WT_1.raw | Raw | |||
| 20220411_TB_SA_TM_HeLa_WT_2.raw | Raw |
Items per page: 5 1 - 5 of 43 |
Similar Datasets
Project description:The proper control of mitosis depends on the ubiquitin-mediated degradation of the right mitotic regulator at the right time. This is under the control of the anaphase promoting complex/cyclosome (APC/C) ubiquitin ligase that is regulated by the Spindle Assembly Checkpoint (SAC). The Checkpoint prevents the APC/C from recognizing Cyclin B1, the essential anaphase and cytokinesis inhibitor, until all chromosomes are attached to the spindle. Once chromosomes are attached, Cyclin B1 is rapidly degraded to enable chromosome segregation and cytokinesis. We have a good understanding of how the SAC inhibits the APC/C, but relatively little is known about how the APC/C recognises Cyclin B1 as soon as the SAC is turned off. Here, by combining live cell imaging, in vitro reconstitution, biochemistry, and structural analysis by cryo-electron microscopy, we provide evidence that the rapid recognition of Cyclin B1 in metaphase requires spatial regulation of the APC/C. Using fluorescence cross correlation spectroscopy, we find that Cyclin B1 and the APC/C primarily interact at the mitotic apparatus. We further show that this is because Cyclin B1, like the APC/C, binds to nucleosomes, and identify an ‘arginine-anchor’ in the N-terminus as necessary and sufficient for binding to the nucleosome. Mutating the nucleosome binding motif on Cyclin B1 reduces its interaction with APC/C and delays its degradation, and cells with the mutant, non-nucleosome-binding Cyclin B1 become aneuploid, demonstrating the physiological relevance of our findings. Together, our data demonstrate that mitotic chromosomes constitute a platform to promote the efficient interaction between Cyclin B1 and APC/C and ensure the timely degradation of Cyclin B1 and genomic stability.
2025-05-06 | PXD046458 | Pride
Project description:The proper control of mitosis depends on the ubiquitin-mediated degradation of the right mitotic regulator at the right time. This is under the control of the anaphase promoting complex/cyclosome (APC/C) ubiquitin ligase that is regulated by the Spindle Assembly Checkpoint (SAC). The Checkpoint prevents the APC/C from recognizing Cyclin B1, the essential anaphase and cytokinesis inhibitor, until all chromosomes are attached to the spindle. Once chromosomes are attached, Cyclin B1 is rapidly degraded to enable chromosome segregation and cytokinesis. We have a good understanding of how the SAC inhibits the APC/C, but relatively little is known about how the APC/C recognises Cyclin B1 as soon as the SAC is turned off. Here, by combining live cell imaging, in vitro reconstitution, biochemistry, and structural analysis by cryo-electron microscopy, we provide evidence that the rapid recognition of Cyclin B1 in metaphase requires spatial regulation of the APC/C. Using fluorescence cross correlation spectroscopy, we find that Cyclin B1 and the APC/C primarily interact at the mitotic apparatus. We further show that this is because Cyclin B1, like the APC/C, binds to nucleosomes, and identify an ‘arginine-anchor’ in the N-terminus as necessary and sufficient for binding to the nucleosome. Mutating the nucleosome binding motif on Cyclin B1 reduces its interaction with APC/C and delays its degradation, and cells with the mutant, non-nucleosome-binding Cyclin B1 become aneuploid, demonstrating the physiological relevance of our findings. Together, our data demonstrate that mitotic chromosomes constitute a platform to promote the efficient interaction between Cyclin B1 and APC/C and ensure the timely degradation of Cyclin B1 and genomic stability.
2025-05-07 | PXD052677 | Pride
Project description:Phosphorylation of substrates by cyclin-dependent kinases (CDKs) is the driving force of cell cycle progression. Several CDK-activating cyclins are involved, yet how they contribute to substrate specificity is still poorly understood. Here, we discovered that a positively charged pocket in cyclin B1, which is exclusively conserved within B-type cyclins and binds phosphorylated serine- or threonine-residues as well as acidic side chains, is essential for correct execution of mitosis. HeLa cells expressing pocket mutant cyclin B1 are strongly delayed in anaphase onset due to multiple defects in mitotic spindle function and timely activation of the E3-ligase APC/C. Non-functional pocket results in decreased APC/C phosphorylation at non-consensus CDK1 sites, compromised in vitro ubiquitylation activity, and reduced binding of the E2-enzyme UBE2S. Our results support a model in which cyclin B1’s pocket serves as specificity factor for sequential substrate phosphorylations involving initial priming events facilitating subsequent pocket-dependent phosphorylations at non-consensus CDK1 motifs.
2025-05-06 | PXD048838 | Pride
Project description:After severe renal injury, renal tubular epithelial cells (TECs) will be arrested in G2/M phase, and the arrested cells will be aging, showing senescence related secretory phenotype (SASP), which mediates renal fibrosis by secreting fibrogenic cytokines. Cyclin B1 is an important protein that promotes G2/M phase transition of cell cycle. Its role in renal fibrosis mediated by G2/M arrest of TECs is unknown. The aim of this study was to investigate the role of cyclin B1 in renal fibrosis induced by TECs G2/M arrest and its mechanism
2024-01-01 | GSE224039 | GEO
Project description:Tight regulation of the APC/C-Cdc20 ubiquitin ligase that targets Cyclin B1 for degradation is important for mitotic fidelity. The spindle assembly checkpoint (SAC) inhibits Cdc20 through the mitotic checkpoint complex (MCC). In addition, phosphorylation of Cdc20 by Cyclin B1-Cdk1 independently inhibits APC/C-Cdc20 activation. This creates a conundrum for how Cdc20 gets activated prior to Cyclin B1 degradation. Here we show that the MCC component BubR1 harbours both Cdc20 inhibition and activation activities, allowing for cross-talk between the two Cdc20 inhibition pathways. Specifically BubR1 acts as a substrate specifier for PP2A-B56 to enable efficient Cdc20 dephosphorylation in the MCC. A mutant Cdc20 mimicking the dephosphorylated state escapes a mitotic checkpoint arrest arguing that restricting Cdc20 dephosphorylation to the MCC is important. Collectively our work reveals how Cdc20 can be dephosphorylated in the presence of Cyclin B1-Cdk1 activity without causing premature anaphase onset.
2021-02-18 | MSV000086910 | MassIVE
Project description:Mitosis in early embryos often proceeds at a rapid pace, but how this pace is achieved is not understood. Here we show that cyclin B3 is the dominant driver of rapid embryonic mitoses in the C. elegans embryo. Cyclins B1 and B2 support slow mitosis (NEBD to Anaphase ~600s) but the presence of cyclin B3 dominantly drives the ~3-fold faster mitosis observed in wildtype. Multiple mitotic events are slowed down in Cyclin B1&B2-driven mitosis and cyclin B3-associated Cdk1 H1 kinase activity is ~25-fold more active than cyclin B1-associated Cdk1. Addition of cyclin B1 to fast cyclin B3-only mitosis introduces an ~60s delay between completion of chromosome alignment and anaphase onset; this delay, which is important for segregation fidelity, is dependent on inhibitory phosphorylation of the anaphase activator Cdc20. Thus, cyclin B3 dominance, coupled to a cyclin B1-dependent delay that acts via Cdc20 phosphorylation, sets the rapid pace and ensures mitotic fidelity in the early C. elegans embryo.
2024-07-29 | PXD053811 | Pride
Project description:Analysis of mammary glands from tet-inducible(rtTA) transgenic mice expressing cyclin D1 using Affymetrix Mouse Gene 1.0 ST GeneChip arrays. MMTV-rtTA transgenic mice (MMTV-Mouse Mammary Tumor Virus promoter) were cross-mated to cyclin D1 transgenic mice under control of tet operon. 8-week-old tetracycline-inducible cyclin D1/rtTA bi-transgenic pregnant female mice (12 days postcoitus) were treated with doxycycline through drinking water supplementation at a final concentration of 2 mg/ml. Control mice were rtTA transgenics alone and treated in the same manner. After 7 days of doxycycline treatment, the mice were sacrificed and mammary glands taken for RNA isolation. Results provide insight into the in vivo gene expression pattern regulated by cyclin D1 through acute induction. Analysis of mammary glands from MMTV-cyclin D1/WT and MMTV-cyclin D1/KE using Affymetrix Mouse 430A v2.0 GeneChip arrays. Cyclin D1 point mutant, cyclin D1/KE K112E (K112E) contains a lysine to glutamine substitution at amino acid position 112. cyclin D1. The cyclin D1/KE mutant fails to induce cyclin D1-dependent kinase activity. Female MFD1, MFD1-KE, and WT mice were monitored twice weekly, up to 760 days, for the development of palpable tumors. Those developing palpable tumors were sacrificed within a week of tumor detection. Tumors were dissected and portions snap frozen for RNA isolation. Results provide insight into the in vivo gene expression pattern regulated by cyclin D1 that is kinase independent. Two separate control mice were positive for MMTV-rtTA transgene compared to 3 separate cyclin D1/rtTA bitransgenic female mice and 3 separate cyclin D1 KE mutant/rtTA bitransgenic female mice (Mouse Gene 1.0 ST arrays). Three separate control WT FvBmice were compared to three MMTV-cyclin D1/WT and 3 MMTV-cyclin D1/KE mice (Mouse 430A v2.0 arrays).
2013-12-31 | E-GEOD-43216 | biostudies-arrayexpress
Project description:Analysis of mammary glands from tet-inducible(rtTA) transgenic mice expressing cyclin D1 using Affymetrix Mouse Gene 1.0 ST GeneChip arrays. MMTV-rtTA transgenic mice (MMTV-Mouse Mammary Tumor Virus promoter) were cross-mated to cyclin D1 transgenic mice under control of tet operon. 8-week-old tetracycline-inducible cyclin D1/rtTA bi-transgenic pregnant female mice (12 days postcoitus) were treated with doxycycline through drinking water supplementation at a final concentration of 2 mg/ml. Control mice were rtTA transgenics alone and treated in the same manner. After 7 days of doxycycline treatment, the mice were sacrificed and mammary glands taken for RNA isolation. Results provide insight into the in vivo gene expression pattern regulated by cyclin D1 through acute induction. Analysis of mammary glands from MMTV-cyclin D1/WT and MMTV-cyclin D1/KE using Affymetrix Mouse 430A v2.0 GeneChip arrays. Cyclin D1 point mutant, cyclin D1/KE K112E (K112E) contains a lysine to glutamine substitution at amino acid position 112. cyclin D1. The cyclin D1/KE mutant fails to induce cyclin D1-dependent kinase activity. Female MFD1, MFD1-KE, and WT mice were monitored twice weekly, up to 760 days, for the development of palpable tumors. Those developing palpable tumors were sacrificed within a week of tumor detection. Tumors were dissected and portions snap frozen for RNA isolation. Results provide insight into the in vivo gene expression pattern regulated by cyclin D1 that is kinase independent.
2013-12-31 | GSE43216 | GEO
Project description:In eukaryotes, cyclin/CDK complexes drive cells through DNA replication and mitosis, establising cell cycle temporal order. The fission yeast S. pombe is able to function with a single cyclin/CDK complex, with cell cycle order emerging from differential substrate sensitivities to CDK activity. What influence cyclin specificity has upon the cell cycle in this situation is currently unknown. Here we show that in a system that is reliant on a single cyclin for both the G1/S and G2/M transition, cyclin specificity is not needed for the G1/S transition, but instead is required for the G2/M transition and correct localisation of cyclin/CDK to the yeast centrosome equivalent, the SPB. This loss of centrosome localisation was also seen in human cells expressing mutant Cyclin B1, suggesting conservation of function. In fission yeast, although interphase centrosomal localisation is lost, mitotic SPB localisation remains. This hitherto unknown second localisation method is dependent on Polo kinase, suggesting a finer spatiotemporal control of cyclin/CDK during cell cycle progression than previously known. Thus, cyclin specificity is intrinsically twinned with spatial control of cyclin/CDK, and we suggest that this regulation may be conserved through evolution.
2019-05-27 | PXD011987 | Pride
Project description:How the cell rapidly and completely reorganises its architecture when it divides is a problem that has fascinated for almost 150 years. We now know that the core regulatory machinery is highly conserved in eukaryotes but how these multiple protein kinases, protein phosphatases, and ubiquitin ligases are coordinated in space and time to remodel the cell in a matter of minutes remains a major question. Cyclin B-Cdk is the primary kinase that drives mitotic remodelling and here we show that it is targeted to the nuclear pore complex (NPC) by binding an acidic face of the kinetochore checkpoint protein, MAD1, where it coordinates NPC disassembly with kinetochore assembly. This localised Cyclin B1-Cdk1 activity is needed for the proper release of MAD1 from the embrace of TPR at the nuclear pore so that it can be recruited to kinetochores before nuclear envelope breakdown to maintain genomic stability.
2020-06-29 | PXD017202 | Pride