The APC/C subunit APC7 promotes hepatocellular carcinoma progression by mediating ubiquitination and degradation of LATS1/2 to activate YAP/TAZ
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE319107 | GEO | 2026/05/15
REPOSITORIES: GEO
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:Spinal muscular atrophy (SMA) due to loss-of-function of SMN protein is associated with severe loss of voluntary muscle control and is a leading inherited cause of infant mortality. SMA treatments will benefit from in-depth knowledge of functional pathways disrupted in disease and identification of SMN modulators. Here, we present a comprehensive temporal profile of proteogenomic expression patterns in developing mouse spinal cords (Δ7 model), alongside endpoint analyses of human spinal and ventral root tissues in SMA disease, identifying targets for assessing disease progression and treatment response. SMA disease results in development-associated deficiencies in transcription, translation initiation, intracellular transport, and protein folding, and diminished RNA translation efficiency for proteins important in axon development/myelination. The broad impact of SMN deficiency prompted the search for co-regulated proteins that modulate SMN protein levels, resulting in identification of the anaphase promoting complex/cyclosome (APC/C) E3 ubiquitin ligase as a potential modulator of SMN protein stability. Functional studies of APC/C showed that both SMN and HuD are specific interactors of the APC/C in neurons and that selective APC/C inhibition significantly limited SMN and HuD degradation. Finally, we demonstrate that APC/C inhibition rescues motor axon defects characteristic of SMA in a zebrafish model of SMA disease.
2022-01-18 | GSE128129 | GEO
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: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:Piwi proteins are normally restricted in germ cells to suppress transposons through association with piRNAs, but are also frequently activated in many types of human cancers. Of great puzzle is the lack of induction of corresponding piRNAs in cancer cells, as we document here in human pancreatic ductal adenocarcinomas (PDAC), implying that such germline-specific proteins are somehow hijacked to promote tumorigenesis through different mode of action. To pursue the underlying mechanism, we now demonstrate that in the absence of piRNAs, the aberrantly induced human PIWIL1 in PDAC functions as an oncoprotein by activating the Anaphase Promoting Complex/Cyclosome (APC/C), which then targets a critical cell adhesion-related protein Pinin to enhance PDAC metastasis. This is in contrast to piRNA-dependent PIWIL1 ubiquitination and removal by APC/C during late spermiogenesis. These findings thus unveil an piRNA-dependent mechanism to switch PIWIL1 from a substrate in spermatids to a co-activator of APC/C in human cancer cells.
2020-02-01 | GSE141340 | GEO
Project description:The anaphase promoting complex/cyclosome (APC/C) is a ubiquitin ligase that controls progression through the eukaryotic cell cycle by targeting key substrates for degradation through the ubiquitin proteasome pathway. During G1, the APC/C works in concert with its co-activator Cdh1 to recognize and ubiquitinate specific substrates during this phase of the cell cycle. While many APC/CCdh1 substrates play a role cell cycle regulation, others are involved in distinct cellular processes, indicating that diverse biological pathways are subject to APC/C-mediated control. To identify novel pathways and substrates regulated by APC/CCdh1, we conducted an unbiased proteomic screen in G1-arrested RPE1 cells acutely treated with small molecule APC/C inhibitors. Combining these results with degron prediction analysis, we discovered a range of putative APC/C substrates. We validated IRS2, a key adaptor protein involved in signaling downstream of the insulin and IGF1 receptors, as a novel direct APC/CCdh1 target. We demonstrate that genetic deletion of IRS2 reduces the expression of proteins involved in cell division and functionally impairs the spindle assembly checkpoint. Together, these findings reveal a novel connection between the insulin/IGF1 signaling network and the cell cycle regulatory machinery.
2020-06-22 | PXD018329 | Pride
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:E3 ubiquitin ligases are the final regulatory enzymes in the ubiquitin cascade, responsible for choosing substrates for ubiquitylation. Despite their central role in governing ubiquitin pathways, technical challenges have precluded development of simple and robust methods to systematically map their substrates. The Anaphase Promoting Complex/Cyclosome (APC/C) is an E3 ligase and master regulator of cell cycle progression and genome maintenance. Here, we develop a sensitive and specific computational strategy to predict APC/C substrates, leveraging orthogonal features among known targets. Interestingly, chromatin regulatory proteins are enriched among putative substrates and we validate several here. We reveal detailed ubiquitylation mechanisms of a key reader and writer of histone modifications, UHRF1, and show that its degradation regulates cell cycle and D methylation maintenance. Our results uncover mechanisms underlying the coordination between cell cycle and the chromatin landscape, and suggest an extensive, post-translational crosstalk with far-reaching consequences in normal cell physiology and disease.
2020-09-23 | GSE137913 | GEO
Project description:Mammalian cells entering the cell cycle favor glycolysis to rapidly generate ATP and produce the biosynthetic intermediates required for rapid biomass accumulation. Simultaneously, the ubiquitin ligase Anaphase-Promoting Complex/Cyclosome (APC/C)-Cdh1 remains active, allowing origin licensing and blocking premature DNA replication. Paradoxically, glycolysis is reduced by APC/CCdh1 through the degradation of key glycolytic enzymes, raising the question of how cells coordinate these mutually exclusive events to ensure proper cell division. Here we show that cells resolve this paradox by transiently inactivating the APC/C during cell cycle entry, which allows a transient metabolic shift favoring glycolysis. Upon mitogen stimulation, rapid mTOR-mediated phosphorylation of the APC/C adapter protein Cdh1 at the N-terminus causes it to partially dissociate from the APC/C. This partial inactivation of the APC/C leads to the accumulation of PFKFB3, a rate-limiting enzyme for glycolysis, promoting a metabolic shift towards glycolysis. Delayed accumulation of phosphatase activity later removes Cdh1 phosphorylation, restoring full APC/C activity, and shifting cells back to favoring oxidative phosphorylation. Thus, cells coordinate the simultaneous demands of cell cycle progression and metabolism through an incoherent feedforward loop, which transiently inhibits APC/C activity to generate a pulse of glycolysis that is required for mammalian cell cycle entry.
2025-06-12 | MSV000098175 | MassIVE
Project description:Cellular proliferation is highly regulated to ensure proper tissue homeostasis and to prevent diseases such as cancer. In actively proliferating cells, entry into S phase of the cell cycle and initiation of DNA replication is promoted by inactivation of the E3 ubiquitin ligase APC/C (anaphase promoting complex/cyclosome), though the critical S phase-promoting substrates have not been fully elucidated. The APC/C is also active in cells that have exited the cell cycle and entered an arrested state, but whether APC/C activity is essential to maintain arrest is unclear. We found that APC/C inactivation is sufficient to bypass cellular arrest induced by the CDK4/6 inhibitor Palbociclib. To identify potential APC/C substrates responsible for driving the escape from cell cycle arrest, we arrested cells using Palbociclib and then induced EMI1, inactivating the APC/C. Samples were collected at 0, 8, 16 and 20h after arrest and analyzed using proteomics. We found that inactivation of the APC/C promotes cell cycle re-entry by inducing RB phosphorylation and E2F-dependent gene transcription. Stabilization of both cyclin A and cyclin B contributes to arrest bypass, but only cyclin A accumulation is absolutely required. Direct expression of APC/C-resistant cyclin A, but not cyclin B, in arrested cells induces S phase entry analogous to APC/C inactivation. Cells bypassing arrest initiate DNA replication with severely reduced origin licensing, at least in part due to premature geminin accumulation. As a result, cells exhibit reduced rates of DNA synthesis, which leads to the accumulation of replication stress and long-term proliferation defects. Our findings suggest that CDK4/6 inhibition in cancers with reduced APC/C activity may be ineffective at promoting cytostatic cell cycle arrest but may nonetheless lead to elevated levels of replication stress that ultimately leads to a more durable cell cycle withdrawal.
2024-07-18 | PXD046783 | Pride