A functional map of DNA-associated proteolysis
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE33821 | GEO | 2013/12/01
SECONDARY ACCESSION(S): PRJNA148047
REPOSITORIES: GEO
Similar Datasets
Project description:We established an assay to localize DNA-associated proteins that are slated for degradation by the ubiquitin-proteasome system. The genome-wide map we describe here ties proteolysis to active enhancer elements and to transcription start sites of specific gene families. ChIP-sequencing of ubiquitin and transcription factors was performed in the presence or absence of proteasome inhibition.
2013-12-01 | E-GEOD-33821 | biostudies-arrayexpress
Project description:Proctor2007 - Age related decline of proteolysis, ubiquitin-proteome system
This
is a stochastic model of the ubiquitin-proteasome system for a
generic pool of native proteins (NatP), which have a half-life of
about 10 hours under normal conditions. It is assumed that these
proteins are only degraded after they have lost their native
structure due to a damage event. This is represented in the model
by the misfolding reaction which depends on the level of reactive
oxygen species (ROS) in the cell. Misfolded proteins (MisP) are
first bound by an E3 ubiquitin ligase. Ubiquitin (Ub) is
activated by E1 (ubiquitin-activating enzyme) and then passed to
E2 (ubiquitin-conjugating enzyme). The E2 enzyme then passes the
ubiquitin molecule to the E3/MisP complex with the net effect
that the misfolded protein is monoubiquitinated and both E2 and
E3 are released. Further ubiquitin molecules are added in a
step-wise manner. When the chain of ubiquitin molecules is of
length 4 or more, the polyubiquitinated misfolded protein may
bind to the proteasome. The model also includes de-ubiquitinating
enzymes (DUB) which cleave ubiquitin molecules from the chain in
a step-wise manner. They work on chains attached to misfolded
proteins both unbound and bound to the proteasomes. Misfolded
proteins bound to the proteasome may be degraded releasing
ubiquitin. Misfolded proteins including ubiquitinated proteins
may also aggregate. Aggregates (AggP) may be sequestered
(Seq_AggP) which takes them out of harm's way or they may bind to
the proteasome (AggP_Proteasome). Proteasomes bound by aggregates
are no longer available for protein degradation.
Figure
2 and Figure 3 has been simulated using Gillespie2.
This model is described in the article:
An in silico model of the
ubiquitin-proteasome system that incorporates normal
homeostasis and age-related decline.
Proctor CJ, Tsirigotis M, Gray
DA.
BMC Syst Biol 2007; 1: 17
Abstract:
BACKGROUND: The ubiquitin-proteasome system is responsible
for homeostatic degradation of intact protein substrates as
well as the elimination of damaged or misfolded proteins that
might otherwise aggregate. During ageing there is a decline in
proteasome activity and an increase in aggregated proteins.
Many neurodegenerative diseases are characterised by the
presence of distinctive ubiquitin-positive inclusion bodies in
affected regions of the brain. These inclusions consist of
insoluble, unfolded, ubiquitinated polypeptides that fail to be
targeted and degraded by the proteasome. We are using a systems
biology approach to try and determine the primary event in the
decline in proteolytic capacity with age and whether there is
in fact a vicious cycle of inhibition, with accumulating
aggregates further inhibiting proteolysis, prompting
accumulation of aggregates and so on. A stochastic model of the
ubiquitin-proteasome system has been developed using the
Systems Biology Mark-up Language (SBML). Simulations are
carried out on the BASIS (Biology of Ageing e-Science
Integration and Simulation) system and the model output is
compared to experimental data wherein levels of ubiquitin and
ubiquitinated substrates are monitored in cultured cells under
various conditions. The model can be used to predict the
effects of different experimental procedures such as inhibition
of the proteasome or shutting down the enzyme cascade
responsible for ubiquitin conjugation. RESULTS: The model
output shows good agreement with experimental data under a
number of different conditions. However, our model predicts
that monomeric ubiquitin pools are always depleted under
conditions of proteasome inhibition, whereas experimental data
show that monomeric pools were depleted in IMR-90 cells but not
in ts20 cells, suggesting that cell lines vary in their ability
to replenish ubiquitin pools and there is the need to
incorporate ubiquitin turnover into the model. Sensitivity
analysis of the model revealed which parameters have an
important effect on protein turnover and aggregation kinetics.
CONCLUSION: We have developed a model of the
ubiquitin-proteasome system using an iterative approach of
model building and validation against experimental data. Using
SBML to encode the model ensures that it can be easily modified
and extended as more data become available. Important aspects
to be included in subsequent models are details of ubiquitin
turnover, models of autophagy, the inclusion of a pool of
short-lived proteins and further details of the aggregation
process.
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2024-09-02 | BIOMD0000000105 | BioModels
Project description:Though limited proteolysis of the histone H3 N-terminal tail (H3NT) is frequently observed during mammalian differentiation, however the specific genomic sites targeted for H3NT proteolysis and their functional significance of H3NT cleavage remain unknown.We used genome wide Chip-seq (ChIPac-Seq) approaches to an established cell model of osteoclast differentiation. We discovered that H3NT proteolysis is selectively targeted near transcription start sites of a small group of genes and that most of these H3NT-cleaved genes are epigenetically regulated during osteoclastogenesis.We also discovered that the principal H3NT protease of osteoclastogenesis is matrix metalloproteinase 9 (MMP-9).Abrogation of H3NT proteolysis impaired osteoclastogenic gene activation concomitant with defective osteoclast differentiation. In summary our results support the necessity of MMP-9-dependent H3NT proteolysis in the epigenetic reprogramming of gene pathways required for proficient osteoclastogenesis.
2016-02-02 | GSE72957 | GEO
Project description:Though limited proteolysis of the histone H3 N-terminal tail (H3NT) is frequently observed during mammalian differentiation, however the specific genomic sites targeted for H3NT proteolysis and their functional significance of H3NT cleavage remain unknown.We used genome wide RNA-seq approaches to an established cell model of osteoclast differentiation. We discovered that H3NT proteolysis is selectively targeted near transcription start sites of a small group of genes and that most of these H3NT-cleaved genes are epigenetically regulated during osteoclastogenesis.We have identified that the principal H3NT protease of osteoclastogenesis is matrix metalloproteinase 9 (MMP-9). We next studied genomewide mRNA expression in MMP9 knockout cells and its effect in the epigenetic reprogramming of gene pathways required for proficient osteoclastogenesis.
2016-02-02 | GSE72846 | GEO
Project description:To explore the mechanism of PTEN function, we determined the gene expression profiles of RBE and HCCC-9810 cells infected with PTEN adenovirus. Pathway and GO-term enrichment analyses suggested that the proteasome and ubiquitin-mediated proteolysis pathways were specifically affected in HCCC-9810 cells
2020-03-03 | GSE146196 | GEO
Project description:Precise localization of the histone H3 variant CENP-A(Cse4) to centromeres is essential for accurate chromosome segregation. In budding yeast, CENP-A(Cse4) is regulated by ubiquitin-mediated proteolysis to ensure its exclusive localization to the centromere. Overexpression of CENP-A(Cse4) is lethal when the CENP-A(Cse4) E3 ubiquitin ligase, Psh1, is deleted. CENP-A(Cse4) mislocalizes to promoters in this condition, so we investigated if there was an effect on gene expression of downstream genes using RNA-seq.
2016-03-08 | GSE77596 | GEO
Project description:Precise localization of the histone H3 variant CENP-A(Cse4) to centromeres is essential for accurate chromosome segregation. In budding yeast, CENP-A(Cse4) is regulated by ubiquitin-mediated proteolysis to ensure its exclusive localization to the centromere. Overexpression of CENP-A(Cse4) is lethal when the CENP-A(Cse4) E3 ubiquitin ligase, Psh1, is deleted. To identify the genomic sites of CENP-A(Cse4) mislocalization in this condition, we investigated the genome-wide mislocalization pattern of CENP-A(Cse4) by ChIP-seq.
2016-03-08 | GSE69695 | GEO
Project description:Repurposing E3 ubiquitin ligases as cell surface protein degraders using Proteolysis Targeting Antibodies
| PRJNA859706 | ENA
Project description:The contribution of copy number (CN)-altered genes in cervical carcinogenesis is unknown owing to a lack of correlation with gene expression. We mapped CN-altered genes in 31 cervical cancers (CCs), and investigated the expression of 21,000 genes in 55 CCs using microarrays. Biological processes associated with genes deregulated by gene dosage and the relationship between gene dosage and patient survival were investigated. CN-altered genome (CN-AG) percentages varied widely among tumors from 0% to 32.2% (mean = 8.1 ± 8.9). Tumors were classified as low (mean = 0.5 ± 0.6, n = 11), medium (mean = 5.4 ± 2.4, n = 10), or high (mean = 19.2 ± 6.6, n = 10) CN. The highest %CN-AG was found in 3q, which contributed an average of 55% of all CN alterations. Genome-wide, only 5.3% of CN-altered genes were deregulated by gene dosage; by contrast, the rate in fully duplicated 3q was twice as high. Amplification of 3q explained 23.6% of deregulated genes in whole tumors (r2 = 0.236, p = 0.006; analysis of variance), including those in 3q and other chromosomes. A total of 862 genes were deregulated exclusively in high-CN tumors, but only 22.9% were CN altered. This result suggests that the remaining genes are not deregulated directly by gene dosage but by mechanisms induced in trans by CN-altered genes. Anaphase-promoting complex/cyclosome (APC/C)-dependent proteasome proteolysis, glycolysis, and apoptosis were upregulated, whereas cell adhesion and angiogenesis were downregulated exclusively in high-CN tumors. The high %CN-AG and upregulated gene expression profiles of APC/C-proteasome-dependent proteolysis and glycolysis were associated with poor patient survival, although only the first 2 correlations were statistically significant (p < 0.05, log-rank test). The data suggest that inhibitors of APC/C-dependent proteasome proteolysis and glycolysis may be useful treatments in these patients. In this study 31 tumors and 25 reference controls were used for analysis of copy number alterations using the 500K microarray. The results obtained from 500K array analysis were validated in 15 of the 31 tumors with a higher density microarray (Cytoscan HD). For the analysis of gene expression 55 cervical tumors (27 of them belong to the group of 31 tumors analyzed for copy number) and 17 exocervical controls were used. Please note that 59 Samples (included in the GSE29570; PMID 22357541) were re-analyzed with 13 new samples and the reanalyzed samples are indicated in the Description/Relations field. Please note that the sample R397 in the CytoScanHD_Array set corresponds to the R392 sample in the other data sets (due to an error in file name).
2015-06-04 | E-GEOD-52903 | biostudies-arrayexpress
Project description:The majority of current therapeutics targeting plasma membrane receptors function by antagonizing ligand binding or enzymatic activities. Typical mammalian proteins, however, consist of multiple domains executing discrete but coordinated activities, and saturating inhibition of one functional domain often incompletely suppresses the totality of the protein’s function. Recent work on targeted protein degradation technologies including Proteolysis Targeting Chimeras (PROTACs) has highlighted clinically important distinctions between target inhibition and target degradation. However, the generation of heterobifunctional compounds requiring linkage of two small molecules, each with high affinity for their targets, is highly complex, particularly with respect to achieving oral bioavailability. Here we describe the development of Proteolysis Targeting Antibodies (PROTABs) that tether cell-surface E3 ubiquitin ligases to transmembrane proteins, resulting in target ubiquitination and subsequent degradation. PROTAB-mediated degradation drives deeper pathway inhibition than inhibitory antibodies and is functional in vivo. The scope of this technology is also demonstrated through the identification of additional cell surface E3 ubiquitin ligases that can function as “on demand” degraders of various cell surface proteins. The generality of this approach enables tissue-selective degradation, as suggested by the Wnt-responsive ligases RNF43 and ZNRF3. Furthermore, through engineering of various optimized antibody formats, we offer insights on the ground rules governing optimal target degradation. Taken together, this work describes a strategy for the rapid development of potent, bioavailable and tissue selective degradation of cell surface proteins.
2022-07-21 | GSE208372 | GEO