The 26S proteasome substrates and the dynamics of nuclear proteome upon DNA damage
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ABSTRACT:
ORGANISM(S): Homo Sapiens
SUBMITTER: 
Xing Guo
PROVIDER: PXD047298 | iProX | Tue Nov 28 00:00:00 GMT 2023
REPOSITORIES: iProX
Similar Datasets
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.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000105.
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.
2007-04-02 | BIOMD0000000105 | BioModels
Project description:VCP is an evolutionary conserved ubiquitin-dependent ATPase that mediates the degradation of proteins through the ubiquitin-proteasome pathway. Despite the central role of VCP in the regulation of protein homeostasis, identity and nature of its cellular substrates remain poorly defined. Here, we combined chemical inhibition of VCP and quantitative ubiquitin remnant profiling to assess the effect of VCP inhibition on the ubiquitin-modified proteome and to probe the substrate spectrum of VCP in human cells. We demonstrate that inhibition of VCP perturbs cellular ubiquitylation and increases ubiquitylation of a different subset of proteins compared to proteasome inhibition. VCP inhibition globally upregulates K6-linked ubiquitylation that is dependent on the HECT-type ubiquitin E3 ligase HUWE1. We report ~450 putative VCP substrates, many of which function in nuclear processes, including gene expression, DNA repair and cell cycle. Moreover, we identify that VCP regulates the level and activity of the transcription factor c-Myc.
2018-02-08 | GSE107313 | GEO
Project description:Barr2017 - Dynamics of p21 in hTert-RPE1
cells
This deteministic model reveals that a
bistable switch created by Cdt2, promotes irreversible S-phase
entry by keeping p21 levels low, prevents premature S-phase exit
upon DNA damage
This model is described in the article:
DNA damage during S-phase
mediates the proliferation-quiescence decision in the
subsequent G1 via p21 expression.
Barr AR, Cooper S, Heldt FS, Butera
F, Stoy H, Mansfeld J, Novák B, Bakal C.
Nat Commun 2017 Mar; 8: 14728
Abstract:
Following DNA damage caused by exogenous sources, such as
ionizing radiation, the tumour suppressor p53 mediates cell
cycle arrest via expression of the CDK inhibitor, p21. However,
the role of p21 in maintaining genomic stability in the absence
of exogenous DNA-damaging agents is unclear. Here, using live
single-cell measurements of p21 protein in proliferating
cultures, we show that naturally occurring DNA damage incurred
over S-phase causes p53-dependent accumulation of p21 during
mother G2- and daughter G1-phases. High p21 levels mediate G1
arrest via CDK inhibition, yet lower levels have no impact on
G1 progression, and the ubiquitin ligases CRL4Cdt2 and SCFSkp2
couple to degrade p21 prior to the G1/S transition.
Mathematical modelling reveals that a bistable switch, created
by CRL4Cdt2, promotes irreversible S-phase entry by keeping p21
levels low, preventing premature S-phase exit upon DNA damage.
Thus, we characterize how p21 regulates the
proliferation-quiescence decision to maintain genomic
stability.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000660.
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
issue):D542-8.
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.
2016-06-09 | BIOMD0000000660 | BioModels
Project description:The rare genetic disease Cockayne syndrome (CS) results in mutations in CSA and CSB. Upon UV irradiation, RNA synthesis was arrested: RNA-seq showed 70% of down-regulated genes in common between CSA and CSB deficient cells. ATF3, the product of an immediate early gene was overexpressed and bound to its CRE/ATF site to inhibit its responsive genes. ChIP experiments showed that CSA/CUL4A/DDB1 together with CSB and MDM2, target ATF3. In vivo and in vitro experiments showed that ATF3 was ubiquitilated by a concerted action of CSA and MDM2 ubiquitin-ligases and was further eliminated by the proteasome concomitantly with the recruitment of RNA polymerase II to restart transcription. In CS cells, dysfunctional CSA or CSB were unable to assemble the ubiquitin/proteasome complex, thereby maintaining the ATF3-dependent transcription arrested. Though, in addition to their function in DNA repair, CSA and CSB might thus regulate the timing of DNA binding factors on its specific target site via the ubiquitin/proteasome machinery.
2017-12-01 | GSE87562 | GEO
Project description:The rare genetic disease Cockayne syndrome (CS) results in mutations in CSA and CSB. Upon UV irradiation, RNA synthesis was arrested: RNA-seq showed 70% of down-regulated genes in common between CSA and CSB deficient cells. ATF3, the product of an immediate early gene was overexpressed and bound to its CRE/ATF site to inhibit its responsive genes. ChIP experiments showed that CSA/CUL4A/DDB1 together with CSB and MDM2, target ATF3. In vivo and in vitro experiments showed that ATF3 was ubiquitilated by a concerted action of CSA and MDM2 ubiquitin-ligases and was further eliminated by the proteasome concomitantly with the recruitment of RNA polymerase II to restart transcription. In CS cells, dysfunctional CSA or CSB were unable to assemble the ubiquitin/proteasome complex, thereby maintaining the ATF3-dependent transcription arrested. Though, in addition to their function in DNA repair, CSA and CSB might thus regulate the timing of DNA binding factors on its specific target site via the ubiquitin/proteasome machinery.
2017-12-01 | GSE87540 | GEO
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:JAB1 is a regulator of ubiquitin mediated protein degradation upstream of the 26S proteasome. JAB1 regulates the ubiquitin proteasome system through controlling the activity of the largest family of E3 ubiquitin ligases, the Cullin-RING Ligases. JAB1 is also a transcriptional co-factor contolling the expression of numerous genes and regulates musculoskeletal development in vivo. It is reported that JAB1 is overexpressed in many cancers, making it a potential oncogene. Thus, JAB1 has a highly spatiotemporal specific role in development and cancer pathogenesis. This study aims to determine the JAB1-mediated transcriptome that exists in osteosarcoma cells.
2020-06-10 | GSE117773 | GEO
Project description:The RING E3 ubiquitin ligase UHRF1 controls DNA methylation through its ability to target the maintenance DNA methyltransferase DNMT1 to newly replicated chromatin. DNMT1 recruitment relies on ubiquitylation of histone H3 by UHRF1, however, how UHRF1 deposits ubiquitin onto the histone is unknown. Here, we demonstrate that the ubiquitin-like domain (UBL) of UHRF1 is essential for RING-mediated H3 ubiquitylation. Using chemical crosslinking and mass spectrometry, biochemical assays and recombinant chromatin substrates we show that the UBL participates in structural rearrangements of UHRF1 upon binding to chromatin and the E2 ubiquitin conjugating enzyme UbcH5a/UBE2D1. Similar to ubiquitin, the UBL exerts its effects through a hydrophobic patch that contacts a regulatory surface on the “backside” of the E2 to stabilise the E2-E3-chromatin complex. Our analysis of the enzymatic mechanism of UHRF1 uncovers an unexpected function of the UBL-domain and defines a new role for this domain in DNMT1-dependent inheritance of DNA methylation.
2018-08-29 | GSE119120 | GEO
Project description:Small Ubiquitin-like Modifiers play critical roles in the DNA Damage Response (DDR). To increase our understanding of SUMOylation in the mammalian DDR, we employed a quantitative proteomics approach to identify dynamically regulated SUMO-2 conjugates and modification sites upon treatment with the DNA damaging agent MMS. We have uncovered a dynamic set of 20 upregulated and 33 downregulated SUMO-2 conjugates, and 755 SUMO-2 sites, of which 362 were dynamic in response to MMS. In contrast to yeast, where a response is centered on homologous recombination, we identified dynamically SUMOylated interaction networks of chromatin modifiers, transcription factors, DNA repair factors and nuclear body components. SUMOylated chromatin modifiers include JARID1B/KDM5B, JARID1C/KDM5C, p300, CBP, PARP1, SetDB1 and MBD1. Whereas SUMOylated JARID1B was ubiquitylated by the SUMO-targeted ubiquitin ligase RNF4 and degraded by the proteasome in response to DNA damage, JARID1C was SUMOylated and recruited to the chromatin to demethylate histone H3K4.
2015-03-16 | PXD001810 | Pride
Project description:This study provides a genome-wide map of changes in degradative ubiquitination in response to proteasome inhibition in the multiple myeloma cell line MM.1S. Following proteasome inhibition with lactacystin, CUT and RUN assays were carried out to determine the genomic locations of ubiquitin in multiple myeloma cells stably expressing a flagged version of ubiquitin (MM.1S-3XFlag Ubiquitin cells). In addition, we report the DNA binding locations of the transcription factor c-MYC in basal conditions in MM.1S parental cells.
2022-11-21 | GSE193302 | GEO