The Shigella kinase effector OspG hijacks host ubiquitin signaling to escape septin-cage entrapment
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo Sapiens
SUBMITTER: 
Xiaoyun Liu
PROVIDER: PXD048447 | iProX | Wed Jan 10 00:00:00 GMT 2024
REPOSITORIES: iProX
Similar Datasets
Project description:Transcriptional Regulation by Cullin Ubiquitin Ligases
| PRJNA614537 | ENA
Project description:Primary HUVEC were treated with 500 nM MLN7243, 500 nM MLN4924 or DMSO (control) for 6 h. The experiment aims to identify up- or downregulated proteins after treatment with the E1 ligase inhibitor MLN7243 and the cullin inhibitor MLN4924 in HUVEC. Proteins that are regulated by ubiquitination or more specifically by cullin-based E3 ligases in the quiescent endothelium, will be identified.
2025-05-07 | PXD053910 | Pride
Project description:Ubiquitination is the key post-translational modification in eukaryotic cells that governs protein degradation, localisation, and activity. This process results in the tagging of ubiquitin to protein substrates by a concerted enzyme cascade of E1, E2 and E3 enzymes. The largest superfamily of these proteins includes the Cullin-Ring-Ligase (CRL) complexes of E3 ligases. Plasmodium falciparum, the causative agent of the most severe form of malaria in humans, encodes the critical proteins required for ubiquitination, but we do not yet understand the function of this pathway. Here the P. falciparum CRL E3 ligases were characterised to reveal an essential but minimal repertoire controlled by two Cullin scaffolds. A PfCullin1-linked CRL complex was identified as being required for parasite inner-membrane biogenesis and DNA replication. This complex recruits only one substrate receptor, compared to the ~70 receptors used interchangeably by human cells. A second CRL complex functioning through a PfCullin4 scaffold was identified that utilised a previously unidentified adaptor protein and receptors to support DNA replication. These results show that the P. falciparum E3 ubiquitin ligases play an essential role in the biology of this important infectious agent.
2025-07-11 | PXD063957 | Pride
Project description:Shigella flexneri invades host cells by entering within a bacteria-containing vacuole (BCV). In order to establish its niche in the host cytosol, the bacterium ruptures its BCV. Contacts between S. flexneri BCV and infection-associated macropinosomes (IAMs) formed in situ have been reported to enhance BCV disintegration. The mechanism underlying S. flexneri vacuolar escape remains however obscure. To decipher the molecular mechanism priming the communication between the IAMs and S. flexneri BCV, we performed mass spectrometry-based analysis of the magnetically purified IAMs from S. flexneri-infected cells. While proteins involved in host recycling and exocytic pathways were significantly enriched at the IAMs, we demonstrate more precisely that the S. flexneri type III effector protein IpgD mediates the recruitment of the exocyst to the IAMs through the Rab8/Rab11 pathway. This recruitment results in IAM clustering around S. flexneri BCV. More importantly, we reveal that IAM clustering subsequently facilitates an IAM-mediated unwrapping of the ruptured vacuole membranes from S. flexneri, enabling the naked bacterium to be ready for intercellular spread via actin-based motility. Taken together, our work untangles the molecular cascade of S. flexneri-driven host trafficking subversion at IAMs to develop its cytosolic lifestyle, a crucial step en route for infection progression at cellular and tissue level.
2021-08-11 | PXD020161 | Pride
Project description:This ChIP-seq experiment was done to investigate the global distribution of H2A ubiquitination (a hallmark of polycomb mediated repression), H2B ubiquitination (introduced by PAF-complex associated ubiquitin ligases and connected to active transcription), and PAF1 occupation in Meer cells. Meer cells are primary cells transformed by a knock-in of an inducible Mll-ENL oncogene. ENL and ENLins ChIP-seqs were done in CD117-positive primary hematopoietic cells without any pretransformation by other oncogenes.
2018-01-23 | E-MTAB-5569 | biostudies-arrayexpress
Project description:S. flexneri is an important human pathogen that causes bacillary dysentery. During infection, S. flexneri invades colonic epithelial cells, hijacks the host cell cytoskeleton to move in the cytosol of infected cells, and spreads from cell to cell through formation of membrane protrusions that project into adjacent cells and resolve into double membrane vacuoles (DMVs). S. flexneri cell-to-cell spread requires the integrity of the bacterial type three secretion system (T3SS). However, the exact role of the T3SS effector proteins in the dissemination process remains poorly understood. Here, we investigated the role of the T3SS effector protein IpgB1 in S. flexneri dissemination. IpgB1 was previously characterized as a guanine nucleotide exchange factor (GEF) that contributes to invasion. In addition to the invasion defect, we showed that the ipgB1 mutant formed smaller infection foci in HT-29 cells. Complementation of this phenotype required the GEF activity of IpgB1. Using live confocal microscopy, we showed that the ipgB1 mutant is specifically impaired in DMV escape. Depletion of Rac1, the host cell target of IpgB1 during invasion, as well as pharmacological inhibition of Rac1 signaling, reduced cell-to-cell spread and DMV escape. In a targeted siRNA screen, we uncovered that RhoA depletion restored ipgB1 cell-to-cell spread and DMV escape, revealing a critical role for the IpgB1-Rac1 axis in antagonizing RhoA-mediated restriction of DMV escape. Using an infant rabbit model of shigellosis, we showed that the ipgB1 mutant formed fewer and smaller infection foci in the colon of infected animals, which correlated with attenuated symptoms of disease, including epithelial fenestration and bloody diarrhea. Our results demonstrate that, in addition to its role during invasion, IpgB1 modulates Rho family small GTPase signaling to promote cell-to-cell spread, DMV escape, and S. flexneri pathogenesis.
| S-EPMC8903249 | biostudies-literature
Project description:NguyenLK2011 - Ubiquitination dynamics in
Ring1B-Bmi1 system
This theoretical model investigates the
dynamics of Ring1B/Bmi1 ubiquitination to identify bistable
switch-like and oscillatory behaviour in the
system. Michaelis-Menten (MM) equations are used to formulate
the model. However, the authors show that the dynamics persist even
for Mass-Action kinetics. This SBML file is the MM version of the
model.
This model is described in the article:
Switches,
excitable responses and oscillations in the Ring1B/Bmi1
ubiquitination system.
Nguyen LK, Muñoz-García J,
Maccario H, Ciechanover A, Kolch W, Kholodenko BN.
PLoS Comput. Biol. 2011 Dec; 7(12):
e1002317
Abstract:
In an active, self-ubiquitinated state, the Ring1B ligase
monoubiquitinates histone H2A playing a critical role in
Polycomb-mediated gene silencing. Following ubiquitination by
external ligases, Ring1B is targeted for proteosomal
degradation. Using biochemical data and computational modeling,
we show that the Ring1B ligase can exhibit abrupt switches,
overshoot transitions and self-perpetuating oscillations
between its distinct ubiquitination and activity states. These
different Ring1B states display canonical or multiply branched,
atypical polyubiquitin chains and involve association with the
Polycomb-group protein Bmi1. Bistable switches and oscillations
may lead to all-or-none histone H2A monoubiquitination rates
and result in discrete periods of gene (in)activity. Switches,
overshoots and oscillations in Ring1B catalytic activity and
proteosomal degradation are controlled by the abundances of
Bmi1 and Ring1B, and the activities and abundances of external
ligases and deubiquitinases, such as E6-AP and USP7.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000622.
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.
2024-09-02 | BIOMD0000000622 | BioModels
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:Ubiquitin and ubiquitin-like proteins (UBLs) are directed to targets by cascades of E1, E2, and E3 enzymes. The largest ubiquitin E3 subclass consists of cullin-RING ligases (CRLs), which contain one each of several cullins (CUL1, -2, -3, -4, or -5) and RING proteins (RBX1 or -2). CRLs are activated by ligation of the UBL NEDD8 to a conserved cullin lysine. How is cullin NEDD8ylation specificity established? Here we report that, like UBE2M (also known as UBC12), the previously uncharacterized E2 UBE2F is a NEDD8-conjugating enzyme in vitro and in vivo. Biochemical and structural analyses indicate how plasticity of hydrophobic E1-E2 interactions and E1 conformational flexibility allow one E1 to charge multiple E2s. The E2s have distinct functions, with UBE2M/RBX1 and UBE2F/RBX2 displaying different target cullin specificities. Together, these studies reveal the molecular basis for and functional importance of hierarchical expansion of the NEDD8 conjugation system in establishing selective CRL activation. Mol Cell 33:483-495, 2009. Keywords: Comparison of gene expression profiles Ube2m and Ube2f are E2 enzymes that direct protein modification by NEDD8. Here we explore the specific functions of Ube2f and Ube2m by comparing gene expression profiles following knockdown of their function in NIH 3T3 cells. We used microarrays to detail the global programme of gene expression changes following knockdown of Ube2m and Ube2f in NIH 3T3 cells. NIH 3T3 cells were transduced with retroviral constructs containing shRNA directed against Ube2m or Ube2f. Three replicates of each condition were analyzed.
2009-03-23 | E-GEOD-14088 | biostudies-arrayexpress
Project description:Neddylation is the post-translational protein modification that is most closely related to
ubiquitination. The Ubiquitin-like protein NEDD8 is mostly studied for its role in activating
the Cullin-RING E3 Ubiquitin ligases, however little is known about other NEDD8 targets.
We developed serial NEDD8-Ubiquitin Substrate Profiling (sNUSP), a method that
employs Nedd8-R74K knock-in cells allowing discrimination of endogenous NEDD8- and
Ubiquitin-modification sites by mass spectrometry after Lys-C digestion and K-GG-
peptide enrichment. Using sNUSP, we identified 607 neddylation sites dynamically
regulated by the neddylation inhibitor MLN4924 and the de-neddylating enzyme
NEDP1/SENP8. Among the candidates, we characterized lysine 112 (K112) of the Actin
regulator Cofilin as a novel neddylation event. Global inhibition of neddylation in
developing neurons leads to cytoskeletal defects, altered Actin dynamics and neurite
growth impairments and site-specific neddylation of Cofilin at K112 regulates neurite
outgrowth. These data show that Cofilin neddylation contributes to the regulation of
neuronal Actin dynamics.
2019-12-12 | MSV000084683 | MassIVE