scholarly journals Characterization of the ubiquitin–proteasome system in bortezomib-adapted cells

Leukemia ◽  
2009 ◽  
Vol 23 (6) ◽  
pp. 1098-1105 ◽  
Author(s):  
T Rückrich ◽  
M Kraus ◽  
J Gogel ◽  
A Beck ◽  
H Ovaa ◽  
...  
Keyword(s):  
Ubiquitin Proteasome System ◽  
Ubiquitin Proteasome

scholarly journals Characterization of MORN2 stability and regulatory function in LC3-associated phagocytosis in macrophages

Biology Open ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. bio051029 ◽  
Author(s):  
Maya Morita ◽  
Mayu Kajiye ◽  
Chiye Sakurai ◽  
Shuichi Kubo ◽  
Miki Takahashi ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Ubiquitin Proteasome System ◽  
Snare Proteins ◽  
Regulatory Function ◽  
Limiting Factor ◽  
Sensitive Factor ◽  
Protein Receptors ◽  
Ubiquitin Proteasome ◽  
Syntaxin 11

ABSTRACTMicrotubule-associated protein A1/B1-light chain 3 (LC3)-associated phagocytosis (LAP) is a type of non-canonical autophagy that regulates phagosome maturation in macrophages. However, the role and regulatory mechanism of LAP remain largely unknown. Recently, the membrane occupation and recognition nexus repeat-containing-2 (MORN2) was identified as a key component of LAP for the efficient formation of LC3-recruiting phagosomes. To characterize MORN2 and elucidate its function in LAP, we established a MORN2-overexpressing macrophage line. At a steady state, MORN2 was partially cleaved by the ubiquitin-proteasome system. MORN2 overexpression promoted not only LC3-II production but also LAP phagosome (LAPosome) acidification during Escherichia coli uptake. Furthermore, the formation of LAPosomes containing the yeast cell wall component zymosan was enhanced in MORN2-overexpressing cells and depended on reactive oxygen species (ROS). Finally, MORN2-mediated LAP was regulated by plasma membrane-localized soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) such as SNAP-23 and syntaxin 11. Taken together, these findings demonstrate that MORN2, whose expression is downregulated via proteasomal digestion, is a limiting factor for LAP, and that membrane trafficking by SNARE proteins is involved in MORN2-mediated LAP.

Proteomic Characterization of Aggregating Proteins after the Inhibition of the Ubiquitin Proteasome System

2011 ◽  
Vol 10 (3) ◽  
pp. 1062-1072 ◽  
Author(s):  
Inga B. Wilde ◽  
Maria Brack ◽  
Jason M. Winget ◽  
Thibault Mayor
Keyword(s):  
Ubiquitin Proteasome System ◽  
Ubiquitin Proteasome

scholarly journals Structural and functional characterization of Rpn12 identifies residues required for Rpn10 proteasome incorporation

2012 ◽  
Vol 448 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Jonas Boehringer ◽  
Christiane Riedinger ◽  
Konstantinos Paraskevopoulos ◽  
Eachan O. D. Johnson ◽  
Edward D. Lowe ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Functional Characterization ◽  
Ubiquitin Proteasome System ◽  
26S Proteasome ◽  
Structural Motif ◽  
Protein Protein Interactions ◽  
Ubiquitin Proteasome

The ubiquitin–proteasome system targets selected proteins for degradation by the 26S proteasome. Rpn12 is an essential component of the 19S regulatory particle and plays a role in recruiting the extrinsic ubiquitin receptor Rpn10. In the present paper we report the crystal structure of Rpn12, a proteasomal PCI-domain-containing protein. The structure helps to define a core structural motif for the PCI domain and identifies potential sites through which Rpn12 might form protein–protein interactions. We demonstrate that mutating residues at one of these sites impairs Rpn12 binding to Rpn10 in vitro and reduces Rpn10 incorporation into proteasomes in vivo.

scholarly journals Characterization of caspase-dependent and caspase-independent deaths in glioblastoma cells treated with inhibitors of the ubiquitin-proteasome system

2009 ◽  
Vol 8 (11) ◽  
pp. 3140-3150 ◽  
Author(s):  
Carmela Foti ◽  
Cristina Florean ◽  
Antonio Pezzutto ◽  
Paola Roncaglia ◽  
Andrea Tomasella ◽  
...  
Keyword(s):  
Ubiquitin Proteasome System ◽  
Glioblastoma Cells ◽  
Ubiquitin Proteasome

scholarly journals Real-time tracking of complex ubiquitination cascades using a fluorescent confocal on-bead assay

2018 ◽  
Author(s):  
Joanna Koszela ◽  
Nhan T Pham ◽  
David Evans ◽  
Stefan Mann ◽  
Irene Perez-Pi ◽  
...  
Keyword(s):  
Real Time ◽  
Ubiquitin Proteasome System ◽  
Enzymatic Activities ◽  
Confocal Imaging ◽  
Experimental Compartment ◽  
Ubiquitin Proteasome ◽  
Real Time Tracking ◽  
The Stability ◽  
Enzymatic Pathways

AbstractThe ubiquitin-proteasome system (UPS) controls the stability, localization and/or activity of the proteome. However, the identification and characterization of complex individual ubiquitination cascades and their modulators remains a challenge. Here, we report a broadly applicable, multiplexed, miniaturized on-bead technique for real-time monitoring of various ubiquitination-related enzymatic activities. The assay, termed UPS-confocal fluorescence nanoscanning (UPS-CONA), employs a substrate of interest immobilized on a micro-bead and a fluorescently labelled ubiquitin which, upon enzymatic conjugation to the substrate, is quantitatively detected on the bead periphery by confocal imaging. UPS-CONA is suitable for studying individual enzymatic activities, including various E1, E2 and HECT-type E3 enzymes, and for monitoring multi-step reactions within ubiquitination cascades in a single experimental compartment. We demonstrate the power of the UPS-CONA technique by simultaneously following ubiquitin transfer from Ube1 through Ube2L3 to E6AP. We applied this multi-step setup to investigate the selectivity of five ubiquitination inhibitors reportedly targeting different classes of ubiquitination enzymes. Using UPS-CONA, we have identified a new activity of a small molecule E2 inhibitor, BAY 11-7082, and of a HECT E3 inhibitor, heclin, towards the Ube1 enzyme. As a sensitive, quantitative, flexible and reagent-efficient method with a straightforward protocol, UPS-CONA constitutes a powerful tool for interrogation of ubiquitination-related enzymatic pathways and their chemical modulators, and is readily scalable for large experiments.

Abstract 2795: Screening and characterization of drugs that inhibit the ubiquitin-proteasome system

2018 ◽  
Author(s):  
Karthik Selvaraju ◽  
Arjan Mofers ◽  
Paola Pellegrini ◽  
Ellin-Kristina Hillert ◽  
Padraig D'Arcy ◽  
...  
Keyword(s):  
Ubiquitin Proteasome System ◽  
Ubiquitin Proteasome

Characterization of a new family of protein kinases from Arabidopsis containing phosphoinositide 3/4-kinase and ubiquitin-like domains

2007 ◽  
Vol 409 (1) ◽  
pp. 117-127 ◽  
Author(s):  
Rafaelo M. Galvão ◽  
Uma Kota ◽  
Erik J. Soderblom ◽  
Michael B. Goshe ◽  
Wendy F. Boss
Keyword(s):  
Protein Kinases ◽  
Ubiquitin Proteasome System ◽  
Lipid Kinase ◽  
Protein Substrates ◽  
New Family ◽  
Thale Cress ◽  
Ubiquitin Proteasome ◽  
Vitro Analysis

At least two of the genes predicted to encode type II PI4K (phosphoinositide 4-kinase) in Arabidopsis thaliana (thale cress), namely AtPI4Kγ4 and AtPI4Kγ7, encode enzymes with catalytic properties similar to those of members of the PIKK (phosphoinositide kinase-related kinase) family. AtPI4Kγ4 and AtPI4Kγ7 undergo autophosphorylation and phosphorylate serine/threonine residues of protein substrates, but have no detectable lipid kinase activity. AtPI4Kγ4 and AtPI4Kγ7 are members of a subset of five putative AtPI4Ks that contain N-terminal UBL (ubiquitin-like) domains. In vitro analysis of AtPI4Kγ4 indicates that it interacts directly with, and phosphorylates, two proteins involved in the ubiquitin–proteasome system, namely UFD1 (ubiquitin fusion degradation 1) and RPN10 (regulatory particle non-ATPase 10). On the basis of the present results, we propose that AtPI4Kγ4 and AtPI4Kγ7 should be designated UbDKγ4 and UbDKγ7 (ubiquitin-like domain kinases γ4 and γ7). These UBL-domain-containing AtPI4Ks correspond to a new PIKK subfamily of protein kinases. Furthermore, UFD1 and RPN10 phosphorylation represents an additional mechanism by which their function can be regulated.

A novel interplay between the ubiquitin–proteasome system and serine proteases during Drosophila development

2013 ◽  
Vol 454 (3) ◽  
pp. 571-583 ◽  
Author(s):  
Zoltán Lipinszki ◽  
Eva Klement ◽  
Eva Hunyadi-Gulyas ◽  
Katalin F. Medzihradszky ◽  
Róbert Márkus ◽  
...  
Keyword(s):  
Serine Proteases ◽  
Developmental Stages ◽  
Functional Characterization ◽  
Ubiquitin Proteasome System ◽  
26S Proteasome ◽  
Misfolded Proteins ◽  
Drosophila Development ◽  
Ubiquitin Proteasome

We describe the discovery and functional characterization of two Drosophila larval serine proteases: endo-I, which down-regulates the ubiquitin-proteasome system by eliminating the polyubiquitin receptors of the 26S proteasome, and Jonah65A-IV, which selectively degrades misfolded proteins in larval developmental stages.

The ubiquitin–proteasome system and skeletal muscle wasting

2005 ◽  
Vol 41 ◽  
pp. 173-186 ◽  
Author(s):  
Didier Attaix ◽  
Sophie Ventadour ◽  
Audrey Codran ◽  
Daniel Béchet ◽  
Daniel Taillandier ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Wasting ◽  
Proteolytic Enzymes ◽  
Cathepsin L ◽  
Ubiquitin Proteasome System ◽  
Complete Breakdown ◽  
Skeletal Muscle Proteins ◽  
Ubiquitin Proteasome ◽  
Tripeptidyl Peptidase Ii ◽  
F Box Protein

The ubiquitin–proteasome system (UPS) is believed to degrade the major contractile skeletal muscle proteins and plays a major role in muscle wasting. Different and multiple events in the ubiquitination, deubiquitination and proteolytic machineries are responsible for the activation of the system and subsequent muscle wasting. However, other proteolytic enzymes act upstream (possibly m-calpain, cathepsin L, and/or caspase 3) and downstream (tripeptidyl-peptidase II and aminopeptidases) of the UPS, for the complete breakdown of the myofibrillar proteins into free amino acids. Recent studies have identified a few critical proteins that seem necessary for muscle wasting {i.e. the MAFbx (muscle atrophy F-box protein, also called atrogin-1) and MuRF-1 [muscle-specific RING (really interesting new gene) finger 1] ubiquitin–protein ligases}. The characterization of their signalling pathways is leading to new pharmacological approaches that can be useful to block or partially prevent muscle wasting in human patients.

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