Chemical approaches for the preparation of ubiquitinated proteins via natural linkages

2021 ◽  
Author(s):  
Yuhui Zhou ◽  
Qingsong Xie ◽  
Huagui Wang ◽  
Hao Sun
Keyword(s):  
Ubiquitinated Proteins

scholarly journals RepID-deficient cancer cells are sensitized to a drug targeting p97/VCP segregase

2021 ◽  
Author(s):  
Sang-Min Jang ◽  
Christophe E. Redon ◽  
Haiqing Fu ◽  
Fred E. Indig ◽  
Mirit I. Aladjem
Keyword(s):  
Dna Damage ◽  
Cancer Cells ◽  
Cell Sorting ◽  
Clonogenic Survival ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Ubiquitinated Proteins ◽  
Damage Response ◽  
Survival Assay

Abstract Background The p97/valosin-containing protein (VCP) complex is a crucial factor for the segregation of ubiquitinated proteins in the DNA damage response and repair pathway. Objective We investigated whether blocking the p97/VCP function can inhibit the proliferation of RepID-deficient cancer cells using immunofluorescence, clonogenic survival assay, fluorescence-activated cell sorting, and immunoblotting. Result p97/VCP was recruited to chromatin and colocalized with DNA double-strand breaks in RepID-deficient cancer cells that undergo spontaneous DNA damage. Inhibition of p97/VCP induced death of RepID-depleted cancer cells. This study highlights the potential of targeting p97/VCP complex as an anticancer therapeutic approach. Conclusion Our results show that RepID is required to prevent excessive DNA damage at the endogenous levels. Localization of p97/VCP to DSB sites was induced based on spontaneous DNA damage in RepID-depleted cancer cells. Anticancer drugs targeting p97/VCP may be highly potent in RepID-deficient cells. Therefore, we suggest that p97/VCP inhibitors synergize with RepID depletion to kill cancer cells.

CHRONIC ATYPICAL NEUTROPHILIC DERMATOSIS WITH LIPODYSTROPHY AND FEVER (CANDLE SYNDROME) IN PEDIATRIC PRACTICE

2021 ◽  
Vol 100 (2) ◽  
pp. 254-261
Author(s):  
O.G. Sukhovjova ◽  
◽  
I.A. Ivanova ◽  
N.A. Kalugina ◽  
E.S. Zholobova ◽  
...  
Keyword(s):  
Clinical Observation ◽  
Clinical Manifestations ◽  
Maculopapular Rash ◽  
The Body ◽  
Neutrophilic Dermatosis ◽  
Inherited Disease ◽  
Laboratory Activity ◽  
Ubiquitinated Proteins ◽  
Systemic Inflammatory Reaction ◽  
Long Time

The purpose of this publication is to describe the CANDLE syndrome (its etiology, pathogenesis, clinical manifestations) and present a clinical observation. CANDLE syndrome is a rare genetically inherited disease caused by impaired assembly by of the protease, which leads to the accumulation of abnormal (ubiquitinated) proteins in B-lymphocytes, fibroblasts, macrophages and some other cells of the body. As a result, an excessive activation of interferon synthesis occurs and a systemic inflammatory reaction develops with symptoms such as febrile fever, skin syndrome, represented by nodules and maculopapular rash, hepatosplenomegaly, lipodystrophy, amyotrophy, delayed physical development, as well as high laboratory activity. The article describes a clinical observation of a female patient with typical symptoms of CANDLE syndrome. However, due to the rarity of the disease and lack of publications describing it, it has not been possible to diagnose the child for a long time.

Lipidation of BmAtg8 is required for autophagic degradation of p62 bodies containing ubiquitinated proteins in the silkworm, Bombyx mori

2017 ◽  
Vol 89 ◽  
pp. 86-96 ◽  
Author(s):  
Ming-Ming Ji ◽  
Jae Man Lee ◽  
Hiroaki Mon ◽  
Kazuhiro Iiyama ◽  
Tsuneyuki Tatsuke ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Ubiquitinated Proteins ◽  
Autophagic Degradation ◽  
Silkworm Bombyx Mori

scholarly journals Ubiquitin-dependent switch during assembly of the proteasomal ATPases mediated by Not4 ubiquitin ligase

2018 ◽  
Vol 115 (52) ◽  
pp. 13246-13251 ◽  
Author(s):  
Xinyi Fu ◽  
Vladyslava Sokolova ◽  
Kristofor J. Webb ◽  
William Old ◽  
Soyeon Park
Keyword(s):  
Ubiquitin Ligase ◽  
Early Stage ◽  
E3 Ligase ◽  
Core Particle ◽  
Ubiquitinated Proteins ◽  
Ring Assembly ◽  
Hexameric Atpase

In the proteasome holoenzyme, the hexameric ATPases (Rpt1-Rpt6) enable degradation of ubiquitinated proteins by unfolding and translocating them into the proteolytic core particle. During early-stage proteasome assembly, individual Rpt proteins assemble into the hexameric “Rpt ring” through binding to their cognate chaperones: Nas2, Hsm3, Nas6, and Rpn14. Here, we show that Rpt ring assembly employs a specific ubiquitination-mediated control. An E3 ligase, Not4, selectively ubiquitinates Rpt5 during Rpt ring assembly. To access Rpt5, Not4 competes with Nas2 until the penultimate step and then with Hsm3 at the final step of Rpt ring completion. Using the known Rpt–chaperone cocrystal structures, we show that Not4-mediated ubiquitination sites in Rpt5 are obstructed by Nas2 and Hsm3. Thus, Not4 can distinguish a Rpt ring that matures without these chaperones, based on its accessibility to Rpt5. Rpt5 ubiquitination does not destabilize the ring but hinders incorporation of incoming subunits—Rpn1 ubiquitin receptor and Ubp6 deubiquitinase—thereby blocking progression of proteasome assembly and ubiquitin regeneration from proteasome substrates. Our findings reveal an assembly checkpoint where Not4 monitors chaperone actions during hexameric ATPase ring assembly, thereby ensuring the accuracy of proteasome holoenzyme maturation.

Identification of ubiquitinated proteins in Arabidopsis

2008 ◽  
Vol 68 (1-2) ◽  
pp. 145-158 ◽  
Author(s):  
Concepción Manzano ◽  
Zamira Abraham ◽  
Gema López-Torrejón ◽  
Juan C. Del Pozo
Keyword(s):  
Ubiquitinated Proteins

scholarly journals NBR1 directly promotes the formation of p62 – ubiquitin condensates via its PB1 and UBA domains

2020 ◽  
Author(s):  
Adriana Savova ◽  
Julia Romanov ◽  
Sascha Martens
Keyword(s):  
Phase Separation ◽  
Wild Type ◽  
Selective Autophagy ◽  
Ubiquitinated Proteins ◽  
Cargo Receptor ◽  
Condensate Formation ◽  
Uba Domain ◽  
Reconstituted System ◽  
Pb1 Domain

SummarySelective autophagy removes harmful intracellular structures such as ubiquitinated, aggregated proteins ensuring cellular homeostasis. This is achieved by the encapsulation of this cargo material within autophagosomes. The cargo receptor p62/SQSTM1 mediates the phase separation of ubiquitinated proteins into condensates, which subsequently become targets for the autophagy machinery. NBR1, another cargo receptor, is a crucial regulator of condensate formation. The mechanisms of the interplay between p62 and NBR1 are not well understood. Employing a fully reconstituted system we show that two domains of NBR1, the PB1 domain which binds to p62 and the UBA domain which binds to ubiquitin, are required to promote p62-ubiquitin condensate formation. In cells, acute depletion of endogenous NBR1 reduces formation of p62 condensates, a phenotype that can be rescued by re-expression of wild-type NBR1, but not PB1 or UBA domain mutants. Our results provide mechanistic insights into the role of NBR1 in selective autophagy.

scholarly journals Mechanism of riboregulation of p62 protein oligomerisation by vault RNA1-1 in selective autophagy

2021 ◽  
Author(s):  
Magdalena Buescher ◽  
Rastislav Horos ◽  
Kevin Haubrich ◽  
Nikolay Dobrev ◽  
Florence Baudin ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Membrane Vesicles ◽  
Underlying Mechanism ◽  
Selective Autophagy ◽  
Ubiquitinated Proteins ◽  
Flexible Loop ◽  
Structure Probing ◽  
Molecular Determinants ◽  
Necessary And Sufficient ◽  
Insight Into

Macroautophagy ensures the clearance of intracellular substrates ranging from single ubiquitinated proteins to large proteotoxic aggregates and defective organelles. The selective autophagy receptor p62 binds these targets and recruits them to double-membrane vesicles, which fuse with lysosomes to degrade their content. We recently uncovered that p62 function is riboregulated by the small non-coding vault RNA1-1. Here, we present detailed insight into the underlying mechanism. We show that the PB1 domain and adjacent linker region of p62 (aa 1-122) are necessary and sufficient for specific vault RNA1-1 binding, and identify lysine 7 and arginine 21 as key hinges for p62 riboregulation. Chemical structure probing of vault RNA1-1 further reveals a central flexible loop within the RNA that mediates the specific p62 interaction. Our data define molecular determinants that govern mammalian autophagy via the p62-vault RNA1-1 riboregulatory pair.

scholarly journals Neuronal Proteomic Analysis of the Ubiquitinated Substrates of the Disease-Linked E3 Ligases Parkin and Ube3a

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Aitor Martinez ◽  
Juanma Ramirez ◽  
Nerea Osinalde ◽  
Jesus M. Arizmendi ◽  
Ugo Mayor
Keyword(s):  
Proteasome Inhibitors ◽  
Brain Dysfunction ◽  
Mass Spectrometry Analysis ◽  
E3 Ligases ◽  
Spectrometry Analysis ◽  
Ubiquitinated Proteins ◽  
Neuronal Proteins ◽  
Culture Models ◽  
First Time ◽  
Cell Culture Models

Both Parkin and UBE3A are E3 ubiquitin ligases whose mutations result in severe brain dysfunction. Several of their substrates have been identified using cell culture models in combination with proteasome inhibitors, but not in more physiological settings. We recently developed theUbbiostrategy to isolate ubiquitinated proteins in flies and have now identified by mass spectrometry analysis the neuronal proteins differentially ubiquitinated by those ligases. This is an example of how flies can be used to provide biological material in order to reveal steady state substrates of disease causing genes. Collectively our results provide new leads to the possible physiological functions of the activity of those two disease causing E3 ligases. Particularly, in the case of Parkin the novelty of our data originates from the experimental setup, which is not overtly biased by acute mitochondrial depolarisation. In the case of UBE3A, it is the first time that a nonbiased screen for its neuronal substrates has been reported.

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