scholarly journals Abnormal Ubiquitination of Ubiquitin-Proteasome System in Lung Squamous Cell Carcinomas

Author(s):  
Xianquan Zhan ◽  
Miaolong Lu

Ubiquitination is an important post-translational modification. Abnormal ubiquitination is extensively associated with cancers. Lung squamous cell carcinoma (LUSC) is the most common pathological type of lung cancer, with unclear molecular mechanism and the poor overall prognosis of LUSC patient. To uncover the existence and potential roles of ubiquitination in LUSC, label-free quantitative ubiquitomics was performed in human LUSC vs. control tissues. In total, 627 ubiquitinated proteins (UPs) with 1209 ubiquitination sites were identified, including 1133 (93.7%) sites with quantitative information and 76 (6.3%) sites with qualitative information. KEGG pathway enrichment analysis found that UPs were significantly enriched in ubiquitin-mediated proteolysis pathway (hsa04120) and proteasome complex (hsa03050). Further analysis of 400 differentially ubiquitinated proteins (DUPs) revealed that 11 subunits of the proteasome complex were differentially ubiquitinated. These findings clearly demonstrated that ubiquitination was widely present in the ubiquitin-proteasome pathway in LUSCs. At the same time, abnormal ubiquitination might affect the function of the proteasome to promote tumorigenesis and development. This book chapter discussed the status of protein ubiquitination in the ubiquitin-proteasome system (UPS) in human LUSC tissues, which offered the scientific data to elucidate the specific molecular mechanisms of abnormal ubiquitination during canceration and the development of anti-tumor drugs targeting UPS.

2020 ◽  
Vol 11 (1) ◽  
pp. 73-94 ◽  
Author(s):  
Miaolong Lu ◽  
Wei Chen ◽  
Wei Zhuang ◽  
Xianquan Zhan

Abstract Background Ubiquitination is an important molecular event in lung squamous cell carcinoma (LSCC), which currently is mainly studied in nonsmall cell lung carcinoma cell models but lacking of ubiquitination studies on LSCC tissues. Here, we presented the ubiquitinated protein profiles of LSCC tissues to explore ubiquitination-involved molecular network alterations and identify abnormally ubiquitinated proteins as useful biomarkers for predictive, preventive, and personalized medicine (PPPM) in LSCC. Methods Anti-ubiquitin antibody-based enrichment coupled with LC-MS/MS was used to identify differentially ubiquitinated proteins (DUPs) between LSCC and control tissues, followed by integrative omics analyses to identify abnormally ubiquitinated protein biomarkers for LSCC. Results Totally, 400 DUPs with 654 ubiquitination sites were identified,, and motifs A-X (1/2/3)-K* were prone to be ubiquitinated in LSCC tissues. Those DUPs were involved in multiple molecular network systems, including the ubiquitin–proteasome system (UPS), cell metabolism, cell adhesion, and signal transduction. Totally, 44 hub molecules were revealed by protein–protein interaction network analysis, followed by survival analysis in TCGA database (494 LSCC patients and 20,530 genes) to obtain 18 prognosis-related mRNAs, of which the highly expressed mRNAs VIM and IGF1R were correlated with poorer prognosis, while the highly expressed mRNA ABCC1 was correlated with better prognosis. VIM-encoded protein vimentin and ABCC1-encoded protein MRP1 were increased in LSCC, which were all associated with poor prognosis. Proteasome-inhibited experiments demonstrated that vimentin and MRP1 were degraded through UPS. Quantitative ubiquitinomics found ubiquitination level was decreased in vimentin and increased in MRP1 in LSCC. These findings showed that the increased vimentin in LSCC might be derived from its decreased ubiquitination level and that the increased MRP1 in LSCC might be derived from its protein synthesis > degradation. GSEA and co-expression gene analyses revealed that VIM and MRP1 were involved in multiple crucial biological processes and pathways. Further, TRIM2 and NEDD4L were predicted as E3 ligases to regulate ubiquitination of vimentin and MRP1, respectively. Conclusion These findings revealed ubiquitinomic variations and molecular network alterations in LSCC, which is in combination with multiomics analysis to identify ubiquitination-related biomarkers for in-depth insight into the molecular mechanism and therapeutic targets and for prediction, diagnosis, and prognostic assessment of LSCC.


2018 ◽  
Author(s):  
Shinrye Lee ◽  
Yu-Mi Jeon ◽  
Seyeon Kim ◽  
Younghwi Kwon ◽  
Myungjin Jo ◽  
...  

AbstractTDP-43 proteinopathy is a common feature in a variety of neurodegenerative disorders including Amyotrophic lateral sclerosis (ALS) cases, Frontotemporal lobar degeneration (FTLD), and Alzheimer’s disease. However, the molecular mechanisms underlying TDP-43-induced neurotoxicity are largely unknown. In this study, we demonstrated that TDP-43 proteinopathy induces impairment in ubiquitin-proteasome system (UPS) evidenced by an accumulation of ubiquitinated proteins and reduction of proteasome activity in neuronal cells. Through kinase inhibitor screening, we identified PTK2 as a suppressor of neurotoxicity induced by UPS impairment. Importantly, PTK2 inhibition significantly reduces ubiquitin aggregates and attenuated TDP-43-induced cytotoxicity in Drosophila model of TDP-43 proteinopathy. We further identified that phosphorylation of p62 at serine 403 (p-p62S403), a key component in the autophagic degradation of poly-ubiquitinated proteins, is increased upon TDP-43 overexpression and dependent on activation of PTK2 in neuronal cells. Moreover, expressing a non-phosphorylated form of p62 (p62S403A) significantly represses accumulation of polyubiquitinated proteins and neurotoxicity induced by TDP-43 overexpression in neuronal cells. In addition, inhibition of TBK1, a kinase which phosphorylates S403 of p62, ameliorates neurotoxicity upon UPS impairment in neuronal cells. Taken together, our data suggest that activation of PTK2-TBK1-p62 axis plays a critical role in the pathogenesis of TDP-43 by regulating neurotoxicity induced by UPS impairment. Therefore, targeting PTK2-TBK1-p62 axis may represent a novel therapeutic intervention for neurodegenerative diseases with TDP-43 proteinopathy.


2016 ◽  
Vol 212 (7) ◽  
pp. 789-801 ◽  
Author(s):  
Maria J. Pinto ◽  
Pedro L. Alves ◽  
Luís Martins ◽  
Joana R. Pedro ◽  
Hyun R. Ryu ◽  
...  

Differentiation of the presynaptic terminal is a complex and rapid event that normally occurs in spatially specific axonal regions distant from the soma; thus, it is believed to be dependent on intra-axonal mechanisms. However, the full nature of the local events governing presynaptic assembly remains unknown. Herein, we investigated the involvement of the ubiquitin–proteasome system (UPS), the major degradative pathway, in the local modulation of presynaptic differentiation. We found that proteasome inhibition has a synaptogenic effect on isolated axons. In addition, formation of a stable cluster of synaptic vesicles onto a postsynaptic partner occurs in parallel to an on-site decrease in proteasome degradation. Accumulation of ubiquitinated proteins at nascent sites is a local trigger for presynaptic clustering. Finally, proteasome-related ubiquitin chains (K11 and K48) function as signals for the assembly of presynaptic terminals. Collectively, we propose a new axon-intrinsic mechanism for presynaptic assembly through local UPS inhibition. Subsequent on-site accumulation of proteins in their polyubiquitinated state triggers formation of presynapses.


2008 ◽  
Vol 363 (1500) ◽  
pp. 2215-2227 ◽  
Author(s):  
Yoshikuni Mizuno ◽  
Nobutaka Hattori ◽  
Shin-ichiro Kubo ◽  
Shigeto Sato ◽  
Kenya Nishioka ◽  
...  

Recent progresses in the pathogenesis of sporadic Parkinson's disease (PD) and genetics of familial PD are reviewed. There are common molecular events between sporadic and familial PD, particularly between sporadic PD and PARK1 -linked PD due to α - synuclein ( SNCA ) mutations. In sporadic form, interaction of genetic predisposition and environmental factors is probably a primary event inducing mitochondrial dysfunction and oxidative damage resulting in oligomer and aggregate formations of α-synuclein. In PARK1 -linked PD, mutant α-synuclein proteins initiate the disease process as they have increased tendency for self-aggregation. As highly phosphorylated aggregated proteins are deposited in nigral neurons in PD, dysfunctions of proteolytic systems, i.e. the ubiquitin–proteasome system and autophagy–lysosomal pathway, seem to be contributing to the final neurodegenerative process. Studies on the molecular mechanisms of nigral neuronal death in familial forms of PD will contribute further on the understanding of the pathogenesis of sporadic PD.


2016 ◽  
Vol 311 (3) ◽  
pp. C392-C403 ◽  
Author(s):  
Philippe A. Bilodeau ◽  
Erin S. Coyne ◽  
Simon S. Wing

Muscle atrophy complicates many diseases as well as aging, and its presence predicts both decreased quality of life and survival. Much work has been conducted to define the molecular mechanisms involved in maintaining protein homeostasis in muscle. To date, the ubiquitin proteasome system (UPS) has been shown to play an important role in mediating muscle wasting. In this review, we have collated the enzymes in the UPS whose roles in muscle wasting have been confirmed through loss-of-function studies. We have integrated information on their mechanisms of action to create a model of how they work together to produce muscle atrophy. These enzymes are involved in promoting myofibrillar disassembly and degradation, activation of autophagy, inhibition of myogenesis as well as in modulating the signaling pathways that control these processes. Many anabolic and catabolic signaling pathways are involved in regulating these UPS genes, but none appear to coordinately regulate a large number of these genes. A number of catabolic signaling pathways appear to instead function by inhibition of the insulin/IGF-I/protein kinase B anabolic pathway. This pathway is a critical determinant of muscle mass, since it can suppress key ubiquitin ligases and autophagy, activate protein synthesis, and promote myogenesis through its downstream mediators such as forkhead box O, mammalian target of rapamycin, and GSK3β, respectively. Although much progress has been made, a more complete inventory of the UPS genes involved in mediating muscle atrophy, their mechanisms of action, and their regulation will be useful for identifying novel therapeutic approaches to this important clinical problem.


2021 ◽  
Vol 11 ◽  
Author(s):  
Chang Gu ◽  
Jiafei Chen ◽  
Xuening Dang ◽  
Chunji Chen ◽  
Zhenyu Huang ◽  
...  

BackgroundWe investigated the prognostic effects and their patterns of immune infiltration of hippo pathway core genes in lung squamous cell carcinoma, in order to find some clues for underlying mechanisms of LUSC tumorigenesis and help developing new therapeutic methods.MethodsThe mutational data, transcriptome data and corresponding clinical medical information of LUSC patients were extracted from The Cancer Genome Atlas (TCGA) database. Differential expression genes (DEGs) and Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were explored. Survival analysis for the hippo core genes and the prognostic model were performed. Immune infiltration was estimated by CIBERSORT algorithm and some immune checkpoints-related genes were further investigated.ResultsOverall, 551 LUSC samples were included in our study, consisting of 502 LUSC tumor samples and 49 adjacent normal samples, respectively. There were 1910 up-regulated DEGs and 2253 down-regulated DEGs were finally identified. The top five mutational hippo pathway core genes were LATS1 (4%), WWC1 (2%), TAOK1 (2%), TAOK3 (2%), and TAOK2 (2%), respectively. the mutation of LATS2 was highly associated with co-mutational NF2 (P <0.05) and TAOK1 (P <0.05). In survival analyses, we found only WWC1 (log-rank p = 0.046, HR = 1.32, 95% CI = 1–1.73) and LATS2 (log-rank p = 0.013, HR = 1.41, 95%CI = 1.08–1.86) had significant prognostic roles. After getting the three subgroups according to the subtyping results, we demonstrated that T cell gamma delta (p = 5.78e-6), B cell memory (p = 4.61e-4) and T cell CD4+ memory resting (p = 2.65e-5) had significant differences among the three groups. SIGLEC15 (P <0.01) and CD274 (P <0.05) also had statistical differences among the three subgroups.ConclusionsOur study verified the prognostic roles of WWC1 and LATS2 in LUSC patients. Immune checkpoints-related genes SIGLEC15 and CD274 had statistical differences among the three subgroups, which may provide new perceptions on the molecular mechanisms in LUSC and maybe helpful for precisely selecting specific LUSC patients with potential immunotherapy benefits.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A438-A438
Author(s):  
Ersin Akarsu ◽  
Can Demirel ◽  
Sibel Oguzkan Balci ◽  
Zeynel A Sayiner ◽  
İbrahim Yilmaz ◽  
...  

Abstract Purpose: The aim of this study is; To examine the destruction of insulin receptor substrate-1 (IRS-1) molecule, which is one of the mechanisms that cause insulin resistance in diabetes and obesity, and its effect to reduce this destruction. For this purpose, the effects of exercise, metformin, exenatide and pioglitazone treatments on IRS-1 ubiquitination in pancreas, muscle and adipose tissue were investigated in an obese and diabetic animal model. Method: Obese rat model was used in this study. This model is characterised by obesity, diabetes and insulin resistance. This study investigated the molecular mechanisms of IRS-1 breakdown in diabetes. IRS1, SOCS1, SOC3 expressions were evaluated in the liver, muscle and adipose tissue of this model. At the same time, immunohistochemical analyses were performed in terms of IRS1, SOCS1 and SOCS3 in the same tissues. Results: Gene expression and Immunohistochemical analysis results were evaluated, the increase in IRS1 was noticeable in rats treated with exenatide, especially in the liver tissue despite the greater decrease in SOCS1 (P> 0.05). It was determined that other drugs in this study and used in the treatment of diabetes may also affect this mechanism to different degrees. Conclusion: Our findings showed that some drugs used in the treatment of diabetes may alter the SOCS effect and / or proteasomal degradation of the IRS-1 protein. This effect was particularly pronounced in liver tissue. However, more comprehensive studies are required to show the contribution of ubiquitination in the destruction of IRS-1 and which drugs are effective on this mechanism. Acknowledgement: This study was supported by the Scientific And Tecnological Research Council Of Turkey (TÜBİTAK) Project No: 217S089


2021 ◽  
Vol 20 (2) ◽  
pp. 160-167
Author(s):  
D. E. Mikhalev ◽  
O. D. Baydik ◽  
I. V. Kondakova ◽  
E. A. Sidenko ◽  
M. R. Mukhamedov ◽  
...  

Biomolecules ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 217 ◽  
Author(s):  
Milic ◽  
Tian ◽  
Bernhagen

The constitutive photomorphogenesis 9 (COP9) signalosome (CSN) is an evolutionarily conserved multi-protein complex, consisting of eight subunits termed CSN1-CSN8. The main biochemical function of the CSN is the control of protein degradation via the ubiquitin-proteasome-system through regulation of cullin-RING E3-ligase (CRL) activity by deNEDDylation of cullins, but the CSN also serves as a docking platform for signaling proteins. The catalytic deNEDDylase (isopeptidase) activity of the complex is executed by CSN5, but only efficiently occurs in the three-dimensional architectural context of the complex. Due to its positioning in a central cellular pathway connected to cell responses such as cell-cycle, proliferation, and signaling, the CSN has been implicated in several human diseases, with most evidence available for a role in cancer. However, emerging evidence also suggests that the CSN is involved in inflammation and cardiovascular diseases. This is both due to its role in controlling CRLs, regulating components of key inflammatory pathways such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and complex-independent interactions of subunits such as CSN5 with inflammatory proteins. In this case, we summarize and discuss studies suggesting that the CSN may have a key role in cardiovascular diseases such as atherosclerosis and heart failure. We discuss the implicated molecular mechanisms ranging from inflammatory NF-κB signaling to proteotoxicity and necrosis, covering disease-relevant cell types such as myeloid and endothelial cells or cardiomyocytes. While the CSN is considered to be disease-exacerbating in most cancer entities, the cardiovascular studies suggest potent protective activities in the vasculature and heart. The underlying mechanisms and potential therapeutic avenues will be critically discussed.


2005 ◽  
Vol 41 ◽  
pp. 113-128 ◽  
Author(s):  
Florian A. Salomons ◽  
Lisette G.G.C. Verhoef ◽  
Nico P. Dantuma

Regulated turnover of proteins in the cytosol and nucleus of eukaryotic cells is primarily performed by the ubiquitin–proteasome system (UPS). The UPS is involved in many essential cellular processes. Alterations in this proteolytic system are associated with a variety of human pathologies, such as neurodegenerative diseases, cancer, immunological disorders and inflammation. The precise role of the UPS in the pathophysiology of these diseases, however, remains poorly understood. Detection of UPS aberrations has been a major challenge because of the complexity of the system. Most studies focus on various aspects of the UPS, such as substrate recognition, ubiquitination, deubiquitination or proteasome activity, and do not provide a complete picture of the UPS as an integral system. To monitor the efficacy of the UPS, a number of reporter substrates have been developed based on fluorescent proteins, such as the green fluorescent protein and its spectral variants. These fluorescent UPS reporters contain specific degradation signals that target them with high efficiency and accuracy for proteasomal degradation. Several studies have shown that these reporters can probe the functionality of the UPS in cellular and animal models and provide us with important information on the status of the UPS under various conditions. Moreover, these reporters can aid the identification and development of novel anti-cancer and anti-inflammatory drugs based on UPS inhibition.


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