scholarly journals Impairment of Proteasome Function in Podocytes Leads to CKD

2021 ◽  
Vol 32 (3) ◽  
pp. 597-613 ◽  
Author(s):  
Shin-ichi Makino ◽  
Naritoshi Shirata ◽  
Juan Alejandro Oliva Trejo ◽  
Kanae Yamamoto-Nonaka ◽  
Hiroyuki Yamada ◽  
...  
Keyword(s):  
Proteasome Inhibition ◽  
Ubiquitin Proteasome System ◽  
26S Proteasome ◽  
Regulatory Subunit ◽  
Glomerular Injury ◽  
Ubiquitinated Proteins ◽  
Autophagic Activity ◽  
Modified Proteins

BackgroundThe ubiquitin-proteasome system (UPS) and the autophagy-lysosomal system (APLS) are major intracellular degradation procedures. The importance of the APLS in podocytes is established, but the role of the UPS is not well understood.MethodsTo investigate the role of the UPS in podocytes, mice were generated that had deletion of Rpt3 (Rpt3pdKO), which encodes an essential regulatory subunit required for construction of the 26S proteasome and its deubiquitinating function.ResultsRpt3pdKO mice showed albuminuria and glomerulosclerosis, leading to CKD. Impairment of proteasome function caused accumulation of ubiquitinated proteins and of oxidative modified proteins, and it induced podocyte apoptosis. Although impairment of proteasome function normally induces autophagic activity, the number of autophagosomes was lower in podocytes of Rpt3pdKO mice than in control mice, suggesting the autophagic activity was suppressed in podocytes with impairment of proteasome function. In an in vitro study, antioxidant apocynin and autophagy activator rapamycin suppressed podocyte apoptosis induced by proteasome inhibition. Moreover, rapamycin ameliorated the glomerular injury in the Rpt3pdKO mice. The accumulation of ubiquitinated proteins and of oxidative modified proteins, which were detected in the podocytes of Rpt3pdKO mice, is a characteristic feature of aging. An aging marker was increased in the podocytes of Rpt3pdKO mice, suggesting that impairment of proteasome function promoted signs of aging in podocytes.ConclusionsImpairment of proteasome function in podocytes led to CKD, and antioxidants and autophagy activators can be therapeutic agents for age-dependent CKD.

The aggravating role of the ubiquitin–proteasome system in neurodegenerative disease

2006 ◽  
Vol 34 (5) ◽  
pp. 743-745 ◽  
Author(s):  
C.-C. Hung ◽  
E.J. Davison ◽  
P.A. Robinson ◽  
H.C. Ardley
Keyword(s):  
Ubiquitin Proteasome System ◽  
Model Systems ◽  
Protective Mechanism ◽  
Ubiquitinated Proteins ◽  
Age Related ◽  
Ubiquitin Proteasome ◽  
Vitro Model ◽  
Novel Therapeutic Strategies

Intraneuronal inclusion bodies are key pathological features of most age-related neurodegenerative disorders including Parkinson's disease and Alzheimer's disease. These inclusions are commonly characterized both by the presence of ubiquitinated proteins and the sequestration of components of the UPS (ubiquitin–proteasome system). Unfortunately, as we age, the efficiency of the UPS declines, suggesting that the presence of ubiquitinated proteins and UPS components in inclusions may reflect unsuccessful attempts by the (failing) UPS to remove the aggregating proteins. Whether the physical presence of inclusions causes cell death or, conversely, whether they are non-toxic and their presence reflects a cellular protective mechanism remains highly controversial. Animal and in vitro model systems that allow detailed characterization of the inclusions and their effects on the cell have been developed by us and others. Identification of the mechanisms involved in inclusion formation is already aiding the development of novel therapeutic strategies to prevent or alleviate aggregate-associated neurodegenerative diseases.

scholarly journals Cloning and Characterization of TaSAP7-A, a Member of the Stress-Associated Protein Family in Common Wheat

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenlu Li ◽  
Yixue Wang ◽  
Runzhi Li ◽  
Xiaoping Chang ◽  
Xiangyang Yuan ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Chlorophyll Content ◽  
Agronomic Traits ◽  
Abiotic Stress Tolerance ◽  
Grain Filling ◽  
26S Proteasome ◽  
Regulatory Subunit ◽  
Germination Stage

Stress association proteins (SAPs) are A20/AN1 zinc-finger domain proteins, which play important roles in plant adaptation to abiotic stress and plant development. The functions of SAPs in some plants were reported, but little is known about it in wheat (Triticum aestivum L.). In this study, we characterized a novel 2AN1-type stress association protein gene TaSAP7-A, which was mapped to chromosome 5A in wheat. Subcellular localization indicated that TaSAP7-A was distributed in the nucleus and cytoplasm. Unlike previously known A20/AN1-type SAP genes, TaSAP7-A was negatively regulated to abiotic stress tolerance. Overexpressing TaSAP7-A Arabidopsis lines were hypersensitive to ABA, osmotic and salt stress at germination stage and post-germination stage. Overexpression of TaSAP7-A Arabidopsis plants accelerated the detached leaves’ chlorophyll degradation. Association analysis of TaSAP7-A haplotypes and agronomic traits showed that Hap-5A-2 was significantly associated with higher chlorophyll content at jointing stage and grain-filling stage. These results jointly revealed that TaSAP7-A is related to the chlorophyll content in the leaves of Arabidopsis and wheat. Both in vivo and in vitro experiments demonstrated that TaSAP7-A interacted with TaS10B, which was the component of regulatory subunit in 26S proteasome. In general, TaSAP7-A was a regulator of chlorophyll content, and favorable haplotypes should be helpful for improving plant chlorophyll content and grain yield of wheat.

scholarly journals Ancient drug curcumin impedes 26S proteasome activity by direct inhibition of dual-specificity tyrosine-regulated kinase 2

2018 ◽  
Vol 115 (32) ◽  
pp. 8155-8160 ◽  
Author(s):  
Sourav Banerjee ◽  
Chenggong Ji ◽  
Joshua E. Mayfield ◽  
Apollina Goel ◽  
Junyu Xiao ◽  
...  
Keyword(s):  
Curcuma Longa ◽  
Xenograft Model ◽  
Proteasome Inhibition ◽  
Binding Pocket ◽  
Tumor Burden ◽  
Proteasome Activity ◽  
26S Proteasome ◽  
Dual Specificity ◽  
Immunocompromised Mice

Curcumin, the active ingredient in Curcuma longa, has been in medicinal use since ancient times. However, the therapeutic targets and signaling cascades modulated by curcumin have been enigmatic despite extensive research. Here we identify dual-specificity tyrosine-regulated kinase 2 (DYRK2), a positive regulator of the 26S proteasome, as a direct target of curcumin. Curcumin occupies the ATP-binding pocket of DYRK2 in the cocrystal structure, and it potently and specifically inhibits DYRK2 over 139 other kinases tested in vitro. As a result, curcumin diminishes DYRK2-mediated 26S proteasome phosphorylation in cells, leading to reduced proteasome activity and impaired cell proliferation. Interestingly, curcumin synergizes with the therapeutic proteasome inhibitor carfilzomib to induce apoptosis in a variety of proteasome-addicted cancer cells, while this drug combination exhibits modest to no cytotoxicity to noncancerous cells. In a breast cancer xenograft model, curcumin treatment significantly reduces tumor burden in immunocompromised mice, showing a similar antitumor effect as CRISPR/Cas9-mediated DYRK2 depletion. These results reveal an unexpected role of curcumin in DYRK2-proteasome inhibition and provide a proof-of-concept that pharmacological manipulation of proteasome regulators may offer new opportunities for anticancer treatment.

scholarly journals The proteasome controls presynaptic differentiation through modulation of an on-site pool of polyubiquitinated conjugates

2016 ◽  
Vol 212 (7) ◽  
pp. 789-801 ◽  
Author(s):  
Maria J. Pinto ◽  
Pedro L. Alves ◽  
Luís Martins ◽  
Joana R. Pedro ◽  
Hyun R. Ryu ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Proteasome Inhibition ◽  
Ubiquitin Proteasome System ◽  
Presynaptic Terminal ◽  
Ubiquitinated Proteins ◽  
Presynaptic Differentiation ◽  
Intrinsic Mechanism ◽  
Ubiquitin Proteasome ◽  
Presynaptic Assembly ◽  
Local Modulation

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.

scholarly journals HSP27 Is a Ubiquitin-Binding Protein Involved in I-κBα Proteasomal Degradation

2003 ◽  
Vol 23 (16) ◽  
pp. 5790-5802 ◽  
Author(s):  
Arnaud Parcellier ◽  
Elise Schmitt ◽  
Sandeep Gurbuxani ◽  
Daphné Seigneurin-Berny ◽  
Alena Pance ◽  
...  
Keyword(s):  
Direct Interaction ◽  
Cell Types ◽  
26S Proteasome ◽  
Necrosis Factor Alpha ◽  
Polyubiquitin Chains ◽  
Ubiquitinated Proteins ◽  
Activation Of Transcription ◽  
Ubiquitin Proteasome

ABSTRACT HSP27 is an ATP-independent chaperone that confers protection against apoptosis through various mechanisms, including a direct interaction with cytochrome c. Here we show that HSP27 overexpression in various cell types enhances the degradation of ubiquitinated proteins by the 26S proteasome in response to stressful stimuli, such as etoposide or tumor necrosis factor alpha (TNF-α). We demonstrate that HSP27 binds to polyubiquitin chains and to the 26S proteasome in vitro and in vivo. The ubiquitin-proteasome pathway is involved in the activation of transcription factor NF-κB by degrading its main inhibitor, I-κBα. HSP27 overexpression increases NF-κB nuclear relocalization, DNA binding, and transcriptional activity induced by etoposide, ΤNF-α, and interleukin 1β. HSP27 does not affect I-κBα phosphorylation but enhances the degradation of phosphorylated I-κBα by the proteasome. The interaction of HSP27 with the 26S proteasome is required to activate the proteasome and the degradation of phosphorylated I-κBα. A protein complex that includes HSP27, phosphorylated I-κBα, and the 26S proteasome is formed. Based on these observations, we propose that HSP27, under stress conditions, favors the degradation of ubiquitinated proteins, such as phosphorylated I-κBα. This novel function of HSP27 would account for its antiapoptotic properties through the enhancement of NF-κB activity.

scholarly journals Evidence for Separable Functions of Srp1p, the Yeast Homolog of Importin α (Karyopherin α): Role for Srp1p and Sts1p in Protein Degradation

2000 ◽  
Vol 20 (16) ◽  
pp. 6062-6073 ◽  
Author(s):  
Michelle M. Tabb ◽  
Prasad Tongaonkar ◽  
Loan Vu ◽  
Masayasu Nomura
Keyword(s):  
Protein Degradation ◽  
Nuclear Localization ◽  
Ubiquitin Proteasome System ◽  
26S Proteasome ◽  
Localization Function ◽  
Importin Α ◽  
Yeast Homolog ◽  
Two Hybrid

ABSTRACT Srp1p (importin α) functions as the nuclear localization signal (NLS) receptor in Saccharomyces cerevisiae. Thesrp1-31 mutant is defective in this nuclear localization function, whereas an srp1-49 mutant exhibits defects that are unrelated to this localization function, as was confirmed by intragenic complementation between the two mutants. RPN11and STS1 (DBF8) were identified as high-dosage suppressors of the srp1-49 mutation but not of thesrp1-31 mutation. We found that Sts1p interacts directly with Srp1p in vitro and also in vivo, as judged by coimmunoprecipitation and two-hybrid analyses. Mutants of Sts1p that cannot interact with Srp1p are incapable of suppressingsrp1-49 defects, strongly suggesting that Sts1p functions in a complex with Srp1p. STS1 also interacted with the second suppressor, RPN11, a subunit of the 26S proteasome, in the two-hybrid system. Further, degradation of Ub-Pro-β-galactosidase, a test substrate for the ubiquitin-proteasome system, was defective in srp1-49 but not insrp1-31. This defect in protein degradation was alleviated by overexpression of either RPN11 or STS1 insrp1-49. These results suggest a role for Srp1p in regulation of protein degradation separate from its well-established role as the NLS receptor.

scholarly journals The yeast SEN3 gene encodes a regulatory subunit of the 26S proteasome complex required for ubiquitin-dependent protein degradation in vivo.

1995 ◽  
Vol 15 (11) ◽  
pp. 6311-6321 ◽  
Author(s):  
D J DeMarini ◽  
F R Papa ◽  
S Swaminathan ◽  
D Ursic ◽  
T P Rasmussen ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Genetic Selection ◽  
26S Proteasome ◽  
Yeast Cells ◽  
Regulatory Subunit ◽  
20S Proteasome ◽  
Amino Terminal ◽  
A Subunit

The yeast Sen1 protein was discovered by virtue of its role in tRNA splicing in vitro. To help determine the role of Sen1 in vivo, we attempted to overexpress the protein in yeast cells. However, cells with a high-copy SEN1-bearing plasmid, although expressing elevated amounts of SEN1 mRNA, show little increase in the level of the encoded protein, indicating that a posttranscriptional mechanism limits SEN1 expression. This control depends on an amino-terminal element of Sen1. Using a genetic selection for mutants with increased expression of Sen1-derived fusion proteins, we identified mutations in a novel gene, designated SEN3. SEN3 is essential and encodes a 945-residue protein with sequence similarity to a subunit of an activator of the 20S proteasome from bovine erythrocytes, called PA700. Earlier work indicated that the 20S proteasome associates with a multisubunit regulatory factor, resulting in a 26S proteasome complex that degrades substrates of the ubiquitin system. Mutant sen3-1 cells have severe defects in the degradation of such substrates and accumulate ubiquitin-protein conjugates. Most importantly, we show biochemically that Sen3 is a subunit of the 26S proteasome. These data provide evidence for the involvement of the 26S proteasome in the degradation of ubiquitinated proteins in vivo and for a close relationship between PA700 and the regulatory complexes within the 26S proteasome, and they directly demonstrate that Sen3 is a component of the yeast 26S proteasome.

scholarly journals A therapeutic dose of doxorubicin activates ubiquitin-proteasome system-mediated proteolysis by acting on both the ubiquitination apparatus and proteasome

2008 ◽  
Vol 295 (6) ◽  
pp. H2541-H2550 ◽  
Author(s):  
Jinbao Liu ◽  
Hanqiao Zheng ◽  
Mingxin Tang ◽  
Youn-Chul Ryu ◽  
Xuejun Wang
Keyword(s):  
Critical Role ◽  
Proteasome Inhibition ◽  
Ubiquitin Proteasome System ◽  
Underlying Mechanism ◽  
3T3 Cells ◽  
New Findings ◽  
Relevant Dose ◽  
Ubiquitin Proteasome ◽  
Endogenous Substrates

The ubiquitin proteasome system (UPS) degrades abnormal proteins and most unneeded normal proteins, thereby playing a critical role in protein homeostasis in the cell. Proteasome inhibition is effective in treating certain forms of cancer, while UPS dysfunction is increasingly implicated in the pathogenesis of many severe and yet common diseases. It has been previously shown that doxorubicin (Dox) enhances the degradation of a UPS surrogate substrate in mouse hearts. To address the underlying mechanism, in the present study, we report that 1) Dox not only enhances the degradation of an exogenous UPS reporter (GFPu) but also antagonizes the proteasome inhibitor-induced accumulation of endogenous substrates (e.g., β-catenin and c-Jun) of the UPS in cultured NIH 3T3 cells and cardiomyocytes; 2) Dox facilitates the in vitro degradation of GFPu and c-Jun by the reconstituted UPS via the enhancement of proteasomal function; 3) Dox at a therapeutically relevant dose directly stimulates the peptidase activities of purified 20S proteasomes; and 4) Dox increases, whereas proteasome inhibition decreases, E3 ligase COOH-terminus of heat shock protein cognate 70 in 3T3 cells via a posttranscriptional mechanism. These new findings suggest that Dox activates the UPS by acting directly on both the ubiquitination apparatus and proteasome.

scholarly journals Pathological Role of Halted Proteasome Machinery in Sickle Cell Disease

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 955-955
Author(s):  
Anren Song ◽  
d'Alessandro Angelo ◽  
Kaiqi Sun ◽  
Hong Liu ◽  
Zhangzhe Peng ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Erythrocyte Membrane ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Proteomic Profiling ◽  
Cell Disease ◽  
E3 Ligases ◽  
Ubiquitinated Proteins

Abstract Although proteasome machinery is a conserved cellular component to maintain their normal function, its function in erythrocyte under stress conditions is largely unknown, especially in sickle cell disease (SCD). To determine whether proteasome machinery is altered in SCD erythrocyte, we conducted western blot to detect total ubiquitinated proteins on the erythrocyte membrane in both mice and humans with or without SCD. We found that ubiquitinated proteins were significantly accumulated in SCD mice and humans compared to WT mice and normal controls, indicating that proteasome machinery is halted in SCD. Next, to determine which specific proteins are ubiquitinated and accumulated in SCD, we conducted robust and nonbiased proteomic profiling by immunoprecipitation ubiquitinated proteins followed by proteomics analysis. We found significant accumulation of several categories of ubiquitinated proteins on the erythrocyte membrane in SCD, including cytoskeleton proteins (Spectrin, Actin, Ankryin), glycolytic enzymes (GAPDH, 2,3-BPG mutase, Pyruvate Kinase, G6PD), transporters (Band3, large neutral AA transporter, calcium transporter, ENT1), hemoglobin, components of proteasome machinery [E2, E3 ligases, and valosin-containing protein (p97)]. Finally, to determine the effect of halted proteasome machinery in SCD functionally, we conducted in vitro hypoxia induced red blood cell (RBC) sickling assay. We found that inhibition of RBC proteasome machinery by targeting p97 using CB-5083 or targeting proteasome using MG132 increases SCD RBC sickling. Overall, our findings reveal a novel role of halted proteasome machinery in the pathophysiology of SCD and open up new therapies for the disease. Disclosures No relevant conflicts of interest to declare.

scholarly journals Neuroprotective Role of Camel α-Lactalbumin Via Regulating SIRT1/FOXO3a Pathway Against Rotenone-Induced Neurotoxicity

2021 ◽  
Author(s):  
Saba Ubaid ◽  
Shivani Pandey ◽  
Mohd. Sohail Akhtar ◽  
Mohammad Rumman ◽  
Babita Singh ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ubiquitin Proteasome System ◽  
Protective Agent ◽  
Brain Disorder ◽  
Current Therapies ◽  
Ubiquitin Proteasome ◽  
Potential Activity ◽  
Apoptotic Pathways

Abstract Camel milk is rich in nutritional factors, such as α- Lactalbumin, and important for brain development. It is known to act as a potential therapeutic candidate for brain disorder via regulation of inflammatory and apoptotic pathways. Mechanisms that are critically involved with Parkinson’s disease (PD) are apoptosis, inflammation, and oxidative stress, and the aberrated ubiquitin-proteasome system. Adverse effects of current therapies are imposing the need for the development of natural neuroprotective agents that are very effective and have fewer or no side effects. The present study aimed to evaluate the potential activity of camel α-Lactalbumin (α-LA) in rotenone induced in-vitro PD model. In this study, we hypothesized the use of camel α-lactalbumin as an effective curative agent for PD. The mechanism of action of camel α-lactalbumin was investigated by assessing the effect of α-LA on the level of nitric oxide, NADH, MMP9, inflammatory markers, and on the expression level of SIRT1 and FOXO3a in SH-SY5Y cell line. Overall, the results revealed the potent neuroprotective efficacy of α-Lactalbumin in rotenone-induced PD model via effectively modulating apoptotic pathways, oxidative stress, and neuroinflammatory cascades. Conclusively, these findings confirmed that α-LA could be a biologically effective protective agent against rotenone induced neurotoxic impacts and neurobehavioral aberrations.

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