1
|
Zhai F, Li J, Ye M, Jin X. The functions and effects of CUL3-E3 ligases mediated non-degradative ubiquitination. Gene X 2022; 832:146562. [PMID: 35580799 DOI: 10.1016/j.gene.2022.146562] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 03/30/2022] [Accepted: 05/06/2022] [Indexed: 02/09/2023] Open
Abstract
Ubiquitination of substrates usually have two fates: one is degraded by 26S proteasome, and the other is non-degradative ubiquitination modification which is associated with cell cycle regulation, chromosome inactivation, protein transportation, tumorigenesis, achondroplasia, and neurological diseases. Cullin3 (CUL3), a scaffold protein, binding with the Bric-a-Brac-Tramtrack-Broad-complex (BTB) domain of substrates recognition adaptor and RING-finger protein 1 (RBX1) form ubiquitin ligases (E3). Based on the current researches, this review has summarized the functions and effects of CUL3-E3 ligases mediated non-degradative ubiquitination.
Collapse
Affiliation(s)
- Fengguang Zhai
- The Affiliated Hospital of Medical School, Ningbo University, Ningbo 315020, China; Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathphysiology, Medical School of Ningbo University, Ningbo 315211, China
| | - Jingyun Li
- The Affiliated Hospital of Medical School, Ningbo University, Ningbo 315020, China; Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathphysiology, Medical School of Ningbo University, Ningbo 315211, China
| | - Meng Ye
- The Affiliated Hospital of Medical School, Ningbo University, Ningbo 315020, China; Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathphysiology, Medical School of Ningbo University, Ningbo 315211, China.
| | - Xiaofeng Jin
- The Affiliated Hospital of Medical School, Ningbo University, Ningbo 315020, China; Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathphysiology, Medical School of Ningbo University, Ningbo 315211, China.
| |
Collapse
|
2
|
Sundaria N, Upadhyay A, Prasad A, Prajapati VK, Poluri KM, Mishra A. Neurodegeneration & imperfect ageing: Technological limitations and challenges? Mech Ageing Dev 2021; 200:111574. [PMID: 34562507 DOI: 10.1016/j.mad.2021.111574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 08/29/2021] [Accepted: 09/21/2021] [Indexed: 11/18/2022]
Abstract
Cellular homeostasis is regulated by the protein quality control (PQC) machinery, comprising multiple chaperones and enzymes. Studies suggest that the loss of the PQC mechanisms in neurons may lead to the formation of abnormal inclusions that may lead to neurological disorders and defective aging. The questions could be raised how protein aggregate formation precisely engenders multifactorial molecular pathomechanism in neuronal cells and affects different brain regions? Such questions await thorough investigation that may help us understand how aberrant proteinaceous bodies lead to neurodegeneration and imperfect aging. However, these studies face multiple technological challenges in utilizing available tools for detailed characterizations of the protein aggregates or amyloids and developing new techniques to understand the biology and pathology of proteopathies. The lack of detection and analysis methods has decelerated the pace of the research in amyloid biology. Here, we address the significance of aggregation and inclusion formation, followed by exploring the evolutionary contribution of these structures. We also provide a detailed overview of current state-of-the-art techniques and advances in studying amyloids in the diseased brain. A comprehensive understanding of the structural, pathological, and clinical characteristics of different types of aggregates (inclusions, fibrils, plaques, etc.) will aid in developing future therapies.
Collapse
Affiliation(s)
- Naveen Sundaria
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India
| | - Arun Upadhyay
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India
| | - Amit Prasad
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, NH‑8 Bandarsindri, Ajmer, Rajasthan, 305817, India
| | - Krishna Mohan Poluri
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India.
| |
Collapse
|
3
|
Kumar S, Basu M, Ghosh MK. Chaperone-assisted E3 ligase CHIP: A double agent in cancer. Genes Dis 2021; 9:1521-1555. [PMID: 36157498 PMCID: PMC9485218 DOI: 10.1016/j.gendis.2021.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/06/2021] [Indexed: 12/11/2022] Open
Abstract
The carboxy-terminus of Hsp70-interacting protein (CHIP) is a ubiquitin ligase and co-chaperone belonging to Ubox family that plays a crucial role in the maintenance of cellular homeostasis by switching the equilibrium of the folding-refolding mechanism towards the proteasomal or lysosomal degradation pathway. It links molecular chaperones viz. HSC70, HSP70 and HSP90 with ubiquitin proteasome system (UPS), acting as a quality control system. CHIP contains charged domain in between N-terminal tetratricopeptide repeat (TPR) and C-terminal Ubox domain. TPR domain interacts with the aberrant client proteins via chaperones while Ubox domain facilitates the ubiquitin transfer to the client proteins for ubiquitination. Thus, CHIP is a classic molecule that executes ubiquitination for degradation of client proteins. Further, CHIP has been found to be indulged in cellular differentiation, proliferation, metastasis and tumorigenesis. Additionally, CHIP can play its dual role as a tumor suppressor as well as an oncogene in numerous malignancies, thus acting as a double agent. Here, in this review, we have reported almost all substrates of CHIP established till date and classified them according to the hallmarks of cancer. In addition, we discussed about its architectural alignment, tissue specific expression, sub-cellular localization, folding-refolding mechanisms of client proteins, E4 ligase activity, normal physiological roles, as well as involvement in various diseases and tumor biology. Further, we aim to discuss its importance in HSP90 inhibitors mediated cancer therapy. Thus, this report concludes that CHIP may be a promising and worthy drug target towards pharmaceutical industry for drug development.
Collapse
|
4
|
Qin S, Jiang C, Gao J. Transcriptional factor Nrf2 is essential for aggresome formation during proteasome inhibition. Biomed Rep 2019; 11:241-252. [PMID: 31798869 PMCID: PMC6873428 DOI: 10.3892/br.2019.1247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 09/18/2019] [Indexed: 12/20/2022] Open
Abstract
Aggrephagy, the aggresome-related protein degradation system, represents a protective cellular response to shuttle misfolded proteins into the microtubule-organizing center for degradation through the autophagic pathway during stress conditions, including heat shock, oxidative stress and proteasome inhibition. In response to proteasome failure, many genes are transcriptionally activated to facilitate ubiquitinated proteins to be cleared via the aggrephagy pathway. Although many regulators involved in aggresome formation have been identified, the mechanism how transcriptional activation promotes aggresome formation remains unknown. Here, we have demonstrated that nuclear factor erythroid 2-related factor 2 (Nrf2) accumulated in the nucleus and activated the transcription of sequestosome-1 (p62) during proteasome inhibition in 293 cells. Loss of Nrf2 resulted in failure of aggresome formation and cell death; whereas overexpression of p62 alleviated Nrf2 knockdown-induced aggresome formation defects and promoted cell survival. Notably, blocking Nrf2 activation using a p38/MAPK inhibitor prevented proteasome inhibitor-induced aggresome formation. These findings suggested that Nrf2 may be a critical regulator of aggresome formation, which protects cells from proteasome dysfunction-induced stress.
Collapse
Affiliation(s)
- Siyue Qin
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, School of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China.,Key Laboratory of Obstetrics, Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu, Sichuan 610065, P.R. China.,Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610065, P.R. China
| | - Changan Jiang
- Key Laboratory of Obstetrics, Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu, Sichuan 610065, P.R. China.,Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610065, P.R. China
| | - Ju Gao
- Key Laboratory of Obstetrics, Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu, Sichuan 610065, P.R. China.,Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610065, P.R. China.,The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, Fujian 350002, P.R. China
| |
Collapse
|
5
|
Lindquist ME, Hicar MD. B Cells and Antibodies in Kawasaki Disease. Int J Mol Sci 2019; 20:ijms20081834. [PMID: 31013925 PMCID: PMC6514959 DOI: 10.3390/ijms20081834] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 12/22/2022] Open
Abstract
The etiology of Kawasaki disease (KD), the leading cause of acquired heart disease in children, is currently unknown. Epidemiology supports a relationship of KD to an infectious disease. Several pathological mechanisms are being considered, including a superantigen response, direct invasion by an infectious etiology or an autoimmune phenomenon. Treating affected patients with intravenous immunoglobulin is effective at reducing the rates of coronary aneurysms. However, the role of B cells and antibodies in KD pathogenesis remains unclear. Murine models are not clear on the role for B cells and antibodies in pathogenesis. Studies on rare aneurysm specimens reveal plasma cell infiltrates. Antibodies generated from these aneurysmal plasma cell infiltrates showed cross-reaction to intracellular inclusions in the bronchial epithelium of a number of pathologic specimens from children with KD. These antibodies have not defined an etiology. Notably, a number of autoantibody responses have been reported in children with KD. Recent studies show acute B cell responses are similar in children with KD compared to children with infections, lending further support of an infectious disease cause of KD. Here, we will review and discuss the inconsistencies in the literature in relation to B cell responses, specific antibodies, and a potential role for humoral immunity in KD pathogenesis or diagnosis.
Collapse
Affiliation(s)
- Michael E Lindquist
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA.
| | - Mark D Hicar
- Department of Pediatrics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14222, USA.
| |
Collapse
|
6
|
Redchuk TA, Karasev MM, Omelina ES, Verkhusha VV. Near-Infrared Light-Controlled Gene Expression and Protein Targeting in Neurons and Non-neuronal Cells. Chembiochem 2018; 19:1334-1340. [PMID: 29465801 PMCID: PMC6317872 DOI: 10.1002/cbic.201700642] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Indexed: 12/15/2022]
Abstract
Near-infrared (NIR) light-inducible binding of bacterial phytochrome BphP1 to its engineered partner, QPAS1, is used for optical protein regulation in mammalian cells. However, there are no data on the application of the BphP1-QPAS1 pair in cells derived from various mammalian tissues. Here, we tested the functionality of two BphP1-QPAS1-based optogenetic tools-an NIR- and blue-light-sensing system for control of protein localization (iRIS) and an NIR light-sensing system for transcription activation (TA)-in several cell types, including cortical neurons. We found that the performance of these optogenetic tools often relied on physiological properties of a specific cell type, such as nuclear transport, which could limit the applicability of the blue-light-sensitive component of iRIS. In contrast, the NIR-light-sensing component of iRIS performed well in all tested cell types. The TA system showed the best performance in cervical cancer (HeLa), bone cancer (U-2 OS), and human embryonic kidney (HEK-293) cells. The small size of the QPAS1 component allowed the design of adeno-associated virus (AAV) particles, which were applied to deliver the TA system to neurons.
Collapse
Affiliation(s)
- Taras A. Redchuk
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - Maksim M. Karasev
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - Evgeniya S. Omelina
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - Vladislav V. Verkhusha
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| |
Collapse
|
7
|
Ferrer-Miralles N, Saccardo P, Corchero JL, Xu Z, García-Fruitós E. General introduction: recombinant protein production and purification of insoluble proteins. Methods Mol Biol 2015; 1258:1-24. [PMID: 25447856 DOI: 10.1007/978-1-4939-2205-5_1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Proteins are synthesized in heterologous systems because of the impossibility to obtain satisfactory yields from natural sources. The production of soluble and functional recombinant proteins is among the main goals in the biotechnological field. In this context, it is important to point out that under stress conditions, protein folding machinery is saturated and this promotes protein misfolding and, consequently, protein aggregation. Thus, the selection of the optimal expression organism and the most appropriate growth conditions to minimize the formation of insoluble proteins should be done according to the protein characteristics and downstream requirements. Escherichia coli is the most popular recombinant protein expression system despite the great development achieved so far by eukaryotic expression systems. Besides, other prokaryotic expression systems, such as lactic acid bacteria and psychrophilic bacteria, are gaining interest in this field. However, it is worth mentioning that prokaryotic expression system poses, in many cases, severe restrictions for a successful heterologous protein production. Thus, eukaryotic systems such as mammalian cells, insect cells, yeast, filamentous fungus, and microalgae are an interesting alternative for the production of these difficult-to-express proteins.
Collapse
Affiliation(s)
- Neus Ferrer-Miralles
- Departament de Genètica i de Microbiologia, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Cerdanyola del Vallès, 08193, Barcelona, Spain
| | | | | | | | | |
Collapse
|
8
|
Paul I, Ghosh MK. A CHIPotle in physiology and disease. Int J Biochem Cell Biol 2014; 58:37-52. [PMID: 25448416 DOI: 10.1016/j.biocel.2014.10.027] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 09/21/2014] [Accepted: 10/25/2014] [Indexed: 01/06/2023]
Abstract
The carboxy-terminus of Hsc70 interacting protein (CHIP) is known to function as a chaperone associated E3 ligase for several proteins and regulates a variety of physiological processes. Being a connecting link between molecular chaperones and 26S proteasomes, it is widely regarded as the central player in the cellular protein quality control system. Recent analyses have provided new insights on the biochemical and functional dynamics of CHIP. In this review article, we give a comprehensive account of our current knowledge on the biology of CHIP, which apart from shedding light on fundamental biological questions promises to provide a potential target for therapeutic intervention.
Collapse
Affiliation(s)
- Indranil Paul
- Cancer Biology and Inflammatory Disorder Division, Council of Scientific and Industrial Research - Indian Institute of Chemical Biology (CSIR-IICB), 4, Raja S.C. Mullick Road, Kolkata 700032, India
| | - Mrinal K Ghosh
- Cancer Biology and Inflammatory Disorder Division, Council of Scientific and Industrial Research - Indian Institute of Chemical Biology (CSIR-IICB), 4, Raja S.C. Mullick Road, Kolkata 700032, India.
| |
Collapse
|
9
|
Factors that affect the intracellular localization and trafficking of African horse sickness virus core protein, VP7. Virology 2014; 456-457:279-91. [DOI: 10.1016/j.virol.2014.03.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/26/2014] [Accepted: 03/29/2014] [Indexed: 11/21/2022]
|
10
|
Jerič B, Dolenc I, Mihelič M, Klarić M, Zavašnik-Bergant T, Gunčar G, Turk B, Turk V, Stoka V. N-terminally truncated forms of human cathepsin F accumulate in aggresome-like inclusions. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1833:2254-66. [PMID: 23684953 DOI: 10.1016/j.bbamcr.2013.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 01/13/2023]
Abstract
The contribution of individual cysteine cathepsins as positive mediators of programmed cell death is dependent on several factors, such as the type of stimuli, intensity and duration of the stimulus, and cell type involved. Of the eleven human cysteine cathepsins, cathepsin F is the only cathepsin that exhibits an extended N-terminal proregion, which contains a cystatin-like domain. We predicted that the wild-type human cathepsin F contains three natively disordered regions within the enzyme's propeptide and various amino acid stretches with high fibrillation propensity. Wild-type human cathepsin F and its N-terminally truncated forms, Ala(20)-Asp(484) (Δ(19)CatF), Pro(126)-Asp(484) (Δ(125)CatF), and Met(147)-Asp(484) (Δ(146)CatF) were cloned into the pcDNA3 vector and overexpressed in HEK 293T cells. Wild-type human cathepsin F displayed a clear vesicular labeling and colocalized with the LAMP2 protein, a lysosomal marker. However, all three N-terminally truncated forms of human cathepsin F were recovered as insoluble proteins, suggesting that the deletion of at least the signal peptides (Δ(19)CatF), results in protein aggregation. Noteworthy, they concentrated large perinuclear-juxtanuclear aggregates that accumulated within aggresome-like inclusions. These inclusions showed p62-positive immunoreactivity and were colocalized with the autophagy marker LC3B, but not with the LAMP2 protein. In addition, an approximately 2-3 fold increase in DEVDase activity was not sufficient to induce apoptotic cell death. These results suggested the clearance of the N-terminally truncated forms of human cathepsin F via the autophagy pathway, underlying its protective and prosurvival mechanisms.
Collapse
Affiliation(s)
- Barbara Jerič
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Ljubljana, Slovenia
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Moser JJ, Fritzler MJ. Relationship of other cytoplasmic ribonucleoprotein bodies (cRNPB) to GW/P bodies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 768:213-42. [PMID: 23224973 DOI: 10.1007/978-1-4614-5107-5_13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
GW/P body components are involved in the post-transcriptional -processing of messenger RNA (mRNA) through the RNA interference and 5' → 3' mRNA degradation pathways, as well as functioning in mRNA transport and stabilization. It is currently thought that the relevant mRNA silencing and degrading factors are partitioned to these cytoplasmic microdomains thus effecting post-transcriptional regulation and the prevention of accidental degradation of functional mRNA. Although much attention has focused on GW/P bodies, a variety of other cytoplasmic RNP bodies (cRNPB) also have highly specialized functions and have been shown to interact or co-localize with components of GW/P bodies. These cRNPB include neuronal transport RNP granules, stress granules, RNP-rich cytoplasmic germline granules or chromatoid bodies, sponge bodies, cytoplasmic prion protein-induced RNP granules, U bodies and TAM bodies. Of clinical relevance, autoantibodies directed against protein and miRNA components of GW/P bodies have been associated with autoimmune diseases, neurological diseases and cancer. Understanding the molecular function of GW/P bodies and their interactions with other cRNPB may provide clues to the etiology or pathogenesis of diseases associated with autoantibodies directed to these structures. This chapter will focus on the similarities and differences of the various cRNPB as an approach to understanding their functional relationships to GW/P bodies.
Collapse
Affiliation(s)
- Joanna J Moser
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Canada
| | | |
Collapse
|
12
|
van Hengel J, Calore M, Bauce B, Dazzo E, Mazzotti E, De Bortoli M, Lorenzon A, Li Mura IE, Beffagna G, Rigato I, Vleeschouwers M, Tyberghein K, Hulpiau P, van Hamme E, Zaglia T, Corrado D, Basso C, Thiene G, Daliento L, Nava A, van Roy F, Rampazzo A. Mutations in the area composita protein αT-catenin are associated with arrhythmogenic right ventricular cardiomyopathy. Eur Heart J 2012; 34:201-10. [DOI: 10.1093/eurheartj/ehs373] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
13
|
Shen D, Coleman J, Chan E, Nicholson TP, Dai L, Sheppard PW, Patton WF. Novel cell- and tissue-based assays for detecting misfolded and aggregated protein accumulation within aggresomes and inclusion bodies. Cell Biochem Biophys 2011; 60:173-85. [PMID: 21132543 PMCID: PMC3112480 DOI: 10.1007/s12013-010-9138-4] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Aggresomes and related inclusion bodies appear to serve as storage depots for misfolded and aggregated proteins within cells, which can potentially be degraded by the autophagy pathway. A homogenous fluorescence-based assay was devised to detect aggregated proteins inside aggresomes and inclusion bodies within an authentic cellular context. The assay employs a novel red fluorescent molecular rotor dye, which is essentially nonfluorescent until it binds to structural features associated with the aggregated protein cargo. Aggresomes and related structures were generated within cultured cells using various potent, cell permeable, proteasome inhibitors: MG-132, lactacystin, epoxomicin and bortezomib, and then selectively detected with the fluorescent probe. Employing the probe in combination with various fluorescein-labeled primary antibodies facilitated co-localization of key components of the autophagy system (ubiquitin, p62, and LC3) with aggregated protein cargo by fluorescence microscopy. Furthermore, cytoplasmic aggregates were highlighted in SK-N-SH human neuroblastoma cells incubated with exogenously supplied amyloid beta peptide 1–42. SMER28, a small molecule modulator of autophagy acting via an mTOR-independent mechanism, prevented the accumulation of amyloid beta peptide within these cells. The described assay allows assessment of the effects of protein aggregation directly in cells, without resorting to the use of non-physiological protein mutations or genetically engineered cell lines. With minor modification, the assay was also adapted to the analysis of frozen or formalin-fixed, paraffin-embedded tissue sections, with demonstration of co-localization of aggregated cargo with β-amyloid and tau proteins in brain tissue sections from Alzheimer’s disease patients.
Collapse
Affiliation(s)
- Dee Shen
- Enzo Life Sciences, 10 Executive Blvd, Farmingdale, NY 11735, USA
| | | | | | | | | | | | | |
Collapse
|
14
|
Interaction of an intracellular pentraxin with a BTB-Kelch protein is associated with ubiquitylation, aggregation and neuronal apoptosis. Mol Cell Neurosci 2011; 47:254-64. [PMID: 21549840 DOI: 10.1016/j.mcn.2011.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 04/06/2011] [Accepted: 04/18/2011] [Indexed: 11/21/2022] Open
Abstract
Neuronal pentraxin with chromo domain (NPCD) comprises a group of neuronally expressed pentraxins with both membrane and cytosolic isoforms; the functions of cytosolic NPCD isoforms are not clear. Here, we demonstrate that a cytosolic NPCD isoform selectively interacts with the BTB-Kelch protein Mayven/Kelch-like 2 (KLHL2), an actin-binding protein implicated in process outgrowth in oligodendrocytes. The KLHL2-NPCD interaction was identified by a yeast two-hybrid screen and confirmed through colocalization and co-immunoprecipitation studies. Truncation analysis indicates that the Kelch domains of KLHL2 interact with the pentraxin domain of NPCD. NPCD forms protein inclusion bodies (aggresomes) when overexpressed in tissue culture cells, KLHL2 localizes to these aggresomes, and overexpression of KLHL2 increases NPCD aggresome formation. Since other members of the BTB-Kelch family can act as Cullin-RING type E3 ubiquitin ligases, we tested the potential role of KLHL2 as a ubiquitin ligase for NPCD. We found that KLHL2 interacts selectively with Cullin 3, a key component of BTB-Kelch ubiquitin ligase complexes. Further, overexpression of KLHL2 promotes NPCD ubiquitylation. Together, these results suggest a novel E3 ubiquitin ligase function of KLHL2, with NPCD as a substrate. As the formation of aggresomes is often associated with protein aggregation in neurodegenerative diseases, we tested the effects of NPCD overexpression and KLHL2 coexpression on neuronal viability. Overexpression of NPCD in hippocampal neurons led to cell death and apoptosis; this effect was exacerbated by KLHL2 co-expression. Our findings implicate KLHL2 in ubiquitin ligase activity, and suggest potential roles of NPCD and KLHL2 in neurodegeneration.
Collapse
|
15
|
Lee J, Yang KH, Joe CO, Kang SS. Formation of distinct inclusion bodies by inhibition of ubiquitin-proteasome and autophagy-lysosome pathways. Biochem Biophys Res Commun 2010; 404:672-7. [PMID: 21147067 DOI: 10.1016/j.bbrc.2010.12.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 12/07/2010] [Indexed: 12/16/2022]
Abstract
Accumulation of misfolded proteins is caused by the impairment of protein quality control systems, such as ubiquitin-proteasome pathway (UPP) and autophagy-lysosome pathway (ALP). In this study, the formation of inclusion bodies was examined after the blockade of UPP and/or ALP in A549 cells. UPP inhibition induced a single and large inclusion body localized in microtubule-organizing center. Interestingly, however, ALP inhibition generated dispersed small inclusion bodies in the cytoplasm. Tuberous sclerosis complex 2 was selectively accumulated in the inclusion bodies of UPP-inhibited cells, but not those of ALP-inhibited cells. Blockade of transcription and translation entirely inhibited the formation of inclusion body induced by UPP inhibition, but partially by ALP inhibition. Moreover, the simultaneous inhibition of two protein catabolic pathways independently developed two distinct inclusion bodies within a single cell. These findings clearly demonstrated that dysfunction of each catabolic pathway induced formation and accumulation of unique inclusion bodies on the basis of morphology, localization and formation process in A549 cells.
Collapse
Affiliation(s)
- Junho Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejon 305-701, Republic of Korea
| | | | | | | |
Collapse
|
16
|
Intracellular aggregation of human stefin B: confocal and electron microscopy study. Biol Cell 2010; 102:319-34. [PMID: 20078424 DOI: 10.1042/bc20090163] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Protein aggregation is a major contributor to the pathogenic mechanisms of human neurodegenerative diseases. Mutations in the CSTB (cystatin B) gene [StB (stefin B)] cause EPM1 (progressive myoclonus epilepsy of type 1), an epilepsy syndrome with features of neurodegeneration and increased oxidative stress. Oligomerization and aggregation of StB in mammalian cells have recently been reported. It has also been observed that StB is overexpressed after seizures and in certain neurodegenerative conditions, which could potentially lead to its aggregation. Human StB proved to be a good model system to study amyloid fibril formation in vitro and, as we show here, to study protein aggregation in cells. RESULTS Endogenous human StB formed smaller, occasional cytoplasmic aggregates and chemical inhibition of the UPS (ubiquitin-proteasome system) led to an increase in the amount of the endogenous protein and also increased its aggregation. Further, we characterized both the untagged and T-Sapphire-tagged StB on overexpression in mammalian cells. Compared with wild-type StB, the EPM1 missense mutant (G4R), the aggregate-prone EPM1 mutant (R68X) and the Y31 StB variant (both tagged and untagged) formed larger cytosolic and often perinuclear aggregates accompanied by cytoskeletal reorganization. Non-homogeneous morphology of these large aggregates was revealed using TEM (transmission electron microscopy) with StB detected by immunogold labelling. StB-positive cytoplasmic aggregates were partially co-localized with ubiquitin, proteasome subunits S20 and S26 and components of microfilament and microtubular cytoskeleton using confocal microscopy. StB aggregates also co-localized with LC3 and the protein adaptor p62, markers of autophagy. Flow cytometry showed that protein aggregation was associated with reduced cell viability. CONCLUSIONS We have shown that endogenous StB aggregates within cells, and that aggregation is increased upon protein overexpression or proteasome inhibition. From confocal and TEM analyses, we conclude that aggregates of StB show some of the molecular characteristics of aggresomes and may be eliminated from the cell by autophagy. Intracellular StB aggregation shows a negative correlation with cell survival.
Collapse
|