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Zheng C, Geetha T, Babu JR. Failure of ubiquitin proteasome system: risk for neurodegenerative diseases. NEURODEGENER DIS 2014; 14:161-75. [PMID: 25413678 DOI: 10.1159/000367694] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 08/19/2014] [Indexed: 11/19/2022] Open
Abstract
The ubiquitin proteasome system (UPS) is the primary proteolytic quality control system in cells and has an essential function in the nervous system. UPS dysfunction has been linked to neurodegenerative conditions, including Alzheimer's, Parkinson's and Huntington's diseases. The pathology of neurodegenerative diseases is characterized by the abnormal accumulation of insoluble protein aggregates or inclusion bodies within neurons. The failure or dysregulation of the UPS prevents the degradation of misfolded/aberrant proteins, leading to deficient synaptic function that eventually affects the nervous system. In this review, we discuss the UPS and its physiological roles in the nervous system, its influence on neuronal function, and how UPS dysfunction contributes to the development of neurodegenerative diseases.
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Affiliation(s)
- Chen Zheng
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, Ala., USA
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Zhang T, Jia Y. Meta-analysis of Ubiquilin1 gene polymorphism and Alzheimer's disease risk. Med Sci Monit 2014; 20:2250-5. [PMID: 25387430 PMCID: PMC4238758 DOI: 10.12659/msm.891030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Some studies have evaluated the association between the Ubiquilin 1 (UBQLN1) gene UBQ-8i polymorphism and Alzheimer's disease (AD). However, the results remain uncertain. We carried out a meta-analysis to derive a more comprehensive estimation of this association. MATERIAL/METHODS Case-control studies were identified by searching databases of PubMed, EMBASE, Web of Science, CNKI, CBM, Wanfang, and VIP. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. RESULTS The UBQ-8i polymorphism was significantly associated with an increased AD risk (OR=1.15; 95%CI 1.05-1.25; P=0.002). The combination of adjusted ORs also found UBQ-8i polymorphism was significantly associated with AD risk (OR=1.15; 95%CI 1.02-1.30; P=0.02). When stratified by APOE ε4 status, both APOE ε4 carriers and APOE non-ε4 carriers with UBQ-8i polymorphism had significantly increased AD risk (OR=1.28; 95%CI 1.05-1.56; P=0.01 and OR=1.25; 95%CI 1.04-1.50; P=0.02). In the subgroup analysis according to age, UBQ-8i polymorphism was significantly associated with LOAD risk (OR=1.17; 95%CI 1.05-1.31; P=0.005), but not with EOAD risk (OR=1.12; 95%CI 0.95-1.31; P=0.17). CONCLUSIONS These results suggest that the UBQ-8i polymorphism is associated with AD risk.
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Affiliation(s)
- Tianpeng Zhang
- Department of Integrated TCM & Western Medicine, People's Hospital, Hegang City, China (mainland)
| | - Yingying Jia
- Department of Neurosurgery, People's Hospital, Hegang City, China (mainland)
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Yue Z, Wang S, Yan W, Zhu F. Association of UBQ-8i polymorphism with Alzheimer's disease in Caucasians: a meta-analysis. Int J Neurosci 2014; 125:395-401. [PMID: 25010605 DOI: 10.3109/00207454.2014.943369] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Several studies have reported an association between the UBQ-8i (rs12344615) polymorphism of the UBQLN1 gene and risk of Alzheimer's disease (AD), but these findings remain controversial. In this study, a meta-analysis was carried out to investigate the relationship between UBQ-8i polymorphism and AD risk and a possible synergy with apolipoprotein E (APOE)ε4 gene status. METHODS Case-control studies were selected from PubMed, Medline and Embase (Ovid) databases. The potential association was evaluated by odds ratios (ORs) with 95% confidence intervals (CIs). Data were analyzed with Stata version 11.0. RESULTS A total of 4679 AD cases and 9928 controls were included in the study. There was no evidence of heterogeneity between studies or publication bias in the meta-analysis. There were no significant differences among the examined genetic models. In the analysis stratified by age of onset, a significant association was detected in the late onset AD group under the allele (OR = 1.12, 95% CI: 1.01-1.24), heterozygote (OR = 1.15, 95% CI: 1.02-1.30) and dominant (OR = 1.13, 95% CI: 1.00-1-26) models. However, UBQ-8i polymorphism was not associated with a higher risk for AD among APOEε4 carriers. CONCLUSION The results suggest that UBQ-8i polymorphism may contribute to AD susceptibility, but does not synergize with APOEε4 status to increase AD risk.
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Affiliation(s)
- Zhen Yue
- 1Department of Neurosurgery, First Affiliated Hospital of Nanjing Medical University , Nanjing , China
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The ubiquilin gene family: evolutionary patterns and functional insights. BMC Evol Biol 2014; 14:63. [PMID: 24674348 PMCID: PMC4230246 DOI: 10.1186/1471-2148-14-63] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 03/17/2014] [Indexed: 12/12/2022] Open
Abstract
Background Ubiquilins are proteins that function as ubiquitin receptors in eukaryotes. Mutations in two ubiquilin-encoding genes have been linked to the genesis of neurodegenerative diseases. However, ubiquilin functions are still poorly understood. Results In this study, evolutionary and functional data are combined to determine the origin and diversification of the ubiquilin gene family and to characterize novel potential roles of ubiquilins in mammalian species, including humans. The analysis of more than six hundred sequences allowed characterizing ubiquilin diversity in all the main eukaryotic groups. Many organisms (e. g. fungi, many animals) have single ubiquilin genes, but duplications in animal, plant, alveolate and excavate species are described. Seven different ubiquilins have been detected in vertebrates. Two of them, here called UBQLN5 and UBQLN6, had not been hitherto described. Significantly, marsupial and eutherian mammals have the most complex ubiquilin gene families, composed of up to 6 genes. This exceptional mammalian-specific expansion is the result of the recent emergence of four new genes, three of them (UBQLN3, UBQLN5 and UBQLNL) with precise testis-specific expression patterns that indicate roles in the postmeiotic stages of spermatogenesis. A gene with related features has independently arisen in species of the Drosophila genus. Positive selection acting on some mammalian ubiquilins has been detected. Conclusions The ubiquilin gene family is highly conserved in eukaryotes. The infrequent lineage-specific amplifications observed may be linked to the emergence of novel functions in particular tissues.
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Takalo M, Haapasalo A, Natunen T, Viswanathan J, Kurkinen KM, Tanzi RE, Soininen H, Hiltunen M. Targeting ubiquilin-1 in Alzheimer's disease. Expert Opin Ther Targets 2013; 17:795-810. [PMID: 23600477 DOI: 10.1517/14728222.2013.791284] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
INTRODUCTION Alzheimer's disease (AD) is a common neurodegenerative disorder affecting an increasing number of people worldwide as the population ages. Currently, there are no drugs available that could prevent AD pathogenesis or slow down its progression. Increasing evidence links ubiquilin-1, an ubiquitin-like protein, into the pathogenic mechanisms of AD and other neurodegenerative diseases. Ubiquilin-1 has been shown to play a key role in the regulation of the levels, subcellular targeting, aggregation and degradation of various neurodegenerative disease-associated proteins. These include the amyloid precursor protein and presenilins that are intimately involved in the mechanisms of AD. AREAS COVERED Here, the properties and diverse functions of ubiquilin-1 protein in the context of the pathogenesis of AD and other neurodegenerative disorders are discussed. This review recapitulates the available knowledge on the involvement of ubiquilin-1 in the genetic and molecular mechanisms in AD. Furthermore, the association of ubiquilin-1 with specific proteins and mechanisms involved in the pathogenesis of neurodegenerative diseases is described and the known ubiquilin-1-interacting proteins summarized. EXPERT OPINION The variety of ubiquilin-1-interacting proteins and its central role in the regulation of protein levels and degradation provides a number of novel candidates and approaches for future research and drug discovery.
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Affiliation(s)
- Mari Takalo
- Institute of Clinical Medicine-Neurology, University of Eastern Finland and Department of Neurology, Kuopio University Hospital, Kuopio, Finland
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Stieren ES, El Ayadi A, Xiao Y, Siller E, Landsverk ML, Oberhauser AF, Barral JM, Boehning D. Ubiquilin-1 is a molecular chaperone for the amyloid precursor protein. J Biol Chem 2011; 286:35689-35698. [PMID: 21852239 DOI: 10.1074/jbc.m111.243147] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alzheimer disease (AD) is associated with extracellular deposition of proteolytic fragments of amyloid precursor protein (APP). Although mutations in APP and proteases that mediate its processing are known to result in familial, early onset forms of AD, the mechanisms underlying the more common sporadic, yet genetically complex forms of the disease are still unclear. Four single-nucleotide polymorphisms within the ubiquilin-1 gene have been shown to be genetically associated with AD, implicating its gene product in the pathogenesis of late onset AD. However, genetic linkage between ubiquilin-1 and AD has not been confirmed in studies examining different populations. Here we show that regardless of genotype, ubiquilin-1 protein levels are significantly decreased in late onset AD patient brains, suggesting that diminished ubiquilin function may be a common denominator in AD progression. Our interrogation of putative ubiquilin-1 activities based on sequence similarities to proteins involved in cellular quality control showed that ubiquilin-1 can be biochemically defined as a bona fide molecular chaperone and that this activity is capable of preventing the aggregation of amyloid precursor protein both in vitro and in live neurons. Furthermore, we show that reduced activity of ubiquilin-1 results in augmented production of pathogenic amyloid precursor protein fragments as well as increased neuronal death. Our results support the notion that ubiquilin-1 chaperone activity is necessary to regulate the production of APP and its fragments and that diminished ubiquilin-1 levels may contribute to AD pathogenesis.
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Affiliation(s)
- Emily S Stieren
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555
| | - Amina El Ayadi
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555
| | - Yao Xiao
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555
| | - Efraín Siller
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555
| | - Megan L Landsverk
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
| | - Andres F Oberhauser
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555
| | - José M Barral
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555; Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, Texas 77555.
| | - Darren Boehning
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555; Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, Texas 77555.
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Chuo LJ, Wu ST, Chang HI, Kuo YM. Extremely rare incidence of the UBQLN1 polymorphism (UBQ-8i) in Taiwan Chinese with Alzheimer's disease. Neurosci Lett 2010; 475:108-9. [PMID: 20350585 DOI: 10.1016/j.neulet.2010.03.061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 03/17/2010] [Accepted: 03/22/2010] [Indexed: 11/30/2022]
Abstract
Recently, a single nucleotide polymorphism (SNP, A-->G) in intron 8 of UBQLN 1 at the rs12344615 site (UBQ-8i) on chromosome 9q22 was associated with a higher risk of late-onset Alzheimer's disease (AD). Here, we aimed to investigate whether an association exists between the UBQ-8i polymorphism and AD in Taiwan Chinese. Initially, we included 100 late-onset AD patients and 100 gender- and age-matched non-demented (ND) control participants. The UBQ-8i polymorphism site was successfully determined in 91 AD and 96 ND individuals using the dye terminator nucleotide sequencing technique. Among the 187 participants, we did not detect any subject carrying the G allele. This finding is in agreement with the report listed in the NCBI SNP Reference Assembly, which states that <1% of Asians carry this SNP. The APOE varepsilon4 allele, an established AD genetic risk factor, was overrepresented in the AD cohort. We conclude from these results that the UBQ-8i polymorphism of the UBQLN1 gene is extremely rare in Taiwan Chinese and unlikely to play a significant role in the risk of AD in Taiwan Chinese.
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Affiliation(s)
- Liang-Jen Chuo
- Department of Psychiatry, Taichung Veterans General Hospital, Taichung, Taiwan
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Emerging role of Alzheimer's disease-associated ubiquilin-1 in protein aggregation. Biochem Soc Trans 2010; 38:150-5. [PMID: 20074050 DOI: 10.1042/bst0380150] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Abnormal protein aggregation and intracellular or extracellular accumulation of misfolded and aggregated proteins are key events in the pathogenesis of different neurodegenerative diseases. Furthermore, endoplasmic reticulum stress and impairment of the ubiquitin-proteasome system probably contribute to neurodegeneration in these diseases. A characteristic feature of AD (Alzheimer's disease) is the abnormal accumulation of Abeta (amyloid beta-peptide) in the brain. Evidence shows that the AD-associated PS (presenilin) also forms aggregates under certain conditions and that another AD-associated protein, ubiquilin-1, controls protein aggregation and deposition of aggregated proteins. Here, we review the current knowledge of ubiquilin-1 and PS in protein aggregation and related events that potentially influence neurodegeneration.
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