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Lester E, Parker R. Tau, RNA, and RNA-Binding Proteins: Complex Interactions in Health and Neurodegenerative Diseases. Neuroscientist 2024; 30:458-472. [PMID: 36892034 DOI: 10.1177/10738584231154551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
The tau protein is a key contributor to multiple neurodegenerative diseases. The pathology of tau is thought to be related to tau's propensity to form self-templating fibrillar structures that allow tau fibers to propagate in the brain by prion-like mechanisms. Unresolved issues with respect to tau pathology are how the normal function of tau and its misregulation contribute to disease, how cofactors and cellular organelles influence the initiation and propagation of tau fibers, and determining the mechanism of tau toxicity. Herein, we review the connection between tau and degenerative diseases, the basis for tau fibrilization, and how that process interacts with cellular molecules and organelles. One emerging theme is that tau interacts with RNA and RNA-binding proteins, normally and in pathologic aggregates, which may provide insight into alterations in RNA regulation observed in disease.
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Affiliation(s)
- Evan Lester
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- Howard Hughes Medical Institute, University of Colorado, Boulder, CO, USA
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2
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Wang F, Chen Z, Zhou Q, Xie L, Zheng N, Chen Z, Lin J, Li B, Li L. Implications of Liquid-Liquid Phase Separation and Ferroptosis in Alzheimer's Disease. Neuropharmacology 2024:110083. [PMID: 39043267 DOI: 10.1016/j.neuropharm.2024.110083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 07/04/2024] [Accepted: 07/15/2024] [Indexed: 07/25/2024]
Abstract
Neuronal cell demise represents a prevalent occurrence throughout the advancement of Alzheimer's disease (AD). However, the mechanism of triggering the death of neuronal cells remains unclear. Its potential mechanisms include aggregation of soluble amyloid-beta (Aβ) to form insoluble amyloid plaques, abnormal phosphorylation of tau protein and formation of intracellular neurofibrillary tangles (NFTs), neuroinflammation, ferroptosis, oxidative stress, liquid-liquid phase separation (LLPS) and metal ion disorders. Among them, ferroptosis is an iron-dependent lipid peroxidation-driven cell death and emerging evidences have demonstrated the involvement of ferroptosis in the pathological process of AD. The sensitivity to ferroptosis is tightly linked to numerous biological processes. Moreover, emerging evidences indicate that LLPS has great impacts on regulating human health and diseases, especially AD. Soluble Aβ can undergo LLPS to form liquid-like droplets, which can lead to the formation of insoluble amyloid plaques. Meanwhile, tau has a high propensity to condensate via the mechanism of LLPS, which can lead to the formation of NFTs. In this review, we summarize the most recent advancements pertaining to LLPS and ferroptosis in AD. Our primary focus is on expounding the influence of Aβ, tau protein, iron ions, and lipid oxidation on the intricate mechanisms underlying ferroptosis and LLPS within the domain of AD pathology. Additionally, we delve into the intricate cross-interactions that occur between LLPS and ferroptosis in the context of AD. Our findings are expected to serve as a theoretical and experimental foundation for clinical research and targeted therapy for AD.
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Affiliation(s)
- Fuwei Wang
- Dongguan Key Laboratory of Traditional Chinese Medicine and New Pharmaceutical Development, School of Pharmacy, Guangdong Medical University, Dongguan, China
| | - Zihao Chen
- Dongguan Key Laboratory of Traditional Chinese Medicine and New Pharmaceutical Development, School of Pharmacy, Guangdong Medical University, Dongguan, China
| | - Qiong Zhou
- Dongguan Key Laboratory of Traditional Chinese Medicine and New Pharmaceutical Development, School of Pharmacy, Guangdong Medical University, Dongguan, China
| | - Lihua Xie
- Dongguan Key Laboratory of Traditional Chinese Medicine and New Pharmaceutical Development, School of Pharmacy, Guangdong Medical University, Dongguan, China
| | - Nan Zheng
- Dongguan Key Laboratory of Traditional Chinese Medicine and New Pharmaceutical Development, School of Pharmacy, Guangdong Medical University, Dongguan, China
| | - Ziwen Chen
- Dongguan Key Laboratory of Traditional Chinese Medicine and New Pharmaceutical Development, School of Pharmacy, Guangdong Medical University, Dongguan, China
| | - Jiantao Lin
- Dongguan Key Laboratory of Traditional Chinese Medicine and New Pharmaceutical Development, School of Pharmacy, Guangdong Medical University, Dongguan, China.
| | - Baohong Li
- Dongguan Key Laboratory of Traditional Chinese Medicine and New Pharmaceutical Development, School of Pharmacy, Guangdong Medical University, Dongguan, China.
| | - Li Li
- Dongguan Key Laboratory of Traditional Chinese Medicine and New Pharmaceutical Development, School of Pharmacy, Guangdong Medical University, Dongguan, China.
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Li CL, Zhou GF, Xie XY, Wang L, Chen X, Pan QL, Pu YL, Yang J, Song L, Chen GJ. STAU1 exhibits a dual function by promoting amyloidogenesis and tau phosphorylation in cultured cells. Exp Neurol 2024; 377:114805. [PMID: 38729552 DOI: 10.1016/j.expneurol.2024.114805] [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: 12/16/2023] [Revised: 04/25/2024] [Accepted: 04/30/2024] [Indexed: 05/12/2024]
Abstract
Staufen-1 (STAU1) is a double-stranded RNA-binding protein (RBP) involved in a variety of pathological conditions. In this study, we investigated the potential role of STAU1 in Alzheimer's disease (AD), in which two hallmarks are well-established as cerebral β-amyloid protein (Aβ) deposition and Tau-centered neurofibrillary tangles. We found that STAU1 protein level was significantly increased in cells that stably express full-length APP and the brain of APP/PS1 mice, an animal model of AD. STAU1 knockdown, as opposed to overexpression, significantly decreased the protein levels of β-amyloid converting enzyme 1 (BACE1) and Aβ. We further found that STAU1 extended the half-life of the BACE1 mRNA through binding to the 3' untranslated region (3'UTR). Transcriptome analysis revealed that STAU1 enhanced the expression of growth arrest and DNA damage 45 β (GADD45B) upstream of P38 MAPK signaling, which contributed to STAU1-induced regulation of Tau phosphorylation at Ser396 and Thr181. Together, STAU1 promoted amyloidogenesis by inhibiting BACE1 mRNA decay, and augmented Tau phosphorylation through activating GADD45B in relation to P38 MAPK. Targeting STAU1 that acts on both amyloidogenesis and tauopathy may serve as an optimistic approach for AD treatment.
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Affiliation(s)
- Chen-Lu Li
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - Gui-Feng Zhou
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - Xiao-Yong Xie
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - Lu Wang
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - Xue Chen
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - Qiu-Ling Pan
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - Ya-Lan Pu
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - Jie Yang
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - Li Song
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - Guo-Jun Chen
- Department of Neurology, The First Affiliated Hospital Of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China.
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Johnson AG, Dammer EB, Webster JA, Duong DM, Seyfried NT, Hales CM. Proteomic networks of gray and white matter reveal tissue-specific changes in human tauopathy. Ann Clin Transl Neurol 2024. [PMID: 38924699 DOI: 10.1002/acn3.52134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 05/06/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
OBJECTIVE To define tauopathy-associated changes in the human gray and white matter proteome. METHOD We applied tandem mass tagged labeling and mass spectrometry, consensus, and ratio weighted gene correlation network analysis (WGCNA) to gray and white matter sampled from postmortem human dorsolateral prefrontal cortex. The sampled tissues included control as well as Alzheimer's disease, corticobasal degeneration, progressive supranuclear palsy, frontotemporal degeneration with tau pathology, and chronic traumatic encephalopathy. RESULTS Only eight proteins were unique to gray matter while six were unique to white matter. Comparison of the gray and white matter proteome revealed an enrichment of microglial proteins in the white matter. Consensus WGCNA sorted over 6700 protein isoforms into 46 consensus modules across the gray and white matter proteomic networks. Consensus network modules demonstrated unique and shared disease-associated microglial and endothelial protein changes. Ratio WGCNA sorted over 6500 protein ratios (white:gray) into 33 modules. Modules associated with mitochondrial proteins and processes demonstrated higher white:gray ratios in diseased tissues relative to control, driven by mitochondrial protein downregulation in gray and upregulation in white. INTERPRETATION The dataset is a valuable resource for understanding proteomic changes in human tauopathy gray and white matter. The identification of unique and shared disease-associated changes across gray and white matter emphasizes the utility of examining both tissue types. Future studies of microglial, endothelial, and mitochondrial changes in white matter may provide novel insights into tauopathy-associated changes in human brain.
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Affiliation(s)
- Ashlyn G Johnson
- Neuroscience Graduate Program, Laney Graduate School, Emory University, Atlanta, Georgia, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Eric B Dammer
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - James A Webster
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Duc M Duong
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Nicholas T Seyfried
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Chadwick M Hales
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
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Paul TM, Jamal S, Ekpenyong E, Prevelige P, Fargason TE, Zhang Z, Zhang J. Expression and Purification of Human U1-70K (snRNP70) and its BAD Domains Using an E. coli Expression System. Curr Protoc 2024; 4:e1059. [PMID: 38896106 PMCID: PMC11189609 DOI: 10.1002/cpz1.1059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
U1-70K (snRNP70) serves as an indispensable protein component within the U1 complex, assuming a pivotal role in both constitutive and alternative RNA splicing processes. Notably, U1-70K engages in interactions with SR proteins, instigating the assembly of the spliceosome. This protein undergoes regulation through phosphorylation at multiple sites. Of significant interest, U1-70K has been implicated in Alzheimer's disease, in which it tends to form detergent-insoluble aggregates. Even though it was identified more than three decades ago, our understanding of U1-70K remains notably constrained, primarily due to challenges such as low levels of recombinant expression, susceptibility to protein degradation, and insolubility. In endeavoring to address these limitations, we devised a multifaceted approach encompassing codon optimization, strategic purification, and a solubilization protocol. This methodology has enabled us to achieve a high yield of full-length, soluble U1-70K, paving the way for its comprehensive biophysical and biochemical characterization. Furthermore, we provide a detailed protocol for the preparation of phosphorylated U1-70K. This set of protocols promises to be a valuable resource for scientists exploring the intricate web of U1-70K-related mechanisms in the context of RNA splicing and its implications in neurodegenerative disorders and other disorders and biological processes. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Expression and purification of full-length U1-70K from E. coli Support Protocol 1: Making chemically competent BL21 Star pRARE/pBB535 cells Basic Protocol 2: Phosphorylation of full-length U1-70K using SRPK1 Support Protocol 2: Purification of SRPK1 Basic Protocol 3: Expression and purification of U1-70K BAD1 from E. coli Basic Protocol 4: Phosphorylation of U1-70K BAD1 using SRPK1 Basic Protocol 5: Expression and purification of U1-70K BAD2 from E. coli.
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Affiliation(s)
- Trenton M Paul
- Department of Chemistry, University of Alabama at Birmingham
| | - Shariq Jamal
- Department of Chemistry, University of Alabama at Birmingham
| | - Ethan Ekpenyong
- Department of Chemistry, University of Alabama at Birmingham
| | - Peter Prevelige
- Department of Microbiology, University of Alabama at Birmingham
| | | | - Zihan Zhang
- Department of Chemistry, University of Alabama at Birmingham
| | - Jun Zhang
- Department of Chemistry, University of Alabama at Birmingham
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6
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Campagne S. U1 snRNP Biogenesis Defects in Neurodegenerative Diseases. Chembiochem 2024; 25:e202300864. [PMID: 38459794 DOI: 10.1002/cbic.202300864] [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: 12/22/2023] [Revised: 03/07/2024] [Accepted: 03/08/2024] [Indexed: 03/10/2024]
Abstract
The U1 small ribonucleoprotein (U1 snRNP) plays a pivotal role in the intricate process of gene expression, specifically within nuclear RNA processing. By initiating the splicing reaction and modulating 3'-end processing, U1 snRNP exerts precise control over RNA metabolism and gene expression. This ribonucleoparticle is abundantly present, and its complex biogenesis necessitates shuttling between the nuclear and cytoplasmic compartments. Over the past three decades, extensive research has illuminated the crucial connection between disrupted U snRNP biogenesis and several prominent human diseases, notably various neurodegenerative conditions. The perturbation of U1 snRNP homeostasis has been firmly established in diseases such as Spinal Muscular Atrophy, Pontocerebellar hypoplasia, and FUS-mediated Amyotrophic Lateral Sclerosis. Intriguingly, compelling evidence suggests a potential correlation in Fronto-temporal dementia and Alzheimer's disease as well. Although the U snRNP biogenesis pathway is conserved across all eukaryotic cells, neurons, in particular, appear to be highly susceptible to alterations in spliceosome homeostasis. In contrast, other cell types exhibit a greater resilience to such disturbances. This vulnerability underscores the intricate relationship between U1 snRNP dynamics and the health of neuronal cells, shedding light on potential avenues for understanding and addressing neurodegenerative disorders.
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Affiliation(s)
- Sebastien Campagne
- University of Bordeaux, INSERM U1212, CNRS UMR5320, ARNA unit 146, rue Leo Saignat, 33077, Bordeaux
- Institut Européen de Chimie et de Biologie, 2, rue Robert Escarpit, 33600, Pessac
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Kumar P, Goettemoeller AM, Espinosa-Garcia C, Tobin BR, Tfaily A, Nelson RS, Natu A, Dammer EB, Santiago JV, Malepati S, Cheng L, Xiao H, Duong DD, Seyfried NT, Wood LB, Rowan MJM, Rangaraju S. Native-state proteomics of Parvalbumin interneurons identifies unique molecular signatures and vulnerabilities to early Alzheimer's pathology. Nat Commun 2024; 15:2823. [PMID: 38561349 PMCID: PMC10985119 DOI: 10.1038/s41467-024-47028-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 03/18/2024] [Indexed: 04/04/2024] Open
Abstract
Dysfunction in fast-spiking parvalbumin interneurons (PV-INs) may represent an early pathophysiological perturbation in Alzheimer's Disease (AD). Defining early proteomic alterations in PV-INs can provide key biological and translationally-relevant insights. We used cell-type-specific in-vivo biotinylation of proteins (CIBOP) coupled with mass spectrometry to obtain native-state PV-IN proteomes. PV-IN proteomic signatures include high metabolic and translational activity, with over-representation of AD-risk and cognitive resilience-related proteins. In bulk proteomes, PV-IN proteins were associated with cognitive decline in humans, and with progressive neuropathology in humans and the 5xFAD mouse model of Aβ pathology. PV-IN CIBOP in early stages of Aβ pathology revealed signatures of increased mitochondria and metabolism, synaptic and cytoskeletal disruption and decreased mTOR signaling, not apparent in whole-brain proteomes. Furthermore, we demonstrated pre-synaptic defects in PV-to-excitatory neurotransmission, validating our proteomic findings. Overall, in this study we present native-state proteomes of PV-INs, revealing molecular insights into their unique roles in cognitive resiliency and AD pathogenesis.
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Affiliation(s)
- Prateek Kumar
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA
- 3 Department of Neurology, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Annie M Goettemoeller
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA
- Neuroscience Graduate Program, Laney Graduate School, Emory University, Atlanta, USA
| | - Claudia Espinosa-Garcia
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- 3 Department of Neurology, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Brendan R Tobin
- Georgia W. Woodruff School of Mechanical Engineering, Parker H. Petit Institute for Bioengineering and Bioscience, and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, 30322, USA
| | - Ali Tfaily
- 3 Department of Neurology, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Ruth S Nelson
- 3 Department of Neurology, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Aditya Natu
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Eric B Dammer
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Juliet V Santiago
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA
- Neuroscience Graduate Program, Laney Graduate School, Emory University, Atlanta, USA
| | - Sneha Malepati
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Lihong Cheng
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA
| | - Hailian Xiao
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA
| | - Duc D Duong
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Nicholas T Seyfried
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Levi B Wood
- Georgia W. Woodruff School of Mechanical Engineering, Parker H. Petit Institute for Bioengineering and Bioscience, and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, 30322, USA
- School of Chemical and Biological Engineering, GeoInsrgia titute of Technology, Atlanta, GA, 30322, USA
| | - Matthew J M Rowan
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA.
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
| | - Srikant Rangaraju
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, USA.
- 3 Department of Neurology, Yale University School of Medicine, New Haven, CT, 06510, USA.
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Cheng F, Chapman T, Zhang S, Morsch M, Chung R, Lee A, Rayner SL. Understanding age-related pathologic changes in TDP-43 functions and the consequence on RNA splicing and signalling in health and disease. Ageing Res Rev 2024; 96:102246. [PMID: 38401571 DOI: 10.1016/j.arr.2024.102246] [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: 10/26/2023] [Revised: 02/07/2024] [Accepted: 02/21/2024] [Indexed: 02/26/2024]
Abstract
TAR DNA binding protein-43 (TDP-43) is a key component in RNA splicing which plays a crucial role in the aging process. In neurodegenerative diseases such as amyotrophic lateral sclerosis, frontotemporal dementia and limbic-predominant age-related TDP-43 encephalopathy, TDP-43 can be mutated, mislocalised out of the nucleus of neurons and glial cells and form cytoplasmic inclusions. These TDP-43 alterations can lead to its RNA splicing dysregulation and contribute to mis-splicing of various types of RNA, such as mRNA, microRNA, and circular RNA. These changes can result in the generation of an altered transcriptome and proteome within cells, ultimately changing the diversity and quantity of gene products. In this review, we summarise the findings of novel atypical RNAs resulting from TDP-43 dysfunction and their potential as biomarkers or targets for therapeutic development.
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Affiliation(s)
- Flora Cheng
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia.
| | - Tyler Chapman
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Selina Zhang
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Marco Morsch
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Roger Chung
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Albert Lee
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Stephanie L Rayner
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia.
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Yeganeh Markid T, Hosseinpour Feizi MA, Talebi M, Rezazadeh M, Khalaj-Kondori M. Gene expression investigation of four key regulators of polyadenylation and alternative adenylation in the periphery of late-onset Alzheimer's disease patients. Gene 2024; 895:148013. [PMID: 37981081 DOI: 10.1016/j.gene.2023.148013] [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: 07/11/2023] [Revised: 10/11/2023] [Accepted: 11/15/2023] [Indexed: 11/21/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) is a genetic and sporadic neurodegenerative disease considered by an archetypal cognitive impairment and a decrease in less common cognitive impairment. Notably, the discovery of goals in this paradigm is still a challenge, and understanding basic mechanisms is an important step toward improving disease management. Polyadenylation (PA) and alternative polyadenylation (APA) are two of the most critical RNA processing stages in 3'UTRs that influence various AD-related genes. METHODS In this study, we assessed Cleavage and polyadenylation specificity factors 1 and 6 (CPSF1 and CPSF6), cleavage stimulation factor 1 (CSTF1), and WD Repeat Domain 33 (WDR33) genes expression in the periphery of 50 AD patients and 50 healthy individuals with age and gender-matched by quantitative real-time PCR. RESULTS Comparing AD patients with healthy people using expression analysis revealed a substantial increase in CSTF1 (posterior beta = 0.773, adjusted P-value = 0.042). Significant positive correlations were found between CSTF1 and CPSF1 (r = 0.365, P < 0.001), WDR33 (r = 0.506, P < 0.001), and CPSF6 (r = 0.446, P < 0.001) expression levels. CONCLUSION Although further research is required to determine their potential contribution to AD, our findings offer a fresh perspective on molecular regulatory pathways associated with AD pathogenic mechanisms associated with PA and APA.
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Affiliation(s)
- Tarlan Yeganeh Markid
- Clinical Research Development Unit of Tabriz Valiasr Hospital, Tabriz University of Medical Sciences, Iran; Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | | | - Mahnaz Talebi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Maryam Rezazadeh
- Clinical Research Development Unit of Tabriz Valiasr Hospital, Tabriz University of Medical Sciences, Iran; Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Mohammad Khalaj-Kondori
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran.
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10
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Fu Q, Zhang B, Chen X, Chu L. Liquid-liquid phase separation in Alzheimer's disease. J Mol Med (Berl) 2024; 102:167-181. [PMID: 38167731 DOI: 10.1007/s00109-023-02407-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 11/26/2023] [Accepted: 12/04/2023] [Indexed: 01/05/2024]
Abstract
The pathological aggregation and misfolding of tau and amyloid-β play a key role in Alzheimer's disease (AD). However, the underlying pathological mechanisms remain unclear. Emerging evidences indicate that liquid-liquid phase separation (LLPS) has great impacts on regulating human health and diseases, especially neurodegenerative diseases. A series of studies have revealed the significance of LLPS in AD. In this review, we summarize the latest progress of LLPS in AD, focusing on the impact of metal ions, small-molecule inhibitors, and proteinaceous partners on tau LLPS and aggregation, as well as toxic oligomerization, the role of LLPS on amyloid-β (Aβ) aggregation, and the cross-interactions between amyloidogenic proteins in AD. Eventually, the fundamental methods and techniques used in LLPS study are introduced. We expect to present readers a deeper understanding of the relationship between LLPS and AD.
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Affiliation(s)
- Qinggang Fu
- Hepatic Surgery Center and Hubei Key Laboratory of Hepato-Pancreatic-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Bixiang Zhang
- Hepatic Surgery Center and Hubei Key Laboratory of Hepato-Pancreatic-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Xiaoping Chen
- Hepatic Surgery Center and Hubei Key Laboratory of Hepato-Pancreatic-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Liang Chu
- Hepatic Surgery Center and Hubei Key Laboratory of Hepato-Pancreatic-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
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11
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García Morato J, Gloeckner CJ, Kahle PJ. Proteomics elucidating physiological and pathological functions of TDP-43. Proteomics 2023; 23:e2200410. [PMID: 37671599 DOI: 10.1002/pmic.202200410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/02/2023] [Accepted: 08/10/2023] [Indexed: 09/07/2023]
Abstract
Trans-activation response DNA binding protein of 43 kDa (TDP-43) regulates a great variety of cellular processes in the nucleus and cytosol. In addition, a defined subset of neurodegenerative diseases is characterized by nuclear depletion of TDP-43 as well as cytosolic mislocalization and aggregation. To perform its diverse functions TDP-43 can associate with different ribonucleoprotein complexes. Combined with transcriptomics, MS interactome studies have unveiled associations between TDP-43 and the spliceosome machinery, polysomes and RNA granules. Moreover, the highly dynamic, low-valency interactions regulated by its low-complexity domain calls for innovative proximity labeling methodologies. In addition to protein partners, the analysis of post-translational modifications showed that they may play a role in the nucleocytoplasmic shuttling, RNA binding, liquid-liquid phase separation and protein aggregation of TDP-43. Here we review the various TDP-43 ribonucleoprotein complexes characterized so far, how they contribute to the diverse functions of TDP-43, and roles of post-translational modifications. Further understanding of the fluid dynamic properties of TDP-43 in ribonucleoprotein complexes, RNA granules, and self-assemblies will advance the understanding of RNA processing in cells and perhaps help to develop novel therapeutic approaches for TDPopathies.
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Affiliation(s)
- Jorge García Morato
- Laboratory of Functional Neurogenetics, Department of Neurodegeneration, German Center of Neurodegenerative Diseases and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Christian Johannes Gloeckner
- Research Group Functional Neuroproteomics, German Center of Neurodegenerative Diseases, Tübingen, Germany
- Core Facility for Medical Bioanalytics, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Philipp J Kahle
- Laboratory of Functional Neurogenetics, Department of Neurodegeneration, German Center of Neurodegenerative Diseases and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Department of Biochemistry, University of Tübingen, Tübingen, Germany
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12
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Zuniga G, Frost B. Selective neuronal vulnerability to deficits in RNA processing. Prog Neurobiol 2023; 229:102500. [PMID: 37454791 DOI: 10.1016/j.pneurobio.2023.102500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/30/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Emerging evidence indicates that errors in RNA processing can causally drive neurodegeneration. Given that RNA produced from expressed genes of all cell types undergoes processing (splicing, polyadenylation, 5' capping, etc.), the particular vulnerability of neurons to deficits in RNA processing calls for careful consideration. The activity-dependent transcriptome remodeling associated with synaptic plasticity in neurons requires rapid, multilevel post-transcriptional RNA processing events that provide additional opportunities for dysregulation and consequent introduction or persistence of errors in RNA transcripts. Here we review the accumulating evidence that neurons have an enhanced propensity for errors in RNA processing alongside grossly insufficient defenses to clear misprocessed RNA compared to other cell types. Additionally, we explore how tau, a microtubule-associated protein implicated in Alzheimer's disease and related tauopathies, contributes to deficits in RNA processing and clearance.
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Affiliation(s)
- Gabrielle Zuniga
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, USA; Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, TX, USA; Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Bess Frost
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, USA; Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, TX, USA; Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA.
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13
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Farhadieh ME, Ghaedi K. Analyzing alternative splicing in Alzheimer's disease postmortem brain: a cell-level perspective. Front Mol Neurosci 2023; 16:1237874. [PMID: 37799732 PMCID: PMC10548223 DOI: 10.3389/fnmol.2023.1237874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 09/01/2023] [Indexed: 10/07/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease with no effective cure that attacks the brain's cells resulting in memory loss and changes in behavior and language skills. Alternative splicing is a highly regulated process influenced by specific cell types and has been implicated in age-related disorders such as neurodegenerative diseases. A comprehensive detection of alternative splicing events (ASEs) at the cellular level in postmortem brain tissue can provide valuable insights into AD pathology. Here, we provided cell-level ASEs in postmortem brain tissue by employing bioinformatics pipelines on a bulk RNA sequencing study sorted by cell types and two single-cell RNA sequencing studies from the prefrontal cortex. This comprehensive analysis revealed previously overlooked splicing and expression changes in AD patient brains. Among the observed alterations were changed in the splicing and expression of transcripts associated with chaperones, including CLU in astrocytes and excitatory neurons, PTGDS in astrocytes and endothelial cells, and HSP90AA1 in microglia and tauopathy-afflicted neurons, which were associated with differential expression of the splicing factor DDX5. In addition, novel, unknown transcripts were altered, and structural changes were observed in lncRNAs such as MEG3 in neurons. This work provides a novel strategy to identify the notable ASEs at the cell level in neurodegeneration, which revealed cell type-specific splicing changes in AD. This finding may contribute to interpreting associations between splicing and neurodegenerative disease outcomes.
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Affiliation(s)
| | - Kamran Ghaedi
- Department of Cell and Molecular Biology and Microbiology, Faculty of Biological Sciences and Technology, University of Isfahan, Isfahan, Iran
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14
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McMillan PJ, Benbow SJ, Uhrich R, Saxton A, Baum M, Strovas T, Wheeler JM, Baker J, Liachko NF, Keene CD, Latimer CS, Kraemer BC. Tau-RNA complexes inhibit microtubule polymerization and drive disease-relevant conformation change. Brain 2023; 146:3206-3220. [PMID: 36732296 PMCID: PMC10393409 DOI: 10.1093/brain/awad032] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 01/09/2023] [Accepted: 01/23/2023] [Indexed: 02/04/2023] Open
Abstract
Alzheimer's disease and related disorders feature neurofibrillary tangles and other neuropathological lesions composed of detergent-insoluble tau protein. In recent structural biology studies of tau proteinopathy, aggregated tau forms a distinct set of conformational variants specific to the different types of tauopathy disorders. However, the constituents driving the formation of distinct pathological tau conformations on pathway to tau-mediated neurodegeneration remain unknown. Previous work demonstrated RNA can serve as a driver of tau aggregation, and RNA associates with tau containing lesions, but tools for evaluating tau/RNA interactions remain limited. Here, we employed molecular interaction studies to measure the impact of tau/RNA binding on tau microtubule binding and aggregation. To investigate the importance of tau/RNA complexes (TRCs) in neurodegenerative disease, we raised a monoclonal antibody (TRC35) against aggregated tau/RNA complexes. We showed that native tau binds RNA with high affinity but low specificity, and tau binding to RNA competes with tau-mediated microtubule assembly functions. Tau/RNA interaction in vitro promotes the formation of higher molecular weight tau/RNA complexes, which represent an oligomeric tau species. Coexpression of tau and poly(A)45 RNA transgenes in Caenorhabditis elegans exacerbates tau-related phenotypes including neuronal dysfunction and pathological tau accumulation. TRC35 exhibits specificity for Alzheimer's disease-derived detergent-insoluble tau relative to soluble recombinant tau. Immunostaining with TRC35 labels a wide variety of pathological tau lesions in animal models of tauopathy, which are reduced in mice lacking the RNA binding protein MSUT2. TRC-positive lesions are evident in many human tauopathies including Alzheimer's disease, progressive supranuclear palsy, corticobasal degeneration and Pick's disease. We also identified ocular pharyngeal muscular dystrophy as a novel tauopathy disorder, where loss of function in the poly(A) RNA binding protein (PABPN1) causes accumulation of pathological tau in tissue from post-mortem human brain. Tau/RNA binding drives tau conformational change and aggregation inhibiting tau-mediated microtubule assembly. Our findings implicate cellular tau/RNA interactions as modulators of both normal tau function and pathological tau toxicity in tauopathy disorders and suggest feasibility for novel therapeutic approaches targeting TRCs.
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Affiliation(s)
- Pamela J McMillan
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Sarah J Benbow
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Rikki Uhrich
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Aleen Saxton
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Misa Baum
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Timothy Strovas
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Jeanna M Wheeler
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Jeremy Baker
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Nicole F Liachko
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - C Dirk Keene
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Caitlin S Latimer
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Brian C Kraemer
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
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15
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Zaman M, Fu Y, Chen PC, Sun H, Yang S, Wu Z, Wang Z, Poudel S, Serrano GE, Beach TG, Li L, Wang X, Peng J. Dissecting Detergent-Insoluble Proteome in Alzheimer's Disease by TMTc-Corrected Quantitative Mass Spectrometry. Mol Cell Proteomics 2023; 22:100608. [PMID: 37356496 PMCID: PMC10392608 DOI: 10.1016/j.mcpro.2023.100608] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 06/16/2023] [Accepted: 06/21/2023] [Indexed: 06/27/2023] Open
Abstract
Protein aggregation of amyloid-β peptides and tau are pathological hallmarks of Alzheimer's disease (AD), which are often resistant to detergent extraction and thus enriched in the insoluble proteome. However, additional proteins that coaccumulate in the detergent-insoluble AD brain proteome remain understudied. Here, we comprehensively characterized key proteins and pathways in the detergent-insoluble proteome from human AD brain samples using differential extraction, tandem mass tag (TMT) labeling, and two-dimensional LC-tandem mass spectrometry. To improve quantification accuracy of the TMT method, we developed a complement TMT-based strategy to correct for ratio compression. Through the meta-analysis of two independent detergent-insoluble AD proteome datasets (8914 and 8917 proteins), we identified 190 differentially expressed proteins in AD compared with control brains, highlighting the pathways of amyloid cascade, RNA splicing, endocytosis/exocytosis, protein degradation, and synaptic activity. To differentiate the truly detergent-insoluble proteins from copurified background during protein extraction, we analyzed the fold of enrichment for each protein by comparing the detergent-insoluble proteome with the whole proteome from the same AD samples. Among the 190 differentially expressed proteins, 84 (51%) proteins of the upregulated proteins (n = 165) were enriched in the insoluble proteome, whereas all downregulated proteins (n = 25) were not enriched, indicating that they were copurified components. The vast majority of these enriched 84 proteins harbor low-complexity regions in their sequences, including amyloid-β, Tau, TARDBP/TAR DNA-binding protein 43, SNRNP70/U1-70K, MDK, PTN, NTN1, NTN3, and SMOC1. Moreover, many of the enriched proteins in AD were validated in the detergent-insoluble proteome by five steps of differential extraction, proteomic analysis, or immunoblotting. Our study reveals a resource list of proteins and pathways that are exclusively present in the detergent-insoluble proteome, providing novel molecular insights to the formation of protein pathology in AD.
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Affiliation(s)
- Masihuz Zaman
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Yingxue Fu
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Ping-Chung Chen
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Huan Sun
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Shu Yang
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Zhiping Wu
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Zhen Wang
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Suresh Poudel
- Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Geidy E Serrano
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | - Thomas G Beach
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | - Ling Li
- Department of Biology, University of North Dakota, Grand Forks, North Dakota, USA
| | - Xusheng Wang
- Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
| | - Junmin Peng
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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16
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Zhang J, Chen WQ, Yang K, Wang ZX, Sun DL, Peng YY, Yu M, Wang SX, Guo Q. RBM25 induces trophoblast epithelial-mesenchymal transition and preeclampsia disorder by enhancing the positive feedback loop between Grhl2 and RBM25. Exp Biol Med (Maywood) 2023; 248:1267-1277. [PMID: 37728157 PMCID: PMC10621477 DOI: 10.1177/15353702231191199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 05/08/2023] [Indexed: 09/21/2023] Open
Abstract
Defects in migration and invasion caused by dysregulation of trophoblast epithelial-mesenchymal transformation (EMT) are one of the key factors in the pathogenesis of preeclampsia (PE). RNA-binding motif protein 25 (RBM25) is an RNA-binding protein involved in a variety of cellular processes, including cell proliferation, apoptosis, cell migration and invasion, and EMT. However, the expression and function of RBM25 in placental of PE remain unclear. In this study, we reveal that the expression of RBM25 is significantly elevated in PE placental tissue. RBM25 depletion and over-expression in trophoblast cells increase and decrease, respectively, cell migration and invasion by regulating EMT marker E-cadherin and Vimentin expression. Mechanistically, Grhl2 is involved in RBM25-regulated trophoblast cell migration, invasion, and EMT through RBM25-facilitated mRNA stabilization. Furthermore, the upregulation of Grhl2 enhances the expression of RBM25 through transcription and forms a positive feedback regulation in the progression of PE. These findings suggest that upregulation of RBM25 induces dysregulation of trophoblast EMT by enhancing positive feedback regulation of Grhl2 and RBM25, leading to defects in cell migration and invasion. Targeting this newly identified regulatory axis may provide benefits in the prevention and treatment of PE.
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Affiliation(s)
- Jing Zhang
- Prenatal Diagnosis Center, Shijiazhuang Obstetrics and Gynecology Hospital, Hebei Key Laboratory of Maternal and Fetal Medicine, Shijiazhuang 050011, China
| | - Wen-qi Chen
- Prenatal Diagnosis Center, Shijiazhuang Obstetrics and Gynecology Hospital, Hebei Key Laboratory of Maternal and Fetal Medicine, Shijiazhuang 050011, China
| | - Kai Yang
- Prenatal Diagnosis Center, Beijing Obstetrics and Gynecology Hospital, Beijing Maternal and Child Health Care Hospital, Capital Medical University, Beijing 100026, China
| | - Zhao-xi Wang
- Prenatal Diagnosis Center, Shijiazhuang Obstetrics and Gynecology Hospital, Hebei Key Laboratory of Maternal and Fetal Medicine, Shijiazhuang 050011, China
| | - Dong-lan Sun
- Prenatal Diagnosis Center, Shijiazhuang Obstetrics and Gynecology Hospital, Hebei Key Laboratory of Maternal and Fetal Medicine, Shijiazhuang 050011, China
| | - Yuan-yuan Peng
- Prenatal Diagnosis Center, Shijiazhuang Obstetrics and Gynecology Hospital, Hebei Key Laboratory of Maternal and Fetal Medicine, Shijiazhuang 050011, China
| | - Mei Yu
- Prenatal Diagnosis Center, Shijiazhuang Obstetrics and Gynecology Hospital, Hebei Key Laboratory of Maternal and Fetal Medicine, Shijiazhuang 050011, China
| | - Shao-xiong Wang
- Prenatal Diagnosis Center, Shijiazhuang Obstetrics and Gynecology Hospital, Hebei Key Laboratory of Maternal and Fetal Medicine, Shijiazhuang 050011, China
| | - Qing Guo
- Prenatal Diagnosis Center, Shijiazhuang Obstetrics and Gynecology Hospital, Hebei Key Laboratory of Maternal and Fetal Medicine, Shijiazhuang 050011, China
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17
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Young-Pearse TL, Lee H, Hsieh YC, Chou V, Selkoe DJ. Moving beyond amyloid and tau to capture the biological heterogeneity of Alzheimer's disease. Trends Neurosci 2023; 46:426-444. [PMID: 37019812 PMCID: PMC10192069 DOI: 10.1016/j.tins.2023.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/28/2023] [Accepted: 03/09/2023] [Indexed: 04/05/2023]
Abstract
Alzheimer's disease (AD) manifests along a spectrum of cognitive deficits and levels of neuropathology. Genetic studies support a heterogeneous disease mechanism, with around 70 associated loci to date, implicating several biological processes that mediate risk for AD. Despite this heterogeneity, most experimental systems for testing new therapeutics are not designed to capture the genetically complex drivers of AD risk. In this review, we first provide an overview of those aspects of AD that are largely stereotyped and those that are heterogeneous, and we review the evidence supporting the concept that different subtypes of AD are important to consider in the design of agents for the prevention and treatment of the disease. We then dive into the multifaceted biological domains implicated to date in AD risk, highlighting studies of the diverse genetic drivers of disease. Finally, we explore recent efforts to identify biological subtypes of AD, with an emphasis on the experimental systems and data sets available to support progress in this area.
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Affiliation(s)
- Tracy L Young-Pearse
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
| | - Hyo Lee
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Yi-Chen Hsieh
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Vicky Chou
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
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18
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Kumar P, Goettemoeller AM, Espinosa-Garcia C, Tobin BR, Tfaily A, Nelson RS, Natu A, Dammer EB, Santiago JV, Malepati S, Cheng L, Xiao H, Duong D, Seyfried NT, Wood LB, Rowan MJ, Rangaraju S. Native-state proteomics of Parvalbumin interneurons identifies novel molecular signatures and metabolic vulnerabilities to early Alzheimer's disease pathology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.17.541038. [PMID: 37292756 PMCID: PMC10245729 DOI: 10.1101/2023.05.17.541038] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
One of the earliest pathophysiological perturbations in Alzheimer's Disease (AD) may arise from dysfunction of fast-spiking parvalbumin (PV) interneurons (PV-INs). Defining early protein-level (proteomic) alterations in PV-INs can provide key biological and translationally relevant insights. Here, we use cell-type-specific in vivo biotinylation of proteins (CIBOP) coupled with mass spectrometry to obtain native-state proteomes of PV interneurons. PV-INs exhibited proteomic signatures of high metabolic, mitochondrial, and translational activity, with over-representation of causally linked AD genetic risk factors. Analyses of bulk brain proteomes indicated strong correlations between PV-IN proteins with cognitive decline in humans, and with progressive neuropathology in humans and mouse models of Aβ pathology. Furthermore, PV-IN-specific proteomes revealed unique signatures of increased mitochondrial and metabolic proteins, but decreased synaptic and mTOR signaling proteins in response to early Aβ pathology. PV-specific changes were not apparent in whole-brain proteomes. These findings showcase the first native state PV-IN proteomes in mammalian brain, revealing a molecular basis for their unique vulnerabilities in AD.
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19
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Pandey RS, Kotredes KP, Sasner M, Howell GR, Carter GW. Differential splicing of neuronal genes in a Trem2*R47H mouse model mimics alterations associated with Alzheimer's disease. BMC Genomics 2023; 24:172. [PMID: 37016304 PMCID: PMC10074678 DOI: 10.1186/s12864-023-09280-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 03/29/2023] [Indexed: 04/06/2023] Open
Abstract
BACKGROUND Molecular characterization of late-onset Alzheimer's disease (LOAD), the leading cause of age-related dementia, has revealed transcripts, proteins, and pathway alterations associated with disease. Assessing these postmortem signatures of LOAD in experimental model systems can further elucidate their relevance to disease origins and progression. Model organisms engineered with human genetic factors further link these signatures to disease-associated variants, especially when studies are designed to leverage homology across species. Here we assess differential gene splicing patterns in aging mouse models carrying humanized APOE4 and/or the Trem2*R47H variant on a C57BL/6J background. We performed a differential expression of gene (DEG) and differential splicing analyses on whole brain transcriptomes at multiple ages. To better understand the difference between differentially expressed and differentially spliced genes, we evaluated enrichment of KEGG pathways and cell-type specific gene signatures of the adult brain from each alteration type. To determine LOAD relevance, we compared differential splicing results from mouse models with multiple human AD splicing studies. RESULTS We found that differentially expressed genes in Trem2*R47H mice were significantly enriched in multiple AD-related pathways, including immune response, osteoclast differentiation, and metabolism, whereas differentially spliced genes were enriched for neuronal related functions, including GABAergic synapse and glutamatergic synapse. These results were reinforced by the enrichment of microglial genes in DEGs and neuronal genes in differentially spliced genes in Trem2*R47H mice. We observed significant overlap between differentially spliced genes in Trem2*R47H mice and brains from human AD subjects. These effects were absent in APOE4 mice and suppressed in APOE4.Trem2*R47H double mutant mice relative to Trem2*R47H mice. CONCLUSIONS The cross-species observation that alternative splicing observed in LOAD are present in Trem2*R47H mouse models suggests a novel link between this candidate risk gene and molecular signatures of LOAD in neurons and demonstrates how deep molecular analysis of new genetic models links molecular disease outcomes to a human candidate gene.
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Affiliation(s)
- Ravi S Pandey
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Drive, Farmington, CT, 06032, USA
| | - Kevin P Kotredes
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Michael Sasner
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Gareth R Howell
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Gregory W Carter
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Drive, Farmington, CT, 06032, USA.
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA.
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20
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Tassinari V, La Rosa P, Guida E, Colopi A, Caratelli S, De Paolis F, Gallo A, Cenciarelli C, Sconocchia G, Dolci S, Cesarini V. Contribution of A-to-I RNA editing, M6A RNA Methylation, and Alternative Splicing to physiological brain aging and neurodegenerative diseases. Mech Ageing Dev 2023; 212:111807. [PMID: 37023929 DOI: 10.1016/j.mad.2023.111807] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/31/2023] [Accepted: 04/03/2023] [Indexed: 04/08/2023]
Abstract
Aging is a physiological and progressive phenomenon in all organisms' life cycle, characterized by the accumulation of degenerative processes triggered by several alterations within molecular pathways. These changes compromise cell fate, resulting in the loss of functions in tissues throughout the body, including the brain. Physiological brain aging has been linked to structural and functional alterations, as well as to an increased risk of neurodegenerative diseases. Post-transcriptional RNA modifications modulate mRNA coding properties, stability, translatability, expanding the coding capacity of the genome, and are involved in all cellular processes. Among mRNA post-transcriptional modifications, the A-to-I RNA editing, m6A RNA Methylation and Alternative Splicing play a critical role in all the phases of a neuronal cell life cycle and alterations in their mechanisms of action significantly contribute to aging and neurodegeneration. Here we review our current understanding of the contribution of A-to-I RNA editing, m6A RNA Methylation, and Alternative Splicing to physiological brain aging process and neurodegenerative diseases.
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Affiliation(s)
- Valentina Tassinari
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy; Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy.
| | - Piergiorgio La Rosa
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy; European Center for Brain Research, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Eugenia Guida
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Ambra Colopi
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Sara Caratelli
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Francesca De Paolis
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Angela Gallo
- RNA Editing Lab., Oncohaematology Department, Cellular and Gene Therapy Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Carlo Cenciarelli
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Giuseppe Sconocchia
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Susanna Dolci
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Valeriana Cesarini
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy.
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21
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Light, Water, and Melatonin: The Synergistic Regulation of Phase Separation in Dementia. Int J Mol Sci 2023; 24:ijms24065835. [PMID: 36982909 PMCID: PMC10054283 DOI: 10.3390/ijms24065835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/17/2023] [Indexed: 03/22/2023] Open
Abstract
The swift rise in acceptance of molecular principles defining phase separation by a broad array of scientific disciplines is shadowed by increasing discoveries linking phase separation to pathological aggregations associated with numerous neurodegenerative disorders, including Alzheimer’s disease, that contribute to dementia. Phase separation is powered by multivalent macromolecular interactions. Importantly, the release of water molecules from protein hydration shells into bulk creates entropic gains that promote phase separation and the subsequent generation of insoluble cytotoxic aggregates that drive healthy brain cells into diseased states. Higher viscosity in interfacial waters and limited hydration in interiors of biomolecular condensates facilitate phase separation. Light, water, and melatonin constitute an ancient synergy that ensures adequate protein hydration to prevent aberrant phase separation. The 670 nm visible red wavelength found in sunlight and employed in photobiomodulation reduces interfacial and mitochondrial matrix viscosity to enhance ATP production via increasing ATP synthase motor efficiency. Melatonin is a potent antioxidant that lowers viscosity to increase ATP by scavenging excess reactive oxygen species and free radicals. Reduced viscosity by light and melatonin elevates the availability of free water molecules that allow melatonin to adopt favorable conformations that enhance intrinsic features, including binding interactions with adenosine that reinforces the adenosine moiety effect of ATP responsible for preventing water removal that causes hydrophobic collapse and aggregation in phase separation. Precise recalibration of interspecies melatonin dosages that account for differences in metabolic rates and bioavailability will ensure the efficacious reinstatement of the once-powerful ancient synergy between light, water, and melatonin in a modern world.
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22
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Aubol BE, Adams JA. SRPK1 regulates RNA binding in a pre-spliceosomal complex using a catalytic bypass mechanism. FEBS J 2022; 289:7428-7445. [PMID: 35730996 DOI: 10.1111/febs.16560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/10/2022] [Accepted: 06/21/2022] [Indexed: 01/14/2023]
Abstract
Serine-arginine protein kinase 1 (SRPK1) phosphorylates serine-arginine (SR) proteins in the cytoplasm, directing them to the nucleus for splicing function. SRPK1 has also been detected in the nucleus but its function here is still not fully understood. We now demonstrate that nuclear SRPK1 can regulate U1-70K, a protein component of the uridine-rich 1 small nuclear ribonucleoprotein (U1 snRNP) that binds SR proteins and facilitates 5' splice-site selection in precursor mRNA. We found that SRPK1 uses a large, disordered domain to bind U1-70K, regulating the interaction of an exonic splicing enhancer (ESE) to the associated SR protein. Surprisingly, the catalytic activity of SRPK1 is not required for this phenomenon. Instead, SRPK1 associates directly with the N-terminus of U1-70K and alters the regulatory function of the distal C-terminus, modifying interactions between the U1-70K:SR protein complex and the ESE. Disruption of SRPK1 binding to this complex affects the alternative splicing of genes modulated by the C-terminus of U1-70K. Such findings suggest that, in addition to operating as a traditional serine-modifying catalyst, SRPK1 can also bypass this intrinsic activity to regulate RNA contacts in an early pre-spliceosomal complex.
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Affiliation(s)
- Brandon E Aubol
- Department of Pharmacology, University of California San Diego, La Jolla, CA, USA
| | - Joseph A Adams
- Department of Pharmacology, University of California San Diego, La Jolla, CA, USA
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23
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Deolankar SC, Najar MA, Ramesh P, Kanichery A, Kudva AK, Raghu SV, Prasad TSK. Discovery of Molecular Networks of Neuroprotection Conferred by Brahmi Extract in Aβ 42-Induced Toxicity Model of Drosophila melanogaster Using a Quantitative Proteomic Approach. Mol Neurobiol 2022; 60:303-316. [PMID: 36261695 DOI: 10.1007/s12035-022-03066-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 10/03/2022] [Indexed: 11/30/2022]
Abstract
Accumulation of Aβ42 peptides forming plaque in various regions of the brain is a hallmark of Alzheimer's disease (AD) progression. However, to date, there is no effective management strategy reported for attenuation of Aβ42-induced toxicity in the early stages of the disease. Alternate medicinal systems such as Ayurveda in the past few decades show promising results in the management of neuronal complications. Medhya Rasayana such as Brahmi is known for its neuroprotective properties via resolving memory-related issues, while the underlying molecular mechanism of the same remains unclear. In the present study, we aimed to understand the neuroprotective effects of the aqueous extract of Bacopa monnieri and Centella asiatica (both commonly known as Brahmi) against the Aβ42 expressing model of the Drosophila melanogaster. By applying a quantitative proteomics approach, the study identified > 90% of differentially expressed proteins from Aβ42 expressing D. melanogaster were either restored to their original expression pattern or showed no change in expression pattern upon receiving either Brahmi extract treatment. The Brahmi restored proteins were part of neuronal pathways associated with cell cycle re-entry, apoptosis, and mitochondrial dynamics. The neuroprotective effect of Brahmi was also validated by negative geotaxis behavioral analysis suggesting its protective role against behavioral deficits exerted by Aβ42 toxicity. We believe that these discoveries will provide a platform for developing novel therapeutics for AD management by deciphering molecular targets of neuroprotection conferred by an aqueous extract of Bacopa monnieri or Centella asiatica.
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Affiliation(s)
- Sayali Chandrashekhar Deolankar
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Mangalore, India
| | - Mohd Altaf Najar
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Mangalore, India
| | - Poornima Ramesh
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Mangalore, India
| | - Anagha Kanichery
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Mangalore, India
| | - Avinash K Kudva
- Department of Biochemistry, Mangalore University, Mangalore, India
| | | | - T S Keshava Prasad
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Mangalore, India.
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24
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Chen PC, Han X, Shaw TI, Fu Y, Sun H, Niu M, Wang Z, Jiao Y, Teubner BJW, Eddins D, Beloate LN, Bai B, Mertz J, Li Y, Cho JH, Wang X, Wu Z, Liu D, Poudel S, Yuan ZF, Mancieri A, Low J, Lee HM, Patton MH, Earls LR, Stewart E, Vogel P, Hui Y, Wan S, Bennett DA, Serrano GE, Beach TG, Dyer MA, Smeyne RJ, Moldoveanu T, Chen T, Wu G, Zakharenko SS, Yu G, Peng J. Alzheimer's disease-associated U1 snRNP splicing dysfunction causes neuronal hyperexcitability and cognitive impairment. NATURE AGING 2022; 2:923-940. [PMID: 36636325 PMCID: PMC9833817 DOI: 10.1038/s43587-022-00290-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/01/2022] [Indexed: 11/05/2022]
Abstract
Recent proteome and transcriptome profiling of Alzheimer's disease (AD) brains reveals RNA splicing dysfunction and U1 small nuclear ribonucleoprotein (snRNP) pathology containing U1-70K and its N-terminal 40-KDa fragment (N40K). Here we present a causative role of U1 snRNP dysfunction to neurodegeneration in primary neurons and transgenic mice (N40K-Tg), in which N40K expression exerts a dominant-negative effect to downregulate full-length U1-70K. N40K-Tg recapitulates N40K insolubility, erroneous splicing events, neuronal degeneration and cognitive impairment. Specifically, N40K-Tg shows the reduction of GABAergic synapse components (e.g., the GABA receptor subunit of GABRA2), and concomitant postsynaptic hyperexcitability that is rescued by a GABA receptor agonist. Crossing of N40K-Tg and the 5xFAD amyloidosis model indicates that the RNA splicing defect synergizes with the amyloid cascade to remodel the brain transcriptome and proteome, deregulate synaptic proteins, and accelerate cognitive decline. Thus, our results support the contribution of U1 snRNP-mediated splicing dysfunction to AD pathogenesis.
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Affiliation(s)
- Ping-Chung Chen
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Xian Han
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Timothy I. Shaw
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Biostatistics and Bioinformatics, Moffitt Cancer Center, Tampa, FL 33612, USA
| | - Yingxue Fu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Huan Sun
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Mingming Niu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Zhen Wang
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yun Jiao
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Brett J. W. Teubner
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Donnie Eddins
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Lauren N. Beloate
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Present address: Department of Biomedical Engineering and Electrical Engineering, Penn State University, State College, PA 16801, USA
| | - Bing Bai
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Present address: Department of Laboratory Medicine, Center for Precision Medicine, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu 210008, China
| | - Joseph Mertz
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Present address: GlaxoSmithKline, Rockville, MD 20850, USA
| | - Yuxin Li
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ji-Hoon Cho
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Xusheng Wang
- Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Present address: Department of Biology, University of North Dakota, Grand Forks, ND 58202, USA
| | - Zhiping Wu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Danting Liu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Suresh Poudel
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Zuo-Fei Yuan
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ariana Mancieri
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jonathan Low
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Hyeong-Min Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Mary H. Patton
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Laurie R. Earls
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Present address: Department of Biological Sciences, Loyola University of New Orleans, LA 70118, USA
| | - Elizabeth Stewart
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Peter Vogel
- Veterinary Pathology Core, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yawei Hui
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Shibiao Wan
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - David A. Bennett
- Department of Neurological Sciences, Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA
| | | | - Thomas G. Beach
- Banner Sun Health Research Institute, Sun City, AZ 85351, USA
| | - Michael A. Dyer
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Richard J. Smeyne
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Present address: Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Present address: Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AK 72205, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Gang Wu
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Stanislav S. Zakharenko
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Gang Yu
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Present address: Department of Neuroscience, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Junmin Peng
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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25
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Hu Z, Li M, Huo Z, Chen L, Liu S, Deng K, Lu X, Chen S, Fu Y, Xu A. U1 snRNP proteins promote proximal alternative polyadenylation sites by directly interacting with 3' end processing core factors. J Mol Cell Biol 2022; 14:6694001. [PMID: 36073763 PMCID: PMC9926334 DOI: 10.1093/jmcb/mjac054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 07/14/2022] [Accepted: 09/06/2022] [Indexed: 11/13/2022] Open
Abstract
In eukaryotic cells, both alternative splicing and alternative polyadenylation (APA) play essential roles in the gene regulation network. U1 small ribonucleoprotein particle (U1 snRNP) is a major component of spliceosome, and U1 snRNP complex can suppress proximal APA sites through crosstalking with 3' end processing factors. However, here we show that both knockdown and overexpression of SNRPA, SNRPC, SNRNP70, and SNRPD2, the U1 snRNP proteins, promote the usage of proximal APA sites at the transcriptome level. SNRNP70 can drive the phase transition of PABPN1 from droplet to aggregate, which may reduce the repressive effects of PABPN1 on the proximal APA sites. Additionally, SNRNP70 can also promote the proximal APA sites by recruiting CPSF6, suggesting that the function of CPSF6 on APA is related with other RNA-binding proteins and cell context-dependent. Consequently, these results reveal that, on the contrary to U1 snRNP complex, the free proteins of U1 snRNP complex can promote proximal APA sites through the interaction with 3' end processing machinery.
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Affiliation(s)
| | | | | | - Liutao Chen
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Higher Education Mega Center, Guangzhou 510006, China
| | - Susu Liu
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Higher Education Mega Center, Guangzhou 510006, China
| | - Ke Deng
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Higher Education Mega Center, Guangzhou 510006, China
| | - Xin Lu
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Higher Education Mega Center, Guangzhou 510006, China
| | - Shangwu Chen
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Higher Education Mega Center, Guangzhou 510006, China
| | | | - Anlong Xu
- Correspondence to: Anlong Xu, E-mail:
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26
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Zwierzchowski-Zarate AN, Mendoza-Oliva A, Kashmer OM, Collazo-Lopez JE, White CL, Diamond MI. RNA induces unique tau strains and stabilizes Alzheimer's disease seeds. J Biol Chem 2022; 298:102132. [PMID: 35700826 PMCID: PMC9364032 DOI: 10.1016/j.jbc.2022.102132] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/25/2022] Open
Abstract
Tau aggregation underlies neurodegenerative tauopathies, and trans-cellular propagation of tau assemblies of unique structure, i.e. strains, may underlie the diversity of these disorders. Polyanions have been reported to induce tau aggregation in vitro, but the precise trigger to convert tau from an inert to a seed-competent form in disease states is unknown. RNA triggers tau fibril formation in vitro and has been observed to associate with neurofibrillary tangles in human brain. Here we have tested whether RNA exerts sequence-specific effects on tau assembly and strain formation. We found that three RNA homopolymers, polyA, polyU, and polyC, all bound tau, but only polyA RNA triggered seed and fibril formation. In addition, polyA:tau seeds and fibrils were sensitive to RNase. We also observed that the origin of the RNA influenced the ability of tau to adopt a structure that would form stable strains. Human RNA potently induced tau seed formation and created tau conformations that preferentially formed stable strains in a HEK293T cell model, whereas RNA from other sources, or heparin, produced strains that were not stably maintained in cultured cells. Finally, we found that soluble, but not insoluble seeds from Alzheimer's disease (AD) brain were also sensitive to RNase. We conclude that human RNA specifically induces formation of stable tau strains, and may trigger the formation of dominant pathological assemblies that propagate in AD, and possibly other tauopathies.
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Affiliation(s)
- Amy N Zwierzchowski-Zarate
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Aydé Mendoza-Oliva
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Omar M Kashmer
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Josue E Collazo-Lopez
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Charles L White
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Marc I Diamond
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA.
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27
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Cell cycle-specific phase separation regulated by protein charge blockiness. Nat Cell Biol 2022; 24:625-632. [PMID: 35513709 PMCID: PMC9106583 DOI: 10.1038/s41556-022-00903-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 03/17/2022] [Indexed: 12/16/2022]
Abstract
Dynamic morphological changes of intracellular organelles are often regulated by protein phosphorylation or dephosphorylation1–6. Phosphorylation modulates stereospecific interactions among structured proteins, but how it controls molecular interactions among unstructured proteins and regulates their macroscopic behaviours remains unknown. Here we determined the cell cycle-specific behaviour of Ki-67, which localizes to the nucleoli during interphase and relocates to the chromosome periphery during mitosis. Mitotic hyperphosphorylation of disordered repeat domains of Ki-67 generates alternating charge blocks in these domains and increases their propensity for liquid–liquid phase separation (LLPS). A phosphomimetic sequence and the sequences with enhanced charge blockiness underwent strong LLPS in vitro and induced chromosome periphery formation in vivo. Conversely, mitotic hyperphosphorylation of NPM1 diminished a charge block and suppressed LLPS, resulting in nucleolar dissolution. Cell cycle-specific phase separation can be modulated via phosphorylation by enhancing or reducing the charge blockiness of disordered regions, rather than by attaching phosphate groups to specific sites. Yamazaki et al. show that cell cycle-regulated changes in hyperphosphorylation of Ki-67 and NPM1 modulate alternating charge blocks in these proteins, which defines their propensity for liquid–liquid phase separation at chromatin.
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28
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Kundinger SR, Dammer EB, Yin L, Hurst C, Shapley S, Ping L, Khoshnevis S, Ghalei H, Duong DM, Seyfried NT. Phosphorylation regulates arginine-rich RNA-binding protein solubility and oligomerization. J Biol Chem 2021; 297:101306. [PMID: 34673031 PMCID: PMC8569591 DOI: 10.1016/j.jbc.2021.101306] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 12/16/2022] Open
Abstract
Posttranslational modifications (PTMs) such as phosphorylation of RNA-binding proteins (RBPs) regulate several critical steps in RNA metabolism, including spliceosome assembly, alternative splicing, and mRNA export. Notably, serine-/arginine- (SR)-rich RBPs are densely phosphorylated compared with the remainder of the proteome. Previously, we showed that dephosphorylation of the splicing factor SRSF2 regulated increased interactions with similar arginine-rich RBPs U1-70K and LUC7L3. However, the large-scale functional and structural impact of these modifications on RBPs remains unclear. In this work, we dephosphorylated nuclear extracts using phosphatase in vitro and analyzed equal amounts of detergent-soluble and -insoluble fractions by mass-spectrometry-based proteomics. Correlation network analysis resolved 27 distinct modules of differentially soluble nucleoplasm proteins. We found classes of arginine-rich RBPs that decrease in solubility following dephosphorylation and enrich the insoluble pelleted fraction, including the SR protein family and the SR-like LUC7L RBP family. Importantly, increased insolubility was not observed across broad classes of RBPs. We determined that phosphorylation regulated SRSF2 structure, as dephosphorylated SRSF2 formed high-molecular-weight oligomeric species in vitro. Reciprocally, phosphorylation of SRSF2 by serine/arginine protein kinase 2 (SRPK2) in vitro decreased high-molecular-weight SRSF2 species formation. Furthermore, upon pharmacological inhibition of SRPKs in mammalian cells, we observed SRSF2 cytoplasmic mislocalization and increased formation of cytoplasmic granules as well as cytoplasmic tubular structures that associated with microtubules by immunocytochemical staining. Collectively, these findings demonstrate that phosphorylation may be a critical modification that prevents arginine-rich RBP insolubility and oligomerization.
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Affiliation(s)
- Sean R Kundinger
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Eric B Dammer
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Luming Yin
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Cheyenne Hurst
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Sarah Shapley
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Lingyan Ping
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | | | - Homa Ghalei
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA; Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA.
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29
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Jiang L, Lin W, Zhang C, Ash PEA, Verma M, Kwan J, van Vliet E, Yang Z, Cruz AL, Boudeau S, Maziuk BF, Lei S, Song J, Alvarez VE, Hovde S, Abisambra JF, Kuo MH, Kanaan N, Murray ME, Crary JF, Zhao J, Cheng JX, Petrucelli L, Li H, Emili A, Wolozin B. Interaction of tau with HNRNPA2B1 and N 6-methyladenosine RNA mediates the progression of tauopathy. Mol Cell 2021; 81:4209-4227.e12. [PMID: 34453888 PMCID: PMC8541906 DOI: 10.1016/j.molcel.2021.07.038] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 06/14/2021] [Accepted: 07/28/2021] [Indexed: 12/12/2022]
Abstract
The microtubule-associated protein tau oligomerizes, but the actions of oligomeric tau (oTau) are unknown. We have used Cry2-based optogenetics to induce tau oligomers (oTau-c). Optical induction of oTau-c elicits tau phosphorylation, aggregation, and a translational stress response that includes stress granules and reduced protein synthesis. Proteomic analysis identifies HNRNPA2B1 as a principle target of oTau-c. The association of HNRNPA2B1 with endogenous oTau was verified in neurons, animal models, and human Alzheimer brain tissues. Mechanistic studies demonstrate that HNRNPA2B1 functions as a linker, connecting oTau with N6-methyladenosine (m6A) modified RNA transcripts. Knockdown of HNRNPA2B1 prevents oTau or oTau-c from associating with m6A or from reducing protein synthesis and reduces oTau-induced neurodegeneration. Levels of m6A and the m6A-oTau-HNRNPA2B1 complex are increased up to 5-fold in the brains of Alzheimer subjects and P301S tau mice. These results reveal a complex containing oTau, HNRNPA2B1, and m6A that contributes to the integrated stress response of oTau.
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Affiliation(s)
- Lulu Jiang
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Weiwei Lin
- Center for Network Systems Biology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Cheng Zhang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Peter E A Ash
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Mamta Verma
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Julian Kwan
- Center for Network Systems Biology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Emily van Vliet
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Zhuo Yang
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Anna Lourdes Cruz
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Samantha Boudeau
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Brandon F Maziuk
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Shuwen Lei
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Jaehyup Song
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Victor E Alvarez
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Stacy Hovde
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Jose F Abisambra
- Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Min-Hao Kuo
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Nicholas Kanaan
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
| | - Melissa E Murray
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - John F Crary
- Department of Pathology, Mount Sinai Medical Center, New York, NY 10029, USA
| | - Jian Zhao
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02459, USA
| | - Ji-Xin Cheng
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02459, USA
| | | | - Hu Li
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Andrew Emili
- Center for Network Systems Biology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Benjamin Wolozin
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA; Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA; Center for Neurophotonics, Boston University, Boston, MA 02215, USA; Center for Systems Neuroscience, Boston University, Boston, MA 02215, USA.
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30
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Wu X, Peng C, Nelson PT, Cheng Q. Random forest-integrated analysis in AD and LATE brain transcriptome-wide data to identify disease-specific gene expression. PLoS One 2021; 16:e0256648. [PMID: 34492068 PMCID: PMC8423259 DOI: 10.1371/journal.pone.0256648] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 07/08/2021] [Indexed: 11/19/2022] Open
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative disorder that affects thinking, memory, and behavior. Limbic-predominant age-related TDP-43 encephalopathy (LATE) is a recently identified common neurodegenerative disease that mimics the clinical symptoms of AD. The development of drugs to prevent or treat these neurodegenerative diseases has been slow, partly because the genes associated with these diseases are incompletely understood. A notable hindrance from data analysis perspective is that, usually, the clinical samples for patients and controls are highly imbalanced, thus rendering it challenging to apply most existing machine learning algorithms to directly analyze such datasets. Meeting this data analysis challenge is critical, as more specific disease-associated gene identification may enable new insights into underlying disease-driving mechanisms and help find biomarkers and, in turn, improve prospects for effective treatment strategies. In order to detect disease-associated genes based on imbalanced transcriptome-wide data, we proposed an integrated multiple random forests (IMRF) algorithm. IMRF is effective in differentiating putative genes associated with subjects having LATE and/or AD from controls based on transcriptome-wide data, thereby enabling effective discrimination between these samples. Various forms of validations, such as cross-domain verification of our method over other datasets, improved and competitive classification performance by using identified genes, effectiveness of testing data with a classifier that is completely independent from decision trees and random forests, and relationships with prior AD and LATE studies on the genes linked to neurodegeneration, all testify to the effectiveness of IMRF in identifying genes with altered expression in LATE and/or AD. We conclude that IMRF, as an effective feature selection algorithm for imbalanced data, is promising to facilitate the development of new gene biomarkers as well as targets for effective strategies of disease prevention and treatment.
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Affiliation(s)
- Xinxing Wu
- University of Kentucky, Lexington, Kentucky, United States of America
| | - Chong Peng
- Qingdao University, Qingdao, Shandong, China
| | - Peter T. Nelson
- University of Kentucky, Lexington, Kentucky, United States of America
| | - Qiang Cheng
- University of Kentucky, Lexington, Kentucky, United States of America
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31
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Intrinsically disordered protein regions and phase separation: sequence determinants of assembly or lack thereof. Emerg Top Life Sci 2021; 4:307-329. [PMID: 33078839 DOI: 10.1042/etls20190164] [Citation(s) in RCA: 130] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/23/2020] [Accepted: 09/28/2020] [Indexed: 02/07/2023]
Abstract
Intrinsically disordered protein regions (IDRs) - regions that do not fold into a fixed three-dimensional structure but instead exist in a heterogeneous ensemble of conformations - have recently entered mainstream cell biology in the context of liquid-liquid phase separation (LLPS). IDRs are frequently found to be enriched in phase-separated compartments. Due to this observation, the presence of an IDR in a protein is frequently assumed to be diagnostic of its ability to phase separate. In this review, we clarify the role of IDRs in biological assembly and explore the physical principles through which amino acids can confer the attractive molecular interactions that underlie phase separation. While some disordered regions will robustly drive phase separation, many others will not. We emphasize that rather than 'disorder' driving phase separation, multivalency drives phase separation. As such, whether or not a disordered region is capable of driving phase separation will depend on the physical chemistry encoded within its amino acid sequence. Consequently, an in-depth understanding of that physical chemistry is a prerequisite to make informed inferences on how and why an IDR may be involved in phase separation or, more generally, in protein-mediated intermolecular interactions.
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32
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Sinsky J, Pichlerova K, Hanes J. Tau Protein Interaction Partners and Their Roles in Alzheimer's Disease and Other Tauopathies. Int J Mol Sci 2021; 22:9207. [PMID: 34502116 PMCID: PMC8431036 DOI: 10.3390/ijms22179207] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 02/06/2023] Open
Abstract
Tau protein plays a critical role in the assembly, stabilization, and modulation of microtubules, which are important for the normal function of neurons and the brain. In diseased conditions, several pathological modifications of tau protein manifest. These changes lead to tau protein aggregation and the formation of paired helical filaments (PHF) and neurofibrillary tangles (NFT), which are common hallmarks of Alzheimer's disease and other tauopathies. The accumulation of PHFs and NFTs results in impairment of physiological functions, apoptosis, and neuronal loss, which is reflected as cognitive impairment, and in the late stages of the disease, leads to death. The causes of this pathological transformation of tau protein haven't been fully understood yet. In both physiological and pathological conditions, tau interacts with several proteins which maintain their proper function or can participate in their pathological modifications. Interaction partners of tau protein and associated molecular pathways can either initiate and drive the tau pathology or can act neuroprotective, by reducing pathological tau proteins or inflammation. In this review, we focus on the tau as a multifunctional protein and its known interacting partners active in regulations of different processes and the roles of these proteins in Alzheimer's disease and tauopathies.
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Affiliation(s)
| | | | - Jozef Hanes
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska Cesta 9, 845 10 Bratislava, Slovakia; (J.S.); (K.P.)
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33
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Rybak-Wolf A, Plass M. RNA Dynamics in Alzheimer's Disease. Molecules 2021; 26:5113. [PMID: 34500547 PMCID: PMC8433936 DOI: 10.3390/molecules26175113] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder that heavily burdens healthcare systems worldwide. There is a significant requirement to understand the still unknown molecular mechanisms underlying AD. Current evidence shows that two of the major features of AD are transcriptome dysregulation and altered function of RNA binding proteins (RBPs), both of which lead to changes in the expression of different RNA species, including microRNAs (miRNAs), circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and messenger RNAs (mRNAs). In this review, we will conduct a comprehensive overview of how RNA dynamics are altered in AD and how this leads to the differential expression of both short and long RNA species. We will describe how RBP expression and function are altered in AD and how this impacts the expression of different RNA species. Furthermore, we will also show how changes in the abundance of specific RNA species are linked to the pathology of AD.
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Affiliation(s)
- Agnieszka Rybak-Wolf
- Max Delbrück Center for Molecular Medicine (MDC), Berlin Institute for Medical Systems Biology (BIMSB), 10115 Berlin, Germany
| | - Mireya Plass
- Gene Regulation of Cell Identity, Regenerative Medicine Program, Bellvitge Institute for Biomedical Research (IDIBELL), L'Hospitalet del Llobregat, 08908 Barcelona, Spain
- Program for Advancing Clinical Translation of Regenerative Medicine of Catalonia, P-CMR[C], L'Hospitalet del Llobregat, 08908 Barcelona, Spain
- Center for Networked Biomedical Research on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain
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34
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McMillan PJ, Strovas TJ, Baum M, Mitchell BK, Eck RJ, Hendricks N, Wheeler JM, Latimer CS, Keene CD, Kraemer BC. Pathological tau drives ectopic nuclear speckle scaffold protein SRRM2 accumulation in neuron cytoplasm in Alzheimer's disease. Acta Neuropathol Commun 2021; 9:117. [PMID: 34187600 PMCID: PMC8243890 DOI: 10.1186/s40478-021-01219-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 01/19/2023] Open
Abstract
Several conserved nuclear RNA binding proteins (sut-1, sut-2, and parn-2) control tau aggregation and toxicity in C. elegans, mice, and human cells. MSUT2 protein normally resides in nuclear speckles, membraneless organelles composed of phase-separated RNAs and RNA-binding proteins that mediate critical steps in mRNA processing including mRNA splicing. We used human pathological tissue and transgenic mice to identify Alzheimer’s disease-specific cellular changes related to nuclear speckles. We observed that nuclear speckle constituent scaffold protein SRRM2 is mislocalized and accumulates in cytoplasmic lesions in AD brain tissue. Furthermore, progression of tauopathy in transgenic mice is accompanied by increasing mislocalization of SRRM2 from the neuronal nucleus to the soma. In AD brain tissue, SRRM2 mislocalization associates with increased severity of pathological tau deposition. These findings suggest potential mechanisms by which pathological tau impacts nuclear speckle function in diverse organisms ranging from C. elegans to mice to humans. Future translational studies aimed at restoring nuclear speckle homeostasis may provide novel candidate therapeutic targets for pharmacological intervention.
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35
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Emenecker RJ, Holehouse AS, Strader LC. Biological Phase Separation and Biomolecular Condensates in Plants. ANNUAL REVIEW OF PLANT BIOLOGY 2021; 72:17-46. [PMID: 33684296 PMCID: PMC8221409 DOI: 10.1146/annurev-arplant-081720-015238] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A surge in research focused on understanding the physical principles governing the formation, properties, and function of membraneless compartments has occurred over the past decade. Compartments such as the nucleolus, stress granules, and nuclear speckles have been designated as biomolecular condensates to describe their shared property of spatially concentrating biomolecules. Although this research has historically been carried out in animal and fungal systems, recent work has begun to explore whether these same principles are relevant in plants. Effectively understanding and studying biomolecular condensates require interdisciplinary expertise that spans cell biology, biochemistry, and condensed matter physics and biophysics. As such, some involved concepts may be unfamiliar to any given individual. This review focuses on introducing concepts essential to the study of biomolecular condensates and phase separation for biologists seeking to carry out research in this area and further examines aspects of biomolecular condensates that are relevant to plant systems.
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Affiliation(s)
- Ryan J Emenecker
- Department of Biology, Washington University, St. Louis, Missouri 63130, USA
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
- Center for Science and Engineering of Living Systems, Washington University, St. Louis, Missouri 63130, USA
- Center for Engineering MechanoBiology, Washington University, St. Louis, Missouri 63130, USA
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
- Center for Science and Engineering of Living Systems, Washington University, St. Louis, Missouri 63130, USA
| | - Lucia C Strader
- Center for Science and Engineering of Living Systems, Washington University, St. Louis, Missouri 63130, USA
- Center for Engineering MechanoBiology, Washington University, St. Louis, Missouri 63130, USA
- Department of Biology, Duke University, Durham, North Carolina 27708, USA;
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36
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Lubelsky Y, Zuckerman B, Ulitsky I. High-resolution mapping of function and protein binding in an RNA nuclear enrichment sequence. EMBO J 2021; 40:e106357. [PMID: 33938020 PMCID: PMC8204871 DOI: 10.15252/embj.2020106357] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 03/14/2021] [Accepted: 03/24/2021] [Indexed: 01/04/2023] Open
Abstract
The functions of long RNAs, including mRNAs and long noncoding RNAs (lncRNAs), critically depend on their subcellular localization. The identity of the sequences that dictate subcellular localization and their high-resolution anatomy remain largely unknown. We used a suite of massively parallel RNA assays and libraries containing thousands of sequence variants to pinpoint the functional features within the SIRLOIN element, which dictates nuclear enrichment through hnRNPK recruitment. In addition, we profiled the endogenous SIRLOIN RNA-nucleoprotein complex and identified the nuclear RNA-binding proteins SLTM and SNRNP70 as novel SIRLOIN binders. Taken together, using massively parallel assays, we identified the features that dictate binding of hnRNPK, SLTM, and SNRNP70 to SIRLOIN and found that these factors are jointly required for SIRLOIN activity. Our study thus provides a roadmap for high-throughput dissection of functional sequence elements in long RNAs.
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Affiliation(s)
- Yoav Lubelsky
- Department of Biological RegulationWeizmann Institute of ScienceRehovotIsrael
| | - Binyamin Zuckerman
- Department of Biological RegulationWeizmann Institute of ScienceRehovotIsrael
| | - Igor Ulitsky
- Department of Biological RegulationWeizmann Institute of ScienceRehovotIsrael
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37
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Kinoshita C, Kubota N, Aoyama K. Interplay of RNA-Binding Proteins and microRNAs in Neurodegenerative Diseases. Int J Mol Sci 2021; 22:ijms22105292. [PMID: 34069857 PMCID: PMC8157344 DOI: 10.3390/ijms22105292] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/14/2021] [Accepted: 05/15/2021] [Indexed: 02/07/2023] Open
Abstract
The number of patients with neurodegenerative diseases (NDs) is increasing, along with the growing number of older adults. This escalation threatens to create a medical and social crisis. NDs include a large spectrum of heterogeneous and multifactorial pathologies, such as amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer’s disease, Parkinson’s disease, Huntington’s disease and multiple system atrophy, and the formation of inclusion bodies resulting from protein misfolding and aggregation is a hallmark of these disorders. The proteinaceous components of the pathological inclusions include several RNA-binding proteins (RBPs), which play important roles in splicing, stability, transcription and translation. In addition, RBPs were shown to play a critical role in regulating miRNA biogenesis and metabolism. The dysfunction of both RBPs and miRNAs is often observed in several NDs. Thus, the data about the interplay among RBPs and miRNAs and their cooperation in brain functions would be important to know for better understanding NDs and the development of effective therapeutics. In this review, we focused on the connection between miRNAs, RBPs and neurodegenerative diseases.
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Affiliation(s)
- Chisato Kinoshita
- Department of Pharmacology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo 173-8605, Japan;
- Correspondence: (C.K.); (K.A.); Tel.: +81-3-3964-3794 (C.K.); +81-3-3964-3793 (K.A.)
| | - Noriko Kubota
- Department of Pharmacology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo 173-8605, Japan;
- Teikyo University Support Center for Women Physicians and Researchers, 2-11-1 Kaga, Itabashi, Tokyo 173-8605, Japan
| | - Koji Aoyama
- Department of Pharmacology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo 173-8605, Japan;
- Correspondence: (C.K.); (K.A.); Tel.: +81-3-3964-3794 (C.K.); +81-3-3964-3793 (K.A.)
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38
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Argudo PG, Giner-Casares JJ. Folding and self-assembly of short intrinsically disordered peptides and protein regions. NANOSCALE ADVANCES 2021; 3:1789-1812. [PMID: 36133101 PMCID: PMC9417027 DOI: 10.1039/d0na00941e] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/17/2021] [Indexed: 05/15/2023]
Abstract
Proteins and peptide fragments are highly relevant building blocks in self-assembly for nanostructures with plenty of applications. Intrinsically disordered proteins (IDPs) and protein regions (IDRs) are defined by the absence of a well-defined secondary structure, yet IDPs/IDRs show a significant biological activity. Experimental techniques and computational modelling procedures for the characterization of IDPs/IDRs are discussed. Directed self-assembly of IDPs/IDRs allows reaching a large variety of nanostructures. Hybrid materials based on the derivatives of IDPs/IDRs show a promising performance as alternative biocides and nanodrugs. Cell mimicking, in vivo compartmentalization, and bone regeneration are demonstrated for IDPs/IDRs in biotechnological applications. The exciting possibilities of IDPs/IDRs in nanotechnology with relevant biological applications are shown.
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Affiliation(s)
- Pablo G Argudo
- Université de Bordeaux, CNRS, Bordeaux INP, LCPO 16 Avenue Pey-Berland 33600 Pessac France
| | - Juan J Giner-Casares
- Departamento de Química Física y T. Aplicada, Instituto Universitario de Nanoquímica IUNAN, Facultad de Ciencias, Universidad de Córdoba (UCO) Campus de Rabanales, Ed. Marie Curie E-14071 Córdoba Spain
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39
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CLK1 reorganizes the splicing factor U1-70K for early spliceosomal protein assembly. Proc Natl Acad Sci U S A 2021; 118:2018251118. [PMID: 33811140 DOI: 10.1073/pnas.2018251118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Early spliceosome assembly requires phosphorylation of U1-70K, a constituent of the U1 small nuclear ribonucleoprotein (snRNP), but it is unclear which sites are phosphorylated, and by what enzyme, and how such modification regulates function. By profiling the proteome, we found that the Cdc2-like kinase 1 (CLK1) phosphorylates Ser-226 in the C terminus of U1-70K. This releases U1-70K from subnuclear granules facilitating interaction with U1 snRNP and the serine-arginine (SR) protein SRSF1, critical steps in establishing the 5' splice site. CLK1 breaks contacts between the C terminus and the RNA recognition motif (RRM) in U1-70K releasing the RRM to bind SRSF1. This reorganization also permits stable interactions between U1-70K and several proteins associated with U1 snRNP. Nuclear induction of the SR protein kinase 1 (SRPK1) facilitates CLK1 dissociation from U1-70K, recycling the kinase for catalysis. These studies demonstrate that CLK1 plays a vital, signal-dependent role in early spliceosomal protein assembly by contouring U1-70K for protein-protein multitasking.
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40
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Darling AL, Shorter J. Combating deleterious phase transitions in neurodegenerative disease. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2021; 1868:118984. [PMID: 33549703 PMCID: PMC7965345 DOI: 10.1016/j.bbamcr.2021.118984] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 12/11/2022]
Abstract
Protein aggregation is a hallmark of neurodegenerative diseases. However, the mechanism that induces pathogenic aggregation is not well understood. Recently, it has emerged that several of the pathological proteins found in an aggregated or mislocalized state in neurodegenerative diseases are also able to undergo liquid-liquid phase separation (LLPS) under physiological conditions. Although these phase transitions are likely important for various physiological functions, neurodegenerative disease-related mutations and conditions can alter the LLPS behavior of these proteins, which can elicit toxicity. Therefore, therapeutics that antagonize aberrant LLPS may be able to mitigate toxicity and aggregation that is ubiquitous in neurodegenerative disease. Here, we discuss the mechanisms by which aberrant protein phase transitions may contribute to neurodegenerative disease. We also outline potential therapeutic strategies to counter deleterious phases. State without borders: Membrane-less organelles and liquid-liquid phase transitions edited by Vladimir N Uversky.
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Affiliation(s)
- April L Darling
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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41
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Guo Q, Dammer EB, Zhou M, Kundinger SR, Gearing M, Lah JJ, Levey AI, Shulman JM, Seyfried NT. Targeted Quantification of Detergent-Insoluble RNA-Binding Proteins in Human Brain Reveals Stage and Disease Specific Co-aggregation in Alzheimer's Disease. Front Mol Neurosci 2021; 14:623659. [PMID: 33815056 PMCID: PMC8014091 DOI: 10.3389/fnmol.2021.623659] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/12/2021] [Indexed: 01/02/2023] Open
Abstract
Core spliceosome and related RNA-binding proteins aggregate in Alzheimer’s disease (AD) brain even in early asymptomatic stages (AsymAD) of disease. To assess the specificity of RNA-binding protein aggregation in AD, we developed a targeted mass spectrometry approach to quantify broad classes of RNA-binding proteins with other pathological proteins including tau and amyloid beta (Aβ) in detergent insoluble fractions from control, AsymAD, AD and Parkinson’s disease (PD) brain. Relative levels of specific insoluble RNA-binding proteins across different disease groups correlated with accumulation of Aβ and tau aggregates. RNA-binding proteins, including splicing factors with homology to the basic-acidic dipeptide repeats of U1-70K, preferentially aggregated in AsymAD and AD. In contrast, PD brain aggregates were relatively depleted of many RNA-binding proteins compared to AsymAD and AD groups. Correlation network analyses resolved 29 distinct modules of co-aggregating proteins including modules linked to spliceosome assembly, nuclear speckles and RNA splicing. Modules related to spliceosome assembly and nuclear speckles showed stage-specific enrichment of insoluble RBPs from AsymAD and AD brains, whereas the RNA splicing module was reduced specifically in PD. Collectively, this work identifies classes of RNA-binding proteins that distinctly co-aggregate in detergent-insoluble fractions across the specific neurodegenerative diseases we examined.
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Affiliation(s)
- Qi Guo
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States
| | - Eric B Dammer
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States.,Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States
| | - Maotian Zhou
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States
| | - Sean R Kundinger
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States
| | - Marla Gearing
- Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States.,Department of Pathology and Laboratory Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - James J Lah
- Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States.,Department of Neurology, School of Medicine, Emory University, Atlanta, GA, United States
| | - Allan I Levey
- Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States.,Department of Neurology, School of Medicine, Emory University, Atlanta, GA, United States
| | - Joshua M Shulman
- Departments of Neurology, Neuroscience and Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, United States.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
| | - Nicholas T Seyfried
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States.,Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States.,Department of Neurology, School of Medicine, Emory University, Atlanta, GA, United States
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42
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Angarola BL, Anczuków O. Splicing alterations in healthy aging and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2021. [PMID: 33565261 DOI: 10.1002/wrna.1643.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Alternative RNA splicing is a key step in gene expression that allows generation of numerous messenger RNA transcripts encoding proteins of varied functions from the same gene. It is thus a rich source of proteomic and functional diversity. Alterations in alternative RNA splicing are observed both during healthy aging and in a number of human diseases, several of which display premature aging phenotypes or increased incidence with age. Age-associated splicing alterations include differential splicing of genes associated with hallmarks of aging, as well as changes in the levels of core spliceosomal genes and regulatory splicing factors. Here, we review the current known links between alternative RNA splicing, its regulators, healthy biological aging, and diseases associated with aging or aging-like phenotypes. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA.,Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA.,Institute for Systems Genomics, UConn Health, Farmington, Connecticut, USA
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43
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Angarola BL, Anczuków O. Splicing alterations in healthy aging and disease. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 12:e1643. [PMID: 33565261 DOI: 10.1002/wrna.1643] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/19/2022]
Abstract
Alternative RNA splicing is a key step in gene expression that allows generation of numerous messenger RNA transcripts encoding proteins of varied functions from the same gene. It is thus a rich source of proteomic and functional diversity. Alterations in alternative RNA splicing are observed both during healthy aging and in a number of human diseases, several of which display premature aging phenotypes or increased incidence with age. Age-associated splicing alterations include differential splicing of genes associated with hallmarks of aging, as well as changes in the levels of core spliceosomal genes and regulatory splicing factors. Here, we review the current known links between alternative RNA splicing, its regulators, healthy biological aging, and diseases associated with aging or aging-like phenotypes. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA.,Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA.,Institute for Systems Genomics, UConn Health, Farmington, Connecticut, USA
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44
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Rayaprolu S, Higginbotham L, Bagchi P, Watson CM, Zhang T, Levey AI, Rangaraju S, Seyfried NT. Systems-based proteomics to resolve the biology of Alzheimer's disease beyond amyloid and tau. Neuropsychopharmacology 2021; 46:98-115. [PMID: 32898852 PMCID: PMC7689445 DOI: 10.1038/s41386-020-00840-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/05/2020] [Accepted: 08/19/2020] [Indexed: 02/07/2023]
Abstract
The repeated failures of amyloid-targeting therapies have challenged our narrow understanding of Alzheimer's disease (AD) pathogenesis and inspired wide-ranging investigations into the underlying mechanisms of disease. Increasing evidence indicates that AD develops from an intricate web of biochemical and cellular processes that extend far beyond amyloid and tau accumulation. This growing recognition surrounding the diversity of AD pathophysiology underscores the need for holistic systems-based approaches to explore AD pathogenesis. Here we describe how network-based proteomics has emerged as a powerful tool and how its application to the AD brain has provided an informative framework for the complex protein pathophysiology underlying the disease. Furthermore, we outline how the AD brain network proteome can be leveraged to advance additional scientific and translational efforts, including the discovery of novel protein biomarkers of disease.
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Affiliation(s)
- Sruti Rayaprolu
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Lenora Higginbotham
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Pritha Bagchi
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Caroline M Watson
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Tian Zhang
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Allan I Levey
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Srikant Rangaraju
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Nicholas T Seyfried
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA.
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45
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Younas N, Zafar S, Shafiq M, Noor A, Siegert A, Arora AS, Galkin A, Zafar A, Schmitz M, Stadelmann C, Andreoletti O, Ferrer I, Zerr I. SFPQ and Tau: critical factors contributing to rapid progression of Alzheimer's disease. Acta Neuropathol 2020; 140:317-339. [PMID: 32577828 PMCID: PMC7423812 DOI: 10.1007/s00401-020-02178-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 06/10/2020] [Accepted: 06/10/2020] [Indexed: 12/12/2022]
Abstract
Dysfunctional RNA-binding proteins (RBPs) have been implicated in several neurodegenerative disorders. Recently, this paradigm of RBPs has been extended to pathophysiology of Alzheimer’s disease (AD). Here, we identified disease subtype specific variations in the RNA-binding proteome (RBPome) of sporadic AD (spAD), rapidly progressive AD (rpAD), and sporadic Creutzfeldt Jakob disease (sCJD), as well as control cases using RNA pull-down assay in combination with proteomics. We show that one of these identified proteins, splicing factor proline and glutamine rich (SFPQ), is downregulated in the post-mortem brains of rapidly progressive AD patients, sCJD patients and 3xTg mice brain at terminal stage of the disease. In contrast, the expression of SFPQ was elevated at early stage of the disease in the 3xTg mice, and in vitro after oxidative stress stimuli. Strikingly, in rpAD patients’ brains SFPQ showed a significant dislocation from the nucleus and cytoplasmic colocalization with TIA-1. Furthermore, in rpAD brain lesions, SFPQ and p-tau showed extranuclear colocalization. Of note, association between SFPQ and tau-oligomers in rpAD brains suggests a possible role of SFPQ in oligomerization and subsequent misfolding of tau protein. In line with the findings from the human brain, our in vitro study showed that SFPQ is recruited into TIA-1-positive stress granules (SGs) after oxidative stress induction, and colocalizes with tau/p-tau in these granules, providing a possible mechanism of SFPQ dislocation through pathological SGs. Furthermore, the expression of human tau in vitro induced significant downregulation of SFPQ, suggesting a causal role of tau in the downregulation of SFPQ. The findings from the current study indicate that the dysregulation and dislocation of SFPQ, the subsequent DNA-related anomalies and aberrant dynamics of SGs in association with pathological tau represents a critical pathway which contributes to rapid progression of AD.
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Affiliation(s)
- Neelam Younas
- Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Saima Zafar
- Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany.
- Biomedical Engineering and Sciences Department, School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Islamabad, Pakistan.
| | - Mohsin Shafiq
- Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Aneeqa Noor
- Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Anna Siegert
- Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Amandeep Singh Arora
- Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
- Institute for Behavioral Medicine Research, The Ohio State University, 460 Medical Center Dr, Columbus, OH, 43210, USA
| | - Alexey Galkin
- St. Petersburg Branch, Vavilov Institute of General Genetics, St. Petersburg, Russia
| | - Ayesha Zafar
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
- College of Medicine Center for Pharmacogenomics, The Ohio State University, 460 W 12th Avenue, Columbus, OH, 1004 BRT, USA
| | - Mathias Schmitz
- Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | | | - Olivier Andreoletti
- UMR INRA ENVT 1225- Interactions Hôte Agent Pathogène-École Nationale Vétérinaire de Toulouse, Toulouse, France
| | - Isidre Ferrer
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Barcelona, Spain
- Bellvitge University Hospital-IDIBELL, Barcelona, Spain
- CIBERNED, Barcelona, Spain
- Hospitalet de Llobregat, Barcelona, Spain
| | - Inga Zerr
- Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany.
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46
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Montalbano M, McAllen S, Puangmalai N, Sengupta U, Bhatt N, Johnson OD, Kharas MG, Kayed R. RNA-binding proteins Musashi and tau soluble aggregates initiate nuclear dysfunction. Nat Commun 2020; 11:4305. [PMID: 32855391 PMCID: PMC7453003 DOI: 10.1038/s41467-020-18022-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 07/30/2020] [Indexed: 11/09/2022] Open
Abstract
Oligomeric assemblies of tau and the RNA-binding proteins (RBPs) Musashi (MSI) are reported in Alzheimer's disease (AD). However, the role of MSI and tau interaction in their aggregation process and its effects are nor clearly known in neurodegenerative diseases. Here, we investigated the expression and cellular localization of MSI1 and MSI2 in the brains tissues of Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) as well as in the wild-type mice and tau knock-out and P301L tau mouse models. We observed that formation of pathologically relevant protein inclusions was driven by the aberrant interactions between MSI and tau in the nuclei associated with age-dependent extracellular depositions of tau/MSI complexes. Furthermore, tau and MSI interactions induced impairment of nuclear/cytoplasm transport, chromatin remodeling and nuclear lamina formation. Our findings provide mechanistic insight for pathological accumulation of MSI/tau aggregates providing a potential basis for therapeutic interventions in neurodegenerative proteinopathies.
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Affiliation(s)
- Mauro Montalbano
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX, 77555, USA.,Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Salome McAllen
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX, 77555, USA.,Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Nicha Puangmalai
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX, 77555, USA.,Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Urmi Sengupta
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX, 77555, USA.,Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Nemil Bhatt
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX, 77555, USA.,Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Omar D Johnson
- School of Medicine, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Michael G Kharas
- Division of Molecular Pharmacology, Memorial Sloan Kettering Institute Cancer Center, New York City, NY, USA
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX, 77555, USA. .,Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
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47
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Greig JA, Nguyen TA, Lee M, Holehouse AS, Posey AE, Pappu RV, Jedd G. Arginine-Enriched Mixed-Charge Domains Provide Cohesion for Nuclear Speckle Condensation. Mol Cell 2020; 77:1237-1250.e4. [PMID: 32048997 PMCID: PMC10715173 DOI: 10.1016/j.molcel.2020.01.025] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 12/04/2019] [Accepted: 01/23/2020] [Indexed: 12/29/2022]
Abstract
Low-complexity protein domains promote the formation of various biomolecular condensates. However, in many cases, the precise sequence features governing condensate formation and identity remain unclear. Here, we investigate the role of intrinsically disordered mixed-charge domains (MCDs) in nuclear speckle condensation. Proteins composed exclusively of arginine-aspartic acid dipeptide repeats undergo length-dependent condensation and speckle incorporation. Substituting arginine with lysine in synthetic and natural speckle-associated MCDs abolishes these activities, identifying a key role for multivalent contacts through arginine's guanidinium ion. MCDs can synergize with a speckle-associated RNA recognition motif to promote speckle specificity and residence. MCD behavior is tunable through net-charge: increasing negative charge abolishes condensation and speckle incorporation. Contrastingly, increasing positive charge through arginine leads to enhanced condensation, speckle enlargement, decreased splicing factor mobility, and defective mRNA export. Together, these results identify key sequence determinants of MCD-promoted speckle condensation and link the dynamic material properties of speckles with function in mRNA processing.
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Affiliation(s)
- Jamie A Greig
- Temasek Life Sciences Laboratory and Department of Biological Sciences, The National University of Singapore, Singapore 117604, Singapore
| | - Tu Anh Nguyen
- Temasek Life Sciences Laboratory and Department of Biological Sciences, The National University of Singapore, Singapore 117604, Singapore
| | - Michelle Lee
- Temasek Life Sciences Laboratory and Department of Biological Sciences, The National University of Singapore, Singapore 117604, Singapore
| | - Alex S Holehouse
- Department of Biomedical Engineering and Center for Science & Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ammon E Posey
- Department of Biomedical Engineering and Center for Science & Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Rohit V Pappu
- Department of Biomedical Engineering and Center for Science & Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Gregory Jedd
- Temasek Life Sciences Laboratory and Department of Biological Sciences, The National University of Singapore, Singapore 117604, Singapore.
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48
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Fujita KI, Ishizuka T, Mitsukawa M, Kurata M, Masuda S. Regulating Divergent Transcriptomes through mRNA Splicing and Its Modulation Using Various Small Compounds. Int J Mol Sci 2020; 21:ijms21062026. [PMID: 32188117 PMCID: PMC7139312 DOI: 10.3390/ijms21062026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 12/14/2022] Open
Abstract
Human transcriptomes are more divergent than genes and contribute to the sophistication of life. This divergence is derived from various isoforms arising from alternative splicing. In addition, alternative splicing regulated by spliceosomal factors and RNA structures, such as the RNA G-quadruplex, is important not only for isoform diversity but also for regulating gene expression. Therefore, abnormal splicing leads to serious diseases such as cancer and neurodegenerative disorders. In the first part of this review, we describe the regulation of divergent transcriptomes using alternative mRNA splicing. In the second part, we present the relationship between the disruption of splicing and diseases. Recently, various compounds with splicing inhibitor activity were established. These splicing inhibitors are recognized as a biological tool to investigate the molecular mechanism of splicing and as a potential therapeutic agent for cancer treatment. Food-derived compounds with similar functions were found and are expected to exhibit anticancer effects. In the final part, we describe the compounds that modulate the messenger RNA (mRNA) splicing process and their availability for basic research and future clinical potential.
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49
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Kundinger SR, Bishof I, Dammer EB, Duong DM, Seyfried NT. Middle-Down Proteomics Reveals Dense Sites of Methylation and Phosphorylation in Arginine-Rich RNA-Binding Proteins. J Proteome Res 2020; 19:1574-1591. [PMID: 31994892 DOI: 10.1021/acs.jproteome.9b00633] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Post-translational modifications (PTMs) within arginine (Arg)-rich RNA-binding proteins, such as phosphorylation and methylation, regulate multiple steps in RNA metabolism. However, the identification of PTMs within Arg-rich domains with complete trypsin digestion is extremely challenging due to the high density of Arg residues within these proteins. Here, we report a middle-down proteomic approach coupled with electron-transfer dissociation (ETD) mass spectrometry to map previously unknown sites of phosphorylation and methylation within the Arg-rich domains of U1-70K and structurally similar RNA-binding proteins from nuclear extracts of human embryonic kidney (HEK)-293T cells. Notably, the Arg-rich domains in RNA-binding proteins are densely modified by methylation and phosphorylation compared with the remainder of the proteome, with methylation and phosphorylation favoring RSRS motifs. Although they favor a common motif, analysis of combinatorial PTMs within RSRS motifs indicates that phosphorylation and methylation do not often co-occur, suggesting that they may functionally oppose one another. Furthermore, we show that phosphorylation may modify interactions between Arg-rich proteins, as serine-arginine splicing factor 2 (SRSF2) has a stronger association with U1-70K and LUC7L3 upon dephosphorylation. Collectively, these findings suggest that the level of PTMs within Arg-rich domains may be among the highest in the proteome and a possible unexplored regulator of RNA-binding protein interactions.
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50
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Montalbano M, McAllen S, Sengupta U, Puangmalai N, Bhatt N, Ellsworth A, Kayed R. Tau oligomers mediate aggregation of RNA-binding proteins Musashi1 and Musashi2 inducing Lamin alteration. Aging Cell 2019; 18:e13035. [PMID: 31532069 PMCID: PMC6826126 DOI: 10.1111/acel.13035] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 08/07/2019] [Accepted: 08/17/2019] [Indexed: 01/01/2023] Open
Abstract
The exact mechanisms leading to neurodegeneration in Alzheimer's disease (AD) and other tauopathies are not yet entirely understood. However, it is known that several RNA-binding proteins (RBPs) form toxic aggregates and also interact with tau in such granules in tauopathies, including AD. The Musashi (MSI) family of RBPs, consisting of two homologues: Musashi1 and Musashi2, have not been extensively investigated in neurodegenerative diseases. Here, using a tau inducible HEK (iHEK) model we investigate whether MSI proteins contribute to the aggregation of toxic tau oligomers (TauO). Wild-type and mutant P301L tau iHEK cells are used to study the effect of different tau variants on the cellular localization of MSI proteins. Interestingly, we observe that tau co-localizes with MSI in the cytoplasm and nuclei, altering the nuclear transport of MSI. Furthermore, incremental changes in the size and density of nuclear MSI/tau foci are observed. We also report here that TauO interact with MSI to cause the formation of distinct nuclear aggregates. Moreover, tau/MSI aggregates induce structural changes to LaminB1, leading to nuclear instability. These results illustrate a possible mechanism of neurodegeneration mediated by the aggregation of MSI proteins and TauO, suggesting that MSI plays a critical role in cellular dysfunction.
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Affiliation(s)
- Mauro Montalbano
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTXUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTXUSA
| | - Salome McAllen
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTXUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTXUSA
| | - Urmi Sengupta
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTXUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTXUSA
| | - Nicha Puangmalai
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTXUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTXUSA
| | - Nemil Bhatt
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTXUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTXUSA
| | - Anna Ellsworth
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTXUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTXUSA
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTXUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTXUSA
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