1
|
Xiang JS, Schafer DM, Rothamel KL, Yeo GW. Decoding protein-RNA interactions using CLIP-based methodologies. Nat Rev Genet 2024:10.1038/s41576-024-00749-3. [PMID: 38982239 DOI: 10.1038/s41576-024-00749-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2024] [Indexed: 07/11/2024]
Abstract
Protein-RNA interactions are central to all RNA processing events, with pivotal roles in the regulation of gene expression and cellular functions. Dysregulation of these interactions has been increasingly linked to the pathogenesis of human diseases. High-throughput approaches to identify RNA-binding proteins and their binding sites on RNA - in particular, ultraviolet crosslinking followed by immunoprecipitation (CLIP) - have helped to map the RNA interactome, yielding transcriptome-wide protein-RNA atlases that have contributed to key mechanistic insights into gene expression and gene-regulatory networks. Here, we review these recent advances, explore the effects of cellular context on RNA binding, and discuss how these insights are shaping our understanding of cellular biology. We also review the potential therapeutic applications arising from new knowledge of protein-RNA interactions.
Collapse
Affiliation(s)
- Joy S Xiang
- Division of Biomedical Sciences, UC Riverside, Riverside, CA, USA
| | - Danielle M Schafer
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA, USA
- Sanford Stem Cell Institute and Stem Cell Program, UC San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine, UC San Diego, La Jolla, CA, USA
| | - Katherine L Rothamel
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA, USA
- Sanford Stem Cell Institute and Stem Cell Program, UC San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine, UC San Diego, La Jolla, CA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA, USA.
- Sanford Stem Cell Institute and Stem Cell Program, UC San Diego, La Jolla, CA, USA.
- Institute for Genomic Medicine, UC San Diego, La Jolla, CA, USA.
- Sanford Laboratories for Innovative Medicines, La Jolla, CA, USA.
| |
Collapse
|
2
|
Matera AG, Steiner RE, Mills CA, Herring LE, Garcia EL. Chaperoning the chaperones: Proteomic analysis of the SMN complex reveals conserved and etiologic connections to the proteostasis network. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.15.594402. [PMID: 38903116 PMCID: PMC11188114 DOI: 10.1101/2024.05.15.594402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Molecular chaperones and co-chaperones are highly conserved cellular components that perform variety of duties related to the proper three-dimensional folding of the proteome. The web of factors that carries out this essential task is called the proteostasis network (PN). Ribonucleoproteins (RNPs) represent an underexplored area in terms of the connections they make with the PN. The Survival Motor Neuron (SMN) complex is an RNP assembly chaperone and serves as a paradigm for studying how specific small nuclear (sn)RNAs are identified and paired with their client substrate proteins. SMN protein is the eponymous component of a large complex required for the biogenesis of uridine-rich small nuclear ribonucleoproteins (U-snRNPs) and localizes to distinct membraneless organelles in both the nucleus and cytoplasm of animal cells. SMN forms the oligomeric core of this complex, and missense mutations in its YG box self-interaction domain are known to cause Spinal Muscular Atrophy (SMA). The basic framework for understanding how snRNAs are assembled into U-snRNPs is known, the pathways and mechanisms used by cells to regulate their biogenesis are poorly understood. Given the importance of these processes to normal development as well as neurodegenerative disease, we set out to identify and characterize novel SMN binding partners. Here, we carried out affinity purification mass spectrometry (AP-MS) of SMN using stable fly lines exclusively expressing either wildtype or SMA-causing missense alleles. Bioinformatic analyses of the pulldown data, along with comparisons to proximity labeling studies carried out in human cells, revealed conserved connections to at least two other major chaperone systems including heat shock folding chaperones (HSPs) and histone/nucleosome assembly chaperones. Notably, we found that heat shock cognate protein Hsc70-4 and other HspA family members preferentially interacted with SMA-causing alleles of SMN. Hsc70-4 is particularly interesting because its mRNA is aberrantly sequestered by a mutant form of TDP-43 in mouse and Drosophila ALS (Amyotrophic Lateral Sclerosis) disease models. Most important, a missense allele of Hsc70-4 (HspA8 in mammals) was recently identified as a bypass suppressor of the SMA phenotype in mice. Collectively, these findings suggest that chaperone-related dysfunction lies at the etiological root of both ALS and SMA.
Collapse
Affiliation(s)
- A. Gregory Matera
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill NC, USA
- Departments of Biology and Genetics, University of North Carolina at Chapel Hill
- RNA Discovery and Lineberger Comprehensive Cancer Centers, University of North Carolina at Chapel Hill
| | - Rebecca E. Steiner
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill NC, USA
| | - C. Alison Mills
- Department of Pharmacology, University of North Carolina at Chapel Hill
| | - Laura E. Herring
- Department of Pharmacology, University of North Carolina at Chapel Hill
| | - Eric L. Garcia
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill NC, USA
- Department of Biology, University of Kentucky, Lexington KY, USA
| |
Collapse
|
3
|
Shelkovnikova TA, Hautbergue GM. RNP granules in ALS and neurodegeneration: From multifunctional membraneless organelles to therapeutic opportunities. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2024; 176:455-479. [PMID: 38802180 DOI: 10.1016/bs.irn.2024.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Amyotrophic lateral sclerosis (ALS) and related neurodegenerative diseases are characterised by dysfunction of a host of RNA-binding proteins (RBPs) and a severely disrupted RNA metabolism. Recently, RBP-harbouring phase-separated complexes, ribonucleoprotein (RNP) granules, have come into the limelight as "crucibles" of neuronal pathology in ALS. RNP granules are indispensable for the multitude of regulatory processes underlying cellular RNA metabolism and serve as critical organisers of cellular biochemistry. Neurons, highly specialised cells, heavily rely on RNP granules for efficient trafficking, signalling and stress responses. Multiple RNP granule components, primarily RBPs such as TDP-43 and FUS, are affected by ALS mutations. However, even in the absence of mutations, RBP proteinopathies represent pathophysiological hallmarks of ALS. Given the high local concentrations of RBPs and RNAs, their weakened or enhanced interactions within RNP granules disrupt their homeostasis. Thus, the physiological process of phase separation and RNP granule formation, vital for maintaining the high-functioning state of neuronal cells, becomes their Achilles heel. Here, we will review the recent literature on the causes and consequences of abnormal RNP granule functioning in ALS and related disorders. In particular, we will summarise the evidence for the network-level dysfunction of RNP granules in these conditions and discuss considerations for therapeutic interventions to target RBPs, RNP granules and their network as a whole.
Collapse
Affiliation(s)
- Tatyana A Shelkovnikova
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom; Neuroscience Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom.
| | - Guillaume M Hautbergue
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom; Neuroscience Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom; Healthy Lifespan Institute (HELSI), University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom.
| |
Collapse
|
4
|
Lépine S, Nauleau-Javaudin A, Deneault E, Chen CXQ, Abdian N, Franco-Flores AK, Haghi G, Castellanos-Montiel MJ, Maussion G, Chaineau M, Durcan TM. Homozygous ALS-linked mutations in TARDBP/TDP-43 lead to hypoactivity and synaptic abnormalities in human iPSC-derived motor neurons. iScience 2024; 27:109166. [PMID: 38433895 PMCID: PMC10905001 DOI: 10.1016/j.isci.2024.109166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/21/2023] [Accepted: 02/05/2024] [Indexed: 03/05/2024] Open
Abstract
Cytoplasmic mislocalization and aggregation of the RNA-binding protein TDP-43 is a pathological hallmark of the motor neuron (MN) disease amyotrophic lateral sclerosis (ALS). Furthermore, while mutations in TARDBP (encoding TDP-43) have been associated with ALS, the pathogenic consequences of these mutations remain poorly understood. Using CRISPR-Cas9, we engineered two homozygous knock-in induced pluripotent stem cell lines carrying mutations in TARDBP encoding TDP-43A382T and TDP-43G348C, two common yet understudied ALS TDP-43 variants. Motor neurons (MNs) differentiated from knock-in iPSCs had normal viability and displayed no significant changes in TDP-43 subcellular localization, phosphorylation, solubility, or aggregation compared with isogenic control MNs. However, our results highlight synaptic impairments in both TDP-43A382T and TDP-43G348C MN cultures, as reflected in synapse abnormalities and alterations in spontaneous neuronal activity. Collectively, our findings suggest that MN dysfunction may precede the occurrence of TDP-43 pathology and neurodegeneration in ALS and further implicate synaptic and excitability defects in the pathobiology of this disease.
Collapse
Affiliation(s)
- Sarah Lépine
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
- Faculty of Medicine and Health Sciences, McGill University, Montreal, QC H3G 2M1, Canada
| | - Angela Nauleau-Javaudin
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
- Faculty of Medicine, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Eric Deneault
- Centre for Oncology, Radiopharmaceuticals and Research; Biologic and Radiopharmaceutical Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Carol X.-Q. Chen
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Narges Abdian
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Anna Krystina Franco-Flores
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Ghazal Haghi
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - María José Castellanos-Montiel
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Gilles Maussion
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Mathilde Chaineau
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Thomas Martin Durcan
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| |
Collapse
|
5
|
Villanueva E, Smith T, Pizzinga M, Elzek M, Queiroz RML, Harvey RF, Breckels LM, Crook OM, Monti M, Dezi V, Willis AE, Lilley KS. System-wide analysis of RNA and protein subcellular localization dynamics. Nat Methods 2024; 21:60-71. [PMID: 38036857 PMCID: PMC10776395 DOI: 10.1038/s41592-023-02101-9] [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: 01/27/2023] [Accepted: 10/24/2023] [Indexed: 12/02/2023]
Abstract
Although the subcellular dynamics of RNA and proteins are key determinants of cell homeostasis, their characterization is still challenging. Here we present an integrative framework to simultaneously interrogate the dynamics of the transcriptome and proteome at subcellular resolution by combining two methods: localization of RNA (LoRNA) and a streamlined density-based localization of proteins by isotope tagging (dLOPIT) to map RNA and protein to organelles (nucleus, endoplasmic reticulum and mitochondria) and membraneless compartments (cytosol, nucleolus and cytosolic granules). Interrogating all RNA subcellular locations at once enables system-wide quantification of the proportional distribution of RNA. We obtain a cell-wide overview of localization dynamics for 31,839 transcripts and 5,314 proteins during the unfolded protein response, revealing that endoplasmic reticulum-localized transcripts are more efficiently recruited to cytosolic granules than cytosolic RNAs, and that the translation initiation factor eIF3d is key to sustaining cytoskeletal function. Overall, we provide the most comprehensive overview so far of RNA and protein subcellular localization dynamics.
Collapse
Affiliation(s)
- Eneko Villanueva
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Tom Smith
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, UK
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | - Mariavittoria Pizzinga
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
- Structural Biology Research Centre, Human Technopole, Milan, Italy
| | - Mohamed Elzek
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | - Rayner M L Queiroz
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | - Lisa M Breckels
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Oliver M Crook
- Department of Statistics, University of Oxford, Oxford, UK
| | - Mie Monti
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | - Veronica Dezi
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK.
| | - Kathryn S Lilley
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, UK.
| |
Collapse
|
6
|
Ugalde MV, Alecki C, Rizwan J, Le P, Jacob-Tomas S, Xu JM, Minotti S, Wu T, Durham H, Yeo G. Localized molecular chaperone synthesis maintains neuronal dendrite proteostasis. RESEARCH SQUARE 2023:rs.3.rs-3673702. [PMID: 38168440 PMCID: PMC10760236 DOI: 10.21203/rs.3.rs-3673702/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Proteostasis is maintained through regulated protein synthesis and degradation and chaperone-assisted protein folding. However, this is challenging in neuronal projections because of their polarized morphology and constant synaptic proteome remodeling. Using high-resolution fluorescence microscopy, we discovered that neurons localize a subset of chaperone mRNAs to their dendrites and use microtubule-based transport to increase this asymmetric localization following proteotoxic stress. The most abundant dendritic chaperone mRNA encodes a constitutive heat shock protein 70 family member (HSPA8). Proteotoxic stress also enhanced HSPA8 mRNA translation efficiency in dendrites. Stress-mediated HSPA8 mRNA localization to the dendrites was impaired by depleting fused in sarcoma-an amyotrophic lateral sclerosis-related protein-in cultured mouse motor neurons and expressing a pathogenic variant of heterogenous nuclear ribonucleoprotein A2/B1 in neurons derived from human induced pluripotent stem cells. These results reveal a crucial and unexpected neuronal stress response in which RNA-binding proteins increase the dendritic localization of HSPA8 mRNA to maintain proteostasis and prevent neurodegeneration.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Gene Yeo
- University of California, San Diego
| |
Collapse
|
7
|
Pino MG, Rich KA, Hall NJ, Jones ML, Fox A, Musier-Forsyth K, Kolb SJ. Heterogeneous splicing patterns resulting from KIF5A variants associated with amyotrophic lateral sclerosis. Hum Mol Genet 2023; 32:3166-3180. [PMID: 37593923 DOI: 10.1093/hmg/ddad134] [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: 04/24/2023] [Revised: 07/28/2023] [Accepted: 08/03/2023] [Indexed: 08/19/2023] Open
Abstract
Single-nucleotide variants (SNVs) in the gene encoding Kinesin Family Member 5A (KIF5A), a neuronal motor protein involved in anterograde transport along microtubules, have been associated with amyotrophic lateral sclerosis (ALS). ALS is a rapidly progressive and fatal neurodegenerative disease that primarily affects the motor neurons. Numerous ALS-associated KIF5A SNVs are clustered near the splice-site junctions of the penultimate exon 27 and are predicted to alter the carboxy-terminal (C-term) cargo-binding domain of KIF5A. Mis-splicing of exon 27, resulting in exon exclusion, is proposed to be the mechanism by which these SNVs cause ALS. Whether all SNVs proximal to exon 27 result in exon exclusion is unclear. To address this question, we designed an in vitro minigene splicing assay in human embryonic kidney 293 cells, which revealed heterogeneous site-specific effects on splicing: only 5' splice-site (5'ss) SNVs resulted in exon skipping. We also quantified splicing in select clustered, regularly interspaced, short palindromic repeats-edited human stem cells, differentiated to motor neurons, and in neuronal tissues from a 5'ss SNV knock-in mouse, which showed the same result. Moreover, the survival of representative 3' splice site, 5'ss, and truncated C-term variant KIF5A (v-KIF5A) motor neurons was severely reduced compared with wild-type motor neurons, and overt morphological changes were apparent. While the total KIF5A mRNA levels were comparable across the cell lines, the total KIF5A protein levels were decreased for v-KIF5A lines, suggesting an impairment of protein synthesis or stability. Thus, despite the heterogeneous effect on ribonucleic acid splicing, KIF5A SNVs similarly reduce the availability of the KIF5A protein, leading to axonal transport defects and motor neuron pathology.
Collapse
Affiliation(s)
- Megan G Pino
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, United States
- Department of Biological Chemistry & Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
| | - Kelly A Rich
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
| | - Nicholas J Hall
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, United States
| | - Meredith L Jones
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
| | - Ashley Fox
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
| | - Karin Musier-Forsyth
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, United States
- Department of Chemistry & Biochemistry, The Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
| | - Stephen J Kolb
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, United States
- Department of Biological Chemistry & Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
| |
Collapse
|
8
|
Ziff OJ, Harley J, Wang Y, Neeves J, Tyzack G, Ibrahim F, Skehel M, Chakrabarti AM, Kelly G, Patani R. Nucleocytoplasmic mRNA redistribution accompanies RNA binding protein mislocalization in ALS motor neurons and is restored by VCP ATPase inhibition. Neuron 2023; 111:3011-3027.e7. [PMID: 37480846 DOI: 10.1016/j.neuron.2023.06.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 05/09/2023] [Accepted: 06/22/2023] [Indexed: 07/24/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is characterized by nucleocytoplasmic mislocalization of the RNA-binding protein (RBP) TDP-43. However, emerging evidence suggests more widespread mRNA and protein mislocalization. Here, we employed nucleocytoplasmic fractionation, RNA sequencing, and mass spectrometry to investigate the localization of mRNA and protein in induced pluripotent stem cell-derived motor neurons (iPSMNs) from ALS patients with TARDBP and VCP mutations. ALS mutant iPSMNs exhibited extensive nucleocytoplasmic mRNA redistribution, RBP mislocalization, and splicing alterations. Mislocalized proteins exhibited a greater affinity for redistributed transcripts, suggesting a link between RBP mislocalization and mRNA redistribution. Notably, treatment with ML240, a VCP ATPase inhibitor, partially restored mRNA and protein localization in ALS mutant iPSMNs. ML240 induced changes in the VCP interactome and lysosomal localization and reduced oxidative stress and DNA damage. These findings emphasize the link between RBP mislocalization and mRNA redistribution in ALS motor neurons and highlight the therapeutic potential of VCP inhibition.
Collapse
Affiliation(s)
- Oliver J Ziff
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK; National Hospital for Neurology and Neurosurgery, University College London NHS Foundation Trust, WC1N 3BG London, UK.
| | - Jasmine Harley
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK; Institute of Molecular and Cell Biology, A(∗)STAR Research Entities, Singapore 138673, Singapore
| | - Yiran Wang
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK
| | - Jacob Neeves
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK
| | - Giulia Tyzack
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK
| | - Fairouz Ibrahim
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK
| | - Mark Skehel
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK
| | | | - Gavin Kelly
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK
| | - Rickie Patani
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK; National Hospital for Neurology and Neurosurgery, University College London NHS Foundation Trust, WC1N 3BG London, UK.
| |
Collapse
|
9
|
Alecki C, Rizwan J, Le P, Jacob-Tomas S, Xu S, Minotti S, Wu T, Durham H, Yeo GW, Vera M. Localized synthesis of molecular chaperones sustains neuronal proteostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560761. [PMID: 37873158 PMCID: PMC10592939 DOI: 10.1101/2023.10.03.560761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Neurons are challenged to maintain proteostasis in neuronal projections, particularly with the physiological stress at synapses to support intercellular communication underlying important functions such as memory and movement control. Proteostasis is maintained through regulated protein synthesis and degradation and chaperone-assisted protein folding. Using high-resolution fluorescent microscopy, we discovered that neurons localize a subset of chaperone mRNAs to their dendrites, particularly more proximal regions, and increase this asymmetric localization following proteotoxic stress through microtubule-based transport from the soma. The most abundant chaperone mRNA in dendrites encodes the constitutive heat shock protein 70, HSPA8. Proteotoxic stress in cultured neurons, induced by inhibiting proteasome activity or inducing oxidative stress, enhanced transport of Hspa8 mRNAs to dendrites and the percentage of mRNAs engaged in translation on mono and polyribosomes. Knocking down the ALS-related protein Fused in Sarcoma (FUS) and a dominant mutation in the heterogenous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1) impaired stress-mediated localization of Hspa8 mRNA to dendrites in cultured murine motor neurons and human iPSC-derived neurons, respectively, revealing the importance of these RNA-binding proteins in maintaining proteostasis. These results reveal the increased dendritic localization and translation of the constitutive HSP70 Hspa8 mRNA as a crucial neuronal stress response to uphold proteostasis and prevent neurodegeneration.
Collapse
Affiliation(s)
- Celia Alecki
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Javeria Rizwan
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Phuong Le
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Suleima Jacob-Tomas
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Stella Xu
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Sandra Minotti
- Department of Neurology and Neurosurgery and Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Tad Wu
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Heather Durham
- Department of Neurology and Neurosurgery and Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Maria Vera
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| |
Collapse
|
10
|
Ma Y, Farny NG. Connecting the dots: Neuronal senescence, stress granules, and neurodegeneration. Gene 2023; 871:147437. [PMID: 37084987 PMCID: PMC10205695 DOI: 10.1016/j.gene.2023.147437] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/09/2023] [Accepted: 04/14/2023] [Indexed: 04/23/2023]
Abstract
Cellular senescence increases with aging. While senescence is associated with an exit of the cell cycle, there is ample evidence that post-mitotic cells including neurons can undergo senescence as the brain ages, and that senescence likely contributes significantly to the progression of neurodegenerative diseases (ND) such as Alzheimer's Disease (AD) and Amyotrophic Lateral Sclerosis (ALS). Stress granules (SGs) are stress-induced cytoplasmic biomolecular condensates of RNA and proteins, which have been linked to the development of AD and ALS. The SG seeding hypothesis of NDs proposes that chronic stress in aging neurons results in static SGs that progress into pathological aggregates Alterations in SG dynamics have also been linked to senescence, though studies that link SGs and senescence in the context of NDs and the aging brain have not yet been performed. In this Review, we summarize the literature on senescence, and explore the contribution of senescence to the aging brain. We describe senescence phenotypes in aging neurons and glia, and their links to neuroinflammation and the development of AD and ALS. We further examine the relationships of SGs to senescence and to ND. We propose a new hypothesis that neuronal senescence may contribute to the mechanism of SG seeding in ND by altering SG dynamics in aged cells, thereby providing additional aggregation opportunities within aged neurons.
Collapse
Affiliation(s)
- Yizhe Ma
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Natalie G Farny
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, USA.
| |
Collapse
|
11
|
Niu X, Zhang L, Wu Y, Zong Z, Wang B, Liu J, Zhang L, Zhou F. Biomolecular condensates: Formation mechanisms, biological functions, and therapeutic targets. MedComm (Beijing) 2023; 4:e223. [PMID: 36875159 PMCID: PMC9974629 DOI: 10.1002/mco2.223] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 01/20/2023] [Accepted: 02/02/2023] [Indexed: 03/06/2023] Open
Abstract
Biomolecular condensates are cellular structures composed of membraneless assemblies comprising proteins or nucleic acids. The formation of these condensates requires components to change from a state of solubility separation from the surrounding environment by undergoing phase transition and condensation. Over the past decade, it has become widely appreciated that biomolecular condensates are ubiquitous in eukaryotic cells and play a vital role in physiological and pathological processes. These condensates may provide promising targets for the clinic research. Recently, a series of pathological and physiological processes have been found associated with the dysfunction of condensates, and a range of targets and methods have been demonstrated to modulate the formation of these condensates. A more extensive description of biomolecular condensates is urgently needed for the development of novel therapies. In this review, we summarized the current understanding of biomolecular condensates and the molecular mechanisms of their formation. Moreover, we reviewed the functions of condensates and therapeutic targets for diseases. We further highlighted the available regulatory targets and methods, discussed the significance and challenges of targeting these condensates. Reviewing the latest developments in biomolecular condensate research could be essential in translating our current knowledge on the use of condensates for clinical therapeutic strategies.
Collapse
Affiliation(s)
- Xin Niu
- Department of Otolaryngology Head and Neck Surgery The First Affiliated Hospital of Soochow University Suzhou China.,MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network Life Sciences Institute Zhejiang University Hangzhou China
| | - Lei Zhang
- Department of Orthopedics The First Affiliated Hospital of Wenzhou Medical University Wenzhou China
| | - Yuchen Wu
- Department of Clinical Medicine, The First School of Medicine Wenzhou Medical University Wenzhou China
| | - Zhi Zong
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network Life Sciences Institute Zhejiang University Hangzhou China
| | - Bin Wang
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network Life Sciences Institute Zhejiang University Hangzhou China
| | - Jisheng Liu
- Department of Otolaryngology Head and Neck Surgery The First Affiliated Hospital of Soochow University Suzhou China
| | - Long Zhang
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network Life Sciences Institute Zhejiang University Hangzhou China
| | - Fangfang Zhou
- Institutes of Biology and Medical Science Soochow University Suzhou China
| |
Collapse
|
12
|
Keating SS, Bademosi AT, San Gil R, Walker AK. Aggregation-prone TDP-43 sequesters and drives pathological transitions of free nuclear TDP-43. Cell Mol Life Sci 2023; 80:95. [PMID: 36930291 PMCID: PMC10023653 DOI: 10.1007/s00018-023-04739-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 03/18/2023]
Abstract
Aggregation of the RNA-binding protein, TDP-43, is the unifying hallmark of amyotrophic lateral sclerosis and frontotemporal dementia. TDP-43-related neurodegeneration involves multiple changes to normal physiological TDP-43, which undergoes nuclear depletion, cytoplasmic mislocalisation, post-translational modification, and aberrant liquid-liquid phase separation, preceding inclusion formation. Along with toxic cytoplasmic aggregation, concurrent depletion and dysfunction of normal nuclear TDP-43 in cells with TDP-43 pathology is likely a key potentiator of neurodegeneration, but is not well understood. To define processes driving TDP-43 dysfunction, we used CRISPR/Cas9-mediated fluorescent tagging to investigate how disease-associated stressors and pathological TDP-43 alter abundance, localisation, self-assembly, aggregation, solubility, and mobility dynamics of normal nuclear TDP-43 over time in live cells. Oxidative stress stimulated liquid-liquid phase separation of endogenous TDP-43 into droplet-like puncta, or spherical shell-like anisosomes. Further, nuclear RNA-binding-ablated or acetylation-mimicking TDP-43 readily sequestered and depleted free normal nuclear TDP-43 into dynamic anisosomes, in which recruited endogenous TDP-43 proteins remained soluble and highly mobile. Large, phosphorylated inclusions formed by nuclear or cytoplasmic aggregation-prone TDP-43 mutants also caused sequestration, but rendered endogenous TDP-43 immobile and insoluble, indicating pathological transition. These findings suggest that RNA-binding deficiency and post-translational modifications including acetylation exacerbate TDP-43 aggregation and dysfunction by driving sequestration, mislocalisation, and depletion of normal nuclear TDP-43 in neurodegenerative diseases.
Collapse
Affiliation(s)
- Sean S Keating
- Neurodegeneration Pathobiology Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Adekunle T Bademosi
- Neurodegeneration Pathobiology Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Rebecca San Gil
- Neurodegeneration Pathobiology Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St. Lucia, QLD, 4072, Australia.
| | - Adam K Walker
- Neurodegeneration Pathobiology Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St. Lucia, QLD, 4072, Australia.
| |
Collapse
|
13
|
Dubinski A, Gagné M, Peyrard S, Gordon D, Talbot K, Vande Velde C. Stress granule assembly in vivo is deficient in the CNS of mutant TDP-43 ALS mice. Hum Mol Genet 2023; 32:319-332. [PMID: 35994036 PMCID: PMC9840205 DOI: 10.1093/hmg/ddac206] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 07/06/2022] [Accepted: 08/17/2022] [Indexed: 01/19/2023] Open
Abstract
Responding effectively to external stress is crucial for neurons. Defective stress granule dynamics has been hypothesized as one of the pathways that renders motor neurons in amyotrophic lateral sclerosis (ALS) more prone to early death. Specifically, it is thought that stress granules seed the cytoplasmic TDP-43 inclusions that are observed in the neurons of most ALS patients, as well as ~50% of all frontotemporal dementia (FTD) patients. In this study, we tested this hypothesis in an intact mammalian nervous system. We established an in vivo heat stress paradigm in mice that effectively triggers the eIF2α pathway and the formation of stress granules in the CNS. In non-transgenic mice, we report an age-dependent decline in the formation of heat-induced stress granules, with 18-month-old animals showing a significant impairment. Furthermore, although neuronal stress granules were robustly observed in non-transgenic mice and SOD1G93A mice, they were largely absent in age-matched TDP-43M337V animals. The observed defect in stress granule formation in TDP-43M337V mice correlated with deficits in expression of key protein components typically required for phase separation. Lastly, while TDP-43 was not localized to stress granules, we observed complete nuclear depletion of TDP-43 in a subset of neurons, with the highest proportion being in the TDP-43M337V mice. Overall, our results indicate that mutant TDP-43 expression is associated with defective stress granule assembly and increased TDP-43 nuclear depletion in the mammalian nervous system, which could be relevant to ALS/FTD pathogenesis.
Collapse
Affiliation(s)
- Alicia Dubinski
- Department of Neuroscience, Université de Montréal, Montréal, Québec H3T 1J4, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec H2X 0A9, Canada
| | - Myriam Gagné
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec H2X 0A9, Canada
- Department of Biochemistry, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Sarah Peyrard
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec H2X 0A9, Canada
| | - David Gordon
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Kevin Talbot
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Christine Vande Velde
- Department of Neuroscience, Université de Montréal, Montréal, Québec H3T 1J4, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec H2X 0A9, Canada
- Department of Biochemistry, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| |
Collapse
|
14
|
Turner M, Danino YM, Barshai M, Yacovzada NS, Cohen Y, Olender T, Rotkopf R, Monchaud D, Hornstein E, Orenstein Y. rG4detector, a novel RNA G-quadruplex predictor, uncovers their impact on stress granule formation. Nucleic Acids Res 2022; 50:11426-11441. [PMID: 36350614 PMCID: PMC9723610 DOI: 10.1093/nar/gkac950] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/21/2022] [Accepted: 10/14/2022] [Indexed: 11/11/2022] Open
Abstract
RNA G-quadruplexes (rG4s) are RNA secondary structures, which are formed by guanine-rich sequences and have important cellular functions. Existing computational tools for rG4 prediction rely on specific sequence features and/or were trained on small datasets, without considering rG4 stability information, and are therefore sub-optimal. Here, we developed rG4detector, a convolutional neural network to identify potential rG4s in transcriptomics data. rG4detector outperforms existing methods in both predicting rG4 stability and in detecting rG4-forming sequences. To demonstrate the biological-relevance of rG4detector, we employed it to study RNAs that are bound by the RNA-binding protein G3BP1. G3BP1 is central to the induction of stress granules (SGs), which are cytoplasmic biomolecular condensates that form in response to a variety of cellular stresses. Unexpectedly, rG4detector revealed a dynamic enrichment of rG4s bound by G3BP1 in response to cellular stress. In addition, we experimentally characterized G3BP1 cross-talk with rG4s, demonstrating that G3BP1 is a bona fide rG4-binding protein and that endogenous rG4s are enriched within SGs. Furthermore, we found that reduced rG4 availability impairs SG formation. Hence, we conclude that rG4s play a direct role in SG biology via their interactions with RNA-binding proteins and that rG4detector is a novel useful tool for rG4 transcriptomics data analyses.
Collapse
Affiliation(s)
| | | | - Mira Barshai
- School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Be’er-Sheva 8410501, Israel
| | - Nancy S Yacovzada
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel,Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yahel Cohen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel,Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ron Rotkopf
- Bioinformatics Unit, Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - David Monchaud
- Institut de Chimie Moleculaire, ICMUB CNRS UMR 6302, UBFC Dijon, France
| | | | - Yaron Orenstein
- Correspondence may also be addressed to Yaron Orenstein. Tel: +972 3 531 7990;
| |
Collapse
|
15
|
Metzner K, Darawsha O, Wang M, Gaur N, Cheng Y, Rödiger A, Frahm C, Witte OW, Perocchi F, Axer H, Grosskreutz J, Brill MS. Age-dependent increase of cytoskeletal components in sensory axons in human skin. Front Cell Dev Biol 2022; 10:965382. [PMID: 36393849 PMCID: PMC9664158 DOI: 10.3389/fcell.2022.965382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 10/12/2022] [Indexed: 01/24/2023] Open
Abstract
Aging is a complex process characterized by several molecular and cellular imbalances. The composition and stability of the neuronal cytoskeleton is essential for the maintenance of homeostasis, especially in long neurites. Using human skin biopsies containing sensory axons from a cohort of healthy individuals, we investigate alterations in cytoskeletal content and sensory axon caliber during aging via quantitative immunostainings. Cytoskeletal components show an increase with aging in both sexes, while elevation in axon diameter is only evident in males. Transcriptomic data from aging males illustrate various patterns in gene expression during aging. Together, the data suggest gender-specific changes during aging in peripheral sensory axons, possibly influencing cytoskeletal functionality and axonal caliber. These changes may cumulatively increase susceptibility of aged individuals to neurodegenerative diseases.
Collapse
Affiliation(s)
- Klara Metzner
- Department of Neurology, Jena University Hospital, Jena, Germany,Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany
| | - Omar Darawsha
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany
| | - Mengzhe Wang
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany
| | - Nayana Gaur
- Department of Neurology, Jena University Hospital, Jena, Germany,Laboratory Animal Centre, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Yiming Cheng
- Helmholtz Diabetes Center (HDC), Helmholtz Center Munich, Institute for Diabetes and Obesity, Munich, Germany
| | | | - Christiane Frahm
- Department of Neurology, Jena University Hospital, Jena, Germany
| | - Otto W. Witte
- Department of Neurology, Jena University Hospital, Jena, Germany
| | - Fabiana Perocchi
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,Helmholtz Diabetes Center (HDC), Helmholtz Center Munich, Institute for Diabetes and Obesity, Munich, Germany,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Hubertus Axer
- Department of Neurology, Jena University Hospital, Jena, Germany
| | - Julian Grosskreutz
- Precision Neurology of the University of Lübeck, Lübeck, Germany,PMI Cluster, University of Lübeck, Lübeck, Germany
| | - Monika S. Brill
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany,*Correspondence: Monika S. Brill,
| |
Collapse
|
16
|
Rhine K, Al-Azzam N, Yu T, Yeo GW. Aging RNA granule dynamics in neurodegeneration. Front Mol Biosci 2022; 9:991641. [PMID: 36188213 PMCID: PMC9523239 DOI: 10.3389/fmolb.2022.991641] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/22/2022] [Indexed: 12/30/2022] Open
Abstract
Disordered RNA-binding proteins and repetitive RNA sequences are the main genetic causes of several neurodegenerative diseases, including amyotrophic lateral sclerosis and Huntington’s disease. Importantly, these components also seed the formation of cytoplasmic liquid-like granules, like stress granules and P bodies. Emerging evidence demonstrates that healthy granules formed via liquid-liquid phase separation can mature into solid- or gel-like inclusions that persist within the cell. These solidified inclusions are a precursor to the aggregates identified in patients, demonstrating that dysregulation of RNA granule biology is an important component of neurodegeneration. Here, we review recent literature highlighting how RNA molecules seed proteinaceous granules, the mechanisms of healthy turnover of RNA granules in cells, which biophysical properties underly a transition to solid- or gel-like material states, and why persistent granules disrupt the cellular homeostasis of neurons. We also identify various methods that will illuminate the contributions of disordered proteins and RNAs to neurodegeneration in ongoing research efforts.
Collapse
Affiliation(s)
- Kevin Rhine
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
| | - Norah Al-Azzam
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
- Neurosciences Graduate Program, University of California, San Diego, San Diego, CA, United States
| | - Tao Yu
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
| | - Gene W. Yeo
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
- Neurosciences Graduate Program, University of California, San Diego, San Diego, CA, United States
- *Correspondence: Gene W. Yeo,
| |
Collapse
|
17
|
Liquid-liquid phase separation in tumor biology. Signal Transduct Target Ther 2022; 7:221. [PMID: 35803926 PMCID: PMC9270353 DOI: 10.1038/s41392-022-01076-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/16/2022] [Accepted: 06/21/2022] [Indexed: 12/12/2022] Open
Abstract
Liquid–liquid phase separation (LLPS) is a novel principle for explaining the precise spatial and temporal regulation in living cells. LLPS compartmentalizes proteins and nucleic acids into micron-scale, liquid-like, membraneless bodies with specific functions, which were recently termed biomolecular condensates. Biomolecular condensates are executors underlying the intracellular spatiotemporal coordination of various biological activities, including chromatin organization, genomic stability, DNA damage response and repair, transcription, and signal transduction. Dysregulation of these cellular processes is a key event in the initiation and/or evolution of cancer, and emerging evidence has linked the formation and regulation of LLPS to malignant transformations in tumor biology. In this review, we comprehensively summarize the detailed mechanisms of biomolecular condensate formation and biophysical function and review the recent major advances toward elucidating the multiple mechanisms involved in cancer cell pathology driven by aberrant LLPS. In addition, we discuss the therapeutic perspectives of LLPS in cancer research and the most recently developed drug candidates targeting LLPS modulation that can be used to combat tumorigenesis.
Collapse
|
18
|
Aberrant NOVA1 function disrupts alternative splicing in early stages of amyotrophic lateral sclerosis. Acta Neuropathol 2022; 144:413-435. [PMID: 35778567 PMCID: PMC9381448 DOI: 10.1007/s00401-022-02450-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 06/02/2022] [Accepted: 06/02/2022] [Indexed: 11/04/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by aberrant alternative splicing (AS). Nuclear loss and cytoplasmic accumulation of the splicing factor TDP-43 in motor neurons (MN) are hallmarks of ALS at late stages of the disease. However, it is unknown if altered AS is present before TDP-43 pathology occurs. Here, we investigate altered AS and its origins in early stages of ALS using human induced pluripotent stem cell-derived motor neurons (MNs) from sporadic and familial ALS patients. We find high levels of the RNA-binding proteins NOVA1, NOVA2, and RBFOX2 in the insoluble protein fractions and observe that AS events in ALS-associated MNs are enriched for binding sites of these proteins. Our study points to an early disrupted function of NOVA1 that drives AS changes in a complex fashion, including events caused by a consistent loss of NOVA1 function. NOVA1 exhibits increased cytoplasmic protein levels in early stage MNs without TDP-43 pathology in ALS postmortem tissue. As nuclear TDP-43 protein level depletes, NOVA1 is reduced. Potential indications for a reduction of NOVA1 also came from mice over-expressing TDP-43 lacking its nuclear localization signal and iPSC-MN stressed with puromycin. This study highlights that additional RBP-RNA perturbations in ALS occur in parallel to TDP-43.
Collapse
|