1
|
Fonda BD, Kato M, Li Y, Murray DT. Cryo-EM and solid state NMR together provide a more comprehensive structural investigation of protein fibrils. Protein Sci 2024; 33:e5168. [PMID: 39276003 PMCID: PMC11400629 DOI: 10.1002/pro.5168] [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: 05/31/2024] [Revised: 08/25/2024] [Accepted: 08/26/2024] [Indexed: 09/16/2024]
Abstract
The tropomyosin 1 isoform I/C C-terminal domain (Tm1-LC) fibril structure is studied jointly with cryogenic electron microscopy (cryo-EM) and solid state nuclear magnetic resonance (NMR). This study demonstrates the complementary nature of these two structural biology techniques. Chemical shift assignments from solid state NMR are used to determine the secondary structure at the level of individual amino acids, which is faithfully seen in cryo-EM reconstructions. Additionally, solid state NMR demonstrates that the region not observed in the reconstructed cryo-EM density is primarily in a highly mobile random coil conformation rather than adopting multiple rigid conformations. Overall, this study illustrates the benefit of investigations combining cryo-EM and solid state NMR to investigate protein fibril structure.
Collapse
Affiliation(s)
- Blake D. Fonda
- Department of ChemistryUniversity of CaliforniaDavisCaliforniaUSA
| | - Masato Kato
- Department of BiochemistryUniversity of Texas Southwestern Medical CenterDallasTexasUSA
| | - Yang Li
- Department of BiophysicsUniversity of Texas Southwestern Medical CenterDallasTexasUSA
| | - Dylan T. Murray
- Department of Molecular and Cell BiologyUniversity of ConnecticutStorrsConnecticutUSA
| |
Collapse
|
2
|
Fonda BD, Kato M, Li Y, Murray DT. Cryo-EM and Solid State NMR Together Provide a More Comprehensive Structural Investigation of Protein Fibrils. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596698. [PMID: 38853912 PMCID: PMC11160737 DOI: 10.1101/2024.05.30.596698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The Tropomyosin 1 isoform I/C C-terminal domain (Tm1-LC) fibril structure is studied jointly with cryogenic electron microscopy (cryo-EM) and solid state nuclear magnetic resonance (NMR). This study demonstrates the complementary nature of these two structural biology techniques. Chemical shift assignments from solid state NMR are used to determine the secondary structure at the level of individual amino acids, which is faithfully seen in cryo-EM reconstructions. Additionally, solid state NMR demonstrates that the region not observed in the reconstructed cryo-EM density is primarily in a highly mobile random coil conformation rather than adopting multiple rigid conformations. Overall, this study illustrates the benefit of investigations combining cryo-EM and solid state NMR to investigate protein fibril structure.
Collapse
Affiliation(s)
- Blake D. Fonda
- Department of Chemistry, University of California, Davis, California, 95616, United States of America
| | - Masato Kato
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
| | - Yang Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
| | - Dylan T. Murray
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, 06269, United States of America
| |
Collapse
|
3
|
Lee J, Cho H, Kwon I. Phase separation of low-complexity domains in cellular function and disease. EXPERIMENTAL & MOLECULAR MEDICINE 2022; 54:1412-1422. [PMID: 36175485 PMCID: PMC9534829 DOI: 10.1038/s12276-022-00857-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/15/2022] [Accepted: 07/19/2022] [Indexed: 11/09/2022]
Abstract
In this review, we discuss the ways in which recent studies of low-complexity (LC) domains have challenged our understanding of the mechanisms underlying cellular organization. LC sequences, long believed to function in the absence of a molecular structure, are abundant in the proteomes of all eukaryotic organisms. Over the past decade, the phase separation of LC domains has emerged as a fundamental mechanism driving dynamic multivalent interactions of many cellular processes. We review the key evidence showing the role of phase separation of individual proteins in organizing cellular assemblies and facilitating biological function while implicating the dynamics of phase separation as a key to biological validity and functional utility. We also highlight the evidence showing that pathogenic LC proteins alter various phase separation-dependent interactions to elicit debilitating human diseases, including cancer and neurodegenerative diseases. Progress in understanding the biology of phase separation may offer useful hints toward possible therapeutic interventions to combat the toxicity of pathogenic proteins.
Collapse
Affiliation(s)
- Jiwon Lee
- Department of Anatomy and Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, Korea
| | - Hana Cho
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon, 16419, Korea.
| | - Ilmin Kwon
- Department of Anatomy and Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, Korea.
| |
Collapse
|
4
|
Jarnot P, Ziemska-Legiecka J, Grynberg M, Gruca A. Insights from analyses of low complexity regions with canonical methods for protein sequence comparison. Brief Bioinform 2022; 23:bbac299. [PMID: 35914952 PMCID: PMC9487646 DOI: 10.1093/bib/bbac299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 11/28/2022] Open
Abstract
Low complexity regions are fragments of protein sequences composed of only a few types of amino acids. These regions frequently occur in proteins and can play an important role in their functions. However, scientists are mainly focused on regions characterized by high diversity of amino acid composition. Similarity between regions of protein sequences frequently reflect functional similarity between them. In this article, we discuss strengths and weaknesses of the similarity analysis of low complexity regions using BLAST, HHblits and CD-HIT. These methods are considered to be the gold standard in protein similarity analysis and were designed for comparison of high complexity regions. However, we lack specialized methods that could be used to compare the similarity of low complexity regions. Therefore, we investigated the existing methods in order to understand how they can be applied to compare such regions. Our results are supported by exploratory study, discussion of amino acid composition and biological roles of selected examples. We show that existing methods need improvements to efficiently search for similar low complexity regions. We suggest features that have to be re-designed specifically for comparing low complexity regions: scoring matrix, multiple sequence alignment, e-value, local alignment and clustering based on a set of representative sequences. Results of this analysis can either be used to improve existing methods or to create new methods for the similarity analysis of low complexity regions.
Collapse
Affiliation(s)
- Patryk Jarnot
- Department of Computer Networks and Systems, Silesian University of Technology, Akademicka 2A, 44-100, Gliwice, Poland
| | - Joanna Ziemska-Legiecka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106, Warsaw, Poland
| | - Marcin Grynberg
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106, Warsaw, Poland
| | - Aleksandra Gruca
- Department of Computer Networks and Systems, Silesian University of Technology, Akademicka 2A, 44-100, Gliwice, Poland
| |
Collapse
|
5
|
Garg DK, Bhat R. Modulation of assembly of TDP-43 low-complexity domain by heparin: From droplets to amyloid fibrils. Biophys J 2022; 121:2568-2582. [PMID: 35644946 PMCID: PMC9300664 DOI: 10.1016/j.bpj.2022.05.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 09/03/2021] [Accepted: 05/25/2022] [Indexed: 11/02/2022] Open
Abstract
TAR DNA-binding protein 43 (TDP-43) is an RNA-regulating protein that carries out many cellular functions through liquid-liquid phase separation (LLPS). The LLPS of TDP-43 is mediated by its C-terminal low-complexity domain (TDP43-LCD) corresponding to the region 267-414. In neurodegenerative disorders amyotrophic lateral sclerosis and frontotemporal dementia, pathological inclusions of the TDP-43 are found that are rich in the C-terminal fragments of ∼25 and ∼35 kDa, of which TDP43-LCD is a part. Thus, understanding the assembly process of TDP43-LCD is essential, given its involvement in the formation of both functional liquid-like assemblies and solid- or gel-like pathological aggregates. Here, we show that the solution pH and salt modulate TDP43-LCD LLPS. A gradual reduction in the pH below its isoelectric point of 9.8 results in a monotonic decrease of TDP43-LCD LLPS due to charge-charge repulsion between monomers, while at pH 6 and below no LLPS was observed. The addition of heparin to TDP43-LCD solution at pH 6, at a 1:2 heparin-to-TDP43-LCD molar ratio, promotes TDP43-LCD LLPS, while at higher concentration, it disrupts LLPS through a reentrant phase transition. Upon incubation at pH 6, TDP43-LCD undergoes gelation without phase separation. However, in the reentrant regime in the presence of a high heparin concentration, it forms thick amyloid aggregates that are significantly more SDS resistant than the gel. The results indicate that the material nature of the TDP43-LCD assembly products can be modulated by heparin which is significant in the context of liquid-to-solid phase transition observed in TDP-43 proteinopathies. Our findings are also crucial in relation to similar transitions that could occur due to alteration in the molecular level interactions among various multivalent biomolecules involving other LCDs and RNAs.
Collapse
Affiliation(s)
| | - Rajiv Bhat
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India.
| |
Collapse
|
6
|
Distinct roles of hnRNPH1 low-complexity domains in splicing and transcription. Proc Natl Acad Sci U S A 2021; 118:2109668118. [PMID: 34873036 PMCID: PMC8685725 DOI: 10.1073/pnas.2109668118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2021] [Indexed: 12/21/2022] Open
Abstract
Phase separation of low-complexity (LC) domains appended to most RNA-binding proteins (RBPs) emerges as a principle underlying spatiotemporal protein recruitment. Yet, how LC domains regulate the function of RBPs in cells remains unclear. An alternative-splicing regulator, hnRNPH1, contains two LC domains (LC1 and LC2). Here, we show that phase separation of the LC1 can exert control over hnRNPH1 function in RNA-splicing possibly by facilitating interactions between hnRNPH1 and a variety of RBPs. In contrast, the LC2 lacking in vitro phase properties, is required for aberrant transcriptional activation in the context of fusion oncoproteins. These results have broad implications for understanding how phase separation contributes to distinct roles of LC domains in control of physiological as well as oncogenic functions. Heterogeneous nuclear ribonucleoproteins (hnRNPs) represent a large family of RNA-binding proteins that control key events in RNA biogenesis under both normal and diseased cellular conditions. The low-complexity (LC) domain of hnRNPs can become liquid-like droplets or reversible amyloid-like polymers by phase separation. Yet, whether phase separation of the LC domains contributes to physiological functions of hnRNPs remains unclear. hnRNPH1 contains two LC domains, LC1 and LC2. Here, we show that reversible phase separation of the LC1 domain is critical for both interaction with different kinds of RNA-binding proteins and control of the alternative-splicing activity of hnRNPH1. Interestingly, although not required for phase separation, the LC2 domain contributes to the robust transcriptional activation of hnRNPH1 when fused to the DNA-binding domain, as found recently in acute lymphoblastic leukemia. Our data suggest that the ability of the LC1 domain to phase-separate into reversible polymers or liquid-like droplets is essential for function of hnRNPH1 as an alternative RNA-splicing regulator, whereas the LC2 domain may contribute to the aberrant transcriptional activity responsible for cancer transformation.
Collapse
|
7
|
Carlston C, Weinmann R, Stec N, Abbatemarco S, Schwager F, Wang J, Ouyang H, Ewald CY, Gotta M, Hammell CM. PQN-59 antagonizes microRNA-mediated repression during post-embryonic temporal patterning and modulates translation and stress granule formation in C. elegans. PLoS Genet 2021; 17:e1009599. [PMID: 34807903 PMCID: PMC8648105 DOI: 10.1371/journal.pgen.1009599] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 12/06/2021] [Accepted: 10/27/2021] [Indexed: 12/14/2022] Open
Abstract
microRNAs (miRNAs) are potent regulators of gene expression that function in a variety of developmental and physiological processes by dampening the expression of their target genes at a post-transcriptional level. In many gene regulatory networks (GRNs), miRNAs function in a switch-like manner whereby their expression and activity elicit a transition from one stable pattern of gene expression to a distinct, equally stable pattern required to define a nascent cell fate. While the importance of miRNAs that function in this capacity are clear, we have less of an understanding of the cellular factors and mechanisms that ensure the robustness of this form of regulatory bistability. In a screen to identify suppressors of temporal patterning phenotypes that result from ineffective miRNA-mediated target repression, we identified pqn-59, an ortholog of human UBAP2L, as a novel factor that antagonizes the activities of multiple heterochronic miRNAs. Specifically, we find that depletion of pqn-59 can restore normal development in animals with reduced lin-4 and let-7-family miRNA activity. Importantly, inactivation of pqn-59 is not sufficient to bypass the requirement of these regulatory RNAs within the heterochronic GRN. The pqn-59 gene encodes an abundant, cytoplasmically-localized, unstructured protein that harbors three essential "prion-like" domains. These domains exhibit LLPS properties in vitro and normally function to limit PQN-59 diffusion in the cytoplasm in vivo. Like human UBAP2L, PQN-59's localization becomes highly dynamic during stress conditions where it re-distributes to cytoplasmic stress granules and is important for their formation. Proteomic analysis of PQN-59 complexes from embryonic extracts indicates that PQN-59 and human UBAP2L interact with orthologous cellular components involved in RNA metabolism and promoting protein translation and that PQN-59 additionally interacts with proteins involved in transcription and intracellular transport. Finally, we demonstrate that pqn-59 depletion reduces protein translation and also results in the stabilization of several mature miRNAs (including those involved in temporal patterning). These data suggest that PQN-59 may ensure the bistability of some GRNs that require miRNA functions by promoting miRNA turnover and, like UBAP2L, enhancing protein translation.
Collapse
Affiliation(s)
- Colleen Carlston
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
| | - Robin Weinmann
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
| | - Natalia Stec
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
| | - Simona Abbatemarco
- Department of Cellular Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Francoise Schwager
- Department of Cellular Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Jing Wang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
| | - Huiwu Ouyang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
| | - Collin Y. Ewald
- Laboratory of Extracellular Matrix Regeneration, Institute of Translational Medicine, Department of Health Sciences and Technology, ETH Zürich, Schwerzenbach, Switzerland
| | - Monica Gotta
- Department of Cellular Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | | |
Collapse
|
8
|
Fassler JS, Skuodas S, Weeks DL, Phillips BT. Protein Aggregation and Disaggregation in Cells and Development. J Mol Biol 2021; 433:167215. [PMID: 34450138 PMCID: PMC8530975 DOI: 10.1016/j.jmb.2021.167215] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 08/01/2021] [Accepted: 08/18/2021] [Indexed: 12/12/2022]
Abstract
Protein aggregation is a feature of numerous neurodegenerative diseases. However, regulated, often reversible, formation of protein aggregates, also known as condensates, helps control a wide range of cellular activities including stress response, gene expression, memory, cell development and differentiation. This review presents examples of aggregates found in biological systems, how they are used, and cellular strategies that control aggregation and disaggregation. We include features of the aggregating proteins themselves, environmental factors, co-aggregates, post-translational modifications and well-known aggregation-directed activities that influence their formation, material state, stability and dissolution. We highlight the emerging roles of biomolecular condensates in early animal development, and disaggregation processing proteins that have recently been shown to play key roles in gametogenesis and embryogenesis.
Collapse
Affiliation(s)
- Jan S Fassler
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States.
| | - Sydney Skuodas
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States. https://twitter.com/@sskuodas
| | - Daniel L Weeks
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, United States
| | - Bryan T Phillips
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States. https://twitter.com/@bt4phillips
| |
Collapse
|
9
|
C9orf72-derived arginine-rich poly-dipeptides impede phase modifiers. Nat Commun 2021; 12:5301. [PMID: 34489423 PMCID: PMC8421406 DOI: 10.1038/s41467-021-25560-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 08/16/2021] [Indexed: 01/13/2023] Open
Abstract
Nuclear import receptors (NIRs) not only transport RNA-binding proteins (RBPs) but also modify phase transitions of RBPs by recognizing nuclear localization signals (NLSs). Toxic arginine-rich poly-dipeptides from C9orf72 interact with NIRs and cause nucleocytoplasmic transport deficit. However, the molecular basis for the toxicity of arginine-rich poly-dipeptides toward NIRs function as phase modifiers of RBPs remains unidentified. Here we show that arginine-rich poly-dipeptides impede the ability of NIRs to modify phase transitions of RBPs. Isothermal titration calorimetry and size-exclusion chromatography revealed that proline:arginine (PR) poly-dipeptides tightly bind karyopherin-β2 (Kapβ2) at 1:1 ratio. The nuclear magnetic resonances of Kapβ2 perturbed by PR poly-dipeptides partially overlapped with those perturbed by the designed NLS peptide, suggesting that PR poly-dipeptides target the NLS binding site of Kapβ2. The findings offer mechanistic insights into how phase transitions of RBPs are disabled in C9orf72-related neurodegeneration. Nuclear import receptors (NIRs) regulate self-association of RNA-binding proteins as phase modifiers, while C9orf72-derived arginine-rich polydipeptides lead to aberrant phase transitions. Here the authors show in molecular basis how arginine-rich poly-dipeptides impede the ability of NIRs, particularly Kapβ2.
Collapse
|
10
|
Survey of Drought-Associated TAWRKY2-D1 Gene Diversity in Bread Wheat and Wheat Relatives. Mol Biotechnol 2021; 63:953-962. [PMID: 34131856 DOI: 10.1007/s12033-021-00350-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/03/2021] [Indexed: 10/21/2022]
Abstract
Recent advances in plant genomics revealed numerous factors related to drought tolerance, including a family of WRKY transcription factors. The aim of this study was to evaluate polymorphism of the TaWRKY2-D1 across a range of bread wheat cultivars, interspecific hybrids, and wild wheat relatives within the Triticum genus as a potential molecular target for marker-assistant selection. The initial sequencing of the TaWRKY2-D1 gene in six Ukrainian commercial cultivars detected some sequence variations along the ~ 1.8 kb of gene promoter and the followed coding region composed of four exons and three introns. Based on the gained sequence information, five sets of primers covering different gene regions were designed to annotate theTaWRKY2-D1 genetic diversity in 202 wheat cultivars, including 77 accessions from the CIMMYT collection, 72 commercial varieties cultivated in Ukraine, and 53 hybrids and wild wheat species. The combination of developed DNA markers enabled effective and reproducible annotation of cultivars genetic diversity. The primers set targeting introns adjusted to the gene's exon 3, turned out to be the most informative for screening heterogeneity of the TaWRKY2-D1. The developed molecular markers represent effective, informative means for selecting drought tolerance germplasm donors to promote wheat breeding programs.
Collapse
|
11
|
McDonald NA, Fetter RD, Shen K. Assembly of synaptic active zones requires phase separation of scaffold molecules. Nature 2020; 588:454-458. [PMID: 33208945 DOI: 10.1038/s41586-020-2942-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 09/03/2020] [Indexed: 12/20/2022]
Abstract
The formation of synapses during neuronal development is essential for establishing neural circuits and a nervous system1. Every presynapse builds a core 'active zone' structure, where ion channels cluster and synaptic vesicles release their neurotransmitters2. Although the composition of active zones is well characterized2,3, it is unclear how active-zone proteins assemble together and recruit the machinery required for vesicle release during development. Here we find that the core active-zone scaffold proteins SYD-2 (also known as liprin-α) and ELKS-1 undergo phase separation during an early stage of synapse development, and later mature into a solid structure. We directly test the in vivo function of phase separation by using mutant SYD-2 and ELKS-1 proteins that specifically lack this activity. These mutant proteins remain enriched at synapses in Caenorhabditis elegans, but show defects in active-zone assembly and synapse function. The defects are rescued by introducing a phase-separation motif from an unrelated protein. In vitro, we reconstitute the SYD-2 and ELKS-1 liquid-phase scaffold, and find that it is competent to bind and incorporate downstream active-zone components. We find that the fluidity of SYD-2 and ELKS-1 condensates is essential for efficient mixing and incorporation of active-zone components. These data reveal that a developmental liquid phase of scaffold molecules is essential for the assembly of the synaptic active zone, before maturation into a stable final structure.
Collapse
Affiliation(s)
| | - Richard D Fetter
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA, USA. .,Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA.
| |
Collapse
|
12
|
Bogaert E, Boeynaems S, Kato M, Guo L, Caulfield TR, Steyaert J, Scheveneels W, Wilmans N, Haeck W, Hersmus N, Schymkowitz J, Rousseau F, Shorter J, Callaerts P, Robberecht W, Van Damme P, Van Den Bosch L. Molecular Dissection of FUS Points at Synergistic Effect of Low-Complexity Domains in Toxicity. Cell Rep 2019; 24:529-537.e4. [PMID: 30021151 PMCID: PMC6077250 DOI: 10.1016/j.celrep.2018.06.070] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 03/11/2018] [Accepted: 06/15/2018] [Indexed: 12/11/2022] Open
Abstract
RNA-binding protein aggregation is a pathological hallmark of several neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). To gain better insight into the molecular interactions underlying this process, we investigated FUS, which is mutated and aggregated in both ALS and FTLD. We generated a Drosophila model of FUS toxicity and identified a previously unrecognized synergistic effect between the N-terminal prion-like domain and the C-terminal arginine-rich domain to mediate toxicity. Although the prion-like domain is generally considered to mediate aggregation of FUS, we find that arginine residues in the C-terminal low-complexity domain are also required for maturation of FUS in cellular stress granules. These data highlight an important role for arginine-rich domains in the pathology of RNA-binding proteins. Both QGSY and RGG2 domains are necessary for FUS-induced neurodegeneration in flies Arginine-rich domains interact with QGSY hydrogels and liquid droplets RGG2 arginines promote phase separation of FUS in vitro and in cells FUS phase separation behavior in vitro correlates with neurodegeneration in vivo
Collapse
Affiliation(s)
- Elke Bogaert
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium
| | - Steven Boeynaems
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Masato Kato
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lin Guo
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Thomas R Caulfield
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224, USA
| | - Jolien Steyaert
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium
| | - Wendy Scheveneels
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium
| | - Nathalie Wilmans
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium
| | - Wanda Haeck
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium
| | - Nicole Hersmus
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Frederic Rousseau
- Switch Laboratory, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Patrick Callaerts
- Laboratory of Behavioral and Developmental Genetics, Department of Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Wim Robberecht
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium; Department of Neurology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Philip Van Damme
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium; Department of Neurology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Ludo Van Den Bosch
- Experimental Neurology, Department of Neurosciences, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000 Leuven, Belgium; Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, 3000 Leuven, Belgium.
| |
Collapse
|
13
|
Mitrea DM, Chandra B, Ferrolino MC, Gibbs EB, Tolbert M, White MR, Kriwacki RW. Methods for Physical Characterization of Phase-Separated Bodies and Membrane-less Organelles. J Mol Biol 2018; 430:4773-4805. [PMID: 30017918 PMCID: PMC6503534 DOI: 10.1016/j.jmb.2018.07.006] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/04/2018] [Accepted: 07/09/2018] [Indexed: 12/17/2022]
Abstract
Membrane-less organelles are cellular structures which arise through the phenomenon of phase separation. This process enables compartmentalization of specific sets of macromolecules (e.g., proteins, nucleic acids), thereby regulating cellular processes by increasing local concentration, and modulating the structure and dynamics of their constituents. Understanding the connection between structure, material properties and function of membrane-less organelles requires inter-disciplinary approaches, which address length and timescales that span several orders of magnitude (e.g., Ångstroms to micrometer, picoseconds to hours). In this review, we discuss the wide variety of methods that have been applied to characterize the morphology, rheology, structure and dynamics of membrane-less organelles and their components, in vitro and in live cells.
Collapse
Affiliation(s)
- Diana M Mitrea
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| | - Bappaditya Chandra
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Mylene C Ferrolino
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Eric B Gibbs
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Michele Tolbert
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Michael R White
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN 38163, USA.
| |
Collapse
|
14
|
Murray DT, Zhou X, Kato M, Xiang S, Tycko R, McKnight SL. Structural characterization of the D290V mutation site in hnRNPA2 low-complexity-domain polymers. Proc Natl Acad Sci U S A 2018; 115:E9782-E9791. [PMID: 30279180 PMCID: PMC6196502 DOI: 10.1073/pnas.1806174115] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Human genetic studies have given evidence of familial, disease-causing mutations in the analogous amino acid residue shared by three related RNA binding proteins causative of three neurological diseases. Alteration of aspartic acid residue 290 of hnRNPA2 to valine is believed to predispose patients to multisystem proteinopathy. Mutation of aspartic acid 262 of hnRNPA1 to either valine or asparagine has been linked to either amyotrophic lateral sclerosis or multisystem proteinopathy. Mutation of aspartic acid 378 of hnRNPDL to either asparagine or histidine has been associated with limb girdle muscular dystrophy. All three of these aspartic acid residues map to evolutionarily conserved regions of low-complexity (LC) sequence that may function in states of either intrinsic disorder or labile self-association. Here, we present a combination of solid-state NMR spectroscopy with segmental isotope labeling and electron microscopy on the LC domain of the hnRNPA2 protein. We show that, for both the wild-type protein and the aspartic acid 290-to-valine mutant, labile polymers are formed in which the LC domain associates into an in-register cross-β conformation. Aspartic acid 290 is shown to be charged at physiological pH and immobilized within the polymer core. Polymers of the aspartic acid 290-to-valine mutant are thermodynamically more stable than wild-type polymers. These observations give evidence that removal of destabilizing electrostatic interactions may be responsible for the increased propensity of the mutated LC domains to self-associate in disease-causing conformations.
Collapse
Affiliation(s)
- Dylan T Murray
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Disease, Bethesda, MD 20892
- Postdoctoral Research Associate Training Program, National Institute of General Medical Sciences, Bethesda, MD 20892
| | - Xiaoming Zhou
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Masato Kato
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Siheng Xiang
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Disease, Bethesda, MD 20892;
| | - Steven L McKnight
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390
| |
Collapse
|
15
|
Murray DT, Kato M, Lin Y, Thurber KR, Hung I, McKnight SL, Tycko R. Structure of FUS Protein Fibrils and Its Relevance to Self-Assembly and Phase Separation of Low-Complexity Domains. Cell 2017; 171:615-627.e16. [PMID: 28942918 PMCID: PMC5650524 DOI: 10.1016/j.cell.2017.08.048] [Citation(s) in RCA: 510] [Impact Index Per Article: 72.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 08/10/2017] [Accepted: 08/25/2017] [Indexed: 12/22/2022]
Abstract
Polymerization and phase separation of proteins containing low-complexity (LC) domains are important factors in gene expression, mRNA processing and trafficking, and localization of translation. We have used solid-state nuclear magnetic resonance methods to characterize the molecular structure of self-assembling fibrils formed by the LC domain of the fused in sarcoma (FUS) RNA-binding protein. From the 214-residue LC domain of FUS (FUS-LC), a segment of only 57 residues forms the fibril core, while other segments remain dynamically disordered. Unlike pathogenic amyloid fibrils, FUS-LC fibrils lack hydrophobic interactions within the core and are not polymorphic at the molecular structural level. Phosphorylation of core-forming residues by DNA-dependent protein kinase blocks binding of soluble FUS-LC to FUS-LC hydrogels and dissolves phase-separated, liquid-like FUS-LC droplets. These studies offer a structural basis for understanding LC domain self-assembly, phase separation, and regulation by post-translational modification.
Collapse
Affiliation(s)
- Dylan T Murray
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA; Postdoctoral Research Associate Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD 20892-6200, USA
| | - Masato Kato
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA
| | - Yi Lin
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA
| | - Kent R Thurber
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA
| | - Ivan Hung
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Steven L McKnight
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA.
| |
Collapse
|
16
|
Janke AM, Seo DH, Rahmanian V, Conicella AE, Mathews KL, Burke KA, Mittal J, Fawzi NL. Lysines in the RNA Polymerase II C-Terminal Domain Contribute to TAF15 Fibril Recruitment. Biochemistry 2017; 57:2549-2563. [PMID: 28945358 DOI: 10.1021/acs.biochem.7b00310] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many cancer-causing chromosomal translocations result in transactivating protein products encoding FET family (FUS, EWSR1, TAF15) low-complexity (LC) domains fused to a DNA binding domain from one of several transcription factors. Recent work demonstrates that higher-order assemblies of FET LC domains bind the carboxy-terminal domain of the large subunit of RNA polymerase II (RNA pol II CTD), suggesting FET oncoproteins may mediate aberrant transcriptional activation by recruiting RNA polymerase II to promoters of target genes. Here we use nuclear magnetic resonance (NMR) spectroscopy and hydrogel fluorescence microscopy localization and fluorescence recovery after photobleaching to visualize atomic details of a model of this process, interactions of RNA pol II CTD with high-molecular weight TAF15 LC assemblies. We report NMR resonance assignments of the intact degenerate repeat half of human RNA pol II CTD alone and verify its predominant intrinsic disorder by molecular simulation. By measuring NMR spin relaxation and dark-state exchange saturation transfer, we characterize the interaction of RNA pol II CTD with amyloid-like hydrogel fibrils of TAF15 and hnRNP A2 LC domains and observe that heptads far from the acidic C-terminal tail of RNA pol II CTD bind TAF15 fibrils most avidly. Mutation of CTD lysines in heptad position 7 to consensus serines reduced the overall level of TAF15 fibril binding, suggesting that electrostatic interactions contribute to complex formation. Conversely, mutations of position 7 asparagine residues and truncation of the acidic tail had little effect. Thus, weak, multivalent interactions between TAF15 fibrils and heptads throughout RNA pol II CTD collectively mediate complex formation.
Collapse
Affiliation(s)
- Abigail M Janke
- Department of Molecular Pharmacology, Physiology, and Biotechnology , Brown University , Providence , Rhode Island 02921 , United States
| | - Da Hee Seo
- Department of Molecular Pharmacology, Physiology, and Biotechnology , Brown University , Providence , Rhode Island 02921 , United States
| | - Vahid Rahmanian
- Department of Chemical and Biomolecular Engineering , Lehigh University , Bethlehem , Pennsylvania 18015 , United States
| | - Alexander E Conicella
- Graduate Program in Molecular Biology, Cell Biology and Biochemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Kaylee L Mathews
- Graduate Program in Molecular Biology, Cell Biology and Biochemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Kathleen A Burke
- Department of Molecular Pharmacology, Physiology, and Biotechnology , Brown University , Providence , Rhode Island 02921 , United States
| | - Jeetain Mittal
- Department of Chemical and Biomolecular Engineering , Lehigh University , Bethlehem , Pennsylvania 18015 , United States
| | - Nicolas L Fawzi
- Department of Molecular Pharmacology, Physiology, and Biotechnology , Brown University , Providence , Rhode Island 02921 , United States.,Graduate Program in Molecular Biology, Cell Biology and Biochemistry , Brown University , Providence , Rhode Island 02912 , United States
| |
Collapse
|
17
|
Lipshitz HD, Claycomb JM, Smibert CA. Post-transcriptional regulation of gene expression. Methods 2017; 126:1-2. [DOI: 10.1016/j.ymeth.2017.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
|