51
|
Prevalence and species distribution of the low-complexity, amyloid-like, reversible, kinked segment structural motif in amyloid-like fibrils. J Biol Chem 2021; 297:101194. [PMID: 34537246 PMCID: PMC8551513 DOI: 10.1016/j.jbc.2021.101194] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 09/03/2021] [Accepted: 09/10/2021] [Indexed: 12/23/2022] Open
Abstract
Membraneless organelles (MLOs) are vital and dynamic reaction centers in cells that compartmentalize the cytoplasm in the absence of a membrane. Multivalent interactions between protein low-complexity domains contribute to MLO organization. Previously, we used computational methods to identify structural motifs termed low-complexity amyloid-like reversible kinked segments (LARKS) that promote phase transition to form hydrogels and that are common in human proteins that participate in MLOs. Here, we searched for LARKS in the proteomes of six model organisms: Homo sapiens, Drosophila melanogaster, Plasmodium falciparum, Saccharomyces cerevisiae, Mycobacterium tuberculosis, and Escherichia coli to gain an understanding of the distribution of LARKS in the proteomes of various species. We found that LARKS are abundant in M. tuberculosis, D. melanogaster, and H. sapiens but not in S. cerevisiae or P. falciparum. LARKS have high glycine content, which enables kinks to form as exemplified by the known LARKS-rich amyloidogenic structures of TDP43, FUS, and hnRNPA2, three proteins that are known to participate in MLOs. These results support the idea of LARKS as an evolved structural motif. Based on these results, we also established the LARKSdb Web server, which permits users to search for LARKS in their protein sequences of interest.
Collapse
|
52
|
Kim G, Lee SE, Jeong S, Lee J, Park D, Chang S. Multivalent electrostatic pi-cation interaction between synaptophysin and synapsin is responsible for the coacervation. Mol Brain 2021; 14:137. [PMID: 34496937 PMCID: PMC8424992 DOI: 10.1186/s13041-021-00846-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/24/2021] [Indexed: 12/26/2022] Open
Abstract
We recently showed that synaptophysin (Syph) and synapsin (Syn) can induce liquid-liquid phase separation (LLPS) to cluster small synaptic-like microvesicles in living cells which are highly reminiscent of SV cluster. However, as there is no physical interaction between them, the underlying mechanism for their coacervation remains unknown. Here, we showed that the coacervation between Syph and Syn is primarily governed by multivalent pi-cation electrostatic interactions among tyrosine residues of Syph C-terminal (Ct) and positively charged Syn. We found that Syph Ct is intrinsically disordered and it alone can form liquid droplets by interactions among themselves at high concentration in a crowding environment in vitro or when assisted by additional interactions by tagging with light-sensitive CRY2PHR or subunits of a multimeric protein in living cells. Syph Ct contains 10 repeated sequences, 9 of them start with tyrosine, and mutating 9 tyrosine to serine (9YS) completely abolished the phase separating property of Syph Ct, indicating tyrosine-mediated pi-interactions are critical. We further found that 9YS mutation failed to coacervate with Syn, and since 9YS retains Syph's negative charge, the results indicate that pi-cation interactions rather than simple charge interactions are responsible for their coacervation. In addition to revealing the underlying mechanism of Syph and Syn coacervation, our results also raise the possibility that physiological regulation of pi-cation interactions between Syph and Syn during synaptic activity may contribute to the dynamics of synaptic vesicle clustering.
Collapse
Affiliation(s)
- Goeun Kim
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Sang-Eun Lee
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
- UK Dementia Research Institute, University College London, Cruciform Building, Gower St, London, WC1E 6BT, UK
| | - Seonyoung Jeong
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Jeongkun Lee
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Daehun Park
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Sunghoe Chang
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea.
| |
Collapse
|
53
|
Salladini E, Gondelaud F, Nilsson JF, Pesce G, Bignon C, Murrali MG, Fabre R, Pierattelli R, Kajava AV, Horvat B, Gerlier D, Mathieu C, Longhi S. Identification of a Region in the Common Amino-terminal Domain of Hendra Virus P, V, and W Proteins Responsible for Phase Transition and Amyloid Formation. Biomolecules 2021; 11:1324. [PMID: 34572537 PMCID: PMC8471210 DOI: 10.3390/biom11091324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 12/14/2022] Open
Abstract
Henipaviruses are BSL-4 zoonotic pathogens responsible in humans for severe encephalitis. Their V protein is a key player in the evasion of the host innate immune response. We previously showed that the Henipavirus V proteins consist of a long intrinsically disordered N-terminal domain (NTD) and a β-enriched C-terminal domain (CTD). These terminals are critical for V binding to DDB1, which is a cellular protein that is a component of the ubiquitin ligase E3 complex, as well as binding to MDA5 and LGP2, which are two host sensors of viral RNA. Here, we serendipitously discovered that the Hendra virus V protein undergoes a liquid-to-hydrogel phase transition and identified the V region responsible for this phenomenon. This region, referred to as PNT3 and encompassing residues 200-310, was further investigated using a combination of biophysical and structural approaches. Congo red binding assays, together with negative-staining transmisison electron microscopy (TEM) studies, show that PNT3 forms amyloid-like fibrils. Fibrillation abilities are dramatically reduced in a rationally designed PNT3 variant in which a stretch of three contiguous tyrosines, falling within an amyloidogenic motif, were replaced by three alanines. Worthy to note, Congo red staining experiments provided hints that these amyloid-like fibrils form not only in vitro but also in cellula after transfection or infection. The present results set the stage for further investigations aimed at assessing the functional role of phase separation and fibrillation by the Henipavirus V proteins.
Collapse
Affiliation(s)
- Edoardo Salladini
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Frank Gondelaud
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Juliet F. Nilsson
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Giulia Pesce
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Christophe Bignon
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Maria Grazia Murrali
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino, Italy; (M.G.M.); (R.P.)
| | - Roxane Fabre
- Centre d’Immunologie de Marseille-Luminy (CIML), CNRS, Institut National de la Santé et de la Recherche Médicale (INSERM), Aix Marseille University, CEDEX 9, 13288 Marseille, France;
| | - Roberta Pierattelli
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino, Italy; (M.G.M.); (R.P.)
| | - Andrey V. Kajava
- Centre de Recherche en Biologie Cellulaire de Montpellier, UMR 5237, CNRS, Université Montpellier, 34293 Montpellier, France;
| | - Branka Horvat
- Team Immunobiology of the Viral Infections, Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM, U1111, CNRS, UMR 5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France; (B.H.); (D.G.); (C.M.)
| | - Denis Gerlier
- Team Immunobiology of the Viral Infections, Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM, U1111, CNRS, UMR 5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France; (B.H.); (D.G.); (C.M.)
| | - Cyrille Mathieu
- Team Immunobiology of the Viral Infections, Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM, U1111, CNRS, UMR 5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France; (B.H.); (D.G.); (C.M.)
| | - Sonia Longhi
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| |
Collapse
|
54
|
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
|
55
|
Vendruscolo M, Fuxreiter M. Sequence Determinants of the Aggregation of Proteins Within Condensates Generated by Liquid-liquid Phase Separation. J Mol Biol 2021; 434:167201. [PMID: 34391803 DOI: 10.1016/j.jmb.2021.167201] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/08/2021] [Accepted: 08/09/2021] [Indexed: 12/12/2022]
Abstract
The transition between the native and amyloid states of proteins can proceed via a deposition pathway via oligomeric intermediates or via a condensation pathway involving liquid droplet intermediates generated through liquid-liquid phase separation. While several computational methods are available to perform sequence-based predictions of the propensity of proteins to aggregate via the deposition pathway, much less is known about the physico-chemical principles that underlie aggregation within condensates. Here we investigate the sequence determinants of aggregation via the condensation pathway, and identify three relevant features: droplet-promoting propensity, aggregation-promoting propensity and multimodal interactions quantified by the binding mode entropy. By using this approach, we show that it is possible to predict aggregation-promoting mutations in droplet-forming proteins associated with amyotrophic lateral sclerosis (ALS). This analysis provides insights into the amino acid code for the conversion of proteins between liquid-like and solid-like condensates.
Collapse
Affiliation(s)
- Michele Vendruscolo
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, UK.
| | - Monika Fuxreiter
- Department of Biomedical Sciences, University of Padova, Italy; Department of Biochemistry and Molecular Biology, University of Debrecen, Hungary.
| |
Collapse
|
56
|
Saulnier O, Guedri-Idjouadiene K, Aynaud MM, Chakraborty A, Bruyr J, Pineau J, O'Grady T, Mirabeau O, Grossetête S, Galvan B, Claes M, Al Oula Hassoun Z, Sadacca B, Laud K, Zaïdi S, Surdez D, Baulande S, Rambout X, Tirode F, Dutertre M, Delattre O, Dequiedt F. ERG transcription factors have a splicing regulatory function involving RBFOX2 that is altered in the EWS-FLI1 oncogenic fusion. Nucleic Acids Res 2021; 49:5038-5056. [PMID: 34009296 PMCID: PMC8136815 DOI: 10.1093/nar/gkab305] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 01/30/2023] Open
Abstract
ERG family proteins (ERG, FLI1 and FEV) are a subfamily of ETS transcription factors with key roles in physiology and development. In Ewing sarcoma, the oncogenic fusion protein EWS-FLI1 regulates both transcription and alternative splicing of pre-messenger RNAs. However, whether wild-type ERG family proteins might regulate splicing is unknown. Here, we show that wild-type ERG proteins associate with spliceosomal components, are found on nascent RNAs, and induce alternative splicing when recruited onto a reporter minigene. Transcriptomic analysis revealed that ERG and FLI1 regulate large numbers of alternative spliced exons (ASEs) enriched with RBFOX2 motifs and co-regulated by this splicing factor. ERG and FLI1 are associated with RBFOX2 via their conserved carboxy-terminal domain, which is present in EWS-FLI1. Accordingly, EWS-FLI1 is also associated with RBFOX2 and regulates ASEs enriched in RBFOX2 motifs. However, in contrast to wild-type ERG and FLI1, EWS-FLI1 often antagonizes RBFOX2 effects on exon inclusion. In particular, EWS-FLI1 reduces RBFOX2 binding to the ADD3 pre-mRNA, thus increasing its long isoform, which represses the mesenchymal phenotype of Ewing sarcoma cells. Our findings reveal a RBFOX2-mediated splicing regulatory function of wild-type ERG family proteins, that is altered in EWS-FLI1 and contributes to the Ewing sarcoma cell phenotype.
Collapse
Affiliation(s)
- Olivier Saulnier
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Katia Guedri-Idjouadiene
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Marie-Ming Aynaud
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Alina Chakraborty
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, F-91405 Orsay, France.,Université Paris-Saclay, CNRS UMR3348, INSERM U1278, F-91405 Orsay, France.,Équipe Labellisée Ligue Nationale Contre le Cancer, F-91405 Orsay, France
| | - Jonathan Bruyr
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Joséphine Pineau
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Tina O'Grady
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Olivier Mirabeau
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Sandrine Grossetête
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Bartimée Galvan
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Margaux Claes
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Zahra Al Oula Hassoun
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Benjamin Sadacca
- INSERM U932, RT2Lab Team, Translational Research Department, PSL Research University, Institut Curie, F-75005 Paris, France.,CNRS UMR5219, Institut de Mathématiques de Toulouse; Université de Toulouse; F-31062 Toulouse, France
| | - Karine Laud
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Sakina Zaïdi
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Didier Surdez
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Sylvain Baulande
- Institut Curie, PSL Research University, NGS Platform, 26 rue d'Ulm, F-75005 Paris, France
| | - Xavier Rambout
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Franck Tirode
- Claude Bernard University Lyon 1, INSERM 1052, CNRS 5286, Cancer Research Center of Lyon (CRCL), Lyon University, Lyon, France
| | - Martin Dutertre
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, F-91405 Orsay, France.,Université Paris-Saclay, CNRS UMR3348, INSERM U1278, F-91405 Orsay, France.,Équipe Labellisée Ligue Nationale Contre le Cancer, F-91405 Orsay, France
| | - Olivier Delattre
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Franck Dequiedt
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| |
Collapse
|
57
|
Cai D, Liu Z, Lippincott-Schwartz J. Biomolecular Condensates and Their Links to Cancer Progression. Trends Biochem Sci 2021; 46:535-549. [PMID: 33579564 DOI: 10.1016/j.tibs.2021.01.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/04/2021] [Accepted: 01/08/2021] [Indexed: 01/14/2023]
Abstract
Liquid-liquid phase separation (LLPS) has emerged in recent years as an important physicochemical process for organizing diverse processes within cells via the formation of membraneless organelles termed biomolecular condensates. Emerging evidence now suggests that the formation and regulation of biomolecular condensates are also intricately linked to cancer formation and progression. We review the most recent literature linking the existence and/or dissolution of biomolecular condensates to different hallmarks of cancer formation and progression. We then discuss the opportunities that this condensate perspective provides for cancer research and the development of novel therapeutic approaches, including the perturbation of condensates by small-molecule inhibitors.
Collapse
Affiliation(s)
- Danfeng Cai
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Zhe Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | | |
Collapse
|
58
|
Phosphorylation of mRNA-Binding Proteins Puf1 and Puf2 by TORC2-Activated Protein Kinase Ypk1 Alleviates Their Repressive Effects. MEMBRANES 2021; 11:membranes11070500. [PMID: 34209236 PMCID: PMC8304900 DOI: 10.3390/membranes11070500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/24/2021] [Accepted: 06/29/2021] [Indexed: 01/13/2023]
Abstract
Members of the Puf family of RNA-binding proteins typically associate via their Pumilio homology domain with specific short motifs in the 3’-UTR of an mRNA and thereby influence the stability, localization and/or efficiency of translation of the bound transcript. In our prior unbiased proteome-wide screen for targets of the TORC2-stimulated protein kinase Ypk1, we identified the paralogs Puf1/Jsn1 and Puf2 as high-confidence substrates. Earlier work by others had demonstrated that Puf1 and Puf2 exhibit a marked preference for interaction with mRNAs encoding plasma membrane-associated proteins, consistent with our previous studies documenting that a primary physiological role of TORC2-Ypk1 signaling is maintenance of plasma membrane homeostasis. Here, we show, first, that both Puf1 and Puf2 are authentic Ypk1 substrates both in vitro and in vivo. Fluorescently tagged Puf1 localizes constitutively in cortical puncta closely apposed to the plasma membrane, whereas Puf2 does so in the absence of its Ypk1 phosphorylation, but is dispersed in the cytosol when phosphorylated. We further demonstrate that Ypk1-mediated phosphorylation of Puf1 and Puf2 upregulates production of the protein products of the transcripts to which they bind, with a concomitant increase in the level of the cognate mRNAs. Thus, Ypk1 phosphorylation relieves Puf1- and Puf2-mediated post-transcriptional repression mainly by counteracting their negative effect on transcript stability. Using a heterologous protein-RNA tethering and fluorescent protein reporter assay, the consequence of Ypk1 phosphorylation in vivo was recapitulated for full-length Puf1 and even for N-terminal fragments (residues 1-340 and 143-295) corresponding to the region upstream of its dimerization domain (an RNA-recognition motif fold) encompassing its two Ypk1 phosphorylation sites (both also conserved in Puf2). This latter result suggests that alleviation of Puf1-imposed transcript destabilization does not obligatorily require dissociation of Ypk1-phosphorylated Puf1 from a transcript. Our findings add new insight about how the TORC2-Ypk1 signaling axis regulates the content of plasma membrane-associated proteins to promote maintenance of the integrity of the cell envelope.
Collapse
|
59
|
Ahmed NS, Harrell LM, Wieland DR, Lay MA, Thompson VF, Schwartz JC. Fusion protein EWS-FLI1 is incorporated into a protein granule in cells. RNA (NEW YORK, N.Y.) 2021; 27:rna.078827.121. [PMID: 34035145 PMCID: PMC8284321 DOI: 10.1261/rna.078827.121] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 05/18/2021] [Indexed: 05/15/2023]
Abstract
Ewing sarcoma is driven by fusion proteins containing a low complexity (LC) domain that is intrinsically disordered and a powerful transcriptional regulator. The most common fusion protein found in Ewing sarcoma, EWS-FLI1, takes its LC domain from the RNA-binding protein EWSR1 (Ewing Sarcoma RNA-binding protein 1) and a DNA-binding domain from the transcription factor FLI1 (Friend Leukemia Virus Integration 1). EWS-FLI1 can bind RNA polymerase II (RNA Pol II) and self-assemble through its low-complexity (LC) domain. The ability of RNA-binding proteins like EWSR1 to self-assemble or phase separate in cells has raised questions about the contribution of this process to EWS-FLI1 activity. We examined EWSR1 and EWS-FLI1 activity in Ewing sarcoma cells by siRNA-mediated knockdown and RNA-seq analysis. More transcripts were affected by the EWSR1 knockdown than expected and these included many EWS-FLI1 regulated genes. We reevaluated physical interactions between EWS-FLI1, EWSR1, and RNA Pol II, and employed a cross-linking based strategy to investigate protein assemblies associated with the proteins. The LC domain of EWS-FLI1 was required for the assemblies observed to form in cells. These results offer new insights into a protein assembly that may enable EWS-FLI1 to bind its wide network of protein partners and contribute to regulation of gene expression in Ewing sarcoma.
Collapse
Affiliation(s)
- Nasiha S Ahmed
- Department of Molecular and Cellular Biology, The University of Arizona, Tucson, AZ 85719
| | - Lucas M Harrell
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ 85719
| | - Daniel R Wieland
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ 85719
| | - Michelle A Lay
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ 85719
| | - Valery F Thompson
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ 85719
| | - Jacob C Schwartz
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ 85719
| |
Collapse
|
60
|
Levone BR, Lenzken SC, Antonaci M, Maiser A, Rapp A, Conte F, Reber S, Mechtersheimer J, Ronchi AE, Mühlemann O, Leonhardt H, Cardoso MC, Ruepp MD, Barabino SM. FUS-dependent liquid-liquid phase separation is important for DNA repair initiation. J Cell Biol 2021; 220:e202008030. [PMID: 33704371 PMCID: PMC7953258 DOI: 10.1083/jcb.202008030] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 01/17/2021] [Accepted: 02/04/2021] [Indexed: 12/17/2022] Open
Abstract
RNA-binding proteins (RBPs) are emerging as important effectors of the cellular DNA damage response (DDR). The RBP FUS is implicated in RNA metabolism and DNA repair, and it undergoes reversible liquid-liquid phase separation (LLPS) in vitro. Here, we demonstrate that FUS-dependent LLPS is necessary for the initiation of the DDR. Using laser microirradiation in FUS-knockout cells, we show that FUS is required for the recruitment to DNA damage sites of the DDR factors KU80, NBS1, and 53BP1 and of SFPQ, another RBP implicated in the DDR. The relocation of KU80, NBS1, and SFPQ is similarly impaired by LLPS inhibitors, or LLPS-deficient FUS variants. We also show that LLPS is necessary for efficient γH2AX foci formation. Finally, using superresolution structured illumination microscopy, we demonstrate that the absence of FUS impairs the proper arrangement of γH2AX nanofoci into higher-order clusters. These findings demonstrate the early requirement for FUS-dependent LLPS in the activation of the DDR and the proper assembly of DSB repair complexes.
Collapse
Affiliation(s)
- Brunno R. Levone
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Silvia C. Lenzken
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Marco Antonaci
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Andreas Maiser
- Department of Biology II, Center for Integrated Protein Science Munich, Ludwig Maximilian University of Munich, Planegg-Martinsried, Germany
| | - Alexander Rapp
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Francesca Conte
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Stefan Reber
- UK Dementia Research Institute, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Jonas Mechtersheimer
- UK Dementia Research Institute, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Antonella E. Ronchi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Oliver Mühlemann
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Heinrich Leonhardt
- Department of Biology II, Center for Integrated Protein Science Munich, Ludwig Maximilian University of Munich, Planegg-Martinsried, Germany
| | - M. Cristina Cardoso
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Marc-David Ruepp
- UK Dementia Research Institute, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Silvia M.L. Barabino
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| |
Collapse
|
61
|
The F-Actin-Binding MPRIP Forms Phase-Separated Condensates and Associates with PI(4,5)P2 and Active RNA Polymerase II in the Cell Nucleus. Cells 2021; 10:cells10040848. [PMID: 33918018 PMCID: PMC8068864 DOI: 10.3390/cells10040848] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/25/2021] [Accepted: 04/06/2021] [Indexed: 12/14/2022] Open
Abstract
Here, we provide evidence for the presence of Myosin phosphatase rho-interacting protein (MPRIP), an F-actin-binding protein, in the cell nucleus. The MPRIP protein binds to Phosphatidylinositol 4,5-bisphosphate (PIP2) and localizes to the nuclear speckles and nuclear lipid islets which are known to be involved in transcription. We identified MPRIP as a component of RNA Polymerase II/Nuclear Myosin 1 complex and showed that MPRIP forms phase-separated condensates which are able to bind nuclear F-actin fibers. Notably, the fibrous MPRIP preserves its liquid-like properties and reforms the spherical shaped condensates when F-actin is disassembled. Moreover, we show that the phase separation of MPRIP is driven by its long intrinsically disordered region at the C-terminus. We propose that the PIP2/MPRIP association might contribute to the regulation of RNAPII transcription via phase separation and nuclear actin polymerization.
Collapse
|
62
|
Singh A, Hulsmeier J, Kandi AR, Pothapragada SS, Hillebrand J, Petrauskas A, Agrawal K, RT K, Thiagarajan D, Jayaprakashappa D, VijayRaghavan K, Ramaswami M, Bakthavachalu B. Antagonistic roles for Ataxin-2 structured and disordered domains in RNP condensation. eLife 2021; 10:e60326. [PMID: 33689682 PMCID: PMC7946432 DOI: 10.7554/elife.60326] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/23/2021] [Indexed: 02/07/2023] Open
Abstract
Ataxin-2 (Atx2) is a translational control molecule mutated in spinocerebellar ataxia type II and amyotrophic lateral sclerosis. While intrinsically disordered domains (IDRs) of Atx2 facilitate mRNP condensation into granules, how IDRs work with structured domains to enable positive and negative regulation of target mRNAs remains unclear. Using the Targets of RNA-Binding Proteins Identified by Editing technology, we identified an extensive data set of Atx2-target mRNAs in the Drosophila brain and S2 cells. Atx2 interactions with AU-rich elements in 3'UTRs appear to modulate stability/turnover of a large fraction of these target mRNAs. Further genomic and cell biological analyses of Atx2 domain deletions demonstrate that Atx2 (1) interacts closely with target mRNAs within mRNP granules, (2) contains distinct protein domains that drive or oppose RNP-granule assembly, and (3) has additional essential roles outside of mRNP granules. These findings increase the understanding of neuronal translational control mechanisms and inform strategies for Atx2-based interventions under development for neurodegenerative disease.
Collapse
Affiliation(s)
- Amanjot Singh
- National Centre for Biological SciencesBangaloreIndia
| | - Joern Hulsmeier
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College DublinDublinIreland
| | - Arvind Reddy Kandi
- National Centre for Biological SciencesBangaloreIndia
- Tata Institute for Genetics and Society Centre at inStem, Bellary RoadBangaloreIndia
| | | | - Jens Hillebrand
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College DublinDublinIreland
| | - Arnas Petrauskas
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College DublinDublinIreland
| | - Khushboo Agrawal
- Tata Institute for Genetics and Society Centre at inStem, Bellary RoadBangaloreIndia
- School of Biotechnology, Amrita Vishwa Vidyapeetham UniversityKollamIndia
| | - Krishnan RT
- National Centre for Biological SciencesBangaloreIndia
| | | | | | | | - Mani Ramaswami
- National Centre for Biological SciencesBangaloreIndia
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College DublinDublinIreland
| | - Baskar Bakthavachalu
- National Centre for Biological SciencesBangaloreIndia
- Tata Institute for Genetics and Society Centre at inStem, Bellary RoadBangaloreIndia
- School of Basic Sciences, Indian Institute of TechnologyMandiIndia
| |
Collapse
|
63
|
Abstract
Recent advancements in detection methods have made protein condensates, also called granules, a major area of study, but tools to characterize these assemblies need continued development to keep up with evolving paradigms. We have optimized a protocol to separate condensates from cells using chemical cross-linking followed by size-exclusion chromatography (SEC). After SEC fractionation, the samples can be characterized by a variety of approaches including enzyme-linked immunosorbent assay, dynamic light scattering, electron microscopy, and mass spectrometry. The protocol described here has been optimized for cultured mammalian cells and E. coli expressing recombinant proteins. Since the lysates are fractionated by size, this protocol can be modified to study other large protein assemblies, including the nuclear pore complex, and for other tissues or organisms. © 2021 Wiley Periodicals LLC. Basic Protocol 1: SEC separation of cross-linked mammalian cell lysates Alternate Protocol: Preparation of non-crosslinked mammalian cells Basic Protocol 2: SEC separation of E. coli lysate Support Protocol 1: Detecting protein of interest by ELISA Support Protocol 2: TCA precipitation of SEC fractions.
Collapse
Affiliation(s)
- Rachel A. Victor
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85745, USA
| | - Valery F. Thompson
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85745, USA
| | - Jacob C. Schwartz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85745, USA
| |
Collapse
|
64
|
Phase transition of fibrillarin LC domain regulates localization and protein interaction of fibrillarin. Biochem J 2021; 478:799-810. [PMID: 33522570 DOI: 10.1042/bcj20200847] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/25/2021] [Accepted: 02/01/2021] [Indexed: 12/11/2022]
Abstract
A key nucleolar protein, fibrillarin, has emerged as an important pharmacological target as its aberrant expression and localization are related to tumorigenesis, chemoresistance and poor survival in breast cancer patients. Fibrillarin contains a N-terminal low complexity sequence (LC) domain with a skewed amino acid distribution, which is known to undergo a phase transition to liquid-like droplets. However, the underlying mechanism of the phase transition of the fibrillarin LC domain and its physiological function are still elusive. In this study, we show that the localization of fibrillarin and its association with RNA binding proteins is regulated by this phase transition. Phenylalanine-to-serine substitutions of the phenylalanine:glycine repeats in the fibrillarin LC domain impede its phase transition into liquid-like droplets, as well as the hydrogel-like state composed of polymers, and also its incorporation into hydrogel or liquid-like droplets composed of wild-type LC domains. When expressed in cultured cells, fibrillarin containing the mutant LC domain fails to localize to the dense fibrillar component of nucleoli in the same way as intact fibrillarin. Moreover, the phase transition of the fibrillarin LC domain is required for the interaction of fibrillarin with other RNA binding proteins, such as FUS, TAF15, DDX5 and DHX9. Taken together, the results suggest that the phenylalanine residues in the LC domain are critical for the phase transition of fibrillarin, which in turn regulates the sub-nucleolar localization of fibrillarin and its interaction with RNA binding proteins, providing a useful framework for regulating the function of fibrillarin.
Collapse
|
65
|
Alberti S, Hyman AA. Biomolecular condensates at the nexus of cellular stress, protein aggregation disease and ageing. Nat Rev Mol Cell Biol 2021; 22:196-213. [PMID: 33510441 DOI: 10.1038/s41580-020-00326-6] [Citation(s) in RCA: 485] [Impact Index Per Article: 161.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2020] [Indexed: 12/14/2022]
Abstract
Biomolecular condensates are membraneless intracellular assemblies that often form via liquid-liquid phase separation and have the ability to concentrate biopolymers. Research over the past 10 years has revealed that condensates play fundamental roles in cellular organization and physiology, and our understanding of the molecular principles, components and forces underlying their formation has substantially increased. Condensate assembly is tightly regulated in the intracellular environment, and failure to control condensate properties, formation and dissolution can lead to protein misfolding and aggregation, which are often the cause of ageing-associated diseases. In this Review, we describe the mechanisms and regulation of condensate assembly and dissolution, highlight recent advances in understanding the role of biomolecular condensates in ageing and disease, and discuss how cellular stress, ageing-related loss of homeostasis and a decline in protein quality control may contribute to the formation of aberrant, disease-causing condensates. Our improved understanding of condensate pathology provides a promising path for the treatment of protein aggregation diseases.
Collapse
Affiliation(s)
- Simon Alberti
- Technische Universität Dresden, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Engineering (CMCB), Dresden, Germany.
| | - Anthony A Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
| |
Collapse
|
66
|
Vladimirova O, De Leo A, Deng Z, Wiedmer A, Hayden J, Lieberman PM. Phase separation and DAXX redistribution contribute to LANA nuclear body and KSHV genome dynamics during latency and reactivation. PLoS Pathog 2021; 17:e1009231. [PMID: 33471863 PMCID: PMC7943007 DOI: 10.1371/journal.ppat.1009231] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 03/09/2021] [Accepted: 12/08/2020] [Indexed: 12/14/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) can drive formation of diverse and essential macromolecular structures, including those specified by viruses. Kaposi’s Sarcoma-Associated Herpesvirus (KSHV) genomes associate with the viral encoded Latency-Associated Nuclear Antigen (LANA) to form stable nuclear bodies (NBs) during latent infection. Here, we show that LANA-NB formation and KSHV genome conformation involves LLPS. Using LLPS disrupting solvents, we show that LANA-NBs are partially disrupted, while DAXX and PML foci are highly resistant. LLPS disruption altered the LANA-dependent KSHV chromosome conformation but did not stimulate lytic reactivation. We found that LANA-NBs undergo major morphological transformation during KSHV lytic reactivation to form LANA-associated replication compartments encompassing KSHV DNA. DAXX colocalizes with the LANA-NBs during latency but is evicted from the LANA-associated lytic replication compartments. These findings indicate the LANA-NBs are dynamic super-molecular nuclear structures that partly depend on LLPS and undergo morphological transitions corresponding to the different modes of viral replication. During latent infection, gamma-herpesvirus genomes are maintained as extrachromosomal circular DNA, referred to as episomes, by dedicated viral-encoded episome maintenance proteins. KSHV-encoded LANA maintains viral episomes through binding as an oligomeric protein to repetitive DNA elements in the viral terminal repeats (TRs). Viral episomes can be visualized as LANA-associated nuclear bodies (LANA-NBs). Here, we show that LANA-NBs utilize mechanisms of self-assembly through liquid-liquid phase separation (LLPS) to build dynamic structures that change during cell cycle and viral life cycle. We find that DAXX is a component of the latent phase LANA-NBs, but is evicted during the transition to lytic replication where LANA remains associated with KSHV DNA to form a ring-like replication compartment.
Collapse
Affiliation(s)
| | - Alessandra De Leo
- Department of Immunology, H. Lee Moffit Cancer and Research Center, Tampa Florida, United States of America
| | - Zhong Deng
- The Wistar Institute, Philadelphia, United States of America
| | - Andreas Wiedmer
- The Wistar Institute, Philadelphia, United States of America
| | - James Hayden
- The Wistar Institute, Philadelphia, United States of America
| | - Paul M. Lieberman
- The Wistar Institute, Philadelphia, United States of America
- * E-mail:
| |
Collapse
|
67
|
Park D, Wu Y, Lee SE, Kim G, Jeong S, Milovanovic D, De Camilli P, Chang S. Cooperative function of synaptophysin and synapsin in the generation of synaptic vesicle-like clusters in non-neuronal cells. Nat Commun 2021; 12:263. [PMID: 33431828 PMCID: PMC7801664 DOI: 10.1038/s41467-020-20462-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 12/02/2020] [Indexed: 02/01/2023] Open
Abstract
Clusters of tightly packed synaptic vesicles (SVs) are a defining feature of nerve terminals. While SVs are mobile within the clusters, the clusters have no boundaries consistent with a liquid phase. We previously found that purified synapsin, a peripheral SV protein, can assemble into liquid condensates and trap liposomes into them. How this finding relates to the physiological formation of SV clusters in living cells remains unclear. Here, we report that synapsin alone, when expressed in fibroblasts, has a diffuse cytosolic distribution. However, when expressed together with synaptophysin, an integral SV membrane protein previously shown to be localized on small synaptic-like microvesicles when expressed in non-neuronal cells, is sufficient to organize such vesicles in clusters highly reminiscent of SV clusters and with liquid-like properties. This minimal reconstitution system can be a powerful model to gain mechanistic insight into the assembly of structures which are of fundamental importance in synaptic transmission. Synaptic vesicle clusters were proposed to represent phase separated condensates. Here, the authors show that only two proteins, synapsin and synaptophysin, are sufficient to make vesicle clusters in fibroblasts which are similar to those found at synapses in morphology and liquid-like properties.
Collapse
Affiliation(s)
- Daehun Park
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute, Program in Cellular Neuroscience, Neurodegeneration and Repair, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Yumei Wu
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute, Program in Cellular Neuroscience, Neurodegeneration and Repair, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Sang-Eun Lee
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Goeun Kim
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Seonyoung Jeong
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Dragomir Milovanovic
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute, Program in Cellular Neuroscience, Neurodegeneration and Repair, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT, 06510, USA.,Laboratory of Molecular Neuroscience, German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117, Berlin, Germany
| | - Pietro De Camilli
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute, Program in Cellular Neuroscience, Neurodegeneration and Repair, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT, 06510, USA.
| | - Sunghoe Chang
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea.
| |
Collapse
|
68
|
Chong S, Mir M. Towards Decoding the Sequence-Based Grammar Governing the Functions of Intrinsically Disordered Protein Regions. J Mol Biol 2020; 433:166724. [PMID: 33248138 DOI: 10.1016/j.jmb.2020.11.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 11/14/2020] [Accepted: 11/19/2020] [Indexed: 01/03/2023]
Abstract
A substantial portion of the proteome consists of intrinsically disordered regions (IDRs) that do not fold into well-defined 3D structures yet perform numerous biological functions and are associated with a broad range of diseases. It has been a long-standing enigma how different IDRs successfully execute their specific functions. Further putting a spotlight on IDRs are recent discoveries of functionally relevant biomolecular assemblies, which in some cases form through liquid-liquid phase separation. At the molecular level, the formation of biomolecular assemblies is largely driven by weak, multivalent, but selective IDR-IDR interactions. Emerging experimental and computational studies suggest that the primary amino acid sequences of IDRs encode a variety of their interaction behaviors. In this review, we focus on findings and insights that connect sequence-derived features of IDRs to their conformations, propensities to form biomolecular assemblies, selectivity of interaction partners, functions in the context of physiology and disease, and regulation of function. We also discuss directions of future research to facilitate establishing a comprehensive sequence-function paradigm that will eventually allow prediction of selective interactions and specificity of function mediated by IDRs.
Collapse
Affiliation(s)
- Shasha Chong
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, United States; The Howard Hughes Medical Institute, University of California Berkeley, Berkeley, CA 94720, United States.
| | - Mustafa Mir
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, United States
| |
Collapse
|
69
|
Guillén-Boixet J, Kopach A, Holehouse AS, Wittmann S, Jahnel M, Schlüßler R, Kim K, Trussina IREA, Wang J, Mateju D, Poser I, Maharana S, Ruer-Gruß M, Richter D, Zhang X, Chang YT, Guck J, Honigmann A, Mahamid J, Hyman AA, Pappu RV, Alberti S, Franzmann TM. RNA-Induced Conformational Switching and Clustering of G3BP Drive Stress Granule Assembly by Condensation. Cell 2020; 181:346-361.e17. [PMID: 32302572 PMCID: PMC7181197 DOI: 10.1016/j.cell.2020.03.049] [Citation(s) in RCA: 472] [Impact Index Per Article: 118.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 10/23/2019] [Accepted: 03/20/2020] [Indexed: 12/14/2022]
Abstract
Stressed cells shut down translation, release mRNA molecules from polysomes, and form stress granules (SGs) via a network of interactions that involve G3BP. Here we focus on the mechanistic underpinnings of SG assembly. We show that, under non-stress conditions, G3BP adopts a compact auto-inhibited state stabilized by electrostatic intramolecular interactions between the intrinsically disordered acidic tracts and the positively charged arginine-rich region. Upon release from polysomes, unfolded mRNAs outcompete G3BP auto-inhibitory interactions, engendering a conformational transition that facilitates clustering of G3BP through protein-RNA interactions. Subsequent physical crosslinking of G3BP clusters drives RNA molecules into networked RNA/protein condensates. We show that G3BP condensates impede RNA entanglement and recruit additional client proteins that promote SG maturation or induce a liquid-to-solid transition that may underlie disease. We propose that condensation coupled to conformational rearrangements and heterotypic multivalent interactions may be a general principle underlying RNP granule assembly. Under non-stressed conditions, G3BP adopts a compact auto-inhibited state Conformational expansion of G3BP increases the interaction valences G3BP clusters crosslink RNA to assemble stress granules upon cellular stress G3BP condensates prevent RNA entanglement
Collapse
Affiliation(s)
- Jordina Guillén-Boixet
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Andrii Kopach
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Alex S Holehouse
- Department of Biomedical Engineering and Center for Science and Engineering of Living Systems, Washington University in St. Louis, St. Louis, MO 63130, USA; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Sina Wittmann
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Marcus Jahnel
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany; Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Raimund Schlüßler
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Kyoohyun Kim
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Irmela R E A Trussina
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Jie Wang
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Daniel Mateju
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Shovamayee Maharana
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Martine Ruer-Gruß
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Doris Richter
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Xiaojie Zhang
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Young-Tae Chang
- Center for Self-Assembly and Complexity, Institute for Basic Science, Pohang 37673, Republic of Korea; Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Jochen Guck
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Alf Honigmann
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Anthony A Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Rohit V Pappu
- Department of Biomedical Engineering and Center for Science and Engineering of Living Systems, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Simon Alberti
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany; Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany.
| | - Titus M Franzmann
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| |
Collapse
|
70
|
Dysregulated ribonucleoprotein granules promote cardiomyopathy in RBM20 gene-edited pigs. Nat Med 2020; 26:1788-1800. [PMID: 33188278 PMCID: PMC9270981 DOI: 10.1038/s41591-020-1087-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/21/2020] [Indexed: 12/12/2022]
Abstract
Ribonucleoprotein (RNP) granules are biomolecular condensates-liquid-liquid phase-separated droplets that organize and manage messenger RNA metabolism, cell signaling, biopolymer assembly, biochemical reactions and stress granule responses to cellular adversity. Dysregulated RNP granules drive neuromuscular degenerative disease but have not previously been linked to heart failure. By exploring the molecular basis of congenital dilated cardiomyopathy (DCM) in genome-edited pigs homozygous for an RBM20 allele encoding the pathogenic R636S variant of human RNA-binding motif protein-20 (RBM20), we discovered that RNP granules accumulated abnormally in the sarcoplasm, and we confirmed this finding in myocardium and reprogrammed cardiomyocytes from patients with DCM carrying the R636S allele. Dysregulated sarcoplasmic RBM20 RNP granules displayed liquid-like material properties, docked at precisely spaced intervals along cytoskeletal elements, promoted phase partitioning of cardiac biomolecules and fused with stress granules. Our results link dysregulated RNP granules to myocardial cellular pathobiology and heart failure in gene-edited pigs and patients with DCM caused by RBM20 mutation.
Collapse
|
71
|
Sabari BR, Dall'Agnese A, Young RA. Biomolecular Condensates in the Nucleus. Trends Biochem Sci 2020; 45:961-977. [PMID: 32684431 PMCID: PMC7572565 DOI: 10.1016/j.tibs.2020.06.007] [Citation(s) in RCA: 217] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/18/2020] [Accepted: 06/20/2020] [Indexed: 12/28/2022]
Abstract
Nuclear processes such as DNA replication, transcription, and RNA processing each depend on the concerted action of many different protein and RNA molecules. How biomolecules with shared functions find their way to specific locations has been assumed to occur largely by diffusion-mediated collisions. Recent studies have shown that many nuclear processes occur within condensates that compartmentalize and concentrate the protein and RNA molecules required for each process, typically at specific genomic loci. These condensates have common features and emergent properties that provide the cell with regulatory capabilities beyond canonical molecular regulatory mechanisms. We describe here the shared features of nuclear condensates, the components that produce locus-specific condensates, elements of specificity, and the emerging understanding of mechanisms regulating these compartments.
Collapse
Affiliation(s)
- Benjamin R Sabari
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, TX, 75390 USA; Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390 USA; Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142 USA.
| | | | - Richard A Young
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142 USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139 USA.
| |
Collapse
|
72
|
Yoshizawa T, Matsumura H. Effect of nuclear import receptors on liquid-liquid phase separation. Biophys Physicobiol 2020; 17:25-29. [PMID: 33110735 PMCID: PMC7550251 DOI: 10.2142/biophysico.bsj-2019052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 02/07/2020] [Indexed: 02/01/2023] Open
Abstract
Low-complexity (LC) sequences, regions that are predominantly made up of limited amino acids, are often observed in eukaryotic nuclear proteins. The role of these LC sequences has remained unclear for decades. Recent studies have shown that LC sequences are important in the formation of membrane-less organelles via liquid–liquid phase separation (LLPS). The RNA binding protein, fused in sarcoma (FUS), is the most widely studied of the proteins that undergo LLPS. It forms droplets, fibers, or hydrogels using its LC sequences. The N-terminal LC sequence of FUS is made up of Ser, Tyr, Gly, and Gln, which form a labile cross-β polymer core while the C-terminal Arg-Gly-Gly repeats accelerate LLPS. Normally, FUS localizes to the nucleus via the nuclear import receptor karyopherin β2 (Kapβ2) with the help of its C-terminal proline-tyrosine nuclear localization signal (PY-NLS). Recent findings revealed that Kapβ2 blocks FUS mediated LLPS, suggesting that Kapβ2 is not only a transport protein but also a chaperone which regulates LLPS during the formation of membrane-less organelles. In this review, we discuss the effects of the nuclear import receptors on LLPS.
Collapse
Affiliation(s)
- Takuya Yoshizawa
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Hiroyoshi Matsumura
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| |
Collapse
|
73
|
Abstract
Enzymatic reactions and noncovalent (i.e., supramolecular) interactions are two fundamental nongenetic attributes of life. Enzymatic noncovalent synthesis (ENS) refers to a process where enzymatic reactions control intermolecular noncovalent interactions for spatial organization of higher-order molecular assemblies that exhibit emergent properties and functions. Like enzymatic covalent synthesis (ECS), in which an enzyme catalyzes the formation of covalent bonds to generate individual molecules, ENS is a unifying theme for understanding the functions, morphologies, and locations of molecular ensembles in cellular environments. This review intends to provide a summary of the works of ENS within the past decade and emphasize ENS for functions. After comparing ECS and ENS, we describe a few representative examples where nature uses ENS, as a rule of life, to create the ensembles of biomacromolecules for emergent properties/functions in a myriad of cellular processes. Then, we focus on ENS of man-made (synthetic) molecules in cell-free conditions, classified by the types of enzymes. After that, we introduce the exploration of ENS of man-made molecules in the context of cells by discussing intercellular, peri/intracellular, and subcellular ENS for cell morphogenesis, molecular imaging, cancer therapy, and other applications. Finally, we provide a perspective on the promises of ENS for developing molecular assemblies/processes for functions. This review aims to be an updated introduction for researchers who are interested in exploring noncovalent synthesis for developing molecular science and technologies to address societal needs.
Collapse
Affiliation(s)
- Hongjian He
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Weiyi Tan
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Jiaqi Guo
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Meihui Yi
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Adrianna N Shy
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Bing Xu
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| |
Collapse
|
74
|
Epigenetic cell fate in Candida albicans is controlled by transcription factor condensates acting at super-enhancer-like elements. Nat Microbiol 2020; 5:1374-1389. [PMID: 32719507 PMCID: PMC7581547 DOI: 10.1038/s41564-020-0760-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 06/25/2020] [Indexed: 12/21/2022]
Abstract
Cell identity in eukaryotes is controlled by transcriptional regulatory networks (TRNs) that define cell type-specific gene expression. In the opportunistic fungal pathogen Candida albicans, TRNs regulate epigenetic switching between two alternative cell states, ‘white’ and ‘opaque’, that exhibit distinct host interactions. Here, we reveal that the transcription factors (TFs) regulating cell identity contain prion-like domains (PrLDs) that enable liquid-liquid demixing and the formation of phase-separated condensates. Multiple white-opaque TFs can co-assemble into complex condensates as observed on single DNA molecules. Moreover, heterotypic interactions between PrLDs supports the assembly of multifactorial condensates at a synthetic locus within live eukaryotic cells. Mutation of the Wor1 PrLD revealed that substitution of acidic residues abolished its ability to phase separate and to co-recruit other TFs in live cells, as well as its function in C. albicans cell fate determination. Together, these studies reveal that PrLDs support the assembly of TF complexes that control fungal cell identity and highlight parallels with the ‘super-enhancers’ that regulate mammalian cell fate.
Collapse
|
75
|
m 6A-binding YTHDF proteins promote stress granule formation. Nat Chem Biol 2020; 16:955-963. [PMID: 32451507 PMCID: PMC7442727 DOI: 10.1038/s41589-020-0524-y] [Citation(s) in RCA: 188] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 02/25/2020] [Accepted: 03/22/2020] [Indexed: 12/20/2022]
Abstract
Diverse RNAs and RNA-binding proteins form phase-separated, membraneless granules in cells under stress conditions. However, the role of the prevalent mRNA methylation, m6A, and its binding proteins in stress granule (SG) assembly remain unclear. Here, we show that m6A-modified mRNAs are enriched in SGs, and that m6A-binding YTHDF proteins are critical for SG formation. Depletion of YTHDF1/3 inhibits SG formation and recruitment of mRNAs to SGs. Both the N-terminal intrinsically disordered region and the C-terminal m6A-binding YTH domain of YTHDF proteins are important for SG formation. Super-resolution imaging further reveals that YTHDF proteins appear to be in a super-saturated state, forming clusters that often reside in the periphery of and at the junctions between SG core clusters, and potentially promote SG formation by reducing the activation energy barrier and critical size for SG condensate formation. Our results suggest a new function of the m6A-binding YTHDF proteins in regulating SG formation.
Collapse
|
76
|
Skuodas S, Clemons A, Hayes M, Goll A, Zora B, Weeks DL, Phillips BT, Fassler JS. The ABCF gene family facilitates disaggregation during animal development. Mol Biol Cell 2020; 31:1324-1345. [PMID: 32320318 PMCID: PMC7353142 DOI: 10.1091/mbc.e19-08-0443] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Protein aggregation, once believed to be a harbinger and/or consequence of stress, age, and pathological conditions, is emerging as a novel concept in cellular regulation. Normal versus pathological aggregation may be distinguished by the capacity of cells to regulate the formation, modification, and dissolution of aggregates. We find that Caenorhabditis elegans aggregates are observed in large cells/blastomeres (oocytes, embryos) and in smaller, further differentiated cells (primordial germ cells), and their analysis using cell biological and genetic tools is straightforward. These observations are consistent with the hypothesis that aggregates are involved in normal development. Using cross-platform analysis in Saccharomyces cerevisiae, C. elegans, and Xenopus laevis, we present studies identifying a novel disaggregase family encoded by animal genomes and expressed embryonically. Our initial analysis of yeast Arb1/Abcf2 in disaggregation and animal ABCF proteins in embryogenesis is consistent with the possibility that members of the ABCF gene family may encode disaggregases needed for aggregate processing during the earliest stages of animal development.
Collapse
Affiliation(s)
- Sydney Skuodas
- Department of Biology, University of Iowa, Iowa City, IA 52242
| | - Amy Clemons
- Department of Biology, University of Iowa, Iowa City, IA 52242
| | - Michael Hayes
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242
| | - Ashley Goll
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242
| | - Betul Zora
- Department of Biology, University of Iowa, Iowa City, IA 52242
| | - Daniel L Weeks
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242
| | | | - Jan S Fassler
- Department of Biology, University of Iowa, Iowa City, IA 52242
| |
Collapse
|
77
|
Abstract
High-throughput sequencing-based methods and their applications in the study of transcriptomes have revolutionized our understanding of alternative splicing. Networks of functionally coordinated and biologically important alternative splicing events continue to be discovered in an ever-increasing diversity of cell types in the context of physiologically normal and disease states. These studies have been complemented by efforts directed at defining sequence codes governing splicing and their cognate trans-acting factors, which have illuminated important combinatorial principles of regulation. Additional studies have revealed critical roles of position-dependent, multivalent protein-RNA interactions that direct splicing outcomes. Investigations of evolutionary changes in RNA binding proteins, splice variants, and associated cis elements have further shed light on the emergence, mechanisms, and functions of splicing networks. Progress in these areas has emphasized the need for a coordinated, community-based effort to systematically address the functions of individual splice variants associated with normal and disease biology.
Collapse
|
78
|
3' UTRs Regulate Protein Functions by Providing a Nurturing Niche during Protein Synthesis. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2020; 84:95-104. [PMID: 31900325 DOI: 10.1101/sqb.2019.84.039206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Messenger RNAs (mRNAs) are the templates for protein synthesis as the coding region is translated into the amino acid sequence. mRNAs also contain 3' untranslated regions (3' UTRs) that harbor additional elements for the regulation of protein function. If the amino acid sequence of a protein is necessary and sufficient for its function, we call it 3' UTR-independent. In contrast, functions that are accomplished by protein complexes whose formation requires the presence of a specific 3' UTR are 3' UTR-dependent protein functions. We showed that 3' UTRs can regulate protein activity without affecting protein abundance, and alternative 3' UTRs can diversify protein functions. We currently think that the regulation of protein function by 3' UTRs is facilitated by the local environment at the site of protein synthesis, which we call the nurturing niche for nascent proteins. This niche is composed of the mRNA and the bound proteins that consist of RNA-binding proteins and recruited proteins. It enables the formation of specific protein complexes, as was shown for TIS granules, a recently discovered cytoplasmic membraneless organelle. This finding suggests that changing the niche for nascent proteins will alter protein activity and function, implying that cytoplasmic membraneless organelles can regulate protein function in a manner that is independent of protein abundance.
Collapse
|
79
|
Sharma A, Smith HJ, Yao P, Mair WB. Causal roles of mitochondrial dynamics in longevity and healthy aging. EMBO Rep 2019; 20:e48395. [PMID: 31667999 PMCID: PMC6893295 DOI: 10.15252/embr.201948395] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/24/2019] [Accepted: 10/09/2019] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are organized in the cell in the form of a dynamic, interconnected network. Mitochondrial dynamics, regulated by mitochondrial fission, fusion, and trafficking, ensure restructuring of this complex reticulum in response to nutrient availability, molecular signals, and cellular stress. Aberrant mitochondrial structures have long been observed in aging and age-related diseases indicating that mitochondrial dynamics are compromised as cells age. However, the specific mechanisms by which aging affects mitochondrial dynamics and whether these changes are causally or casually associated with cellular and organismal aging is not clear. Here, we review recent studies that show specifically how mitochondrial fission, fusion, and trafficking are altered with age. We discuss factors that change with age to directly or indirectly influence mitochondrial dynamics while examining causal roles for altered mitochondrial dynamics in healthy aging and underlying functional outputs that might affect longevity. Lastly, we propose that altered mitochondrial dynamics might not just be a passive consequence of aging but might constitute an adaptive mechanism to mitigate age-dependent cellular impairments and might be targeted to increase longevity and promote healthy aging.
Collapse
Affiliation(s)
- Arpit Sharma
- Department of Genetics and Complex DiseasesHarvard T.H. Chan School of Public HealthBostonMAUSA
| | - Hannah J Smith
- Department of Genetics and Complex DiseasesHarvard T.H. Chan School of Public HealthBostonMAUSA
| | - Pallas Yao
- Department of Genetics and Complex DiseasesHarvard T.H. Chan School of Public HealthBostonMAUSA
| | - William B Mair
- Department of Genetics and Complex DiseasesHarvard T.H. Chan School of Public HealthBostonMAUSA
| |
Collapse
|
80
|
Fukuda T, Kawai-Noma S, Pack CG, Taguchi H. Large-scale analysis of diffusional dynamics of proteins in living yeast cells using fluorescence correlation spectroscopy. Biochem Biophys Res Commun 2019; 520:237-242. [PMID: 31594638 DOI: 10.1016/j.bbrc.2019.09.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 09/17/2019] [Indexed: 10/25/2022]
Abstract
In the living cells, the majority of proteins does not work alone, but interact with other proteins or other biomolecules to maintain the cellular function, constituting a "protein community". Previous efforts on mass spectroscopy-based protein interaction networks, interactomes, have provided a picture on the protein community. However, these were static information after cells were disrupted. For a better understanding of the protein community in cells, it is important to know the properties of intracellular dynamics and interactions. Since hydrodynamic size and mobility of proteins are related into such properties, direct measurement of diffusional motion of proteins in single living cells will be helpful for uncovering the properties. Here we completed measurement of the diffusion and homo-oligomeric properties of 369 cytoplasmic GFP-fusion proteins in living yeast Saccharomyces cerevisiae cells using fluorescence correlation spectroscopy (FCS). The large-scale analysis showed that the motions of majority of proteins obeyed a two-component (i.e. slow and fast components) diffusion model. Remarkably, both of the two components diffused more slowly than expected monomeric states. In addition, further analysis suggested that more proteins existed as homo-oligomeric states in living cells than previously expected. Our study, which characterizes the dynamics of proteins in living cells on a large-scale, provided a global view on intracellular protein dynamics to understand the protein community.
Collapse
Affiliation(s)
- Takafumi Fukuda
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Shigeko Kawai-Noma
- Department of Applied Chemistry and Biotechnology, Chiba University, Chiba, Japan
| | - Chan-Gi Pack
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, South Korea
| | - Hideki Taguchi
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan; Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.
| |
Collapse
|
81
|
Abstract
mRNAs move to the right place in cells to facilitate localized translation. The pathway of mRNA movement involves nuclear and cytoplasmic puncta not surrounded by investing membranes. Discoveries reported by Hondele et al. explain how mRNA molecules can be passed from one puncta to another, forming a relay that directs mRNAs to their proper location.
Collapse
Affiliation(s)
- Steven L McKnight
- Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA.
| |
Collapse
|
82
|
Abstract
Selectively targeting the cell nucleolus remains a challenge. Here, we report the first case in which d-peptides form membraneless molecular condensates with RNA for targeting cell nucleolus. A d-peptide derivative, enriched with lysine and hydrophobic residues, self-assembles to form nanoparticles, which enter cells through clathrin-dependent endocytosis and mainly accumulate at the cell nucleolus. A structural analogue of the d-peptide reveals that the particle morphology of the assemblies, which depends on the side chain modification, favors the cellular uptake. In contrast to those of the d-peptide, the assemblies of the corresponding l-enantiomer largely localize in cell lysosomes. Preliminary mechanism study suggests that the d-peptide nanoparticles interact with RNA to form membraneless condensates in the nucleolus, which further induces DNA damage and results in cell death. This work illustrates a new strategy for rationally designing supramolecular assemblies of d-peptides for targeting subcellular organelles.
Collapse
Affiliation(s)
- Huaimin Wang
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Zhaoqianqi Feng
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Weiyi Tan
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Bing Xu
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| |
Collapse
|
83
|
Rabouille C. The Upper Hand of the Otu Amyloid Fibers: Increasing Enzymatic Activity and Prolonging Lifespan. Mol Cell 2019; 74:225-226. [PMID: 31002803 DOI: 10.1016/j.molcel.2019.03.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The formation of amyloid fibers is usually associated with aging and neurodegeneration. In this issue of Molecular Cell, Ji et al. (2019) demonstrate that the deubiquitinase Otu coalesces into amyloid-like fibers to enhance its activity and ensure its optimum biological function.
Collapse
Affiliation(s)
- Catherine Rabouille
- Hubrecht Institute of the Royal Netherlands Academy of Arts and Sciences & University Medical Center Utrecht, Utrecht, the Netherlands; Department of Biomedical Science of Cells and Systems, University Medical Center Groningen, Groningen, the Netherlands.
| |
Collapse
|
84
|
de Oliveira GAP, Cordeiro Y, Silva JL, Vieira TCRG. Liquid-liquid phase transitions and amyloid aggregation in proteins related to cancer and neurodegenerative diseases. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 118:289-331. [PMID: 31928729 DOI: 10.1016/bs.apcsb.2019.08.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Liquid-liquid phase separation (LLPS) and phase transition (LLPT) of proteins and nucleic acids have emerged as a new paradigm in cell biology. Here we will describe the recent findings about LLPS and LLPT, including the molecular and physical determinants leading to their formation, the resulting functions and their implications in cell physiology and disease. Amyloid aggregation is implicated in many neurodegenerative diseases and cancer, and LLPS of proteins involved in these diseases appear to be related to their function in different cell contexts. Amyloid formation would correspond to an irreversible liquid-to-solid transition, as clearly observed in the case of PrP, TDP43, FUS/TLS and tau protein in neurodegenerative pathologies as well as with the mutant tumor suppressor p53 in cancer. Nucleic acids play a modulatory effect on both LLPS and amyloid aggregation. Understanding the molecular events regulating how the demixing process advances to solid-like fibril materials is crucial for the development of novel therapeutic strategies against cancer and neurodegenerative maladies.
Collapse
Affiliation(s)
- Guilherme A P de Oliveira
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Instituto Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, United States
| | - Yraima Cordeiro
- Faculty of Pharmacy, Federal University of Rio de Janeiro, Rio de Janeiro-RJ, Brazil
| | - Jerson L Silva
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Instituto Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Tuane C R G Vieira
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Instituto Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| |
Collapse
|
85
|
Organization and regulation of gene transcription. Nature 2019; 573:45-54. [PMID: 31462772 DOI: 10.1038/s41586-019-1517-4] [Citation(s) in RCA: 367] [Impact Index Per Article: 73.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 07/30/2019] [Indexed: 12/18/2022]
Abstract
The regulated transcription of genes determines cell identity and function. Recent structural studies have elucidated mechanisms that govern the regulation of transcription by RNA polymerases during the initiation and elongation phases. Microscopy studies have revealed that transcription involves the condensation of factors in the cell nucleus. A model is emerging for the transcription of protein-coding genes in which distinct transient condensates form at gene promoters and in gene bodies to concentrate the factors required for transcription initiation and elongation, respectively. The transcribing enzyme RNA polymerase II may shuttle between these condensates in a phosphorylation-dependent manner. Molecular principles are being defined that rationalize transcriptional organization and regulation, and that will guide future investigations.
Collapse
|
86
|
Brouwer I, Lenstra TL. Visualizing transcription: key to understanding gene expression dynamics. Curr Opin Chem Biol 2019; 51:122-129. [DOI: 10.1016/j.cbpa.2019.05.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 05/03/2019] [Accepted: 05/28/2019] [Indexed: 12/24/2022]
|
87
|
Wang H, Feng Z, Xu B. Assemblies of Peptides in a Complex Environment and their Applications. Angew Chem Int Ed Engl 2019; 58:10423-10432. [PMID: 30903643 PMCID: PMC6656613 DOI: 10.1002/anie.201814552] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Indexed: 01/28/2023]
Abstract
Using peptide assemblies with emergent properties to achieve elaborate functions has attracted increasing attention in recent years. Besides tailoring the self-assembly of peptides in vitro, peptide research is advancing into a new and exciting frontier: the rational design of peptide assemblies (or their derivatives) for biological functions in a complex environment. This Minireview highlights recent developments in peptide assemblies and their applications in biological systems. After introducing the unique merits of peptide assemblies, we discuss the recent progress in designing peptides (or peptide derivatives) for self-assembly with conformational control. Then, we describe biological functions of peptide assemblies, with an emphasis on approach-instructed assembly for spatiotemporal control of peptide assemblies, in the cellular context. Finally, we discuss the future promises and challenges of this exciting area of chemistry.
Collapse
Affiliation(s)
- Huaimin Wang
- Department of chemistry, Brandeis University, 415 South St, Waltham, MA 02454, USA
| | - Zhaoqianqi Feng
- Department of chemistry, Brandeis University, 415 South St, Waltham, MA 02454, USA
| | - Bing Xu
- Department of chemistry, Brandeis University, 415 South St, Waltham, MA 02454, USA
| |
Collapse
|
88
|
Cryo-EM structures of four polymorphic TDP-43 amyloid cores. Nat Struct Mol Biol 2019; 26:619-627. [PMID: 31235914 PMCID: PMC7047951 DOI: 10.1038/s41594-019-0248-4] [Citation(s) in RCA: 166] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 05/10/2019] [Indexed: 12/13/2022]
Abstract
The DNA/RNA processing protein TDP-43 undergoes both functional and pathogennic aggregation. Functional TDP-43 aggregates form reversible, transient species such as nuclear bodies, stress granules, and myo-granules. Pathogenic, irreversible TDP-43 aggregates form in amyotrophic lateral sclerosis (ALS) and other neurodegenerative conditions. Here we find the features of TDP-43 fibrils that confer both reversibility and irreversibility by determining structures of two segments reported to be the pathogenic cores of human TDP-43 aggregation: SegA (residues 311–360), which forms three polymorphs, all with dagger-shaped folds; and SegB A315E (residues 286–331 containing the ALS hereditary mutation A315E), which forms R-shaped folds. Energetic analysis suggests that the dagger-shaped polymorphs represent irreversible fibril structures, whereas the SegB polymorph may participate in both reversible and irreversible fibrils. Our structures reveal the polymorphic nature of TDP-43 and suggest how the A315E mutation converts the R-shaped polymorph to an irreversible form which enhances pathology.
Collapse
|
89
|
Abstract
Cells under stress must adjust their physiology, metabolism, and architecture to adapt to the new conditions. Most importantly, they must down-regulate general gene expression, but at the same time induce synthesis of stress-protective factors, such as molecular chaperones. Here, we investigate how the process of phase separation is used by cells to ensure adaptation to stress. We summarize recent findings and propose that the solubility of important translation factors is specifically affected by changes in physical-chemical parameters such temperature or pH and modulated by intrinsically disordered prion-like domains. These stress-triggered changes in protein solubility induce phase separation into condensates that regulate the activity of the translation factors and promote cellular fitness. Prion-like domains play important roles in this process as environmentally regulated stress sensors and modifier sequences that determine protein solubility and phase behavior. We propose that protein phase separation is an evolutionary conserved feature of proteins that cells harness to regulate adaptive stress responses and ensure survival in extreme environmental conditions.
Collapse
Affiliation(s)
- Titus M Franzmann
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| |
Collapse
|
90
|
Wang C, Lu T, Emanuel G, Babcock HP, Zhuang X. Imaging-based pooled CRISPR screening reveals regulators of lncRNA localization. Proc Natl Acad Sci U S A 2019; 116:10842-10851. [PMID: 31085639 PMCID: PMC6561216 DOI: 10.1073/pnas.1903808116] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pooled-library CRISPR screening provides a powerful means to discover genetic factors involved in cellular processes in a high-throughput manner. However, the phenotypes accessible to pooled-library screening are limited. Complex phenotypes, such as cellular morphology and subcellular molecular organization, as well as their dynamics, require imaging-based readout and are currently beyond the reach of pooled-library CRISPR screening. Here we report an all imaging-based pooled-library CRISPR screening approach that combines high-content phenotype imaging with high-throughput single guide RNA (sgRNA) identification in individual cells. In this approach, sgRNAs are codelivered to cells with corresponding barcodes placed at the 3' untranslated region of a reporter gene using a lentiviral delivery system with reduced recombination-induced sgRNA-barcode mispairing. Multiplexed error-robust fluorescence in situ hybridization (MERFISH) is used to read out the barcodes and hence identify the sgRNAs with high accuracy. We used this approach to screen 162 sgRNAs targeting 54 RNA-binding proteins for their effects on RNA localization to nuclear compartments and uncovered previously unknown regulatory factors for nuclear RNA localization. Notably, our screen revealed both positive and negative regulators for the nuclear speckle localization of a long noncoding RNA, MALAT1, suggesting a dynamic regulation of lncRNA localization in subcellular compartments.
Collapse
MESH Headings
- CRISPR-Cas Systems/genetics
- Cell Line, Tumor
- Cell Nucleus/chemistry
- Cell Nucleus/metabolism
- Gene Editing
- High-Throughput Nucleotide Sequencing/methods
- Humans
- Image Processing, Computer-Assisted/methods
- In Situ Hybridization, Fluorescence/methods
- Molecular Probes/chemistry
- Molecular Probes/genetics
- Molecular Probes/metabolism
- RNA, Guide, CRISPR-Cas Systems/chemistry
- RNA, Guide, CRISPR-Cas Systems/genetics
- RNA, Guide, CRISPR-Cas Systems/metabolism
- RNA, Long Noncoding/chemistry
- RNA, Long Noncoding/genetics
- RNA, Long Noncoding/metabolism
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/metabolism
- Single-Cell Analysis/methods
Collapse
Affiliation(s)
- Chong Wang
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
- Department of Physics, Harvard University, Cambridge, MA 02138
| | - Tian Lu
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
- Department of Physics, Harvard University, Cambridge, MA 02138
| | - George Emanuel
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
- Department of Physics, Harvard University, Cambridge, MA 02138
| | - Hazen P Babcock
- Center for Advanced Imaging, Harvard University, Cambridge, MA 02138
| | - Xiaowei Zhuang
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138;
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
- Department of Physics, Harvard University, Cambridge, MA 02138
| |
Collapse
|
91
|
Wang H, Feng Z, Xu B. Assemblies of Peptides in a Complex Environment and their Applications. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201814552] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Huaimin Wang
- Department of Chemistry Brandeis University 415 South St Waltham MA 02454 USA
| | - Zhaoqianqi Feng
- Department of Chemistry Brandeis University 415 South St Waltham MA 02454 USA
| | - Bing Xu
- Department of Chemistry Brandeis University 415 South St Waltham MA 02454 USA
| |
Collapse
|
92
|
Gui X, Luo F, Li Y, Zhou H, Qin Z, Liu Z, Gu J, Xie M, Zhao K, Dai B, Shin WS, He J, He L, Jiang L, Zhao M, Sun B, Li X, Liu C, Li D. Structural basis for reversible amyloids of hnRNPA1 elucidates their role in stress granule assembly. Nat Commun 2019; 10:2006. [PMID: 31043593 PMCID: PMC6494871 DOI: 10.1038/s41467-019-09902-7] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/29/2019] [Indexed: 11/09/2022] Open
Abstract
Subcellular membrane-less organelles consist of proteins with low complexity domains. Many of them, such as hnRNPA1, can assemble into both a polydisperse liquid phase and an ordered solid phase of amyloid fibril. The former mirrors biological granule assembly, while the latter is usually associated with neurodegenerative disease. Here, we observe a reversible amyloid formation of hnRNPA1 that synchronizes with liquid–liquid phase separation, regulates the fluidity and mobility of the liquid-like droplets, and facilitates the recruitment of hnRNPA1 into stress granules. We identify the reversible amyloid-forming cores of hnRNPA1 (named hnRACs). The atomic structures of hnRACs reveal a distinct feature of stacking Asp residues, which contributes to fibril reversibility and explains the irreversible pathological fibril formation caused by the Asp mutations identified in familial ALS. Our work characterizes the structural diversity and heterogeneity of reversible amyloid fibrils and illuminates the biological function of reversible amyloid formation in protein phase separation. Low complexity (LC) domains can drive the formation of both amyloid fibrils and protein droplets. Here, the authors identify reversible amyloid cores from the LC of hnRNPA1, based on which they elucidate the structural basis of reversible fibrillation and its interplay with hnRNPA1 droplet formation.
Collapse
Affiliation(s)
- Xinrui Gui
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Feng Luo
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yichen Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Heng Zhou
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Zhenheng Qin
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Zhenying Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinge Gu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Muyun Xie
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 239 Zhang Heng Road, Pudong New District, Shanghai, 201203, China
| | - Kun Zhao
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bin Dai
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Woo Shik Shin
- Department of Neurology, Molecular Biology Institute, and Brain Research Institute, UCLA, Los Angeles, CA, 90095, USA
| | - Jianhua He
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 239 Zhang Heng Road, Pudong New District, Shanghai, 201203, China
| | - Lin He
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Lin Jiang
- Department of Neurology, Molecular Biology Institute, and Brain Research Institute, UCLA, Los Angeles, CA, 90095, USA
| | - Minglei Zhao
- Department of Biochemistry and Molecular Biology, the University of Chicago, Chicago, IL, 60637, USA
| | - Bo Sun
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xueming Li
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China.
| |
Collapse
|
93
|
Kumar H, Udgaonkar JB. Mechanistic approaches to understand the prion-like propagation of aggregates of the human tau protein. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1867:922-932. [PMID: 30986567 DOI: 10.1016/j.bbapap.2019.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 12/13/2022]
Abstract
The dynamic nature of the tau protein under physiological conditions is likely to be critical for it to perform its diverse functions inside a cell. Under some conditions, this intrinsically disordered protein assembles into pathogenic aggregates that are self-perpetuating, toxic and infectious in nature. The role of liquid-liquid phase separation in the initiation of the aggregation reaction remains to be delineated. Depending on the nature of the aggregate, its structure, and its localization, neurodegenerative disorders with diverse clinical features are manifested. The prion-like mechanism by which these aggregates propagate and spread across the brain is not well understood. Various factors (PTMs, mutations) have been strongly associated with the pathological aggregates of tau. However, little is known about how these factors modulate the pathological properties linked to aggregation. This review describes the current progress towards understanding the mechanism of propagation of tau aggregates.
Collapse
Affiliation(s)
- Harish Kumar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India; Indian Institute of Science Education and Research, Pune 411008, India.
| |
Collapse
|
94
|
Nair SJ, Yang L, Meluzzi D, Oh S, Yang F, Friedman MJ, Wang S, Suter T, Alshareedah I, Gamliel A, Ma Q, Zhang J, Hu Y, Tan Y, Ohgi KA, Jayani RS, Banerjee PR, Aggarwal AK, Rosenfeld MG. Phase separation of ligand-activated enhancers licenses cooperative chromosomal enhancer assembly. Nat Struct Mol Biol 2019; 26:193-203. [PMID: 30833784 PMCID: PMC6709854 DOI: 10.1038/s41594-019-0190-5] [Citation(s) in RCA: 212] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/18/2019] [Indexed: 12/16/2022]
Abstract
A crucial feature of differentiated cells is the rapid activation of enhancer-driven transcriptional programs in response to signals. The potential contributions of physicochemical properties of enhancer assembly in signaling events remain poorly understood. Here we report that in human breast cancer cells, the acute 17β-estradiol-dependent activation of functional enhancers requires assembly of an enhancer RNA-dependent ribonucleoprotein (eRNP) complex exhibiting properties of phase-separated condensates. Unexpectedly, while acute ligand-dependent assembly of eRNPs resulted in enhancer activation sensitive to chemical disruption of phase separation, chronically activated enhancers proved resistant to such disruption, with progressive maturation of eRNPs to a more gel-like state. Acute, but not chronic, stimulation resulted in ligand-induced, condensin-dependent changes in spatial chromatin conformation based on homotypic enhancer association, resulting in cooperative enhancer-activation events. Thus, distinct physicochemical properties of eRNP condensates on enhancers serve as determinants of rapid ligand-dependent alterations in chromosomal architecture and cooperative enhancer activation.
Collapse
Affiliation(s)
- Sreejith J Nair
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA.
| | - Lu Yang
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Dario Meluzzi
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Soohwan Oh
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
- Biological Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
| | - Feng Yang
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Meyer J Friedman
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Susan Wang
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
- Cellular and Molecular Medicine Graduate Program, University of California, San Diego, La Jolla, CA, USA
| | - Tom Suter
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | | | - Amir Gamliel
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Qi Ma
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jie Zhang
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Yiren Hu
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
- Biological Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
| | - Yuliang Tan
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Kenneth A Ohgi
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Ranveer Singh Jayani
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Priya R Banerjee
- Department of Physics, University at Buffalo-SUNY, Buffalo, NY, USA
| | - Aneel K Aggarwal
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Michael G Rosenfeld
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA.
| |
Collapse
|
95
|
Mir M, Stadler MR, Ortiz SA, Hannon CE, Harrison MM, Darzacq X, Eisen MB. Dynamic multifactor hubs interact transiently with sites of active transcription in Drosophila embryos. eLife 2018; 7:e40497. [PMID: 30589412 PMCID: PMC6307861 DOI: 10.7554/elife.40497] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 11/30/2018] [Indexed: 12/12/2022] Open
Abstract
The regulation of transcription requires the coordination of numerous activities on DNA, yet how transcription factors mediate these activities remains poorly understood. Here, we use lattice light-sheet microscopy to integrate single-molecule and high-speed 4D imaging in developing Drosophila embryos to study the nuclear organization and interactions of the key transcription factors Zelda and Bicoid. In contrast to previous studies suggesting stable, cooperative binding, we show that both factors interact with DNA with surprisingly high off-rates. We find that both factors form dynamic subnuclear hubs, and that Bicoid binding is enriched within Zelda hubs. Remarkably, these hubs are both short lived and interact only transiently with sites of active Bicoid-dependent transcription. Based on our observations, we hypothesize that, beyond simply forming bridges between DNA and the transcription machinery, transcription factors can organize other proteins into hubs that transiently drive multiple activities at their gene targets. Editorial note This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
Collapse
Affiliation(s)
- Mustafa Mir
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
| | - Michael R Stadler
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical Institute, University of California, BerkeleyBerkeleyUnited States
| | - Stephan A Ortiz
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
| | - Colleen E Hannon
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
| | - Melissa M Harrison
- Department of Biomolecular ChemistryUniversity of Wisconsin–MadisonMadisonUnited States
| | - Xavier Darzacq
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
| | - Michael B Eisen
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical Institute, University of California, BerkeleyBerkeleyUnited States
- Department of Integrative BiologyUniversity of California, BerkeleyBerkeleyUnited States
| |
Collapse
|
96
|
Ma W, Mayr C. A Membraneless Organelle Associated with the Endoplasmic Reticulum Enables 3'UTR-Mediated Protein-Protein Interactions. Cell 2018; 175:1492-1506.e19. [PMID: 30449617 DOI: 10.1016/j.cell.2018.10.007] [Citation(s) in RCA: 205] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/23/2018] [Accepted: 09/29/2018] [Indexed: 01/05/2023]
Abstract
Approximately half of human genes generate mRNAs with alternative 3' untranslated regions (3'UTRs). Through 3'UTR-mediated protein-protein interactions, alternative 3'UTRs enable multi-functionality of proteins with identical amino acid sequence. While studying how information on protein features is transferred from 3'UTRs to proteins, we discovered that the broadly expressed RNA-binding protein TIS11B forms a membraneless organelle, called TIS granule, that enriches membrane protein-encoding mRNAs with multiple AU-rich elements. TIS granules form a reticular meshwork intertwined with the endoplasmic reticulum (ER). The association between TIS granules and the ER creates a subcellular compartment-the TIGER domain-with a biophysically and biochemically distinct environment from the cytoplasm. This compartment promotes 3'UTR-mediated interaction of SET with membrane proteins, thus allowing increased surface expression and functional diversity of proteins, including CD47 and PD-L1. The TIGER domain is a subcellular compartment that enables formation of specific and functionally relevant protein-protein interactions that cannot be established outside.
Collapse
Affiliation(s)
- Weirui Ma
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Christine Mayr
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| |
Collapse
|
97
|
Hofmann JW, Seeley WW, Huang EJ. RNA Binding Proteins and the Pathogenesis of Frontotemporal Lobar Degeneration. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2018; 14:469-495. [PMID: 30355151 DOI: 10.1146/annurev-pathmechdis-012418-012955] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Frontotemporal dementia is a group of early onset dementia syndromes linked to underlying frontotemporal lobar degeneration (FTLD) pathology that can be classified based on the formation of abnormal protein aggregates involving tau and two RNA binding proteins, TDP-43 and FUS. Although elucidation of the mechanisms leading to FTLD pathology is in progress, recent advances in genetics and neuropathology indicate that a majority of FTLD cases with proteinopathy involving RNA binding proteins show highly congruent genotype-phenotype correlations. Specifically, recent studies have uncovered the unique properties of the low-complexity domains in RNA binding proteins that can facilitate liquid-liquid phase separation in the formation of membraneless organelles. Furthermore, there is compelling evidence that mutations in FTLD genes lead to dysfunction in diverse cellular pathways that converge on the endolysosomal pathway, autophagy, and neuroinflammation. Together, these results provide key mechanistic insights into the pathogenesis and potential therapeutic targets of FTLD.
Collapse
Affiliation(s)
- Jeffrey W Hofmann
- Department of Pathology, University of California, San Francisco, California 94143, USA;
| | - William W Seeley
- Department of Pathology, University of California, San Francisco, California 94143, USA; .,Department of Neurology, University of California, San Francisco, California 94148, USA
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, California 94143, USA; .,Pathology Service 113B, Veterans Affairs Medical Center, San Francisco, California 94121, USA
| |
Collapse
|
98
|
Li Q, Liao M, Yang M, Xiong C, Jin X, Chen Z, Huang W. Characterization of the mitochondrial genomes of three species in the ectomycorrhizal genus Cantharellus and phylogeny of Agaricomycetes. Int J Biol Macromol 2018; 118:756-769. [DOI: 10.1016/j.ijbiomac.2018.06.129] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/23/2018] [Accepted: 06/26/2018] [Indexed: 12/15/2022]
|
99
|
Boehning M, Dugast-Darzacq C, Rankovic M, Hansen AS, Yu T, Marie-Nelly H, McSwiggen DT, Kokic G, Dailey GM, Cramer P, Darzacq X, Zweckstetter M. RNA polymerase II clustering through carboxy-terminal domain phase separation. Nat Struct Mol Biol 2018; 25:833-840. [PMID: 30127355 DOI: 10.1038/s41594-018-0112-y] [Citation(s) in RCA: 376] [Impact Index Per Article: 62.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/17/2018] [Indexed: 12/25/2022]
Abstract
The carboxy-terminal domain (CTD) of RNA polymerase (Pol) II is an intrinsically disordered low-complexity region that is critical for pre-mRNA transcription and processing. The CTD consists of hepta-amino acid repeats varying in number from 52 in humans to 26 in yeast. Here we report that human and yeast CTDs undergo cooperative liquid phase separation, with the shorter yeast CTD forming less-stable droplets. In human cells, truncation of the CTD to the length of the yeast CTD decreases Pol II clustering and chromatin association, whereas CTD extension has the opposite effect. CTD droplets can incorporate intact Pol II and are dissolved by CTD phosphorylation with the transcription initiation factor IIH kinase CDK7. Together with published data, our results suggest that Pol II forms clusters or hubs at active genes through interactions between CTDs and with activators and that CTD phosphorylation liberates Pol II enzymes from hubs for promoter escape and transcription elongation.
Collapse
Affiliation(s)
- Marc Boehning
- Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, Göttingen, Germany
| | - Claire Dugast-Darzacq
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA.,CIRM Center of Excellence, University of California, Berkeley, California, USA
| | - Marija Rankovic
- Max Planck Institute for Biophysical Chemistry, Department of NMR-based Structural Biology, Göttingen, Germany
| | - Anders S Hansen
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA.,CIRM Center of Excellence, University of California, Berkeley, California, USA
| | - Taekyung Yu
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Herve Marie-Nelly
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA.,CIRM Center of Excellence, University of California, Berkeley, California, USA
| | - David T McSwiggen
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA.,CIRM Center of Excellence, University of California, Berkeley, California, USA
| | - Goran Kokic
- Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, Göttingen, Germany
| | - Gina M Dailey
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA.,CIRM Center of Excellence, University of California, Berkeley, California, USA
| | - Patrick Cramer
- Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, Göttingen, Germany.
| | - Xavier Darzacq
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA. .,CIRM Center of Excellence, University of California, Berkeley, California, USA.
| | - Markus Zweckstetter
- Max Planck Institute for Biophysical Chemistry, Department of NMR-based Structural Biology, Göttingen, Germany. .,German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany.
| |
Collapse
|
100
|
Franzmann TM, Alberti S. Prion-like low-complexity sequences: Key regulators of protein solubility and phase behavior. J Biol Chem 2018; 294:7128-7136. [PMID: 29921587 DOI: 10.1074/jbc.tm118.001190] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Many proteins, such as RNA-binding proteins, have complex folding landscapes. How cells maintain the solubility and folding state of such proteins, particularly under stress conditions, is largely unknown. Here, we argue that prion-like low-complexity regions (LCRs) are key regulators of protein solubility and folding. We discuss emerging evidence that prion-like LCRs are not, as commonly thought, autonomous aggregation modules that adopt amyloid-like conformations, but protein-specific sequences with chaperone-like functions. On the basis of recent findings, we propose that prion-like LCRs have evolved to regulate protein phase behavior and to protect proteins against proteotoxic damage.
Collapse
Affiliation(s)
- Titus M Franzmann
- From the Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Simon Alberti
- From the Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| |
Collapse
|