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Hao S, Lee YJ, Benhamou Goldfajn N, Flores E, Liang J, Fuehrer H, Demmerle J, Lippincott-Schwartz J, Liu Z, Sukenik S, Cai D. YAP condensates are highly organized hubs. iScience 2024; 27:109927. [PMID: 38784009 PMCID: PMC11111833 DOI: 10.1016/j.isci.2024.109927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 10/24/2023] [Accepted: 05/03/2024] [Indexed: 05/25/2024] Open
Abstract
YAP/TEAD signaling is essential for organismal development, cell proliferation, and cancer progression. As a transcriptional coactivator, how YAP activates its downstream target genes is incompletely understood. YAP forms biomolecular condensates in response to hyperosmotic stress, concentrating transcription-related factors to activate downstream target genes. However, whether YAP forms condensates under other signals, how YAP condensates organize and function, and how YAP condensates activate transcription in general are unknown. Here, we report that endogenous YAP forms sub-micron scale condensates in response to Hippo pathway regulation and actin cytoskeletal tension. YAP condensates are stabilized by the transcription factor TEAD1, and recruit BRD4, a coactivator that is enriched at active enhancers. Using single-particle tracking, we found that YAP condensates slowed YAP diffusion within condensate boundaries, a possible mechanism for promoting YAP target search. These results reveal that YAP condensate formation is a highly regulated process that is critical for YAP/TEAD target gene expression.
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Affiliation(s)
- Siyuan Hao
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Ye Jin Lee
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Nadav Benhamou Goldfajn
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
- Department of Biophysics, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Eduardo Flores
- Department of Chemistry and Chemical Biology, University of California, Merced, Merced, CA 95343, USA
| | - Jindayi Liang
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Hannah Fuehrer
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Justin Demmerle
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | | | - Zhe Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Shahar Sukenik
- Department of Chemistry and Chemical Biology, University of California, Merced, Merced, CA 95343, USA
| | - Danfeng Cai
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
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2
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Mukherjee S, Poudyal M, Dave K, Kadu P, Maji SK. Protein misfolding and amyloid nucleation through liquid-liquid phase separation. Chem Soc Rev 2024; 53:4976-5013. [PMID: 38597222 DOI: 10.1039/d3cs01065a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Liquid-liquid phase separation (LLPS) is an emerging phenomenon in cell physiology and diseases. The weak multivalent interaction prerequisite for LLPS is believed to be facilitated through intrinsically disordered regions, which are prevalent in neurodegenerative disease-associated proteins. These aggregation-prone proteins also exhibit an inherent property for phase separation, resulting in protein-rich liquid-like droplets. The very high local protein concentration in the water-deficient confined microenvironment not only drives the viscoelastic transition from the liquid to solid-like state but also most often nucleate amyloid fibril formation. Indeed, protein misfolding, oligomerization, and amyloid aggregation are observed to be initiated from the LLPS of various neurodegeneration-related proteins. Moreover, in these cases, neurodegeneration-promoting genetic and environmental factors play a direct role in amyloid aggregation preceded by the phase separation. These cumulative recent observations ignite the possibility of LLPS being a prominent nucleation mechanism associated with aberrant protein aggregation. The present review elaborates on the nucleation mechanism of the amyloid aggregation pathway and the possible early molecular events associated with amyloid-related protein phase separation. It also summarizes the recent advancement in understanding the aberrant phase transition of major proteins contributing to neurodegeneration focusing on the common disease-associated factors. Overall, this review proposes a generic LLPS-mediated multistep nucleation mechanism for amyloid aggregation and its implication in neurodegeneration.
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Affiliation(s)
- Semanti Mukherjee
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Manisha Poudyal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Kritika Dave
- Sunita Sanghi Centre of Aging and Neurodegenerative Diseases, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Pradeep Kadu
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Samir K Maji
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
- Sunita Sanghi Centre of Aging and Neurodegenerative Diseases, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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3
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Daugird TA, Shi Y, Holland KL, Rostamian H, Liu Z, Lavis LD, Rodriguez J, Strahl BD, Legant WR. Correlative single molecule lattice light sheet imaging reveals the dynamic relationship between nucleosomes and the local chromatin environment. Nat Commun 2024; 15:4178. [PMID: 38755200 PMCID: PMC11099156 DOI: 10.1038/s41467-024-48562-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 05/03/2024] [Indexed: 05/18/2024] Open
Abstract
In the nucleus, biological processes are driven by proteins that diffuse through and bind to a meshwork of nucleic acid polymers. To better understand this interplay, we present an imaging platform to simultaneously visualize single protein dynamics together with the local chromatin environment in live cells. Together with super-resolution imaging, new fluorescent probes, and biophysical modeling, we demonstrate that nucleosomes display differential diffusion and packing arrangements as chromatin density increases whereas the viscoelastic properties and accessibility of the interchromatin space remain constant. Perturbing nuclear functions impacts nucleosome diffusive properties in a manner that is dependent both on local chromatin density and on relative location within the nucleus. Our results support a model wherein transcription locally stabilizes nucleosomes while simultaneously allowing for the free exchange of nuclear proteins. Additionally, they reveal that nuclear heterogeneity arises from both active and passive processes and highlight the need to account for different organizational principles when modeling different chromatin environments.
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Affiliation(s)
- Timothy A Daugird
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yu Shi
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, North Carolina State University, Chapel Hill, NC, USA
| | - Katie L Holland
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA
| | - Hosein Rostamian
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Zhe Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA
| | - Luke D Lavis
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA
| | - Joseph Rodriguez
- National Institute of Environmental Health Sciences, Durham, NC, 27709, USA
| | - Brian D Strahl
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Wesley R Legant
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, North Carolina State University, Chapel Hill, NC, USA.
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4
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Mohanty P, Phan TM, Mittal J. Transient interdomain interactions modulate the monomeric structural ensemble and oligomerization landscape of Huntingtin Exon 1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.03.592468. [PMID: 38766024 PMCID: PMC11100600 DOI: 10.1101/2024.05.03.592468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Polyglutamine expansion (≥ 36 residues) within the N-terminal exon-1 of Huntingtin (Httex1) leads to Huntington's disease, a neurogenerative condition marked by the presence of intranuclear Htt inclusions. Notably, the polyglutamine tract in Httex1 is flanked by an N-terminal coiled-coil domain - N17 (17 amino acids), which undergoes self-association to promote the formation of soluble Httex1 oligomers and brings the aggregation-prone polyQ tracts in close spatial proximity. However, the mechanisms underlying the subsequent conversion of soluble oligomers into insoluble β-rich aggregates with increasing polyQ length, remain unclear. Current knowledge suggests that expansion of the polyQ tract increases its helicity, and this favors its oligomerization and aggregation. In addition, studies utilizing conformation-specific antibodies and a stable coiled-coil heterotetrametric system fused to polyQ indicate that domain "cross-talk" (i.e., interdomain interactions) may be necessary to efficiently promote the emergence of toxic conformations (in monomers and oligomers) and fibrillar aggregation. Here, we performed extensive atomistic molecular dynamics (MD) simulations (aggregate time ∼ 0.7 ms) of N17-polyQ fragments to uncover the interplay between structural transformation and domain "cross-talk" on the monomeric structural ensemble and oligomerization landscape of Httex1. Our simulation ensembles of N17-polyQ monomers validated against 13 C NMR chemical shifts indicated that in addition to elevated α-helicity, polyQ expansion also favors transient, interdomain (N17-polyQ) interactions which result in the emergence of β-conformations. Further, interdomain interactions decreased the overall stability of N17-mediated dimers by counteracting the stabilizing effect of increased α-helicity and promoted a heterogenous oligomerization landscape on the sub-microsecond timescale. Overall, our study uncovers the significance of domain "cross-talk" in modulating the monomeric conformational ensemble and oligomerization landscape of Httex1 to favor the formation of amyloid aggregates.
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Tong H, Yang T, Xu S, Li X, Liu L, Zhou G, Yang S, Yin S, Li XJ, Li S. Huntington's Disease: Complex Pathogenesis and Therapeutic Strategies. Int J Mol Sci 2024; 25:3845. [PMID: 38612657 PMCID: PMC11011923 DOI: 10.3390/ijms25073845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024] Open
Abstract
Huntington's disease (HD) arises from the abnormal expansion of CAG repeats in the huntingtin gene (HTT), resulting in the production of the mutant huntingtin protein (mHTT) with a polyglutamine stretch in its N-terminus. The pathogenic mechanisms underlying HD are complex and not yet fully elucidated. However, mHTT forms aggregates and accumulates abnormally in neuronal nuclei and processes, leading to disruptions in multiple cellular functions. Although there is currently no effective curative treatment for HD, significant progress has been made in developing various therapeutic strategies to treat HD. In addition to drugs targeting the neuronal toxicity of mHTT, gene therapy approaches that aim to reduce the expression of the mutant HTT gene hold great promise for effective HD therapy. This review provides an overview of current HD treatments, discusses different therapeutic strategies, and aims to facilitate future therapeutic advancements in the field.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Xiao-Jiang Li
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (H.T.); (T.Y.); (S.X.); (X.L.); (L.L.); (G.Z.); (S.Y.); (S.Y.)
| | - Shihua Li
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (H.T.); (T.Y.); (S.X.); (X.L.); (L.L.); (G.Z.); (S.Y.); (S.Y.)
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6
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Gaudet ID, Xu H, Gordon E, Cannestro GA, Lu ML, Wei J. Elevated SLC7A2 expression is associated with an abnormal neuroinflammatory response and nitrosative stress in Huntington's disease. J Neuroinflammation 2024; 21:59. [PMID: 38419038 PMCID: PMC10900710 DOI: 10.1186/s12974-024-03038-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
We previously identified solute carrier family 7 member 2 (SLC7A2) as one of the top upregulated genes when normal Huntingtin was deleted. SLC7A2 has a high affinity for L-arginine. Arginine is implicated in inflammatory responses, and SLC7A2 is an important regulator of innate and adaptive immunity in macrophages. Although neuroinflammation is clearly demonstrated in animal models and patients with Huntington's disease (HD), the question of whether neuroinflammation actively participates in HD pathogenesis is a topic of ongoing research and debate. Here, we studied the role of SLC7A2 in mediating the neuroinflammatory stress response in HD cells. RNA sequencing (RNA-seq), quantitative RT-PCR and data mining of publicly available RNA-seq datasets of human patients were performed to assess the levels of SLC7A2 mRNA in different HD cellular models and patients. Biochemical studies were then conducted on cell lines and primary mouse astrocytes to investigate arginine metabolism and nitrosative stress in response to neuroinflammation. The CRISPR-Cas9 system was used to knock out SLC7A2 in STHdhQ7 and Q111 cells to investigate its role in mediating the neuroinflammatory response. Live-cell imaging was used to measure mitochondrial dynamics. Finally, exploratory studies were performed using the Enroll-HD periodic human patient dataset to analyze the effect of arginine supplements on HD progression. We found that SLC7A2 is selectively upregulated in HD cellular models and patients. HD cells exhibit an overactive response to neuroinflammatory challenges, as demonstrated by abnormally high iNOS induction and NO production, leading to increased protein nitrosylation. Depleting extracellular Arg or knocking out SLC7A2 blocked iNOS induction and NO production in STHdhQ111 cells. We further examined the functional impact of protein nitrosylation on a well-documented protein target, DRP-1, and found that more mitochondria were fragmented in challenged STHdhQ111 cells. Last, analysis of Enroll-HD datasets suggested that HD patients taking arginine supplements progressed more rapidly than others. Our data suggest a novel pathway that links arginine uptake to nitrosative stress via upregulation of SLC7A2 in the pathogenesis and progression of HD. This further implies that arginine supplements may potentially pose a greater risk to HD patients.
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Affiliation(s)
- Ian D Gaudet
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Hongyuan Xu
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Emily Gordon
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Gianna A Cannestro
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Michael L Lu
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Jianning Wei
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA.
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7
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Ying Y, Yang Y, Chen AK. Roles of RNA scaffolding in nanoscale Gag multimerization and selective protein sorting at HIV membranes. SCIENCE ADVANCES 2024; 10:eadk8297. [PMID: 38394201 PMCID: PMC10889351 DOI: 10.1126/sciadv.adk8297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/19/2024] [Indexed: 02/25/2024]
Abstract
HIV-1 Gag proteins can multimerize upon the viral genomic RNA or multiple random cellular messenger RNAs to form a virus particle or a virus-like particle, respectively. To date, whether the two types of particles form via the same Gag multimerization process has remained unclarified. Using photoactivated localization microscopy to illuminate Gag organizations and dynamics at the nanoscale, here, we showed that genomic RNA mediates Gag multimerization in a more cluster-centric, cooperative, and spatiotemporally coordinated fashion, with the ability to drive dense Gag clustering dependent on its ability to act as a long-stranded scaffold not easily attainable by cellular messenger RNAs. These differences in Gag multimerization were further shown to affect downstream selective protein sorting into HIV membranes, indicating that the choice of RNA for packaging can modulate viral membrane compositions. These findings should advance the understanding of HIV assembly and further benefit the development of virus-like particle-based therapeutics.
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Affiliation(s)
- Yachen Ying
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing 100871, China
| | - Yantao Yang
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing 100871, China
| | - Antony K Chen
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing 100871, China
- National Biomedical Imaging Center, Peking University, Beijing 100871, China
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8
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Martinez-Yamout MA, Nasir I, Shnitkind S, Ellis JP, Berlow RB, Kroon G, Deniz AA, Dyson HJ, Wright PE. Glutamine-rich regions of the disordered CREB transactivation domain mediate dynamic intra- and intermolecular interactions. Proc Natl Acad Sci U S A 2023; 120:e2313835120. [PMID: 37971402 PMCID: PMC10666024 DOI: 10.1073/pnas.2313835120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 10/10/2023] [Indexed: 11/19/2023] Open
Abstract
The cyclic AMP response element (CRE) binding protein (CREB) is a transcription factor that contains a 280-residue N-terminal transactivation domain and a basic leucine zipper that mediates interaction with DNA. The transactivation domain comprises three subdomains, the glutamine-rich domains Q1 and Q2 and the kinase inducible activation domain (KID). NMR chemical shifts show that the isolated subdomains are intrinsically disordered but have a propensity to populate local elements of secondary structure. The Q1 and Q2 domains exhibit a propensity for formation of short β-hairpin motifs that function as binding sites for glutamine-rich sequences. These motifs mediate intramolecular interactions between the CREB Q1 and Q2 domains as well as intermolecular interactions with the glutamine-rich Q1 domain of the TATA-box binding protein associated factor 4 (TAF4) subunit of transcription factor IID (TFIID). Using small-angle X-ray scattering, NMR, and single-molecule Förster resonance energy transfer, we show that the Q1, Q2, and KID regions remain dynamically disordered in a full-length CREB transactivation domain (CREBTAD) construct. The CREBTAD polypeptide chain is largely extended although some compaction is evident in the KID and Q2 domains. Paramagnetic relaxation enhancement reveals transient long-range contacts both within and between the Q1 and Q2 domains while the intervening KID domain is largely devoid of intramolecular interactions. Phosphorylation results in expansion of the KID domain, presumably making it more accessible for binding the CBP/p300 transcriptional coactivators. Our study reveals the complex nature of the interactions within the intrinsically disordered transactivation domain of CREB and provides molecular-level insights into dynamic and transient interactions mediated by the glutamine-rich domains.
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Affiliation(s)
- Maria A. Martinez-Yamout
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Irem Nasir
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Sergey Shnitkind
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Jamie P. Ellis
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Rebecca B. Berlow
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Gerard Kroon
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Ashok A. Deniz
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - H. Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Peter E. Wright
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
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9
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Daugird TA, Shi Y, Holland KL, Rostamian H, Liu Z, Lavis LD, Rodriguez J, Strahl BD, Legant WR. Correlative single molecule lattice light sheet imaging reveals the dynamic relationship between nucleosomes and the local chromatin environment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.09.566470. [PMID: 38014222 PMCID: PMC10680651 DOI: 10.1101/2023.11.09.566470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
In the nucleus, biological processes are driven by proteins that diffuse through and bind to a meshwork of nucleic acid polymers. To better understand this interplay, we developed an imaging platform to simultaneously visualize single protein dynamics together with the local chromatin environment in live cells. Together with super-resolution imaging, new fluorescent probes, and biophysical modeling, we demonstrated that nucleosomes display differential diffusion and packing arrangements as chromatin density increases whereas the viscoelastic properties and accessibility of the interchromatin space remain constant. Perturbing nuclear functions impacted nucleosome diffusive properties in a manner that was dependent on local chromatin density and supportive of a model wherein transcription locally stabilizes nucleosomes while simultaneously allowing for the free exchange of nuclear proteins. Our results reveal that nuclear heterogeneity arises from both active and passive process and highlights the need to account for different organizational principals when modeling different chromatin environments.
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10
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Bai Y, Zhang S, Dong H, Liu Y, Liu C, Zhang X. Advanced Techniques for Detecting Protein Misfolding and Aggregation in Cellular Environments. Chem Rev 2023; 123:12254-12311. [PMID: 37874548 DOI: 10.1021/acs.chemrev.3c00494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Protein misfolding and aggregation, a key contributor to the progression of numerous neurodegenerative diseases, results in functional deficiencies and the creation of harmful intermediates. Detailed visualization of this misfolding process is of paramount importance for improving our understanding of disease mechanisms and for the development of potential therapeutic strategies. While in vitro studies using purified proteins have been instrumental in delivering significant insights into protein misfolding, the behavior of these proteins in the complex milieu of living cells often diverges significantly from such simplified environments. Biomedical imaging performed in cell provides cellular-level information with high physiological and pathological relevance, often surpassing the depth of information attainable through in vitro methods. This review highlights a variety of methodologies used to scrutinize protein misfolding within biological systems. This includes optical-based methods, strategies leaning on mass spectrometry, in-cell nuclear magnetic resonance, and cryo-electron microscopy. Recent advancements in these techniques have notably deepened our understanding of protein misfolding processes and the features of the resulting misfolded species within living cells. The progression in these fields promises to catalyze further breakthroughs in our comprehension of neurodegenerative disease mechanisms and potential therapeutic interventions.
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Affiliation(s)
- Yulong Bai
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Shengnan Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Hui Dong
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Yu Liu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Xin Zhang
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
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11
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Poruthoor AJ, Sharma A, Grossfield A. Understanding the free-energy landscape of phase separation in lipid bilayers using molecular dynamics. Biophys J 2023; 122:4144-4159. [PMID: 37742069 PMCID: PMC10645549 DOI: 10.1016/j.bpj.2023.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/28/2023] [Accepted: 09/19/2023] [Indexed: 09/25/2023] Open
Abstract
Liquid-liquid phase separation inside the cell often results in biological condensates that can critically affect cell homeostasis. Such phase separation events occur in multiple parts of cells, including the cell membranes, where the "lipid raft" hypothesis posits the formation of ordered domains floating in a sea of disordered lipids. The resulting lipid domains often have functional roles. However, the thermodynamics of lipid phase separation and their resulting mechanistic effects on cell function and dysfunction are poorly understood. Understanding such complex phenomena in cell membranes, with their diverse lipid compositions, is exceptionally difficult. For these reasons, simple model systems that can recapitulate similar behavior are widely used to study this phenomenon. Despite these simplifications, the timescale and length scales of domain formation pose a challenge for molecular dynamics (MD) simulations. Thus, most MD studies focus on spontaneous lipid phase separation-essentially measuring the sign (but not the amplitude) of the free-energy change upon separation-rather than directly interrogating the thermodynamics. Here, we propose a proof-of-concept pipeline that can directly measure this free energy by combining coarse-grained MD with enhanced sampling protocols using a novel collective variable. This approach will be a useful tool to help connect the thermodynamics of phase separation with the mechanistic insights already available from MD simulations.
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Affiliation(s)
- Ashlin J Poruthoor
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York
| | - Akshara Sharma
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York
| | - Alan Grossfield
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York.
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12
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Cariulo C, Martufi P, Verani M, Toledo-Sherman L, Lee R, Dominguez C, Petricca L, Caricasole A. IKBKB reduces huntingtin aggregation by phosphorylating serine 13 via a non-canonical IKK pathway. Life Sci Alliance 2023; 6:e202302006. [PMID: 37553253 PMCID: PMC10410066 DOI: 10.26508/lsa.202302006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 08/10/2023] Open
Abstract
N-terminal phosphorylation at residues T3 and S13 is believed to have important beneficial implications for the biological and pathological properties of mutant huntingtin, where inhibitor of nuclear factor kappa B kinase subunit beta (IKBKB) was identified as a candidate regulator of huntingtin N-terminal phosphorylation. The paucity of mechanistic information on IKK pathways, together with the lack of sensitive methods to quantify endogenous huntingtin phosphorylation, prevented detailed study of the role of IKBKB in Huntington's disease. Using novel ultrasensitive assays, we demonstrate that IKBKB can regulate endogenous S13 huntingtin phosphorylation in a manner, dependent on its kinase activity and known regulators. We found that the ability of IKBKB to phosphorylate endogenous huntingtin S13 is mediated through a non-canonical interferon regulatory factor3-mediated IKK pathway, distinct from the established involvement of IKBKB in mutant huntingtin's pathological mechanisms mediated via the canonical pathway. Furthermore, increased huntingtin S13 phosphorylation by IKBKB resulted in decreased aggregation of mutant huntingtin in cells, again dependent on its kinase activity. These findings point to a non-canonical IKK pathway linking S13 huntingtin phosphorylation to the pathological properties of mutant huntingtin aggregation, thought to be significant to Huntington's disease.
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Affiliation(s)
- Cristina Cariulo
- Neuroscience Unit, Translational and Discovery Research Department, IRBM S.p.A., Rome, Italy
| | - Paola Martufi
- Neuroscience Unit, Translational and Discovery Research Department, IRBM S.p.A., Rome, Italy
| | - Margherita Verani
- Neuroscience Unit, Translational and Discovery Research Department, IRBM S.p.A., Rome, Italy
| | - Leticia Toledo-Sherman
- Rainwatercf.org Tau Consortium, Rainwater Charitable Foundation, Fort Worth, TX, USA
- UCLA, Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA
| | - Ramee Lee
- CHDI Management/CHDI Foundation, Princeton, NJ, USA
| | | | - Lara Petricca
- Neuroscience Unit, Translational and Discovery Research Department, IRBM S.p.A., Rome, Italy
| | - Andrea Caricasole
- Neuroscience Unit, Translational and Discovery Research Department, IRBM S.p.A., Rome, Italy
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13
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Laundos TL, Li S, Cheang E, De Santis R, Piccolo FM, Brivanlou AH. Huntingtin CAG-expansion mutation results in a dominant negative effect. Front Cell Dev Biol 2023; 11:1252521. [PMID: 37727506 PMCID: PMC10505792 DOI: 10.3389/fcell.2023.1252521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 08/14/2023] [Indexed: 09/21/2023] Open
Abstract
Introduction: Huntington's disease (HD) remains an incurable and fatal neurodegenerative disease long after CAG-expansion mutation in the huntingtin gene (HTT) was identified as the cause. The underlying pathological mechanism, whether HTT loss of function or gain of toxicity results from mutation, remains a matter of debate. Methods: In this study, we genetically modulated wild-type or mutant HTT expression levels in isogenic human embryonic stem cells to systematically investigate their contribution to HD-specific phenotypes. Results: Using highly reproducible and quantifiable in vitro micropattern-based assays, we observed comparable phenotypes with HD mutation and HTT depletion. However, halving endogenous wild-type HTT levels did not strongly recapitulate the HD phenotypes, arguing against a classical loss of function mechanism. Remarkably, expression of CAG-expanded HTT in non-HD cells induced HD like phenotypes akin to HTT depletion. Discussion: By corollary, these results indicate a dominant negative effect of mutated HTT on its wild-type counterpart. Complementation with additional copies of wild-type HTT ameliorated the HD-associated phenotypes, strongly supporting a classical dominant negative mechanism. Understanding the molecular basis of this dominant negative effect will guide the development of efficient clinical strategies to counteract the deleterious impact of mutant HTT on the wild-type HTT function.
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Affiliation(s)
- Tiago L. Laundos
- Laboratory of Synthetic Embryology, The Rockefeller University, New York City, NY, United States
- ICBAS—Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
| | - Shu Li
- Laboratory of Synthetic Embryology, The Rockefeller University, New York City, NY, United States
| | - Eric Cheang
- Laboratory of Synthetic Embryology, The Rockefeller University, New York City, NY, United States
| | - Riccardo De Santis
- Laboratory of Synthetic Embryology, The Rockefeller University, New York City, NY, United States
| | - Francesco M. Piccolo
- Laboratory of Synthetic Embryology, The Rockefeller University, New York City, NY, United States
| | - Ali H. Brivanlou
- Laboratory of Synthetic Embryology, The Rockefeller University, New York City, NY, United States
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14
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Schnermann MJ, Lavis LD. Rejuvenating old fluorophores with new chemistry. Curr Opin Chem Biol 2023; 75:102335. [PMID: 37269674 PMCID: PMC10524207 DOI: 10.1016/j.cbpa.2023.102335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/26/2023] [Accepted: 05/02/2023] [Indexed: 06/05/2023]
Abstract
The field of organic chemistry began with 19th century scientists identifying and then expanding upon synthetic dye molecules for textiles. In the 20th century, dye chemistry continued with the aim of developing photographic sensitizers and laser dyes. Now, in the 21st century, the rapid evolution of biological imaging techniques provides a new driving force for dye chemistry. Of the extant collection of synthetic fluorescent dyes for biological imaging, two classes reign supreme: rhodamines and cyanines. Here, we provide an overview of recent examples where modern chemistry is used to build these old-but-venerable classes of optically responsive molecules. These new synthetic methods access new fluorophores, which then enable sophisticated imaging experiments leading to new biological insights.
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Affiliation(s)
- Martin J Schnermann
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Building 376, Frederick, MD 20850, USA.
| | - Luke D Lavis
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, 20147, USA.
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15
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Guo G, Wang X, Zhang Y, Li T. Sequence variations of phase-separating proteins and resources for studying biomolecular condensates. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1119-1132. [PMID: 37464880 PMCID: PMC10423696 DOI: 10.3724/abbs.2023131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 06/06/2023] [Indexed: 07/20/2023] Open
Abstract
Phase separation (PS) is an important mechanism underlying the formation of biomolecular condensates. Physiological condensates are associated with numerous biological processes, such as transcription, immunity, signaling, and synaptic transmission. Changes in particular amino acids or segments can disturb the protein's phase behavior and interactions with other biomolecules in condensates. It is thus presumed that variations in the phase-separating-prone domains can significantly impact the properties and functions of condensates. The dysfunction of condensates contributes to a number of pathological processes. Pharmacological perturbation of these condensates is proposed as a promising way to restore physiological states. In this review, we characterize the variations observed in PS proteins that lead to aberrant biomolecular compartmentalization. We also showcase recent advancements in bioinformatics of membraneless organelles (MLOs), focusing on available databases useful for screening PS proteins and describing endogenous condensates, guiding researchers to seek the underlying pathogenic mechanisms of biomolecular condensates.
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Affiliation(s)
- Gaigai Guo
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
| | - Xinxin Wang
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
| | - Yi Zhang
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
| | - Tingting Li
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
- Key Laboratory for NeuroscienceMinistry of Education/National Health Commission of ChinaPeking UniversityBeijing100191China
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16
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Tripathi SJ, Chakraborty S, Miller E, Pieper AA, Paul BD. Hydrogen sulfide signalling in neurodegenerative diseases. Br J Pharmacol 2023:10.1111/bph.16170. [PMID: 37338307 PMCID: PMC10730776 DOI: 10.1111/bph.16170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 06/21/2023] Open
Abstract
The gaseous neurotransmitter hydrogen sulfide (H2 S) exerts neuroprotective efficacy in the brain via post-translational modification of cysteine residues by sulfhydration, also known as persulfidation. This process is comparable in biological impact to phosphorylation and mediates a variety of signalling events. Unlike conventional neurotransmitters, H2 S cannot be stored in vesicles due to its gaseous nature. Instead, it is either locally synthesized or released from endogenous stores. Sulfhydration affords both specific and general neuroprotective effects and is critically diminished in several neurodegenerative disorders. Conversely, some forms of neurodegenerative disease are linked to excessive cellular H2 S. Here, we review the signalling roles of H2 S across the spectrum of neurodegenerative diseases, including Huntington's disease, Parkinson's disease, Alzheimer's disease, Down syndrome, traumatic brain injury, the ataxias, and amyotrophic lateral sclerosis, as well as neurodegeneration generally associated with ageing.
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Affiliation(s)
- Sunil Jamuna Tripathi
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Suwarna Chakraborty
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Emiko Miller
- Brain Health Medicines Center, Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Andrew A Pieper
- Brain Health Medicines Center, Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
- Department of Psychiatry, Case Western Reserve University, Cleveland, Ohio, USA
- Geriatric Psychiatry, GRECC, Louis Stokes Cleveland VA Medical Center; Cleveland, Ohio, USA
- School of Medicine, Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Neuroscience, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Translational Therapeutics Core, Cleveland Alzheimer's Disease Research Center, Cleveland, Ohio, USA
| | - Bindu D Paul
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Lieber Institute for Brain Development, Baltimore, Maryland, USA
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17
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Kim YJ, Lee M, Lee YT, Jing J, Sanders JT, Botten GA, He L, Lyu J, Zhang Y, Mettlen M, Ly P, Zhou Y, Xu J. Light-activated macromolecular phase separation modulates transcription by reconfiguring chromatin interactions. SCIENCE ADVANCES 2023; 9:eadg1123. [PMID: 37000871 PMCID: PMC10065442 DOI: 10.1126/sciadv.adg1123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
Biomolecular condensates participate in the regulation of gene transcription, yet the relationship between nuclear condensation and transcriptional activation remains elusive. Here, we devised a biotinylated CRISPR-dCas9-based optogenetic method, light-activated macromolecular phase separation (LAMPS), to enable inducible formation, affinity purification, and multiomic dissection of nuclear condensates at the targeted genomic loci. LAMPS-induced condensation at enhancers and promoters activates endogenous gene transcription by chromatin reconfiguration, causing increased chromatin accessibility and de novo formation of long-range chromosomal loops. Proteomic profiling of light-induced condensates by dCas9-mediated affinity purification uncovers multivalent interaction-dependent remodeling of macromolecular composition, resulting in the selective enrichment of transcriptional coactivators and chromatin structure proteins. Our findings support a model whereby the formation of nuclear condensates at native genomic loci reconfigures chromatin architecture and multiprotein assemblies to modulate gene transcription. Hence, LAMPS facilitates mechanistic interrogation of the relationship between nuclear condensation, genome structure, and gene transcription in living cells.
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Affiliation(s)
- Yoon Jung Kim
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael Lee
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yi-Tsang Lee
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
| | - Ji Jing
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
| | - Jacob T. Sanders
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Giovanni A. Botten
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lian He
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
| | - Junhua Lyu
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yuannyu Zhang
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Peter Ly
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
- Department of Translational Medical Sciences, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Jian Xu
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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18
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Zhang J, Shi H, Huang C, Mei L, Guo Q, Cheng K, Wu P, Su D, Chen Q, Gan S, Wing Chan CK, Shi J, Chen JL, Jonathan Choi CH, Yao SQ, Chen XK, Tang BZ, He J, Sun H. De Novo Designed Self-Assembling Rhodamine Probe for Real-Time, Long-Term and Quantitative Live-Cell Nanoscopy. ACS NANO 2023; 17:3632-3644. [PMID: 36744992 DOI: 10.1021/acsnano.2c10467] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Super-resolution imaging provides a powerful approach to image dynamic biomolecule events at nanoscale resolution. An ingenious method involving tuning intramolecular spirocyclization in rhodamine offers an appealing strategy to design cell-permeable fluorogenic probes for super-resolution imaging. Nevertheless, precise control of rhodamine spirocyclization presents a significant challenge. Through detailed study of the structure-activity relationship, we identified that multiple key factors control rhodamime spirocyclization. The findings provide opportunities to create fluorogenic probes with tailored properties. On the basis of our findings, we constructed self-assembling rhodamine probes for no-wash live-cell confocal and super-resolution imaging. The designed self-assembling probe Rho-2CF3 specifically labeled its target proteins and displayed high ring-opening ability, fast labeling kinetics (<1 min), and large turn-on fold (>80 folds), which is very difficult to be realized by the existing methods. Using the probe, we achieved high-contrast super-resolution imaging of nuclei and mitochondria with a spatial resolution of up to 42 nm. The probe also showed excellent photostability and proved ideal for real-time and long-term tracking of mitochondrial fission and fusion events with high spatiotemporal resolution. Furthermore, Rho-2CF3 could resolve the ultrastructure of mitochondrial cristae and quantify their morphological changes under drug treatment at nanoscale. Our strategy thus demonstrates its usefulness in designing self-assembling probes for super-resolution imaging.
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Affiliation(s)
- Jie Zhang
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
- Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Chinese Academy of Sciences, Hong Kong, 999077, China
| | - Heng Shi
- Departments of Neuroscience and Biomedical Sciences, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, Guangdong Province 510530, China
| | - Chen Huang
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Le Mei
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Qiang Guo
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
- Department of Science, School of Science and Technology, Hong Kong Metropolitan University, Good Shepherd Street, Ho Man Tin, Hong Kong SAR, 999077, China
| | - Ke Cheng
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Pingzhou Wu
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Dan Su
- Departments of Neuroscience and Biomedical Sciences, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Qingxin Chen
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Shenglong Gan
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Cecilia Ka Wing Chan
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
| | - Jiahai Shi
- Departments of Neuroscience and Biomedical Sciences, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Jian Lin Chen
- Department of Science, School of Science and Technology, Hong Kong Metropolitan University, Good Shepherd Street, Ho Man Tin, Hong Kong SAR, 999077, China
| | - Chung Hang Jonathan Choi
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
| | - Shao Q Yao
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Xian-Kai Chen
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Ben Zhong Tang
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077, China
| | - Jufang He
- Departments of Neuroscience and Biomedical Sciences, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
- Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Chinese Academy of Sciences, Hong Kong, 999077, China
| | - Hongyan Sun
- Department of Chemistry and COSDAF (Centre of Super-Diamond and Advanced Films), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
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19
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Pepe G, Capocci L, Marracino F, Realini N, Lenzi P, Martinello K, Bovier TF, Bichell TJ, Scarselli P, Di Cicco C, Bowman AB, Digilio FA, Fucile S, Fornai F, Armirotti A, Parlato R, Di Pardo A, Maglione V. Treatment with THI, an inhibitor of sphingosine-1-phosphate lyase, modulates glycosphingolipid metabolism and results therapeutically effective in experimental models of Huntington's disease. Mol Ther 2023; 31:282-299. [PMID: 36116006 PMCID: PMC9840122 DOI: 10.1016/j.ymthe.2022.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/05/2022] [Accepted: 09/06/2022] [Indexed: 02/06/2023] Open
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disorder with no effective cure currently available. Over the past few years our research has shown that alterations in sphingolipid metabolism represent a critical determinant in HD pathogenesis. In particular, aberrant metabolism of sphingosine-1-phosphate (S1P) has been reported in multiple disease settings, including human postmortem brains from HD patients. In this study, we investigate the potential therapeutic effect of the inhibition of S1P degradative enzyme SGPL1, by the chronic administration of the 2-acetyl-5-tetrahydroxybutyl imidazole (THI) inhibitor. We show that THI mitigated motor dysfunctions in both mouse and fly models of HD. The compound evoked the activation of pro-survival pathways, normalized levels of brain-derived neurotrophic factor, preserved white matter integrity, and stimulated synaptic functions in HD mice. Metabolically, THI restored normal levels of hexosylceramides and stimulated the autophagic and lysosomal machinery, facilitating the reduction of nuclear inclusions of both wild-type and mutant huntingtin proteins.
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Affiliation(s)
| | | | | | - Natalia Realini
- Analytical Chemistry Lab, Fondazione Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Paola Lenzi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy
| | | | - Tiziana Francesca Bovier
- Research Institute on Terrestrial Ecosystems (IRET), UOS Naples-CNR, Via Pietro Castellino 111, 80131 Naples, Italy; Department of Pediatrics Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA; Center for Host-Pathogen Interaction, Columbia University Vagelos College of Physicians and Surgeons, New York 10032, NY, USA
| | - Terry Jo Bichell
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA
| | | | | | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, USA
| | - Filomena A Digilio
- Research Institute on Terrestrial Ecosystems (IRET), UOS Naples-CNR, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Sergio Fucile
- IRCCS Neuromed, Pozzilli (IS) 86077, Italy; Department of Physiology and Pharmacology, Sapienza Rome University, Rome 00185, Italy
| | - Francesco Fornai
- IRCCS Neuromed, Pozzilli (IS) 86077, Italy; Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy
| | - Andrea Armirotti
- Analytical Chemistry Lab, Fondazione Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Rosanna Parlato
- Division for Neurodegenerative Diseases, Department of Neurology, Mannheim Center for Translational Neuroscience, Medical Faculty Mannheim Heidelberg University, Mannheim 68167, Germany
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20
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González-Rodríguez P, Delorme-Axford E, Bernard A, Keane L, Stratoulias V, Grabert K, Engskog-Vlachos P, Füllgrabe J, Klionsky DJ, Joseph B. SETD2 transcriptional control of ATG14L/S isoforms regulates autophagosome-lysosome fusion. Cell Death Dis 2022; 13:953. [PMID: 36371383 PMCID: PMC9653477 DOI: 10.1038/s41419-022-05381-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/19/2022] [Accepted: 10/26/2022] [Indexed: 11/13/2022]
Abstract
Macroautophagy/autophagy is an evolutionarily conserved and tightly regulated catabolic process involved in the maintenance of cellular homeostasis whose dysregulation is implicated in several pathological processes. Autophagy begins with the formation of phagophores that engulf cytoplasmic cargo and mature into double-membrane autophagosomes; the latter fuse with lysosomes/vacuoles for cargo degradation and recycling. Here, we report that yeast Set2, a histone lysine methyltransferase, and its mammalian homolog, SETD2, both act as positive transcriptional regulators of autophagy. However, whereas Set2 regulates the expression of several autophagy-related (Atg) genes upon nitrogen starvation, SETD2 effects in mammals were found to be more restricted. In fact, SETD2 appears to primarily regulate the differential expression of protein isoforms encoded by the ATG14 gene. SETD2 promotes the expression of a long ATG14 isoform, ATG14L, that contains an N-terminal cysteine repeats domain, essential for the efficient fusion of the autophagosome with the lysosome, that is absent in the short ATG14 isoform, ATG14S. Accordingly, SETD2 loss of function decreases autophagic flux, as well as the turnover of aggregation-prone proteins such as mutant HTT (huntingtin) leading to increased cellular toxicity. Hence, our findings bring evidence to the emerging concept that the production of autophagy-related protein isoforms can differentially affect core autophagy machinery bringing an additional level of complexity to the regulation of this biological process in more complex organisms.
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Affiliation(s)
- Patricia González-Rodríguez
- Institute of Environmental Medicine, Toxicology Unit, Karolinska Institutet, 17177, Stockholm, Sweden
- Department of Oncology Pathology, Cancer Centrum Karolinska, Karolinska Institutet, 171 76, Stockholm, Sweden
- Division of Biochemistry, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Elizabeth Delorme-Axford
- Life Sciences Institute, and the Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
- Department of Biological Sciences, Oakland University, Rochester, MI, USA
| | - Amélie Bernard
- Life Sciences Institute, and the Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
- University of Bordeaux, CNRS, Laboratoire de Biogenèse Membranaire, UMR 5200, F-33140, Villenave d'Ornon, France
| | - Lily Keane
- Institute of Environmental Medicine, Toxicology Unit, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Vassilis Stratoulias
- Institute of Environmental Medicine, Toxicology Unit, Karolinska Institutet, 17177, Stockholm, Sweden
- Department of Oncology Pathology, Cancer Centrum Karolinska, Karolinska Institutet, 171 76, Stockholm, Sweden
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Kathleen Grabert
- Institute of Environmental Medicine, Toxicology Unit, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Pinelopi Engskog-Vlachos
- Institute of Environmental Medicine, Toxicology Unit, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Jens Füllgrabe
- Department of Oncology Pathology, Cancer Centrum Karolinska, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Daniel J Klionsky
- Life Sciences Institute, and the Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Bertrand Joseph
- Institute of Environmental Medicine, Toxicology Unit, Karolinska Institutet, 17177, Stockholm, Sweden.
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21
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“Structure”-function relationships in eukaryotic transcription factors: The role of intrinsically disordered regions in gene regulation. Mol Cell 2022; 82:3970-3984. [DOI: 10.1016/j.molcel.2022.09.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/19/2022] [Accepted: 09/21/2022] [Indexed: 11/06/2022]
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22
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Rhine K, Al-Azzam N, Yu T, Yeo GW. Aging RNA granule dynamics in neurodegeneration. Front Mol Biosci 2022; 9:991641. [PMID: 36188213 PMCID: PMC9523239 DOI: 10.3389/fmolb.2022.991641] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/22/2022] [Indexed: 12/30/2022] Open
Abstract
Disordered RNA-binding proteins and repetitive RNA sequences are the main genetic causes of several neurodegenerative diseases, including amyotrophic lateral sclerosis and Huntington’s disease. Importantly, these components also seed the formation of cytoplasmic liquid-like granules, like stress granules and P bodies. Emerging evidence demonstrates that healthy granules formed via liquid-liquid phase separation can mature into solid- or gel-like inclusions that persist within the cell. These solidified inclusions are a precursor to the aggregates identified in patients, demonstrating that dysregulation of RNA granule biology is an important component of neurodegeneration. Here, we review recent literature highlighting how RNA molecules seed proteinaceous granules, the mechanisms of healthy turnover of RNA granules in cells, which biophysical properties underly a transition to solid- or gel-like material states, and why persistent granules disrupt the cellular homeostasis of neurons. We also identify various methods that will illuminate the contributions of disordered proteins and RNAs to neurodegeneration in ongoing research efforts.
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Affiliation(s)
- Kevin Rhine
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
| | - Norah Al-Azzam
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
- Neurosciences Graduate Program, University of California, San Diego, San Diego, CA, United States
| | - Tao Yu
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
| | - Gene W. Yeo
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
- Neurosciences Graduate Program, University of California, San Diego, San Diego, CA, United States
- *Correspondence: Gene W. Yeo,
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23
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Liu H, Wang HG, Pitt G, Liu Z. Direct Observation of Compartment-Specific Localization and Dynamics of Voltage-Gated Sodium Channels. J Neurosci 2022; 42:5482-5498. [PMID: 35672149 PMCID: PMC9295844 DOI: 10.1523/jneurosci.0086-22.2022] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/15/2022] [Accepted: 05/18/2022] [Indexed: 11/21/2022] Open
Abstract
Brain enriched voltage-gated sodium channel (VGSC) Nav1.2 and Nav1.6 are critical for electrical signaling in the CNS. Previous studies have extensively characterized cell-type-specific expression and electrophysiological properties of these two VGSCs and how their differences contribute to fine-tuning of neuronal excitability. However, because of a lack of reliable labeling and imaging methods, the subcellular localization and dynamics of these homologous Nav1.2 and Nav1.6 channels remain understudied. To overcome this challenge, we combined genome editing, super-resolution, and live-cell single-molecule imaging to probe subcellular composition, relative abundances, and trafficking dynamics of Nav1.2 and Nav1.6 in cultured mouse and rat neurons and in male and female mouse brain. We discovered a previously uncharacterized trafficking pathway that targets Nav1.2 to the distal axon of unmyelinated neurons. This pathway uses distinct signals residing in the intracellular loop 1 between transmembrane domain I and II to suppress the retention of Nav1.2 in the axon initial segment and facilitate its membrane loading at the distal axon. As mouse pyramidal neurons undergo myelination, Nav1.2 is gradually excluded from the distal axon as Nav1.6 becomes the dominant VGSC in the axon initial segment and nodes of Ranvier. In addition, we revealed exquisite developmental regulation of Nav1.2 and Nav1.6 localizations in the axon initial segment and dendrites, clarifying the molecular identity of sodium channels in these subcellular compartments. Together, these results unveiled compartment-specific localizations and trafficking mechanisms for VGSCs, which could be regulated separately to modulate membrane excitability in the brain.SIGNIFICANCE STATEMENT Direct observation of endogenous voltage-gated sodium channels reveals a previously uncharacterized distal axon targeting mechanism and the molecular identity of sodium channels in distinct subcellular compartments.
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Affiliation(s)
- Hui Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147
| | - Hong-Gang Wang
- Weill Cornell Medicine, Cardiovascular Research Institute, New York, New York 10021
| | - Geoffrey Pitt
- Weill Cornell Medicine, Cardiovascular Research Institute, New York, New York 10021
| | - Zhe Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147
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24
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Dynamic Mode Decomposition of Fluorescence Loss in Photobleaching Microscopy Data for Model-Free Analysis of Protein Transport and Aggregation in Living Cells. SENSORS 2022; 22:s22134731. [PMID: 35808232 PMCID: PMC9269098 DOI: 10.3390/s22134731] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/16/2022] [Accepted: 06/20/2022] [Indexed: 02/05/2023]
Abstract
The phase separation and aggregation of proteins are hallmarks of many neurodegenerative diseases. These processes can be studied in living cells using fluorescent protein constructs and quantitative live-cell imaging techniques, such as fluorescence recovery after photobleaching (FRAP) or the related fluorescence loss in photobleaching (FLIP). While the acquisition of FLIP images is straightforward on most commercial confocal microscope systems, the analysis and computational modeling of such data is challenging. Here, a novel model-free method is presented, which resolves complex spatiotemporal fluorescence-loss kinetics based on dynamic-mode decomposition (DMD) of FLIP live-cell image sequences. It is shown that the DMD of synthetic and experimental FLIP image series (DMD-FLIP) allows for the unequivocal discrimination of subcellular compartments, such as nuclei, cytoplasm, and protein condensates based on their differing transport and therefore fluorescence loss kinetics. By decomposing fluorescence-loss kinetics into distinct dynamic modes, DMD-FLIP will enable researchers to study protein dynamics at each time scale individually. Furthermore, it is shown that DMD-FLIP is very efficient in denoising confocal time series data. Thus, DMD-FLIP is an easy-to-use method for the model-free detection of barriers to protein diffusion, of phase-separated protein assemblies, and of insoluble protein aggregates. It should, therefore, find wide application in the analysis of protein transport and aggregation, in particular in relation to neurodegenerative diseases and the formation of protein condensates in living cells.
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25
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Paul BD. Cysteine metabolism and hydrogen sulfide signaling in Huntington's disease. Free Radic Biol Med 2022; 186:93-98. [PMID: 35550919 PMCID: PMC10066926 DOI: 10.1016/j.freeradbiomed.2022.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/17/2022] [Accepted: 05/05/2022] [Indexed: 02/06/2023]
Abstract
The semi-essential amino acid, cysteine, plays important roles in both essential cellular processes as well as in modulation of signaling cascades. Cysteine is obtained both from the diet as well as generated endogenously via the transsulfuration pathway. Cysteine is further utilized in protein synthesis and biosynthesis of various sulfur containing molecules. One of the products of cysteine catabolism, hydrogen sulfide (H2S), is a gaseous signaling molecule, which regulates a multitude of cellular processes. Cysteine metabolism is dysregulated in several neurodegenerative diseases and during aging. This minireview focuses on aberrant cysteine and H2S metabolism in Huntington's disease, a neurodegenerative disease caused by expansion of polyglutamine encoding repeats in the gene huntingtin, which leads to motor and cognitive deficits.
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Affiliation(s)
- Bindu D Paul
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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26
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Rhine K, Skanchy S, Myong S. Single-molecule and ensemble methods to probe RNP nucleation and condensate properties. Methods 2022; 197:74-81. [PMID: 33610691 PMCID: PMC8374000 DOI: 10.1016/j.ymeth.2021.02.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/02/2021] [Accepted: 02/13/2021] [Indexed: 01/03/2023] Open
Abstract
Biomolecular condensates often consist of intrinsically disordered protein and RNA molecules, which together promote the formation of membraneless organelles in cells. The nucleation, condensation, and maturation of condensates is a critical yet poorly understood process. Here, we present single-molecule and accompanying ensemble methods to quantify these processes more comprehensively. In particular, we focus on how to properly design and execute a single-molecule nucleation assay, in which we detect signals arising from individual units of fluorescently labeled RNA-binding proteins associating with an RNA substrate. The analysis of this data allows one to determine the kinetics involved with each step of nucleation. Complemented with meso-scale techniques that measure the biophysical properties of ribonucleoprotein condensates, the methods described herein are powerful tools that can be adopted for studying any protein-RNA interactions that promote phase separation.
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Affiliation(s)
- Kevin Rhine
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218,Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218
| | - Sophie Skanchy
- Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218
| | - Sua Myong
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218,Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218,Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, 506 S Wright St, Urbana, IL 61801,Corresponding Author;
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27
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Nuclear and cytoplasmic huntingtin inclusions exhibit distinct biochemical composition, interactome and ultrastructural properties. Nat Commun 2021; 12:6579. [PMID: 34772920 PMCID: PMC8589980 DOI: 10.1038/s41467-021-26684-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/11/2021] [Indexed: 12/20/2022] Open
Abstract
Despite the strong evidence linking the aggregation of the Huntingtin protein (Htt) to the pathogenesis of Huntington's disease (HD), the mechanisms underlying Htt aggregation and neurodegeneration remain poorly understood. Herein, we investigated the ultrastructural properties and protein composition of Htt cytoplasmic and nuclear inclusions in mammalian cells and primary neurons overexpressing mutant exon1 of the Htt protein. Our findings provide unique insight into the ultrastructural properties of cytoplasmic and nuclear Htt inclusions and their mechanisms of formation. We show that Htt inclusion formation and maturation are complex processes that, although initially driven by polyQ-dependent Htt aggregation, also involve the polyQ and PRD domain-dependent sequestration of lipids and cytoplasmic and cytoskeletal proteins related to HD dysregulated pathways; the recruitment and accumulation of remodeled or dysfunctional membranous organelles, and the impairment of the protein quality control and degradation machinery. We also show that nuclear and cytoplasmic Htt inclusions exhibit distinct biochemical compositions and ultrastructural properties, suggesting different mechanisms of aggregation and toxicity.
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28
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Abstract
To predict transcription, one needs a mechanistic understanding of how the numerous required transcription factors (TFs) explore the nuclear space to find their target genes, assemble, cooperate, and compete with one another. Advances in fluorescence microscopy have made it possible to visualize real-time TF dynamics in living cells, leading to two intriguing observations: first, most TFs contact chromatin only transiently; and second, TFs can assemble into clusters through their intrinsically disordered regions. These findings suggest that highly dynamic events and spatially structured nuclear microenvironments might play key roles in transcription regulation that are not yet fully understood. The emerging model is that while some promoters directly convert TF-binding events into on/off cycles of transcription, many others apply complex regulatory layers that ultimately lead to diverse phenotypic outputs. Cracking this kinetic code is an ongoing and challenging task that is made possible by combining innovative imaging approaches with biophysical models.
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Affiliation(s)
- Feiyue Lu
- Institute for Systems Genetics and Cell Biology Department, NYU School of Medicine, New York, New York 10016, USA
| | - Timothée Lionnet
- Institute for Systems Genetics and Cell Biology Department, NYU School of Medicine, New York, New York 10016, USA
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29
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Abstract
Fluorescence imaging techniques play a pivotal role in our understanding of the nervous system. The emergence of various super-resolution microscopy methods and specialized fluorescent probes enables direct insight into neuronal structure and protein arrangements in cellular subcompartments with so far unmatched resolution. Super-resolving visualization techniques in neurons unveil a novel understanding of cytoskeletal composition, distribution, motility, and signaling of membrane proteins, subsynaptic structure and function, and neuron-glia interaction. Well-defined molecular targets in autoimmune and neurodegenerative disease models provide excellent starting points for in-depth investigation of disease pathophysiology using novel and innovative imaging methodology. Application of super-resolution microscopy in human brain samples and for testing clinical biomarkers is still in its infancy but opens new opportunities for translational research in neurology and neuroscience. In this review, we describe how super-resolving microscopy has improved our understanding of neuronal and brain function and dysfunction in the last two decades.
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Affiliation(s)
- Christian Werner
- Department of Biotechnology & Biophysics, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Markus Sauer
- Department of Biotechnology & Biophysics, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Christian Geis
- Section Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
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30
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Galgoczi S, Ruzo A, Markopoulos C, Yoney A, Phan-Everson T, Li S, Haremaki T, Metzger JJ, Etoc F, Brivanlou AH. Huntingtin CAG expansion impairs germ layer patterning in synthetic human 2D gastruloids through polarity defects. Development 2021; 148:272380. [PMID: 34608934 PMCID: PMC8513611 DOI: 10.1242/dev.199513] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 08/20/2021] [Indexed: 11/20/2022]
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disorder caused by an expansion of the CAG repeats in the huntingtin gene (HTT). Although HD has been shown to have a developmental component, how early during human embryogenesis the HTT-CAG expansion can cause embryonic defects remains unknown. Here, we demonstrate a specific and highly reproducible CAG length-dependent phenotypic signature in a synthetic model for human gastrulation derived from human embryonic stem cells (hESCs). Specifically, we observed a reduction in the extension of the ectodermal compartment that is associated with enhanced activin signaling. Surprisingly, rather than a cell-autonomous effect, tracking the dynamics of TGFβ signaling demonstrated that HTT-CAG expansion perturbs the spatial restriction of activin response. This is due to defects in the apicobasal polarization in the context of the polarized epithelium of the 2D gastruloid, leading to ectopic subcellular localization of TGFβ receptors. This work refines the earliest developmental window for the prodromal phase of HD to the first 2 weeks of human development, as modeled by our 2D gastruloids. Summary: 2D gastruloids of isogenic human embryonic stem cells modeling Huntington's Disease reveal that huntingtin CAG expansion perturbs the spatial restriction of the activin response in the context of the polarized epithelium.
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Affiliation(s)
- Szilvia Galgoczi
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA
| | - Albert Ruzo
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA
| | - Christian Markopoulos
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA
| | - Anna Yoney
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA.,Laboratory of condensed matter physics, The Rockefeller University, New York, NY 10065, USA
| | - Tien Phan-Everson
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA.,Laboratory of condensed matter physics, The Rockefeller University, New York, NY 10065, USA
| | - Shu Li
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA
| | - Tomomi Haremaki
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA
| | - Jakob J Metzger
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA.,Laboratory of condensed matter physics, The Rockefeller University, New York, NY 10065, USA
| | - Fred Etoc
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA.,Laboratory of condensed matter physics, The Rockefeller University, New York, NY 10065, USA
| | - Ali H Brivanlou
- Laboratory of Stem Cell Biology and Molecular Embryology, The Rockefeller University, New York, NY 10065, USA
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31
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Angelova PR. Sources and triggers of oxidative damage in neurodegeneration. Free Radic Biol Med 2021; 173:52-63. [PMID: 34224816 DOI: 10.1016/j.freeradbiomed.2021.07.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/19/2021] [Accepted: 07/01/2021] [Indexed: 02/07/2023]
Abstract
Neurodegeneration describes a group of more than 300 neurological diseases, characterised by neuronal loss and intra- or extracellular protein depositions, as key neuropathological features. Multiple factors play role in the pathogenesis of these group of disorders: mitochondrial dysfunction, membrane damage, calcium dyshomeostasis, metallostasis, defect clearance and renewal mechanisms, to name a few. All these factors, without exceptions, have in common the involvement of immensely increased generation of free radicals and occurrence of oxidative stress, and as a result - exhaustion of the scavenging potency of the cellular redox defence mechanisms. Besides genetic predisposition and environmental exposure to toxins, the main risk factor for developing neurodegeneration is age. And although the "Free radical theory of ageing" was declared dead, it is undisputable that accumulation of damage occurs with age, especially in systems that are regulated by free radical messengers and those that oppose oxidative stress, protein oxidation and the accuracy in protein synthesis and degradation machinery has difficulties to be maintained. This brief review provides a comprehensive summary on the main sources of free radical damage, occurring in the setting of neurodegeneration.
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32
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Patange S, Ball DA, Karpova TS, Larson DR. Towards a 'Spot On' Understanding of Transcription in the Nucleus. J Mol Biol 2021; 433:167016. [PMID: 33951451 PMCID: PMC8184600 DOI: 10.1016/j.jmb.2021.167016] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 04/16/2021] [Accepted: 04/22/2021] [Indexed: 11/29/2022]
Abstract
Regulation of transcription by RNA Polymerase II (RNAPII) is a rapidly evolving area of research. Technological developments in microscopy have revealed insight into the dynamics, structure, and localization of transcription components within single cells. A frequent observation in many studies is the appearance of 'spots' in cell nuclei associated with the transcription process. In this review we highlight studies that characterize the temporal and spatial characteristics of these spots, examine possible pitfalls in interpreting these kind of imaging data, and outline directions where single-cell imaging may advance in ways to further our understanding of transcription regulation.
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Affiliation(s)
- Simona Patange
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - David A Ball
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Tatiana S Karpova
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Daniel R Larson
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States.
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33
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Mazzocca M, Fillot T, Loffreda A, Gnani D, Mazza D. The needle and the haystack: single molecule tracking to probe the transcription factor search in eukaryotes. Biochem Soc Trans 2021; 49:1121-1132. [PMID: 34003257 PMCID: PMC8286828 DOI: 10.1042/bst20200709] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/18/2021] [Accepted: 04/19/2021] [Indexed: 12/13/2022]
Abstract
Transcription factors (TFs) regulate transcription of their target genes by identifying and binding to regulatory regions of the genome among billions of potential non-specific decoy sites, a task that is often presented as a 'needle in the haystack' challenge. The TF search process is now well understood in bacteria, but its characterization in eukaryotes needs to account for the complex organization of the nuclear environment. Here we review how live-cell single molecule tracking is starting to shed light on the TF search mechanism in the eukaryotic cell and we outline the future challenges to tackle in order to understand how nuclear organization modulates the TF search process in physiological and pathological conditions.
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Affiliation(s)
- Matteo Mazzocca
- Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
| | - Tom Fillot
- Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
| | - Alessia Loffreda
- Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
| | - Daniela Gnani
- Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
| | - Davide Mazza
- Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
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34
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Lin LE, Miao K, Qian C, Wei L. High spatial-resolution imaging of label-free in vivo protein aggregates by VISTA. Analyst 2021; 146:4135-4145. [PMID: 33949430 PMCID: PMC8238904 DOI: 10.1039/d1an00060h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Amyloid aggregation, formed by aberrant proteins, is a pathological hallmark for neurodegenerative diseases, including Alzheimer's disease and Huntington's disease. High-resolution holistic mapping of the fine structures from these aggregates should facilitate our understanding of their pathological roles. Here, we achieved label-free high-resolution imaging of the polyQ and the amyloid-beta (Aβ) aggregates in cells and tissues utilizing a sample-expansion stimulated Raman strategy. We further focused on characterizing the Aβ plaques in 5XFAD mouse brain tissues. 3D volumetric imaging enabled visualization of the whole plaques, resolving both the fine protein filaments and the surrounding components. Coupling our expanded label-free Raman imaging with machine learning, we obtained specific segmentation of aggregate cores, peripheral filaments together with cell nuclei and blood vessels by pre-trained convolutional neural network models. Combining with 2-channel fluorescence imaging, we achieved a 6-color holistic view of the same sample. This ability for precise and multiplex high-resolution imaging of the protein aggregates and their micro-environment without the requirement of labeling would open new biomedical applications.
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Affiliation(s)
- Li-En Lin
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
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35
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von Diezmann L, Rog O. Single-Molecule Tracking of Chromatin-Associated Proteins in the C. elegans Gonad. J Phys Chem B 2021; 125:6162-6170. [PMID: 34097417 DOI: 10.1021/acs.jpcb.1c03040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biomolecules are distributed within cells by molecular-scale diffusion and binding events that are invisible in standard fluorescence microscopy. These molecular search kinetics are key to understanding nuclear signaling and chromosome organization and can be directly observed by single-molecule tracking microscopy. Here, we report a method to track individual proteins within intact C. elegans gonads and apply it to study the molecular dynamics of the axis, a proteinaceous backbone that organizes meiotic chromosomes. Using either fluorescent proteins or enzymatically ligated dyes, we obtain multisecond trajectories with a localization precision of 15-25 nm in nuclei actively undergoing meiosis. Correlation with a reference channel allows for accurate measurement of protein dynamics, compensating for movements of the nuclei and chromosomes within the gonad. We find that axis proteins exhibit either static binding to chromatin or free diffusion in the nucleoplasm, and we separately quantify the motion parameters of these distinct populations. Freely diffusing axis proteins selectively explore chromatin-rich regions, suggesting they are circumventing the central phase-separated region of the nucleus. This work demonstrates that single-molecule microscopy can infer nanoscale-resolution dynamics within living tissue, expanding the possible applications of this approach.
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36
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Plaza-Oliver M, Cano EL, Arroyo-Jimenez MM, Gámez M, Lozano-López MV, Santander-Ortega MJ. Taking Particle Tracking into Practice by Novel Software and Screening Approach: Case-Study of Oral Lipid Nanocarriers. Pharmaceutics 2021; 13:370. [PMID: 33802226 PMCID: PMC8001040 DOI: 10.3390/pharmaceutics13030370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/03/2021] [Accepted: 03/03/2021] [Indexed: 02/07/2023] Open
Abstract
The success on the design of new oral nanocarriers greatly depends on the identification of the best physicochemical properties that would allow their diffusion across the mucus layer that protects the intestinal epithelium. In this context, particle tracking (PT) has arisen in the pharmaceutical field as an excellent tool to evaluate the diffusion of individual particles across the intestinal mucus. In PT, the trajectories of individual particles are characterized by the mean square displacement (MSD), which is used to calculate the coefficient of diffusion (D) and the anomalous diffusion parameter (α) as MSD=4Dτα. Unfortunately, there is no stablished criteria to evaluate the goodness-of-fit of the experimental data to the mathematical model. This work shows that the commonly used R2 parameter may lead to an overestimation of the diffusion capacity of oral nanocarriers. We propose a screening approach based on a combination of R2 with further statistical parameters. We have analyzed the effect of this approach to study the intestinal mucodiffusion of lipid oral nanocarriers, compared to the conventional screening approach. Last, we have developed software able to perform the whole PT analysis in a time-saving, user-friendly, and rational fashion.
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Affiliation(s)
- María Plaza-Oliver
- Cellular Neurobiology and Molecular Chemistry of the Central Nervous System Group, Faculty of Pharmacy, University of Castilla-La Mancha (UCLM), 02071 Albacete, Spain; (M.P.-O.); (M.M.A.-J.); (M.V.L.-L.)
- Regional Centre of Biomedical Research (CRIB), University of Castilla-La Mancha (UCLM), 02008 Albacete, Spain
| | - Emilio L. Cano
- Quantitative Methods and Socio-economic Development Group, Institute for Regional Development (IDR), University of Castilla-La Mancha (UCLM), 02006 Albacete, Spain;
- Data Science laboratory, Rey Juan Carlos University, 28933 Madrid, Spain
| | - María Mar Arroyo-Jimenez
- Cellular Neurobiology and Molecular Chemistry of the Central Nervous System Group, Faculty of Pharmacy, University of Castilla-La Mancha (UCLM), 02071 Albacete, Spain; (M.P.-O.); (M.M.A.-J.); (M.V.L.-L.)
- Regional Centre of Biomedical Research (CRIB), University of Castilla-La Mancha (UCLM), 02008 Albacete, Spain
| | - Matías Gámez
- Quantitative Methods and Socio-economic Development Group, Institute for Regional Development (IDR), University of Castilla-La Mancha (UCLM), 02006 Albacete, Spain;
| | - María Victoria Lozano-López
- Cellular Neurobiology and Molecular Chemistry of the Central Nervous System Group, Faculty of Pharmacy, University of Castilla-La Mancha (UCLM), 02071 Albacete, Spain; (M.P.-O.); (M.M.A.-J.); (M.V.L.-L.)
- Regional Centre of Biomedical Research (CRIB), University of Castilla-La Mancha (UCLM), 02008 Albacete, Spain
| | - Manuel J. Santander-Ortega
- Cellular Neurobiology and Molecular Chemistry of the Central Nervous System Group, Faculty of Pharmacy, University of Castilla-La Mancha (UCLM), 02071 Albacete, Spain; (M.P.-O.); (M.M.A.-J.); (M.V.L.-L.)
- Regional Centre of Biomedical Research (CRIB), University of Castilla-La Mancha (UCLM), 02008 Albacete, Spain
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37
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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: 23] [Impact Index Per Article: 5.8] [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.
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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
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38
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Rhine K, Makurath MA, Liu J, Skanchy S, Lopez C, Catalan KF, Ma Y, Fare CM, Shorter J, Ha T, Chemla YR, Myong S. ALS/FTLD-Linked Mutations in FUS Glycine Residues Cause Accelerated Gelation and Reduced Interactions with Wild-Type FUS. Mol Cell 2020; 80:666-681.e8. [PMID: 33159856 PMCID: PMC7688085 DOI: 10.1016/j.molcel.2020.10.014] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/06/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022]
Abstract
The RNA-binding protein fused in sarcoma (FUS) can form pathogenic inclusions in neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD). Over 70 mutations in Fus are linked to ALS/FTLD. In patients, all Fus mutations are heterozygous, indicating that the mutant drives disease progression despite the presence of wild-type (WT) FUS. Here, we demonstrate that ALS/FTLD-linked FUS mutations in glycine (G) strikingly drive formation of droplets that do not readily interact with WT FUS, whereas arginine (R) mutants form mixed condensates with WT FUS. Remarkably, interactions between WT and G mutants are disfavored at the earliest stages of FUS nucleation. In contrast, R mutants physically interact with the WT FUS such that WT FUS recovers the mutant defects by reducing droplet size and increasing dynamic interactions with RNA. This result suggests disparate molecular mechanisms underlying ALS/FTLD pathogenesis and differing recovery potential depending on the type of mutation.
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Affiliation(s)
- Kevin Rhine
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Monika A Makurath
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - James Liu
- Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Medical Genetics and Ophthalmic Genomics Unit, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sophie Skanchy
- Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Christian Lopez
- Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Kevin F Catalan
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Ye Ma
- Department of Biomedical Engineering, Johns Hopkins Medical Institute, 615 N Wolfe St, Baltimore, MD 21231, USA
| | - Charlotte M Fare
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Taekjip Ha
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Biomedical Engineering, Johns Hopkins Medical Institute, 615 N Wolfe St, Baltimore, MD 21231, USA; Howard Hughes Medical Institute, Baltimore, MD 21218, USA
| | - Yann R Chemla
- Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Sua Myong
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA.
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39
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Tabachnick-Cherny S, Pinto S, Berko D, Curato C, Wolf Y, Porat Z, Karmona R, Tirosh B, Jung S, Navon A. Polyglutamine-Related Aggregates Can Serve as a Potent Antigen Source for Cross-Presentation by Dendritic Cells. THE JOURNAL OF IMMUNOLOGY 2020; 205:2583-2594. [PMID: 33067378 DOI: 10.4049/jimmunol.1901535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 09/15/2020] [Indexed: 01/16/2023]
Abstract
Protective MHC class I-dependent immune responses require an overlap between repertoires of proteins directly presented on target cells and cross-presented by professional APC, specifically dendritic cells. How stable proteins that rely on defective ribosomal proteins for direct presentation are captured for cell-to-cell transfer remains enigmatic. In this study, we address this issue using a combination of in vitro (C57BL/6-derived mouse cell lines) and in vivo (C57BL/6 mouse strains) approaches involving stable and unstable versions of OVA model Ags displaying defective ribosomal protein-dependent and -independent Ag presentation, respectively. Apoptosis, but not necrosis, of donor cells was found associated with robust global protein aggregate formation and captured stable proteins permissive for cross-presentation. Potency of aggregates to serve as Ag source was directly demonstrated using polyglutamine-equipped model substrates. Collectively, our data implicate global protein aggregation in apoptotic cells as a mechanism that ensures the overlap between MHC class I epitopes presented directly or cross-presented by APC and demonstrate the unusual ability of dendritic cells to process stable protein aggregates.
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Affiliation(s)
- Shira Tabachnick-Cherny
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Sivan Pinto
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Dikla Berko
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Caterina Curato
- Department of Immunology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yochai Wolf
- Department of Immunology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ziv Porat
- Department of Biological Services, The Weizmann Institute of Science, Rehovot 76100, Israel; and
| | - Rotem Karmona
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Boaz Tirosh
- The Institute for Drug Research, The School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Steffen Jung
- Department of Immunology, The Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Ami Navon
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot 76100, Israel;
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40
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Parra-Damas A, Saura CA. Tissue Clearing and Expansion Methods for Imaging Brain Pathology in Neurodegeneration: From Circuits to Synapses and Beyond. Front Neurosci 2020; 14:914. [PMID: 33122983 PMCID: PMC7571329 DOI: 10.3389/fnins.2020.00914] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 08/07/2020] [Indexed: 11/30/2022] Open
Abstract
Studying the structural alterations occurring during diseases of the nervous system requires imaging heterogeneous cell populations at the circuit, cellular and subcellular levels. Recent advancements in brain tissue clearing and expansion methods allow unprecedented detailed imaging of the nervous system through its entire scale, from circuits to synapses, including neurovascular and brain lymphatics elements. Here, we review the state-of-the-art of brain tissue clearing and expansion methods, mentioning their main advantages and limitations, and suggest their parallel implementation for circuits-to-synapses brain imaging using conventional (diffraction-limited) light microscopy -such as confocal, two-photon and light-sheet microscopy- to interrogate the cellular and molecular basis of neurodegenerative diseases. We discuss recent studies in which clearing and expansion methods have been successfully applied to study neuropathological processes in mouse models and postmortem human brain tissue. Volumetric imaging of cleared intact mouse brains and large human brain samples has allowed unbiased assessment of neuropathological hallmarks. In contrast, nanoscale imaging of expanded cells and brain tissue has been used to study the effect of protein aggregates on specific subcellular structures. Therefore, these approaches can be readily applied to study a wide range of brain processes and pathological mechanisms with cellular and subcellular resolution in a time- and cost-efficient manner. We consider that a broader implementation of these technologies is necessary to reveal the full landscape of cellular and molecular mechanisms underlying neurodegenerative diseases.
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Affiliation(s)
- Arnaldo Parra-Damas
- Institut de Neurociències, Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Madrid, Spain
| | - Carlos A Saura
- Institut de Neurociències, Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Madrid, Spain
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41
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Investigating the Structure of Neurotoxic Protein Aggregates Inside Cells. Trends Cell Biol 2020; 30:951-966. [PMID: 32981805 DOI: 10.1016/j.tcb.2020.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/13/2020] [Accepted: 08/17/2020] [Indexed: 12/22/2022]
Abstract
Neurodegenerative diseases affect the lives of millions of people across the world, being particularly prevalent in the aging population. Despite huge research efforts, conclusive insights into the disease mechanisms are still lacking. Therefore, therapeutic strategies are limited to symptomatic treatments. A common histopathological hallmark of many neurodegenerative diseases is the presence of large pathognomonic protein aggregates, but their role in the disease pathology is unclear and subject to controversy. Here, we discuss imaging methods allowing investigation of these structures within their cellular environment: conventional electron microscopy (EM), super-resolution light microscopy (SR-LM), and cryo-electron tomography (cryo-ET). Multidisciplinary approaches are key for understanding neurodegenerative diseases and may contribute to the development of effective treatments. For simplicity, we focus on huntingtin aggregates, characteristic of Huntington's disease.
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42
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Hobson CM, Kern M, O'Brien ET, Stephens AD, Falvo MR, Superfine R. Correlating nuclear morphology and external force with combined atomic force microscopy and light sheet imaging separates roles of chromatin and lamin A/C in nuclear mechanics. Mol Biol Cell 2020; 31:1788-1801. [PMID: 32267206 DOI: 10.1101/2020.02.10.942581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023] Open
Abstract
Nuclei are often under external stress, be it during migration through tight constrictions or compressive pressure by the actin cap, and the mechanical properties of nuclei govern their subsequent deformations. Both altered mechanical properties of nuclei and abnormal nuclear morphologies are hallmarks of a variety of disease states. Little work, however, has been done to link specific changes in nuclear shape to external forces. Here, we utilize a combined atomic force microscope and light sheet microscope to show SKOV3 nuclei exhibit a two-regime force response that correlates with changes in nuclear volume and surface area, allowing us to develop an empirical model of nuclear deformation. Our technique further decouples the roles of chromatin and lamin A/C in compression, showing they separately resist changes in nuclear volume and surface area, respectively; this insight was not previously accessible by Hertzian analysis. A two-material finite element model supports our conclusions. We also observed that chromatin decompaction leads to lower nuclear curvature under compression, which is important for maintaining nuclear compartmentalization and function. The demonstrated link between specific types of nuclear morphological change and applied force will allow researchers to better understand the stress on nuclei throughout various biological processes.
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Affiliation(s)
- Chad M Hobson
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Megan Kern
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - E Timothy O'Brien
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Andrew D Stephens
- Biology Department, The University of Massachusetts at Amherst, Amherst, MA 01003, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Michael R Falvo
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Richard Superfine
- Department of Applied Physical Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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43
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Miao K, Wei L. Live-Cell Imaging and Quantification of PolyQ Aggregates by Stimulated Raman Scattering of Selective Deuterium Labeling. ACS CENTRAL SCIENCE 2020; 6:478-486. [PMID: 32341997 PMCID: PMC7181319 DOI: 10.1021/acscentsci.9b01196] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Indexed: 05/05/2023]
Abstract
Polyglutamine (polyQ) diseases are a group of neurodegenerative disorders, involving the deposition of aggregation-prone proteins with long polyQ expansions. However, the cytotoxic roles of these aggregates remain highly controversial, largely due to a lack of proper tools for quantitative and nonperturbative interrogations. Common methods including in vitro biochemical, spectroscopic assays, and live-cell fluorescence imaging all suffer from certain limitations. Here, we propose coupling stimulated Raman scattering microscopy with deuterium-labeled glutamine for live-cell imaging, quantification, and spectral analysis of native polyQ aggregates with subcellular resolution. First, through the enrichment of deuterated glutamine in the polyQ sequence of mutant Huntingtin (mHtt) exon1 proteins for Huntington's disease, we achieved sensitive and specific stimulated Raman scattering (SRS) imaging of carbon-deuterium bonds (C-D) from aggregates without GFP labeling, which is commonly employed in fluorescence microscopy. We revealed that these aggregates became 1.8-fold denser compared to those with GFP. Second, we performed ratiometric quantifications, which indicate a surprising dependence of protein compositions on aggregation sizes. Our further calculations, for the first time, reported the absolute concentrations for sequestered mHtt and non-mHtt proteins within the same aggregates. Third, we adopted hyperspectral SRS for Raman spectroscopic studies of aggregate structures. By inducing a cellular heat shock response, a potential therapeutic approach for inhibiting aggregate formation, we found a possible aggregate intermediate state with changed solvation microenvironments. Our method may hence readily unveil new features and mechanistic insight of polyQ aggregates and pave the way for comprehensive in vivo investigations.
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44
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Hobson CM, Kern M, O'Brien ET, Stephens AD, Falvo MR, Superfine R. Correlating nuclear morphology and external force with combined atomic force microscopy and light sheet imaging separates roles of chromatin and lamin A/C in nuclear mechanics. Mol Biol Cell 2020; 31:1788-1801. [PMID: 32267206 PMCID: PMC7521857 DOI: 10.1091/mbc.e20-01-0073] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Nuclei are often under external stress, be it during migration through tight constrictions or compressive pressure by the actin cap, and the mechanical properties of nuclei govern their subsequent deformations. Both altered mechanical properties of nuclei and abnormal nuclear morphologies are hallmarks of a variety of disease states. Little work, however, has been done to link specific changes in nuclear shape to external forces. Here, we utilize a combined atomic force microscope and light sheet microscope to show SKOV3 nuclei exhibit a two-regime force response that correlates with changes in nuclear volume and surface area, allowing us to develop an empirical model of nuclear deformation. Our technique further decouples the roles of chromatin and lamin A/C in compression, showing they separately resist changes in nuclear volume and surface area, respectively; this insight was not previously accessible by Hertzian analysis. A two-material finite element model supports our conclusions. We also observed that chromatin decompaction leads to lower nuclear curvature under compression, which is important for maintaining nuclear compartmentalization and function. The demonstrated link between specific types of nuclear morphological change and applied force will allow researchers to better understand the stress on nuclei throughout various biological processes.
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Affiliation(s)
- Chad M Hobson
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Megan Kern
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - E Timothy O'Brien
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Andrew D Stephens
- Biology Department, The University of Massachusetts at Amherst, Amherst, MA 01003, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Michael R Falvo
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Richard Superfine
- Department of Applied Physical Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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45
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Lasker K, von Diezmann L, Zhou X, Ahrens DG, Mann TH, Moerner WE, Shapiro L. Selective sequestration of signalling proteins in a membraneless organelle reinforces the spatial regulation of asymmetry in Caulobacter crescentus. Nat Microbiol 2020; 5:418-429. [PMID: 31959967 PMCID: PMC7549192 DOI: 10.1038/s41564-019-0647-7] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/25/2019] [Indexed: 12/16/2022]
Abstract
Selective recruitment and concentration of signalling proteins within membraneless compartments is a ubiquitous mechanism for subcellular organization1-3. The dynamic flow of molecules into and out of these compartments occurs on faster timescales than for membrane-enclosed organelles, presenting a possible mechanism to control spatial patterning within cells. Here, we combine single-molecule tracking and super-resolution microscopy, light-induced subcellular localization, reaction-diffusion modelling and a spatially resolved promoter activation assay to study signal exchange in and out of the 200 nm cytoplasmic pole-organizing protein popZ (PopZ) microdomain at the cell pole of the asymmetrically dividing bacterium Caulobacter crescentus4-8. Two phospho-signalling proteins, the transmembrane histidine kinase CckA and the cytoplasmic phosphotransferase ChpT, provide the only phosphate source for the cell fate-determining transcription factor CtrA9-18. We find that all three proteins exhibit restricted rates of entry into and escape from the microdomain as well as enhanced phospho-signalling within, leading to a submicron gradient of activated CtrA-P19 that is stable and sublinear. Entry into the microdomain is selective for cytosolic proteins and requires a binding pathway to PopZ. Our work demonstrates how nanoscale protein assemblies can modulate signal propagation with fine spatial resolution, and that in Caulobacter, this modulation serves to reinforce asymmetry and differential cell fate of the two daughter cells.
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Affiliation(s)
- Keren Lasker
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lexy von Diezmann
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Center for Cell and Genome Science, University of Utah, Salt Lake City, UT, USA
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Xiaofeng Zhou
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Daniel G Ahrens
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Thomas H Mann
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
- NOMIS Center for Immunobiology and Microbial Pathogenesis, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - W E Moerner
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Lucy Shapiro
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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46
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Lu M, Kaminski CF, Schierle GSK. Advanced fluorescence imaging of in situ protein aggregation. Phys Biol 2020; 17:021001. [DOI: 10.1088/1478-3975/ab694e] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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47
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Marolf DM, Jones MR. Measurement Challenges in Dynamic and Nonequilibrium Nanoscale Systems. Anal Chem 2019; 91:13324-13336. [DOI: 10.1021/acs.analchem.9b02702] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- David M. Marolf
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Matthew R. Jones
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States
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48
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Nmnat restores neuronal integrity by neutralizing mutant Huntingtin aggregate-induced progressive toxicity. Proc Natl Acad Sci U S A 2019; 116:19165-19175. [PMID: 31484760 DOI: 10.1073/pnas.1904563116] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Accumulative aggregation of mutant Huntingtin (Htt) is a primary neuropathological hallmark of Huntington's disease (HD). Currently, mechanistic understanding of the cytotoxicity of mutant Htt aggregates remains limited, and neuroprotective strategies combating mutant Htt-induced neurodegeneration are lacking. Here, we show that in Drosophila models of HD, neuronal compartment-specific accumulation of mutant Htt aggregates causes neurodegenerative phenotypes. In addition to the increase in the number and size, we discovered an age-dependent acquisition of thioflavin S+, amyloid-like adhesive properties of mutant Htt aggregates and a concomitant progressive clustering of aggregates with mitochondria and synaptic proteins, indicating that the amyloid-like adhesive property underlies the neurotoxicity of mutant Htt aggregation. Importantly, nicotinamide mononucleotide adenylyltransferase (NMNAT), an evolutionarily conserved nicotinamide adenine dinucleotide (NAD+) synthase and neuroprotective factor, significantly mitigates mutant Htt-induced neurodegeneration by reducing mutant Htt aggregation through promoting autophagic clearance. Additionally, Nmnat overexpression reduces progressive accumulation of amyloid-like Htt aggregates, neutralizes adhesiveness, and inhibits the clustering of mutant Htt with mitochondria and synaptic proteins, thereby restoring neuronal function. Conversely, partial loss of endogenous Nmnat exacerbates mutant Htt-induced neurodegeneration through enhancing mutant Htt aggregation and adhesive property. Finally, conditional expression of Nmnat after the onset of degenerative phenotypes significantly delays the progression of neurodegeneration, revealing the therapeutic potential of Nmnat-mediated neuroprotection at advanced stages of HD. Our study uncovers essential mechanistic insights to the neurotoxicity of mutant Htt aggregation and describes the molecular basis of Nmnat-mediated neuroprotection in HD.
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49
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van Well EM, Bader V, Patra M, Sánchez-Vicente A, Meschede J, Furthmann N, Schnack C, Blusch A, Longworth J, Petrasch-Parwez E, Mori K, Arzberger T, Trümbach D, Angersbach L, Showkat C, Sehr DA, Berlemann LA, Goldmann P, Clement AM, Behl C, Woerner AC, Saft C, Wurst W, Haass C, Ellrichmann G, Gold R, Dittmar G, Hipp MS, Hartl FU, Tatzelt J, Winklhofer KF. A protein quality control pathway regulated by linear ubiquitination. EMBO J 2019; 38:e100730. [PMID: 30886048 PMCID: PMC6484417 DOI: 10.15252/embj.2018100730] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/12/2019] [Accepted: 02/13/2019] [Indexed: 12/22/2022] Open
Abstract
Neurodegenerative diseases are characterized by the accumulation of misfolded proteins in the brain. Insights into protein quality control mechanisms to prevent neuronal dysfunction and cell death are crucial in developing causal therapies. Here, we report that various disease-associated protein aggregates are modified by the linear ubiquitin chain assembly complex (LUBAC). HOIP, the catalytic component of LUBAC, is recruited to misfolded Huntingtin in a p97/VCP-dependent manner, resulting in the assembly of linear polyubiquitin. As a consequence, the interactive surface of misfolded Huntingtin species is shielded from unwanted interactions, for example with the low complexity sequence domain-containing transcription factor Sp1, and proteasomal degradation of misfolded Huntingtin is facilitated. Notably, all three core LUBAC components are transcriptionally regulated by Sp1, linking defective LUBAC expression to Huntington's disease. In support of a protective activity of linear ubiquitination, silencing of OTULIN, a deubiquitinase with unique specificity for linear polyubiquitin, decreases proteotoxicity, whereas silencing of HOIP has the opposite effect. These findings identify linear ubiquitination as a protein quality control mechanism and hence a novel target for disease-modifying strategies in proteinopathies.
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Affiliation(s)
- Eva M van Well
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Verian Bader
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Maria Patra
- Neurobiochemistry, Adolf Butenandt Institute, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Ana Sánchez-Vicente
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Jens Meschede
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Nikolas Furthmann
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Cathrin Schnack
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Alina Blusch
- Department of Neurology, St Josef Hospital, Ruhr University Bochum, Bochum, Germany
| | - Joseph Longworth
- Proteome and Genome Research Unit, Department of Oncology, Luxembourg Institute of Health, Strassen, Luxembourg
| | | | - Kohji Mori
- Biomedical Center (BMC), Ludwig-Maximilians-University Munich, Munich, Germany
| | - Thomas Arzberger
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany
- Centre for Neuropathology and Prion Research, Ludwig-Maximilians-University Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Dietrich Trümbach
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Lena Angersbach
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Cathrin Showkat
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Dominik A Sehr
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Lena A Berlemann
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Petra Goldmann
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Albrecht M Clement
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Christian Behl
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Andreas C Woerner
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Carsten Saft
- Department of Neurology, St Josef Hospital, Ruhr University Bochum, Bochum, Germany
| | - Wolfgang Wurst
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Developmental Genetics, Technical University Munich, Neuherberg, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Christian Haass
- Biomedical Center (BMC), Ludwig-Maximilians-University Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Gisa Ellrichmann
- Department of Neurology, St Josef Hospital, Ruhr University Bochum, Bochum, Germany
| | - Ralf Gold
- Department of Neurology, St Josef Hospital, Ruhr University Bochum, Bochum, Germany
| | - Gunnar Dittmar
- Proteome and Genome Research Unit, Department of Oncology, Luxembourg Institute of Health, Strassen, Luxembourg
| | - Mark S Hipp
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Jörg Tatzelt
- Neurobiochemistry, Adolf Butenandt Institute, Ludwig-Maximilians-University Munich, Munich, Germany
- Department of Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
- Cluster of Excellence RESOLV, Bochum, Germany
| | - Konstanze F Winklhofer
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
- Neurobiochemistry, Adolf Butenandt Institute, Ludwig-Maximilians-University Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
- Cluster of Excellence RESOLV, Bochum, Germany
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Jiang Y, Berg MD, Genereaux J, Ahmed K, Duennwald ML, Brandl CJ, Lajoie P. Sfp1 links TORC1 and cell growth regulation to the yeast SAGA‐complex component Tra1 in response to polyQ proteotoxicity. Traffic 2019; 20:267-283. [DOI: 10.1111/tra.12637] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/08/2019] [Accepted: 02/08/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Yuwei Jiang
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
| | - Matthew D. Berg
- Department of BiochemistryThe University of Western Ontario London Ontario Canada
| | - Julie Genereaux
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
- Department of BiochemistryThe University of Western Ontario London Ontario Canada
| | - Khadija Ahmed
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
| | - Martin L. Duennwald
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
- Department of Pathology and Laboratory MedicineThe University of Western Ontario London Ontario Canada
| | | | - Patrick Lajoie
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
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