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Liu L, Lan H, Cui Y, Tang Q, Bai J, An X, Sun M, Liu H, Qu J. A Janus membrane with electro-induced multi-affinity interfaces for high-efficiency water purification. SCIENCE ADVANCES 2024; 10:eadn8696. [PMID: 38787943 PMCID: PMC11122666 DOI: 10.1126/sciadv.adn8696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 04/22/2024] [Indexed: 05/26/2024]
Abstract
Drinking water with micropollutants is a notable environmental concern worldwide. Membrane separation is one of the few methods capable of removing micropollutants from water. However, existing membranes face challenges in the simultaneous and efficient treatment of small-molecular and ionic contaminants because of their limited permselectivity. Here, we propose a high-efficiency water purification method using a low-pressure Janus membrane with electro-induced multi-affinity. By virtue of hydrophobic and electrostatic interactions between the functional interfaces and contaminants, the Janus membrane achieves simultaneous separation of diverse types of organics and heavy metals from water via single-pass filtration, with an approximately 100% removal efficiency, high water flux (>680 liters m-2 hour-1), and 98% lower energy consumption compared with commercial nanofiltration membranes. The electro-induced switching of interfacial affinity enables 100% regeneration of membrane performance; thus, our work paves a sustainable avenue for drinking water purification by regulating the interfacial affinity of membranes.
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Affiliation(s)
- Lie Liu
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing 100084, China
| | | | - Yuqi Cui
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing 100084, China
| | - Qingwen Tang
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiaqi Bai
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaoqiang An
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing 100084, China
| | - Meng Sun
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing 100084, China
| | - Huijuan Liu
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiuhui Qu
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing 100084, China
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2
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Song J. Adenosine Triphosphate: The Primordial Molecule That Controls Protein Homeostasis and Shapes the Genome-Proteome Interface. Biomolecules 2024; 14:500. [PMID: 38672516 PMCID: PMC11048592 DOI: 10.3390/biom14040500] [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: 03/29/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Adenosine triphosphate (ATP) acts as the universal energy currency that drives various biological processes, while nucleic acids function to store and transmit genetic information for all living organisms. Liquid-liquid phase separation (LLPS) represents the common principle for the formation of membrane-less organelles (MLOs) composed of proteins rich in intrinsically disordered regions (IDRs) and nucleic acids. Currently, while IDRs are well recognized to facilitate LLPS through dynamic and multivalent interactions, the precise mechanisms by which ATP and nucleic acids affect LLPS still remain elusive. This review summarizes recent NMR results on the LLPS of human FUS, TDP-43, and the viral nucleocapsid (N) protein of SARS-CoV-2, as modulated by ATP and nucleic acids, revealing the following: (1) ATP binds to folded domains overlapping with nucleic-acid-binding interfaces; (2) ATP and nucleic acids interplay to biphasically modulate LLPS by competitively binding to overlapping pockets of folded domains and Arg/Lys within IDRs; (3) ATP energy-independently induces protein folding with the highest efficiency known so far. As ATP likely emerged in the prebiotic monomeric world, while LLPS represents a pivotal mechanism to concentrate and compartmentalize rare molecules for forming primordial cells, ATP appears to control protein homeostasis and shape genome-proteome interfaces throughout the evolutionary trajectory, from prebiotic origins to modern cells.
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Affiliation(s)
- Jianxing Song
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
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3
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Guo D, Xiong Y, Fu B, Sha Z, Li B, Wu H. Liquid-Liquid phase separation in bacteria. Microbiol Res 2024; 281:127627. [PMID: 38262205 DOI: 10.1016/j.micres.2024.127627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/16/2023] [Accepted: 01/15/2024] [Indexed: 01/25/2024]
Abstract
Cells are the essential building blocks of living organisms, responsible for carrying out various biochemical reactions and performing specific functions. In eukaryotic cells, numerous membrane organelles have evolved to facilitate these processes by providing specific spatial locations. In recent years, it has also been discovered that membraneless organelles play a crucial role in the subcellular organization of bacteria, which are single-celled prokaryotic microorganisms characterized by their simple structure and small size. These membraneless organelles in bacteria have been found to undergo Liquid-Liquid phase separation (LLPS), a molecular mechanism that allows for their assembly. Through extensive research, the occurrence of LLPS and its role in the spatial organization of bacteria have been better understood. Various biomacromolecules have been identified to exhibit LLPS properties in different bacterial species. LLPS which is introduced into synthetic biology applies to bacteria has important implications, and three recent research reports have shed light on its potential applications in this field. Overall, this review investigates the molecular mechanisms of LLPS occurrence and its significance in bacteria while also considering the future prospects of implementing LLPS in synthetic biology.
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Affiliation(s)
- Dong Guo
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Yan Xiong
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Beibei Fu
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Zhou Sha
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Bohao Li
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Haibo Wu
- School of Life Sciences, Chongqing University, Chongqing 401331, China.
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4
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Xie S, Yue C, Ye S, Li Z. Probing the hierarchical dynamics of DNA-sperm nuclear transition protein complexes through fuzzy interaction and mesoscale condensation. Phys Chem Chem Phys 2024; 26:10408-10418. [PMID: 38502252 DOI: 10.1039/d3cp05957j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Nuclear transition protein TNP1 is a crucial player mediating histone-protamine exchange in condensing spermatids. A unique combination of intrinsic disorder and multivalent properties turns TNP1 into an ideal agent for orchestrating the formation of versatile TNP-DNA assemblies. Despite its significance, the physicochemical property and the molecular mechanism followed by TNP1 for histone replacement and DNA condensation are still poorly understood. This study reports the first-time in vitro expression and purification of human TNP1 and investigates the hierarchical dynamics of TNP1-DNA interaction using a combination of computational simulations, biochemical assays, fluorescence imaging, and atomic force microscopy. We explored three crucial facets of TNP1-DNA interactions. Initially, we delve into the molecular binding process that entails fuzzy interactions between TNP1 and DNA at the atomistic scale. Subsequently, we analyze how TNP1 binding affects the electrostatic and mechanical characteristics of DNA and influences its morphology. Finally, we study the biomolecular condensation of TNP1-DNA when subjected to high concentrations. The findings of our study set the foundation for comprehending the potential involvement of TNP1 in histone replacement and DNA condensation in spermatogenesis.
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Affiliation(s)
- Shangqiang Xie
- School of Life Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China.
| | - Congran Yue
- School of Life Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China.
| | - Sheng Ye
- School of Life Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China.
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Zhenlu Li
- School of Life Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China.
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin University, 92 Weijin Road, Tianjin 300072, China
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5
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Xia X, Ni R. Designing Superselectivity in Linker-Mediated Multivalent Nanoparticle Adsorption. PHYSICAL REVIEW LETTERS 2024; 132:118202. [PMID: 38563948 DOI: 10.1103/physrevlett.132.118202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/09/2024] [Accepted: 02/22/2024] [Indexed: 04/04/2024]
Abstract
Using a statistical mechanical model and numerical simulations, we provide the design principle for the bridging strength (ξ) and linker density (ρ) dependent superselectivity in linker-mediated multivalent nanoparticle adsorption. When the bridges are insufficient, the formation of multiple bridges leads to both ξ- and ρ-dependent superselectivity. When the bridges are excessive, the system becomes insensitive to bridging strength due to entropy-induced self-saturation and shows a superselective desorption with respect to the linker density. Counterintuitively, lower linker density or stronger bridging strength enhances the superselectivity. These findings help the understanding of relevant biological processes and open up opportunities for applications in biosensing, drug delivery, and programmable self-assembly.
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Affiliation(s)
- Xiuyang Xia
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, 637459, Singapore
| | - Ran Ni
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, 637459, Singapore
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6
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Kota D, Prasad R, Zhou HX. Adenosine Triphosphate Mediates Phase Separation of Disordered Basic Proteins by Bridging Intermolecular Interaction Networks. J Am Chem Soc 2024; 146:1326-1336. [PMID: 38174879 PMCID: PMC10843746 DOI: 10.1021/jacs.3c09134] [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] [Indexed: 01/05/2024]
Abstract
Adenosine triphosphate (ATP) is an abundant molecule with crucial cellular roles as the energy currency and a building block of nucleic acids and for protein phosphorylation. Here we show that ATP mediates the phase separation of basic intrinsically disordered proteins (bIDPs). In the resulting condensates, ATP is highly concentrated (apparent partition coefficients up to 7700) and serves as bridges between bIDP chains. These liquid-like droplets have some of the lowest interfacial tension (∼25 pN/μm) but high zero-shear viscosities (1-15 Pa s) due to the bridged protein networks, and yet their fusion has some of the highest speeds (∼1 μm/ms). The rapid fusion manifests extreme shear thinning, where the apparent viscosity is lower than zero-shear viscosity by over 100-fold, made possible by fast reformation of the ATP bridges. At still higher concentrations, ATP does not dissolve bIDP droplets but results in aggregates and fibrils.
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Affiliation(s)
- Divya Kota
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
| | - Ramesh Prasad
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
| | - Huan-Xiang Zhou
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
- Department of Physics, University of Illinois Chicago, Chicago IL 60607, USA
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7
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Liu F, Wang J. ATP Acts as a Hydrotrope to Regulate the Phase Separation of NBDY Clusters. JACS AU 2023; 3:2578-2585. [PMID: 37772172 PMCID: PMC10523361 DOI: 10.1021/jacsau.3c00391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/16/2023] [Accepted: 08/25/2023] [Indexed: 09/30/2023]
Abstract
Nonannotated P-body dissociating polypeptide (NBDY) is a recently discovered human microprotein that has been found to be a novel component of the mRNA decapping complex. Previous studies have shown that the phosphorylation of NBDY promotes the liquid phase of the NBDY remixing in vitro. Typically, during the process of phosphorylation, a phosphate group is added to the protein through adenosine triphosphate (ATP) hydrolysis. It has been shown that ATP acts as a biological hydrotrope, affecting the phase separation of proteins in solution. In this study, we utilized simulation methods to investigate the dynamic properties of the NBDY clusters at various ATP concentrations. Our findings demonstrate that ATP can regulate the phase separation of NBDY clusters. Specifically, we identified a critical point in the concentration ratio between ATP and NBDY that exhibits a dual effect on the phase separation of NBDY. We observed that the nonsaturated ATP concentration can facilitate the formation of phase separation, while oversaturated ATP concentration promotes the diffusion of NBDY, and the oversaturated ATP-NBDY interaction impedes the phase separation of NBDY. Additionally, we found that ATPs can bind to the protein surface by aggregating into ATP clusters, which further hinders the diffusion of NBDY clusters. Our work provides general insight into the role of ATP in the phase separation of protein condensates.
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Affiliation(s)
- Fei Liu
- Wenzhou
Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
| | - Jin Wang
- Wenzhou
Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
- Department
of Chemistry and Physics, State University
of New York at Stony Brook, Stony Brook New York 11794, United States
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8
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Kota D, Prasad R, Zhou HX. ATP Mediates Phase Separation of Disordered Basic Proteins by Bridging Intermolecular Interaction Networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.20.554035. [PMID: 37645809 PMCID: PMC10462115 DOI: 10.1101/2023.08.20.554035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
ATP is an abundant molecule with crucial cellular roles as the energy currency and a building block of nucleic acids and for protein phosphorylation. Here we show that ATP mediates the phase separation of basic intrinsically disordered proteins (bIDPs). In the resulting condensates, ATP is highly concentrated (apparent partition coefficients at 200-5000) and serves as bridges between bIDP chains. These liquid-like droplets have some of the lowest interfacial tension (~25 pN/μm) but high zero-shear viscosities (1-15 Pa s) due to the bridged protein networks, and yet their fusion has some of the highest speeds (~1 μm/ms). The rapid fusion manifests extreme shear thinning, where the apparent viscosity is lower than zero-shear viscosity by over 100-fold, made possible by fast reformation of the ATP bridges. At still higher concentrations, ATP does not dissolve bIDP droplets but results in aggregates and fibrils.
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Affiliation(s)
- Divya Kota
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
| | - Ramesh Prasad
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
| | - Huan-Xiang Zhou
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
- Department of Physics, University of Illinois Chicago, Chicago IL 60607, USA
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9
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Szała-Mendyk B, Phan TM, Mohanty P, Mittal J. Challenges in studying the liquid-to-solid phase transitions of proteins using computer simulations. Curr Opin Chem Biol 2023; 75:102333. [PMID: 37267850 PMCID: PMC10527940 DOI: 10.1016/j.cbpa.2023.102333] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/24/2023] [Accepted: 04/30/2023] [Indexed: 06/04/2023]
Abstract
"Membraneless organelles," also referred to as biomolecular condensates, perform a variety of cellular functions and their dysregulation is implicated in cancer and neurodegeneration. In the last two decades, liquid-liquid phase separation (LLPS) of intrinsically disordered and multidomain proteins has emerged as a plausible mechanism underlying the formation of various biomolecular condensates. Further, the occurrence of liquid-to-solid transitions within liquid-like condensates may give rise to amyloid structures, implying a biophysical link between phase separation and protein aggregation. Despite significant advances, uncovering the microscopic details of liquid-to-solid phase transitions using experiments remains a considerable challenge and presents an exciting opportunity for the development of computational models which provide valuable, complementary insights into the underlying phenomenon. In this review, we first highlight recent biophysical studies which provide new insights into the molecular mechanisms underlying liquid-to-solid (fibril) phase transitions of folded, disordered and multi-domain proteins. Next, we summarize the range of computational models used to study protein aggregation and phase separation. Finally, we discuss recent computational approaches which attempt to capture the underlying physics of liquid-to-solid transitions along with their merits and shortcomings.
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Affiliation(s)
- Beata Szała-Mendyk
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, TAMU 3127, College Station, 77843, Texas, United States.
| | - Tien Minh Phan
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, TAMU 3127, College Station, 77843, Texas, United States.
| | - Priyesh Mohanty
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, TAMU 3127, College Station, 77843, Texas, United States.
| | - Jeetain Mittal
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, TAMU 3127, College Station, 77843, Texas, United States; Department of Chemistry, Texas A&M University, TAMU 3255, College Station, 77843, Texas, United States; Interdisciplinary Graduate Program in Genetics and Genomics, Texas A&M University, TAMU 3255, College Station, 77843, Texas, United States.
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10
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Maruri-Lopez I, Chodasiewicz M. Involvement of small molecules and metabolites in regulation of biomolecular condensate properties. CURRENT OPINION IN PLANT BIOLOGY 2023; 74:102385. [PMID: 37348448 DOI: 10.1016/j.pbi.2023.102385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 05/01/2023] [Accepted: 05/05/2023] [Indexed: 06/24/2023]
Abstract
Biomolecular condensate (BMCs) formation facilitates the grouping of molecules, including proteins, nucleic acids, and small molecules, creating specific microenvironments with particular functions. They are often assembled through liquid-liquid phase separation (LLPS), a phenomenon that arises when specific proteins, nucleic acids, and small molecules demix from the aqueous environment into another phase with different physiochemical properties. BMCs assemble and disassemble in response to external and internal stimuli such as temperature, molecule concentration, ionic strength, pH, and cellular redox state. Likewise, the nature of the regulatory stimuli may affect the lifespan, morphology, and content of BMCs. In humans, compelling evidence points to the critical role of BMCs in diseases. By contrast, the link between BMC formation, stress resistance, and cell survival has not been revealed in plants. Recent studies have pointed out the nascent roles of small molecules in the assembly and dynamics of BMCs; however, this is still an emerging field of study. This review briefly highlights the most significant efforts to identify the molecular mechanisms between small molecules and BMC formation and regulation in plants and other organisms. We then discuss (i) how small molecules exert control over the BMC assembly and dynamics in plants and (ii) how small molecules can influence the formation and material properties of plant BMCs. Finally, we propose novel alternatives that might help to understand the relationship between chemicals and condensation dynamics and their possible application to plant biotechnology.
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Affiliation(s)
- Israel Maruri-Lopez
- Biological and Environmental Science and Engineering Division, Center for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Monika Chodasiewicz
- Biological and Environmental Science and Engineering Division, Center for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
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11
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Light, Water, and Melatonin: The Synergistic Regulation of Phase Separation in Dementia. Int J Mol Sci 2023; 24:ijms24065835. [PMID: 36982909 PMCID: PMC10054283 DOI: 10.3390/ijms24065835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/17/2023] [Indexed: 03/22/2023] Open
Abstract
The swift rise in acceptance of molecular principles defining phase separation by a broad array of scientific disciplines is shadowed by increasing discoveries linking phase separation to pathological aggregations associated with numerous neurodegenerative disorders, including Alzheimer’s disease, that contribute to dementia. Phase separation is powered by multivalent macromolecular interactions. Importantly, the release of water molecules from protein hydration shells into bulk creates entropic gains that promote phase separation and the subsequent generation of insoluble cytotoxic aggregates that drive healthy brain cells into diseased states. Higher viscosity in interfacial waters and limited hydration in interiors of biomolecular condensates facilitate phase separation. Light, water, and melatonin constitute an ancient synergy that ensures adequate protein hydration to prevent aberrant phase separation. The 670 nm visible red wavelength found in sunlight and employed in photobiomodulation reduces interfacial and mitochondrial matrix viscosity to enhance ATP production via increasing ATP synthase motor efficiency. Melatonin is a potent antioxidant that lowers viscosity to increase ATP by scavenging excess reactive oxygen species and free radicals. Reduced viscosity by light and melatonin elevates the availability of free water molecules that allow melatonin to adopt favorable conformations that enhance intrinsic features, including binding interactions with adenosine that reinforces the adenosine moiety effect of ATP responsible for preventing water removal that causes hydrophobic collapse and aggregation in phase separation. Precise recalibration of interspecies melatonin dosages that account for differences in metabolic rates and bioavailability will ensure the efficacious reinstatement of the once-powerful ancient synergy between light, water, and melatonin in a modern world.
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12
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Dang M, Li T, Song J. ATP and nucleic acids competitively modulate LLPS of the SARS-CoV2 nucleocapsid protein. Commun Biol 2023; 6:80. [PMID: 36681763 PMCID: PMC9862227 DOI: 10.1038/s42003-023-04480-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 01/13/2023] [Indexed: 01/22/2023] Open
Abstract
SARS-CoV-2 nucleocapsid (N) protein with very low mutation rates is the only structural protein which not only functions to package viral genomic RNA, but also manipulates host-cell machineries, thus representing a key target for drug development. Recent discovery of its liquid-liquid phase separation (LLPS) opens up a new direction for developing anti-SARS-CoV-2 strategies/drugs. However, so far the high-resolution mechanism of its LLPS still remains unknown. Here by DIC and NMR characterization, we have demonstrated: 1) nucleic acids modulate LLPS by dynamic and multivalent interactions over both folded NTD/CTD and Arg/Lys residues within IDRs; 2) ATP with concentrations > mM in all living cells but absent in viruses not only binds NTD/CTD, but also Arg residues within IDRs with a Kd of 2.8 mM; and 3) ATP dissolves nucleic-acid-induced LLPS by competitively displacing nucleic acid from binding the protein. Our study deciphers that the essential binding of N protein with nucleic acid and its LLPS are targetable by small molecules including ATP, which is emerging as a cellular factor controlling the host-SARS-CoV-2 interaction. Fundamentally, our results imply that the mechanisms of LLPS of IDR-containing proteins mediated by ATP and nucleic acids appear to be highly conserved from human to virus.
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Affiliation(s)
- Mei Dang
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore, Singapore
| | - Tongyang Li
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore, Singapore
| | - Jianxing Song
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore, Singapore.
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13
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Arg/Lys-containing IDRs are cryptic binding domains for ATP and nucleic acids that interplay to modulate LLPS. Commun Biol 2022; 5:1315. [PMID: 36450893 PMCID: PMC9712531 DOI: 10.1038/s42003-022-04293-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 11/23/2022] [Indexed: 12/03/2022] Open
Abstract
Most membrane-less organelles (MLOs) formed by LLPS contain both nucleic acids and IDR-rich proteins. Currently while IDRs are well-recognized to drive LLPS, nucleic acids are thought to exert non-specific electrostatic/salt effects. TDP-43 functions by binding RNA/ssDNA and its LLPS was characterized without nucleic acids to be driven mainly by PLD-oligomerization, which may further transit into aggregation characteristic of various neurodegenerative diseases. Here by NMR, we discovered unexpectedly for TDP-43 PLD: 1) ssDNAs drive and then dissolve LLPS by multivalently and specifically binding Arg/Lys. 2) LLPS is driven by nucleic-acid-binding coupled with PLD-oligomerization. 3) ATP and nucleic acids universally interplay in modulating LLPS by competing for binding Arg/Lys. However, the unique hydrophobic region within PLD renders LLPS to exaggerate into aggregation. The study not only unveils the first residue-resolution mechanism of the nucleic-acid-driven LLPS of TDP-43 PLD, but also decodes a general principle that not just TDP-43 PLD, all Arg/Lys-containing IDRs are cryptic nucleic-acid-binding domains that may phase separate upon binding nucleic acids. Strikingly, ATP shares a common mechanism with nucleic acids in binding IDRs, thus emerging as a universal mediator for interactions between IDRs and nucleic acids, which may underlie previously-unrecognized roles of ATP at mM in physiology and pathology.
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14
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Gordon-Kim C, Rha A, Poppitz GA, Smith-Carpenter J, Luu R, Roberson AB, Conklin R, Blake A, Lynn DG. Polyanion order controls liquid-to-solid phase transition in peptide/nucleic acid co-assembly. Front Mol Biosci 2022; 9:991728. [PMID: 36452451 PMCID: PMC9702359 DOI: 10.3389/fmolb.2022.991728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/25/2022] [Indexed: 01/06/2024] Open
Abstract
The Central Dogma highlights the mutualistic functions of protein and nucleic acid biopolymers, and this synergy appears prominently in the membraneless organelles widely distributed throughout prokaryotic and eukaryotic organisms alike. Ribonucleoprotein granules (RNPs), which are complex coacervates of RNA with proteins, are a prime example of these membranelles organelles and underly multiple essential cellular functions. Inspired by the highly dynamic character of these organelles and the recent studies that ATP both inhibits and templates phase separation of the fused in sarcoma (FUS) protein implicated in several neurodegenerative diseases, we explored the RNA templated ordering of a single motif of the Aβ peptide of Alzheimer's disease. We now know that this strong cross-β propensity motif alone assembles through a liquid-like coacervate phase that can be externally templated to form distinct supramolecular assemblies. Now we provide evidence that structured phosphates, ranging from complex structures like double stranded and quadraplex DNA to simple trimetaphosphate, differentially impact the liquid to solid phase transition necessary for paracrystalline assembly. The results from this simple model illustrate the potential of ordered environmental templates in the transition to potentially irreversible pathogenic assemblies and provides insight into the ordering dynamics necessary for creating functional synthetic polymer co-assemblies.
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Affiliation(s)
| | - Allisandra Rha
- Children’s Health of Orange County, Research Institute, Orange, CA, United States
| | - George A. Poppitz
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | | | - Regina Luu
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | | | - Russell Conklin
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | - Alexis Blake
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | - David G. Lynn
- Department of Chemistry, Emory University, Atlanta, GA, United States
- Department of Biology, Emory University, Atlanta, GA, United States
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