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Boyd-Shiwarski CR, Shiwarski DJ, Subramanya AR. A New Phase for WNK Kinase Signaling Complexes as Biomolecular Condensates. Physiology (Bethesda) 2024; 39:0. [PMID: 38624245 DOI: 10.1152/physiol.00013.2024] [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: 02/22/2024] [Revised: 04/09/2024] [Accepted: 04/09/2024] [Indexed: 04/17/2024] Open
Abstract
The purpose of this review is to highlight transformative advances that have been made in the field of biomolecular condensates, with special emphasis on condensate material properties, physiology, and kinases, using the With-No-Lysine (WNK) kinases as a prototypical example. To convey how WNK kinases illustrate important concepts for biomolecular condensates, we start with a brief history, focus on defining features of biomolecular condensates, and delve into some examples of how condensates are implicated in cellular physiology (and pathophysiology). We then highlight how WNK kinases, through the action of "WNK droplets" that ubiquitously regulate intracellular volume and kidney-specific "WNK bodies" that are implicated in distal tubule salt reabsorption and potassium homeostasis, exemplify many of the defining features of condensates. Finally, this review addresses the controversies within this emerging field and questions to address.
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Affiliation(s)
- Cary R Boyd-Shiwarski
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
- Pittsburgh Heart, Lung, Blood Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Daniel J Shiwarski
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Arohan R Subramanya
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
- Pittsburgh Heart, Lung, Blood Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, United States
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2
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Ruger-Herreros C, Svoboda L, Mogk A, Bukau B. Role of J-domain Proteins in Yeast Physiology and Protein Quality Control. J Mol Biol 2024; 436:168484. [PMID: 38331212 DOI: 10.1016/j.jmb.2024.168484] [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: 10/20/2023] [Revised: 02/02/2024] [Accepted: 02/02/2024] [Indexed: 02/10/2024]
Abstract
The Hsp70 chaperone system is a central component of cellular protein quality control (PQC) by acting in a multitude of protein folding processes ranging from the folding of newly synthesized proteins to the disassembly and refolding of protein aggregates. This multifunctionality of Hsp70 is governed by J-domain proteins (JDPs), which act as indispensable co-chaperones that target specific substrates to Hsp70. The number of distinct JDPs present in a species always outnumbers Hsp70, documenting JDP function in functional diversification of Hsp70. In this review, we describe the physiological roles of JDPs in the Saccharomyces cerevisiae PQC system, with a focus on the abundant JDP generalists, Zuo1, Ydj1 and Sis1, which function in fundamental cellular processes. Ribosome-bound Zuo1 cooperates with the Hsp70 chaperones Ssb1/2 in folding and assembly of nascent polypeptides. Ydj1 and Sis1 cooperate with the Hsp70 members Ssa1 to Ssa4 to exert overlapping functions in protein folding and targeting of newly synthesized proteins to organelles including mitochondria and facilitating the degradation of aberrant proteins by E3 ligases. Furthermore, they act in protein disaggregation reactions, though Ydj1 and Sis1 differ in their modes of Hsp70 cooperation and substrate specificities. This results in functional specialization as seen in prion propagation and the underlying dominant role of Sis1 in targeting Hsp70 for shearing of prion amyloid fibrils.
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Affiliation(s)
- Carmen Ruger-Herreros
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany; Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot, s/n, E-41013 Sevilla, Spain
| | - Lucia Svoboda
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Axel Mogk
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
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3
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Cairo LV, Hong X, Müller MBD, Yuste-Checa P, Jagadeesan C, Bracher A, Park SH, Hayer-Hartl M, Hartl FU. Stress-dependent condensate formation regulated by the ubiquitin-related modifier Urm1. Cell 2024:S0092-8674(24)00649-4. [PMID: 38942013 DOI: 10.1016/j.cell.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 04/12/2024] [Accepted: 06/08/2024] [Indexed: 06/30/2024]
Abstract
The ability of proteins and RNA to coalesce into phase-separated assemblies, such as the nucleolus and stress granules, is a basic principle in organizing membraneless cellular compartments. While the constituents of biomolecular condensates are generally well documented, the mechanisms underlying their formation under stress are only partially understood. Here, we show in yeast that covalent modification with the ubiquitin-like modifier Urm1 promotes the phase separation of a wide range of proteins. We find that the drop in cellular pH induced by stress triggers Urm1 self-association and its interaction with both target proteins and the Urm1-conjugating enzyme Uba4. Urmylation of stress-sensitive proteins promotes their deposition into stress granules and nuclear condensates. Yeast cells lacking Urm1 exhibit condensate defects that manifest in reduced stress resilience. We propose that Urm1 acts as a reversible molecular "adhesive" to drive protective phase separation of functionally critical proteins under cellular stress.
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Affiliation(s)
- Lucas V Cairo
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Xiaoyu Hong
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Martin B D Müller
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Patricia Yuste-Checa
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Chandhuru Jagadeesan
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sae-Hun Park
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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4
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Davis MC, André AAM, Kjaergaard M. Entering the Next Phase: Predicting Biological Effects of Biomolecular Condensates. J Mol Biol 2024:168645. [PMID: 38848869 DOI: 10.1016/j.jmb.2024.168645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 06/02/2024] [Accepted: 06/03/2024] [Indexed: 06/09/2024]
Abstract
Biomolecular condensates are increasingly recognized as important drivers of cellular function; their dysregulation leads to pathology and disease. We discuss three questions in terms of the impending utility of data-driven techniques to predict condensate-driven biological outcomes, i.e., the impact of cellular state changes on condensates, the effect of condensates on biochemical processes within, and condensate properties that result in cellular dysregulation and disease.
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Affiliation(s)
- Maria C Davis
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Alain A M André
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Magnus Kjaergaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; The Danish Research Institute for Translational Neuroscience (DANDRITE), Denmark.
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5
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Chauhan G, Bremer A, Dar F, Mittag T, Pappu RV. Crowder titrations enable the quantification of driving forces for macromolecular phase separation. Biophys J 2024; 123:1376-1392. [PMID: 37717144 PMCID: PMC11163301 DOI: 10.1016/j.bpj.2023.09.006] [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: 07/03/2023] [Revised: 09/03/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023] Open
Abstract
Macromolecular solubility is an important contributor to the driving forces for phase separation. Formally, the driving forces in a binary mixture comprising a macromolecule dissolved in a solvent can be quantified in terms of the saturation concentration, which is the threshold macromolecular concentration above which the mixture separates into coexisting dense and dilute phases. In addition, the second virial coefficient, which measures the effective strength of solvent-mediated intermolecular interactions provides direct assessments of solvent quality. The sign and magnitude of second virial coefficients will be governed by a combination of solution conditions and the nature of the macromolecule of interest. Here, we show, using a combination of theory, simulation, and in vitro experiments, that titrations of crowders, providing they are true depletants, can be used to extract the intrinsic driving forces for macromolecular phase separation. This refers to saturation concentrations in the absence of crowders and the second virial coefficients that quantify the magnitude of the incompatibility between macromolecules and the solvent. Our results show how the depletion-mediated attractions afforded by crowders can be leveraged to obtain comparative assessments of macromolecule-specific, intrinsic driving forces for phase separation.
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Affiliation(s)
- Gaurav Chauhan
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Anne Bremer
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Furqan Dar
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Tanja Mittag
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Rohit V Pappu
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri.
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6
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Rathnayaka-Mudiyanselage IW, Nandana V, Schrader JM. Proteomic composition of eukaryotic and bacterial RNA decay condensates suggests convergent evolution. Curr Opin Microbiol 2024; 79:102467. [PMID: 38569418 PMCID: PMC11162941 DOI: 10.1016/j.mib.2024.102467] [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: 12/19/2023] [Revised: 02/21/2024] [Accepted: 03/12/2024] [Indexed: 04/05/2024]
Abstract
Bacterial cells have a unique challenge to organize their cytoplasm without the use of membrane-bound organelles. Biomolecular condensates (henceforth BMCs) are a class of nonmembrane-bound organelles, which, through the physical process of phase separation, can form liquid-like droplets with proteins/nucleic acids. BMCs have been broadly characterized in eukaryotic cells, and BMCs have been recently identified in bacteria, with the first and best studied example being bacterial ribonucleoprotein bodies (BR-bodies). BR-bodies contain the RNA decay machinery and show functional parallels to eukaryotic P-bodies (PBs) and stress granules (SGs). Due to the finding that mRNA decay machinery is compartmentalized in BR-bodies and in eukaryotic PBs/SGs, we will explore the functional similarities in the proteins, which are known to enrich in these structures based on recent proteomic studies. Interestingly, despite the use of different mRNA decay and post-transcriptional regulatory machinery, this analysis has revealed evolutionary convergence in the classes of enriched enzymes in these structures.
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Affiliation(s)
- I W Rathnayaka-Mudiyanselage
- Wayne State University, Department of Biological Sciences, Detroit, MI, USA; Wayne State University, Department of Chemistry, Detroit, MI, USA
| | - V Nandana
- Wayne State University, Department of Biological Sciences, Detroit, MI, USA
| | - J M Schrader
- Wayne State University, Department of Biological Sciences, Detroit, MI, USA.
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7
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Li J, Wang W, Li S, Qiao Z, Jiang H, Chang X, Zhu Y, Tan H, Ma X, Dong Y, He Z, Wang Z, Liu Q, Yao S, Yang C, Yang M, Cao L, Zhang J, Li W, Wang W, Yang Z, Rong P. Smad2/3/4 complex could undergo liquid liquid phase separation and induce apoptosis through TAT in hepatocellular carcinoma. Cancer Cell Int 2024; 24:176. [PMID: 38769521 PMCID: PMC11106862 DOI: 10.1186/s12935-024-03353-x] [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: 08/14/2023] [Accepted: 05/02/2024] [Indexed: 05/22/2024] Open
Abstract
BACKGROUND Hepatocellular carcinoma (HCC) represents one of the most significant causes of mortality due to cancer-related deaths. It has been previously reported that the TGF-β signaling pathway may be associated with tumor progression. However, the relationship between TGF-β signaling pathway and HCC remains to be further elucidated. The objective of our research was to investigate the impact of TGF-β signaling pathway on HCC progression as well as the potential regulatory mechanism involved. METHODS We conducted a series of bioinformatics analyses to screen and filter the most relevant hub genes associated with HCC. E. coli was utilized to express recombinant protein, and the Ni-NTA column was employed for purification of the target protein. Liquid liquid phase separation (LLPS) of protein in vitro, and fluorescent recovery after photobleaching (FRAP) were utilized to verify whether the target proteins had the ability to drive force LLPS. Western blot and quantitative real-time polymerase chain reaction (qPCR) were utilized to assess gene expression levels. Transcription factor binding sites of DNA were identified by chromatin immunoprecipitation (CHIP) qPCR. Flow cytometry was employed to examine cell apoptosis. Knockdown of target genes was achieved through shRNA. Cell Counting Kit-8 (CCK-8), colony formation assays, and nude mice tumor transplantation were utilized to test cell proliferation ability in vitro and in vivo. RESULTS We found that Smad2/3/4 complex could regulate tyrosine aminotransferase (TAT) expression, and this regulation could relate to LLPS. CHIP qPCR results showed that the key targeted DNA binding site of Smad2/3/4 complex in TAT promoter region is -1032 to -1182. In addition. CCK-8, colony formation, and nude mice tumor transplantation assays showed that Smad2/3/4 complex could repress cell proliferation through TAT. Flow cytometry assay results showed that Smad2/3/4 complex could increase the apoptosis of hepatoma cells. Western blot results showed that Smad2/3/4 complex would active caspase-9 through TAT, which uncovered the mechanism of Smad2/3/4 complex inducing hepatoma cell apoptosis. CONCLUSION This study proved that Smad2/3/4 complex could undergo LLPS to active TAT transcription, then active caspase-9 to induce hepatoma cell apoptosis in inhibiting HCC progress. The research further elucidate the relationship between TGF-β signaling pathway and HCC, which contributes to discover the mechanism of HCC development.
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Affiliation(s)
- Jiong Li
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
- Postdoctoral Station of Medical Aspects of Specific Environments, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wendi Wang
- College of Life Science, Liaoning University, Shenyang, China
| | - Sang Li
- Engineering and Technology Research Center for Xenotransplantation of Human Province, Changsha, China
| | - Zhengkang Qiao
- College of Life Science, Liaoning University, Shenyang, China
| | - Haoyue Jiang
- College of Life Science, Liaoning University, Shenyang, China
| | - Xinyue Chang
- College of Life Science, Liaoning University, Shenyang, China
| | - Yaning Zhu
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hongpei Tan
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiaoqian Ma
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yuqian Dong
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhenhu He
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhen Wang
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Qin Liu
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shanhu Yao
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Cejun Yang
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Min Yang
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lu Cao
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Juan Zhang
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wei Li
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wei Wang
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhe Yang
- College of Life Science, Liaoning University, Shenyang, China.
- Shenyang Key Laboratory of Chronic Disease Occurrence and Nutrition Intervention, College of Life Sciences, Liaoning University, Shenyang, 110036, China.
| | - Pengfei Rong
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China.
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8
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Cereghetti G, Kissling VM, Koch LM, Arm A, Schmidt CC, Thüringer Y, Zamboni N, Afanasyev P, Linsenmeier M, Eichmann C, Kroschwald S, Zhou J, Cao Y, Pfizenmaier DM, Wiegand T, Cadalbert R, Gupta G, Boehringer D, Knowles TPJ, Mezzenga R, Arosio P, Riek R, Peter M. An evolutionarily conserved mechanism controls reversible amyloids of pyruvate kinase via pH-sensing regions. Dev Cell 2024:S1534-5807(24)00271-5. [PMID: 38788715 DOI: 10.1016/j.devcel.2024.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/15/2023] [Accepted: 04/26/2024] [Indexed: 05/26/2024]
Abstract
Amyloids are known as irreversible aggregates associated with neurodegenerative diseases. However, recent evidence shows that a subset of amyloids can form reversibly and fulfill essential cellular functions. Yet, the molecular mechanisms regulating functional amyloids and distinguishing them from pathological aggregates remain unclear. Here, we investigate the conserved principles of amyloid reversibility by studying the essential metabolic enzyme pyruvate kinase (PK) in yeast and human cells. We demonstrate that yeast PK (Cdc19) and human PK (PKM2) form reversible amyloids through a pH-sensitive amyloid core. Stress-induced cytosolic acidification promotes aggregation via protonation of specific glutamate (yeast) or histidine (human) residues within the amyloid core. Mutations mimicking protonation cause constitutive PK aggregation, while non-protonatable PK mutants remain soluble even upon stress. Physiological PK aggregation is coupled to metabolic rewiring and glycolysis arrest, causing severe growth defects when misregulated. Our work thus identifies an evolutionarily conserved, potentially widespread mechanism regulating functional amyloids during stress.
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Affiliation(s)
- Gea Cereghetti
- Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland; Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, CB2 1EW Cambridge, UK.
| | - Vera M Kissling
- Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland; Particles-Biology Interactions Laboratory, Department of Materials Meet Life, Empa, 9014 St. Gallen, Switzerland
| | - Lisa M Koch
- Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Alexandra Arm
- Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Claudia C Schmidt
- Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Yannik Thüringer
- Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Nicola Zamboni
- Institute of Molecular Systems Biology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Pavel Afanasyev
- Cryo-EM Knowledge Hub (CEMK), ETH Zurich, 8093 Zürich, Switzerland
| | - Miriam Linsenmeier
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Cédric Eichmann
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Sonja Kroschwald
- Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Jiangtao Zhou
- Department of Health Sciences & Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - Yiping Cao
- Department of Health Sciences & Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - Dorota M Pfizenmaier
- Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Thomas Wiegand
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; Max Planck Institute for Chemical Energy Conversion, 45470 Mülheim an der Ruhr, Germany; Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074 Aachen, Germany
| | - Riccardo Cadalbert
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Govind Gupta
- Particles-Biology Interactions Laboratory, Department of Materials Meet Life, Empa, 9014 St. Gallen, Switzerland
| | | | - Tuomas P J Knowles
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, CB2 1EW Cambridge, UK
| | - Raffaele Mezzenga
- Department of Health Sciences & Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - Paolo Arosio
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Roland Riek
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Matthias Peter
- Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland.
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Glauninger H, Bard JA, Wong Hickernell CJ, Airoldi EM, Li W, Singer RH, Paul S, Fei J, Sosnick TR, Wallace EWJ, Drummond DA. Transcriptome-wide mRNA condensation precedes stress granule formation and excludes stress-induced transcripts. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589678. [PMID: 38659805 PMCID: PMC11042329 DOI: 10.1101/2024.04.15.589678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Stress-induced condensation of mRNA and proteins into stress granules is conserved across eukaryotes, yet the function, formation mechanisms, and relation to well-studied conserved transcriptional responses remain largely unresolved. Stress-induced exposure of ribosome-free mRNA following translational shutoff is thought to cause condensation by allowing new multivalent RNA-dependent interactions, with RNA length and associated interaction capacity driving increased condensation. Here we show that, in striking contrast, virtually all mRNA species condense in response to multiple unrelated stresses in budding yeast, length plays a minor role, and instead, stress-induced transcripts are preferentially excluded from condensates, enabling their selective translation. Using both endogenous genes and reporter constructs, we show that translation initiation blockade, rather than resulting ribosome-free RNA, causes condensation. These translation initiation-inhibited condensates (TIICs) are biochemically detectable even when stress granules, defined as microscopically visible foci, are absent or blocked. TIICs occur in unstressed yeast cells, and, during stress, grow before the appearance of visible stress granules. Stress-induced transcripts are excluded from TIICs primarily due to the timing of their expression, rather than their sequence features. Together, our results reveal a simple system by which cells redirect translational activity to newly synthesized transcripts during stress, with broad implications for cellular regulation in changing conditions.
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Affiliation(s)
- Hendrik Glauninger
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL, USA
- Interdisciplinary Scientist Training Program, The University of Chicago, Chicago, IL, USA
| | - Jared A.M. Bard
- Department of Biology, Texas A&M University, College Station, TX, USA
| | | | - Edo M. Airoldi
- Fox School of Business and Management, Temple University, Philadelphia, PA, USA
| | - Weihan Li
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Robert H. Singer
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
- Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Sneha Paul
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Jingyi Fei
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
| | - Tobin R. Sosnick
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | | | - D. Allan Drummond
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL, USA
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10
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Liu Y, Yang P. eIF4G as a switch for heat shock mRNA translation. Mol Cell 2024; 84:1633-1634. [PMID: 38701739 DOI: 10.1016/j.molcel.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 04/03/2024] [Accepted: 04/03/2024] [Indexed: 05/05/2024]
Abstract
The heat shock response is crucial for cell survival. In this issue of Molecular Cell, Desroches Altamirano et al.1 demonstrate that a temperature-induced conformational change in the translation initiation factor eIF4G is a key mechanism regulating translation during the heat shock response.
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Affiliation(s)
- Yi Liu
- Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Peiguo Yang
- Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China.
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11
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Desroches Altamirano C, Kang MK, Jordan MA, Borianne T, Dilmen I, Gnädig M, von Appen A, Honigmann A, Franzmann TM, Alberti S. eIF4F is a thermo-sensing regulatory node in the translational heat shock response. Mol Cell 2024; 84:1727-1741.e12. [PMID: 38547866 DOI: 10.1016/j.molcel.2024.02.038] [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: 06/28/2023] [Revised: 12/18/2023] [Accepted: 02/29/2024] [Indexed: 05/05/2024]
Abstract
Heat-shocked cells prioritize the translation of heat shock (HS) mRNAs, but the underlying mechanism is unclear. We report that HS in budding yeast induces the disassembly of the eIF4F complex, where eIF4G and eIF4E assemble into translationally arrested mRNA ribonucleoprotein particles (mRNPs) and HS granules (HSGs), whereas eIF4A promotes HS translation. Using in vitro reconstitution biochemistry, we show that a conformational rearrangement of the thermo-sensing eIF4A-binding domain of eIF4G dissociates eIF4A and promotes the assembly with mRNA into HS-mRNPs, which recruit additional translation factors, including Pab1p and eIF4E, to form multi-component condensates. Using extracts and cellular experiments, we demonstrate that HS-mRNPs and condensates repress the translation of associated mRNA and deplete translation factors that are required for housekeeping translation, whereas HS mRNAs can be efficiently translated by eIF4A. We conclude that the eIF4F complex is a thermo-sensing node that regulates translation during HS.
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Affiliation(s)
- Christine Desroches Altamirano
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Moo-Koo Kang
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Mareike A Jordan
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Tom Borianne
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Irem Dilmen
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Maren Gnädig
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Alexander von Appen
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Alf Honigmann
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Titus M Franzmann
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Simon Alberti
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany.
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12
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Eljebbawi A, Hutin S, Zubieta C, Stahl Y. Environmental signals driving liquid-liquid phase separation - a molecular memory in plants? FRONTIERS IN PLANT SCIENCE 2024; 15:1391043. [PMID: 38736449 PMCID: PMC11082374 DOI: 10.3389/fpls.2024.1391043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 04/17/2024] [Indexed: 05/14/2024]
Affiliation(s)
- Ali Eljebbawi
- Institute for Developmental Genetics, Heinrich-Heine University, Düsseldorf, Germany
| | - Stephanie Hutin
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National de la Recherche Scientifique, Commissariat à l’énergie Atomique et aux Énergies Alternatives, Institut National de Recherche pour l’agriculture, l’alimentation et l’environnement, Institut de Recherche Interdisciplinaire de Grenoble, Grenoble, France
| | - Chloe Zubieta
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National de la Recherche Scientifique, Commissariat à l’énergie Atomique et aux Énergies Alternatives, Institut National de Recherche pour l’agriculture, l’alimentation et l’environnement, Institut de Recherche Interdisciplinaire de Grenoble, Grenoble, France
| | - Yvonne Stahl
- Institute for Developmental Genetics, Heinrich-Heine University, Düsseldorf, Germany
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13
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Vizjak P, Kamp D, Hepp N, Scacchetti A, Gonzalez Pisfil M, Bartho J, Halic M, Becker PB, Smolle M, Stigler J, Mueller-Planitz F. ISWI catalyzes nucleosome sliding in condensed nucleosome arrays. Nat Struct Mol Biol 2024:10.1038/s41594-024-01290-x. [PMID: 38664566 DOI: 10.1038/s41594-024-01290-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 03/25/2024] [Indexed: 05/07/2024]
Abstract
How chromatin enzymes work in condensed chromatin and how they maintain diffusional mobility inside remains unexplored. Here we investigated these challenges using the Drosophila ISWI remodeling ATPase, which slides nucleosomes along DNA. Folding of chromatin fibers did not affect sliding in vitro. Catalytic rates were also comparable in- and outside of chromatin condensates. ISWI cross-links and thereby stiffens condensates, except when ATP hydrolysis is possible. Active hydrolysis is also required for ISWI's mobility in condensates. Energy from ATP hydrolysis therefore fuels ISWI's diffusion through chromatin and prevents ISWI from cross-linking chromatin. Molecular dynamics simulations of a 'monkey-bar' model in which ISWI grabs onto neighboring nucleosomes, then withdraws from one before rebinding another in an ATP hydrolysis-dependent manner, qualitatively agree with our data. We speculate that monkey-bar mechanisms could be shared with other chromatin factors and that changes in chromatin dynamics caused by mutations in remodelers could contribute to pathologies.
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Affiliation(s)
- Petra Vizjak
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Department of Molecular Biology, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Early Stage Bioprocess Development, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Dieter Kamp
- Gene Center, Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Nicola Hepp
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Department of Molecular Biology, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Department of Clinical Genetics, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Alessandro Scacchetti
- Department of Molecular Biology, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Epigenetics Institute and Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mariano Gonzalez Pisfil
- Core Facility Bioimaging and Walter-Brendel-Centre of Experimental Medicine, Biomedical Center, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Joseph Bartho
- Gene Center, Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Mario Halic
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Peter B Becker
- Department of Molecular Biology, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Michaela Smolle
- Department of Physiological Chemistry, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- BioPhysics Core Facility, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- ViraTherapeutics GmbH, Rum, Austria
| | - Johannes Stigler
- Gene Center, Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.
| | - Felix Mueller-Planitz
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
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14
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Keyport Kik S, Christopher D, Glauninger H, Hickernell CW, Bard JAM, Lin KM, Squires AH, Ford M, Sosnick TR, Drummond DA. An adaptive biomolecular condensation response is conserved across environmentally divergent species. Nat Commun 2024; 15:3127. [PMID: 38605014 PMCID: PMC11009240 DOI: 10.1038/s41467-024-47355-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 03/27/2024] [Indexed: 04/13/2024] Open
Abstract
Cells must sense and respond to sudden maladaptive environmental changes-stresses-to survive and thrive. Across eukaryotes, stresses such as heat shock trigger conserved responses: growth arrest, a specific transcriptional response, and biomolecular condensation of protein and mRNA into structures known as stress granules under severe stress. The composition, formation mechanism, adaptive significance, and even evolutionary conservation of these condensed structures remain enigmatic. Here we provide a remarkable view into stress-triggered condensation, its evolutionary conservation and tuning, and its integration into other well-studied aspects of the stress response. Using three morphologically near-identical budding yeast species adapted to different thermal environments and diverged by up to 100 million years, we show that proteome-scale biomolecular condensation is tuned to species-specific thermal niches, closely tracking corresponding growth and transcriptional responses. In each species, poly(A)-binding protein-a core marker of stress granules-condenses in isolation at species-specific temperatures, with conserved molecular features and conformational changes modulating condensation. From the ecological to the molecular scale, our results reveal previously unappreciated levels of evolutionary selection in the eukaryotic stress response, while establishing a rich, tractable system for further inquiry.
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Affiliation(s)
- Samantha Keyport Kik
- Committee on Genetics, Genomics, and Systems Biology, The University of Chicago, Chicago, IL, USA
| | - Dana Christopher
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Hendrik Glauninger
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL, USA
- Interdisciplinary Scientist Training Program, The University of Chicago, Chicago, IL, USA
| | - Caitlin Wong Hickernell
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Jared A M Bard
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Kyle M Lin
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL, USA
- Interdisciplinary Scientist Training Program, The University of Chicago, Chicago, IL, USA
| | - Allison H Squires
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
| | | | - Tobin R Sosnick
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
| | - D Allan Drummond
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA.
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA.
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL, USA.
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15
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Chen R, Glauninger H, Kahan DN, Shangguan J, Sachleben JR, Riback JA, Drummond DA, Sosnick TR. HDX-MS finds that partial unfolding with sequential domain activation controls condensation of a cellular stress marker. Proc Natl Acad Sci U S A 2024; 121:e2321606121. [PMID: 38513106 PMCID: PMC10990091 DOI: 10.1073/pnas.2321606121] [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: 12/12/2023] [Accepted: 01/29/2024] [Indexed: 03/23/2024] Open
Abstract
Eukaryotic cells form condensates to sense and adapt to their environment [S. F. Banani, H. O. Lee, A. A. Hyman, M. K. Rosen, Nat. Rev. Mol. Cell Biol. 18, 285-298 (2017), H. Yoo, C. Triandafillou, D. A. Drummond, J. Biol. Chem. 294, 7151-7159 (2019)]. Poly(A)-binding protein (Pab1), a canonical stress granule marker, condenses upon heat shock or starvation, promoting adaptation [J. A. Riback et al., Cell 168, 1028-1040.e19 (2017)]. The molecular basis of condensation has remained elusive due to a dearth of techniques to probe structure directly in condensates. We apply hydrogen-deuterium exchange/mass spectrometry to investigate the mechanism of Pab1's condensation. Pab1's four RNA recognition motifs (RRMs) undergo different levels of partial unfolding upon condensation, and the changes are similar for thermal and pH stresses. Although structural heterogeneity is observed, the ability of MS to describe populations allows us to identify which regions contribute to the condensate's interaction network. Our data yield a picture of Pab1's stress-triggered condensation, which we term sequential activation (Fig. 1A), wherein each RRM becomes activated at a temperature where it partially unfolds and associates with other likewise activated RRMs to form the condensate. Subsequent association is dictated more by the underlying free energy surface than specific interactions, an effect we refer to as thermodynamic specificity. Our study represents an advance for elucidating the interactions that drive condensation. Furthermore, our findings demonstrate how condensation can use thermodynamic specificity to perform an acute response to multiple stresses, a potentially general mechanism for stress-responsive proteins.
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Affiliation(s)
- Ruofan Chen
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL60637
| | - Hendrik Glauninger
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL60637
- Graduate Program in Biophysical Sciences, Division of Physical Sciences, University of Chicago, Chicago, IL60637
| | - Darren N. Kahan
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL60637
| | - Julia Shangguan
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL60637
| | | | - Joshua A. Riback
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL60637
- Graduate Program in Biophysical Sciences, Division of Physical Sciences, University of Chicago, Chicago, IL60637
| | - D. Allan Drummond
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL60637
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL60637
| | - Tobin R. Sosnick
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL60637
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL60637
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL60637
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16
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Gorsheneva NA, Sopova JV, Azarov VV, Grizel AV, Rubel AA. Biomolecular Condensates: Structure, Functions, Methods of Research. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:S205-S223. [PMID: 38621751 DOI: 10.1134/s0006297924140116] [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: 09/29/2023] [Revised: 10/12/2023] [Accepted: 10/16/2023] [Indexed: 04/17/2024]
Abstract
The term "biomolecular condensates" is used to describe membraneless compartments in eukaryotic cells, accumulating proteins and nucleic acids. Biomolecular condensates are formed as a result of liquid-liquid phase separation (LLPS). Often, they demonstrate properties of liquid-like droplets or gel-like aggregates; however, some of them may appear to have a more complex structure and high-order organization. Membraneless microcompartments are involved in diverse processes both in cytoplasm and in nucleus, among them ribosome biogenesis, regulation of gene expression, cell signaling, and stress response. Condensates properties and structure could be highly dynamic and are affected by various internal and external factors, e.g., concentration and interactions of components, solution temperature, pH, osmolarity, etc. In this review, we discuss variety of biomolecular condensates and their functions in live cells, describe their structure variants, highlight domain and primary sequence organization of the constituent proteins and nucleic acids. Finally, we describe current advances in methods that characterize structure, properties, morphology, and dynamics of biomolecular condensates in vitro and in vivo.
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Affiliation(s)
| | - Julia V Sopova
- St. Petersburg State University, St. Petersburg, 199034, Russia.
| | | | - Anastasia V Grizel
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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17
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Vizjak P, Kamp D, Hepp N, Scacchetti A, Pisfil MG, Bartho J, Halic M, Becker PB, Smolle M, Stigler J, Mueller-Planitz F. ISWI catalyzes nucleosome sliding in condensed nucleosome arrays. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.04.569516. [PMID: 38106060 PMCID: PMC10723341 DOI: 10.1101/2023.12.04.569516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
How chromatin enzymes work in condensed chromatin and how they maintain diffusional mobility inside remains unexplored. We investigated these challenges using the Drosophila ISWI remodeling ATPase, which slides nucleosomes along DNA. Folding of chromatin fibers did not affect sliding in vitro. Catalytic rates were also comparable in- and outside of chromatin condensates. ISWI cross-links and thereby stiffens condensates, except when ATP hydrolysis is possible. Active hydrolysis is also required for ISWI's mobility in condensates. Energy from ATP hydrolysis therefore fuels ISWI's diffusion through chromatin and prevents ISWI from cross-linking chromatin. Molecular dynamics simulations of a 'monkey-bar' model in which ISWI grabs onto neighboring nucleosomes, then withdraws from one before rebinding another in an ATP hydrolysis-dependent manner qualitatively agree with our data. We speculate that 'monkey-bar' mechanisms could be shared with other chromatin factors and that changes in chromatin dynamics caused by mutations in remodelers could contribute to pathologies.
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Affiliation(s)
- Petra Vizjak
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
- Department of Molecular Biology, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhadernerstr. 9, 82152 Planegg-Martinsried, Germany
| | - Dieter Kamp
- Gene Center, Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str 25, 81377 München, Germany
| | - Nicola Hepp
- Department of Molecular Biology, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhadernerstr. 9, 82152 Planegg-Martinsried, Germany
- Current address: Department of Clinical Genetics, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Alessandro Scacchetti
- Department of Molecular Biology, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhadernerstr. 9, 82152 Planegg-Martinsried, Germany
- Current address: Epigenetics Institute & Department of Cell and Developmental Biology, University of Pennsylvania, Perelman School of Medicine, Philadelphia (PA), USA
| | - Mariano Gonzalez Pisfil
- Core Facility Bioimaging and Walter-Brendel-Centre of Experimental Medicine, Biomedical Center, Ludwig-Maximilians-Universität München, Großhaderner Straße 9, 82152, Planegg-Martinsried, Germany
| | - Joseph Bartho
- Gene Center, Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str 25, 81377 München, Germany
| | - Mario Halic
- Department of Structural Biology, St. Jude Children's Research Hospital, 263 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Peter B Becker
- Department of Molecular Biology, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhadernerstr. 9, 82152 Planegg-Martinsried, Germany
| | - Michaela Smolle
- Department of Physiological Chemistry, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhadernerstr. 9, 82152 Planegg-Martinsried, Germany
- BioPhysics Core Facility, Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhadernerstr. 9, 82152 Planegg-Martinsried, Germany
| | - Johannes Stigler
- Gene Center, Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str 25, 81377 München, Germany
| | - Felix Mueller-Planitz
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
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18
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Feng J, Gabryelczyk B, Tunn I, Osmekhina E, Linder MB. A Minispidroin Guides the Molecular Design for Cellular Condensation Mechanisms in S. cerevisiae. ACS Synth Biol 2023; 12:3050-3063. [PMID: 37688556 PMCID: PMC10594646 DOI: 10.1021/acssynbio.3c00374] [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: 06/18/2023] [Indexed: 09/11/2023]
Abstract
Structural engineering of molecules for condensation is an emerging technique within synthetic biology. Liquid-liquid phase separation of biomolecules leading to condensation is a central step in the assembly of biological materials into their functional forms. Intracellular condensates can also function within cells in a regulatory manner to facilitate reaction pathways and to compartmentalize interactions. We need to develop a strong understanding of how to design molecules for condensates and how their in vivo-in vitro properties are related. The spider silk protein NT2RepCT undergoes condensation during its fiber-forming process. Using parallel in vivo and in vitro characterization, in this study, we mapped the effects of intracellular conditions for NT2RepCT and its several structural variants. We found that intracellular conditions may suppress to some extent condensation whereas molecular crowding affects both condensate properties and their formation. Intracellular characterization of protein condensation allowed experiments on pH effects and solubilization to be performed within yeast cells. The growth of intracellular NT2RepCT condensates was restricted, and Ostwald ripening was not observed in yeast cells, in contrast to earlier observations in E. coli. Our results lead the way to using intracellular condensation to screen for properties of molecular assembly. For characterizing different structural variants, intracellular functional characterization can eliminate the need for time-consuming batch purification and in vitro condensation. Therefore, we suggest that the in vivo-in vitro understanding will become useful in, e.g., high-throughput screening for molecular functions and in strategies for designing tunable intracellular condensates.
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Affiliation(s)
- Jianhui Feng
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
| | - Bartosz Gabryelczyk
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
| | - Isabell Tunn
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
| | - Ekaterina Osmekhina
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
| | - Markus B. Linder
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
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19
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Grimes B, Jacob W, Liberman AR, Kim N, Zhao X, Masison DC, Greene LE. The Properties and Domain Requirements for Phase Separation of the Sup35 Prion Protein In Vivo. Biomolecules 2023; 13:1370. [PMID: 37759770 PMCID: PMC10526957 DOI: 10.3390/biom13091370] [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: 08/01/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
The Sup35 prion protein of budding yeast has been reported to undergo phase separation to form liquid droplets both at low pH in vitro and when energy depletion decreases the intracellular pH in vivo. It also has been shown using purified proteins that this phase separation is driven by the prion domain of Sup35 and does not re-quire its C-terminal domain. In contrast, we now find that a Sup35 fragment consisting of only the N-terminal prion domain and the M-domain does not phase separate in vivo; this phase separation of Sup35 requires the C-terminal domain, which binds Sup45 to form the translation termination complex. The phase-separated Sup35 not only colocalizes with Sup45 but also with Pub1, a stress granule marker protein. In addition, like stress granules, phase separation of Sup35 appears to require mRNA since cycloheximide treatment, which inhibits mRNA release from ribosomes, prevents phase separation of Sup35. Finally, unlike Sup35 in vitro, Sup35 condensates do not disassemble in vivo when the intracellular pH is increased. These results suggest that, in energy-depleted cells, Sup35 forms supramolecular assemblies that differ from the Sup35 liquid droplets that form in vitro.
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Affiliation(s)
- Bryan Grimes
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Walter Jacob
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amanda R. Liberman
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nathan Kim
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiaohong Zhao
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Daniel C. Masison
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lois E. Greene
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
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20
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Farag M, Borcherds WM, Bremer A, Mittag T, Pappu RV. Phase separation of protein mixtures is driven by the interplay of homotypic and heterotypic interactions. Nat Commun 2023; 14:5527. [PMID: 37684240 PMCID: PMC10491635 DOI: 10.1038/s41467-023-41274-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
Prion-like low-complexity domains (PLCDs) are involved in the formation and regulation of distinct biomolecular condensates that form via phase separation coupled to percolation. Intracellular condensates often encompass numerous distinct proteins with PLCDs. Here, we combine simulations and experiments to study mixtures of PLCDs from two RNA-binding proteins, hnRNPA1 and FUS. Using simulations and experiments, we find that 1:1 mixtures of A1-LCD and FUS-LCD undergo phase separation more readily than either of the PLCDs on their own due to complementary electrostatic interactions. Tie line analysis reveals that stoichiometric ratios of different components and their sequence-encoded interactions contribute jointly to the driving forces for condensate formation. Simulations also show that the spatial organization of PLCDs within condensates is governed by relative strengths of homotypic versus heterotypic interactions. We uncover rules for how interaction strengths and sequence lengths modulate conformational preferences of molecules at interfaces of condensates formed by mixtures of proteins.
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Affiliation(s)
- Mina Farag
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Wade M Borcherds
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Anne Bremer
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Tanja Mittag
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
| | - Rohit V Pappu
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO, 63130, USA.
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21
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Zhang M, Trushina NK, Lang T, Hahn M, Pasmanik-Chor M, Sharon A. Serine peptidases and increased amounts of soluble proteins contribute to heat priming of the plant pathogenic fungus Botrytis cinerea. mBio 2023; 14:e0107723. [PMID: 37409814 PMCID: PMC10470532 DOI: 10.1128/mbio.01077-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 05/23/2023] [Indexed: 07/07/2023] Open
Abstract
Botrytis cinerea causes gray mold disease in leading crop plants. The disease develops only at cool temperatures, but the fungus remains viable in warm climates and can survive periods of extreme heat. We discovered a strong heat priming effect in which the exposure of B. cinerea to moderately high temperatures greatly improves its ability to cope with subsequent, potentially lethal temperature conditions. We showed that priming promotes protein solubility during heat stress and discovered a group of priming-induced serine-type peptidases. Several lines of evidence, including transcriptomics, proteomics, pharmacology, and mutagenesis data, link these peptidases to the B. cinerea priming response, highlighting their important roles in regulating priming-mediated heat adaptation. By imposing a series of sub-lethal temperature pulses that subverted the priming effect, we managed to eliminate the fungus and prevent disease development, demonstrating the potential for developing temperature-based plant protection methods by targeting the fungal heat priming response. IMPORTANCE Priming is a general and important stress adaptation mechanism. Our work highlights the importance of priming in fungal heat adaptation, reveals novel regulators and aspects of heat adaptation mechanisms, and demonstrates the potential of affecting microorganisms, including pathogens through manipulations of the heat adaptation response.
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Affiliation(s)
- Mingzhe Zhang
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Naomi Kagan Trushina
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Tabea Lang
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
- Department of Biology, Technical University of Kaiserslautern, Kaiserslautern, Germany
| | - Matthias Hahn
- Department of Biology, Technical University of Kaiserslautern, Kaiserslautern, Germany
| | | | - Amir Sharon
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
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22
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Qin S, Zhou HX. Atomistic modeling of liquid-liquid phase equilibrium explains dependence of critical temperature on γ-crystallin sequence. Commun Biol 2023; 6:886. [PMID: 37644195 PMCID: PMC10465548 DOI: 10.1038/s42003-023-05270-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 08/22/2023] [Indexed: 08/31/2023] Open
Abstract
Liquid-liquid phase separation of protein solutions has regained heightened attention for its biological importance and pathogenic relevance. Coarse-grained models are limited when explaining residue-level effects on phase equilibrium. Here we report phase diagrams for γ-crystallins using atomistic modeling. The calculations were made possible by combining our FMAP method for computing chemical potentials and Brownian dynamics simulations for configurational sampling of dense protein solutions, yielding the binodal and critic temperature (Tc). We obtain a higher Tc for a known high-Tc γ-crystallin, γF, than for a low-Tc paralog, γB. The difference in Tc is corroborated by a gap in second virial coefficient. Decomposition of inter-protein interactions reveals one amino-acid substitution between γB and γF, from Ser to Trp at position 130, as the major contributor to the difference in Tc. This type of analysis enables us to link phase equilibrium to amino-acid sequence and to design mutations for altering phase equilibrium.
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Affiliation(s)
- Sanbo Qin
- 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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23
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Saha D, Jana B. Decoupling of Interactions between Model-Charged Peptides Reveals Key Factors Responsible for Liquid-Liquid Phase Separation. J Phys Chem B 2023; 127:6656-6667. [PMID: 37480340 DOI: 10.1021/acs.jpcb.3c03087] [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: 07/24/2023]
Abstract
Liquid-liquid phase separation (LLPS) by disordered proteins has been shown to govern biological processes and cause numerous diseases. Therefore, a deeper understanding of the interactions and their variation with external factors is key to modulating the LLPS behavior of different systems and protecting proteins from pathological aggregation. In this context, we have looked at interactions between similarly charged peptides to understand the molecular features that may drive or prevent condensate formation under various conditions. We have studied dimer formation for model peptides where charged and noncharged amino acids have been placed alternatively. Using arginine and glutamic acid as the charged residues and varying the other residues with glycine, alanine, and proline to alter hydrophobicity, we have obtained the free-energy surface (FES) for the dimer formation for these systems under high salt concentration at two different temperatures using all-atom molecular dynamics simulations and the well-tempered metadynamics method. Our results indicate that a combination of effects such as hydrophobicity, arginine-arginine interactions, or water release from the solvation shell makes dimerization free energy more favorable for the positively charged peptides with lower flexibility. For the negatively charged peptides, the crucial role of water has been found in governing the FES. Systems having charged residues and phenylalanine in the peptide sequence also have been studied at high salt concentrations using unbiased simulations. In this case, only the positively charged peptides were found to aggregate through temperature-dependent hydrophobic and cation-π interactions. Overall, our study indicates that the negatively charged peptides are more likely to remain in the dilute phase under various conditions compared to the positively charged systems. The findings from our study would be helpful in designing and controlling systems to obtain LLPS behavior for therapeutic usage.
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Affiliation(s)
- Debasis Saha
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Biman Jana
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
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24
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Zhou Y, Liao H, Pei L, Pu Y. Combatting persister cells: The daunting task in post-antibiotics era. CELL INSIGHT 2023; 2:100104. [PMID: 37304393 PMCID: PMC10250163 DOI: 10.1016/j.cellin.2023.100104] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/25/2023] [Accepted: 04/21/2023] [Indexed: 06/13/2023]
Abstract
Over the years, much attention has been drawn to antibiotic resistance bacteria, but drug inefficacy caused by a subgroup of special phenotypic variants - persisters - has been largely neglected in both scientific and clinical field. Interestingly, this subgroup of phenotypic variants displayed their power of withstanding sufficient antibiotics exposure in a mechanism different from antibiotic resistance. In this review, we summarized the clinical importance of bacterial persisters, the evolutionary link between resistance, tolerance, and persistence, redundant mechanisms of persister formation as well as methods of studying persister cells. In the light of our recent findings of membrane-less organelle aggresome and its important roles in regulating bacterial dormancy depth, we propose an alternative approach for anti-persister therapy. That is, to force a persister into a deeper dormancy state to become a VBNC (viable but non-culturable) cell that is incapable of regrowth. We hope to provide the latest insights on persister studies and call upon more research interest into this field.
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Affiliation(s)
- Yidan Zhou
- Department of Clinical Laboratory, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei- MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430079, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430079, China
| | - Hebin Liao
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei- MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430079, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430079, China
| | - Linsen Pei
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei- MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430079, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430079, China
| | - Yingying Pu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei- MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430079, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430079, China
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25
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Kik SK, Christopher D, Glauninger H, Hickernell CW, Bard JAM, Ford M, Sosnick TR, Drummond DA. An adaptive biomolecular condensation response is conserved across environmentally divergent species. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.551061. [PMID: 37546789 PMCID: PMC10402146 DOI: 10.1101/2023.07.28.551061] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Cells must sense and respond to sudden maladaptive environmental changes-stresses-to survive and thrive. Across eukaryotes, stresses such as heat shock trigger conserved responses: growth arrest, a specific transcriptional response, and biomolecular condensation of protein and mRNA into structures known as stress granules under severe stress. The composition, formation mechanism, adaptive significance, and even evolutionary conservation of these condensed structures remain enigmatic. Here we provide an unprecedented view into stress-triggered condensation, its evolutionary conservation and tuning, and its integration into other well-studied aspects of the stress response. Using three morphologically near-identical budding yeast species adapted to different thermal environments and diverged by up to 100 million years, we show that proteome-scale biomolecular condensation is tuned to species-specific thermal niches, closely tracking corresponding growth and transcriptional responses. In each species, poly(A)-binding protein-a core marker of stress granules-condenses in isolation at species-specific temperatures, with conserved molecular features and conformational changes modulating condensation. From the ecological to the molecular scale, our results reveal previously unappreciated levels of evolutionary selection in the eukaryotic stress response, while establishing a rich, tractable system for further inquiry.
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Affiliation(s)
- Samantha Keyport Kik
- Committee on Genetics, Genomics, and Systems Biology, The University of Chicago, Chicago, IL
| | - Dana Christopher
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL
| | - Hendrik Glauninger
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL
| | | | - Jared A. M. Bard
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL
| | | | - Tobin R. Sosnick
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL
| | - D. Allan Drummond
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL
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26
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Xie Y, Liu T, Gresham D, Holt LJ. mRNA condensation fluidizes the cytoplasm. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542963. [PMID: 37398029 PMCID: PMC10312499 DOI: 10.1101/2023.05.30.542963] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The intracellular environment is packed with macromolecules of mesoscale size, and this crowded milieu significantly influences cell physiology. When exposed to stress, mRNAs released after translational arrest condense with RNA binding proteins, resulting in the formation of membraneless RNA protein (RNP) condensates known as processing bodies (P-bodies) and stress granules (SGs). However, the impact of the assembly of these condensates on the biophysical properties of the crowded cytoplasmic environment remains unclear. Here, we find that upon exposure to stress, polysome collapse and condensation of mRNAs increases mesoscale particle diffusivity in the cytoplasm. Increased mesoscale diffusivity is required for the efficient formation of Q-bodies, membraneless organelles that coordinate degradation of misfolded peptides that accumulate during stress. Additionally, we demonstrate that polysome collapse and stress granule formation has a similar effect in mammalian cells, fluidizing the cytoplasm at the mesoscale. We find that synthetic, light-induced RNA condensation is sufficient to fluidize the cytoplasm, demonstrating a causal effect of RNA condensation. Together, our work reveals a new functional role for stress-induced translation inhibition and formation of RNP condensates in modulating the physical properties of the cytoplasm to effectively respond to stressful conditions.
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Affiliation(s)
- Ying Xie
- Institute for Systems Genetics, New York University Langone Medical Center, New York, New York, United States
- Department of Biology, New York University, New York, New York, United States
| | - Tiewei Liu
- Institute for Systems Genetics, New York University Langone Medical Center, New York, New York, United States
| | - David Gresham
- Department of Biology, New York University, New York, New York, United States
| | - Liam J Holt
- Institute for Systems Genetics, New York University Langone Medical Center, New York, New York, United States
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27
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Malhotra I, Potoyan DA. Re-entrant transitions of locally stiff RNA chains in the presence of polycations leads to gelated architectures. SOFT MATTER 2023. [PMID: 37449795 PMCID: PMC10369498 DOI: 10.1039/d3sm00320e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
The liquid-liquid phase separation of protein and nucleic acid mixtures drives the formation of numerous membraneless compartments in cells. Temperature variation is commonly used for mapping condensate phase diagrams, which often display unique upper critical temperatures. Recent report on peptide-RNA mixtures has shown the existence of lower and upper critical solution temperatures, highlighting the importance of temperature-dependent solvent and ion-mediated forces. In the present work, we employ residue-level coarse-grained models of RNA and polycation peptide chains for simulating temperature-induced re-entrant transitions and shedding light on the role played by mobile ions, temperature-dependent dielectric permittivity, and local chain stiffness. We show that differences in bending rigidity can significantly modulate condensate topology leading to the formation of gelated or fibril like architectures. The study also finds that temperature dependence of water permittivity is generally sufficient for recapitulating experimentally observed closed loop and LCST phase diagrams of highly charged protein-RNA mixtures. However, we find that similar-looking closed-loop phase diagrams can correspond to vastly different condensate topologies.
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Affiliation(s)
- Isha Malhotra
- Department of Chemistry, Iowa State University, Ames, Iowa 50014, USA.
| | - Davit A Potoyan
- Department of Chemistry, Iowa State University, Ames, Iowa 50014, USA.
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28
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Hutin S, Kumita JR, Strotmann VI, Dolata A, Ling WL, Louafi N, Popov A, Milhiet PE, Blackledge M, Nanao MH, Wigge PA, Stahl Y, Costa L, Tully MD, Zubieta C. Phase separation and molecular ordering of the prion-like domain of the Arabidopsis thermosensory protein EARLY FLOWERING 3. Proc Natl Acad Sci U S A 2023; 120:e2304714120. [PMID: 37399408 PMCID: PMC10334799 DOI: 10.1073/pnas.2304714120] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 06/06/2023] [Indexed: 07/05/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) is an important mechanism enabling the dynamic compartmentalization of macromolecules, including complex polymers such as proteins and nucleic acids, and occurs as a function of the physicochemical environment. In the model plant, Arabidopsis thaliana, LLPS by the protein EARLY FLOWERING3 (ELF3) occurs in a temperature-sensitive manner and controls thermoresponsive growth. ELF3 contains a largely unstructured prion-like domain (PrLD) that acts as a driver of LLPS in vivo and in vitro. The PrLD contains a poly-glutamine (polyQ) tract, whose length varies across natural Arabidopsis accessions. Here, we use a combination of biochemical, biophysical, and structural techniques to investigate the dilute and condensed phases of the ELF3 PrLD with varying polyQ lengths. We demonstrate that the dilute phase of the ELF3 PrLD forms a monodisperse higher-order oligomer that does not depend on the presence of the polyQ sequence. This species undergoes LLPS in a pH- and temperature-sensitive manner and the polyQ region of the protein tunes the initial stages of phase separation. The liquid phase rapidly undergoes aging and forms a hydrogel as shown by fluorescence and atomic force microscopies. Furthermore, we demonstrate that the hydrogel assumes a semiordered structure as determined by small-angle X-ray scattering, electron microscopy, and X-ray diffraction. These experiments demonstrate a rich structural landscape for a PrLD protein and provide a framework to describe the structural and biophysical properties of biomolecular condensates.
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Affiliation(s)
- Stephanie Hutin
- Laboratoire de Physiologie Cellulaire et Végétale, University Grenoble Alpes, Centre national de la recherche scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut national de recherche pour l’agriculture, l’alimentation et l’environnement, Institut de recherche interdisciplinaire de Grenoble, Grenoble38054, France
| | - Janet R. Kumita
- Department of Pharmacology, University of Cambridge, CambridgeCB2 1PD, United Kingdom
| | - Vivien I. Strotmann
- Institute for Developmental Genetics, Heinrich-Heine University, DüsseldorfD-40225, Germany
| | - Anika Dolata
- Institute for Developmental Genetics, Heinrich-Heine University, DüsseldorfD-40225, Germany
| | - Wai Li Ling
- University Grenoble Alpes, Commissariat à l'énergie atomique et aux énergies alternatives, Centre national de la recherche scientifique, Institut de Biologie Structurale, Institut de recherche interdisciplinaire de Grenoble, Grenoble38000, France
| | - Nessim Louafi
- Centre de Biologie Structurale, University Montpellier, Centre national de la recherche scientifique, Institut national de la santé et de la recherche médicale, Montpellier34090, France
| | - Anton Popov
- European Synchrotron Radiation Facility, Structural Biology Group, Grenoble38000, France
| | - Pierre-Emmanuel Milhiet
- Centre de Biologie Structurale, University Montpellier, Centre national de la recherche scientifique, Institut national de la santé et de la recherche médicale, Montpellier34090, France
| | - Martin Blackledge
- University Grenoble Alpes, Commissariat à l'énergie atomique et aux énergies alternatives, Centre national de la recherche scientifique, Institut de Biologie Structurale, Institut de recherche interdisciplinaire de Grenoble, Grenoble38000, France
| | - Max H. Nanao
- European Synchrotron Radiation Facility, Structural Biology Group, Grenoble38000, France
| | - Philip A. Wigge
- Leibniz-Institut für Gemüse- und Zierpflanzenbau, 14979Grossbeeren, Germany
- Institute of Biochemistry and Biology, University of Potsdam, 14476Potsdam, Germany
| | - Yvonne Stahl
- Institute for Developmental Genetics, Heinrich-Heine University, DüsseldorfD-40225, Germany
- Cluster of Excellence on Plant Sciences, Heinrich-Heine University, DüsseldorfD-40225, Germany
| | - Luca Costa
- Centre de Biologie Structurale, University Montpellier, Centre national de la recherche scientifique, Institut national de la santé et de la recherche médicale, Montpellier34090, France
| | - Mark D. Tully
- European Synchrotron Radiation Facility, Structural Biology Group, Grenoble38000, France
| | - Chloe Zubieta
- Laboratoire de Physiologie Cellulaire et Végétale, University Grenoble Alpes, Centre national de la recherche scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut national de recherche pour l’agriculture, l’alimentation et l’environnement, Institut de recherche interdisciplinaire de Grenoble, Grenoble38054, France
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29
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Chauhan G, Bremer A, Dar F, Mittag T, Pappu RV. Crowder titrations enable the quantification of driving forces for macromolecular phase separation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.03.547544. [PMID: 37461587 PMCID: PMC10350001 DOI: 10.1101/2023.07.03.547544] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Macromolecular solubility is an important contributor to the driving forces for phase separation. Formally, the driving forces in a binary mixture comprising a macromolecule dissolved in a solvent can be quantified in terms of the saturation concentration, which is the threshold macromolecular concentration above which the mixture separates into coexisting dense and dilute phases. Additionally, the second virial coefficient, which measures the effective strength of solvent-mediated intermolecular interactions provides direct assessments of solvent quality. The sign and magnitude of second virial coefficients will be governed by a combination of solution conditions and the nature of the macromolecule of interest. Here, we show, using a combination of theory, simulation, and in vitro experiments, that titrations of crowders, providing they are true depletants, can be used to extract the intrinsic driving forces for macromolecular phase separation. This refers to saturation concentrations in the absence of crowders and the second virial coefficients that quantify the magnitude of the incompatibility between macromolecules and the solvent. Our results show how the depletion-mediated attractions afforded by crowders can be leveraged to obtain comparative assessments of macromolecule-specific, intrinsic driving forces for phase separation. SIGNIFICANCE Phase separation has emerged as a process of significant relevance to sorting macromolecules into distinct compartments, thereby enabling spatial and temporal control over cellular matter. Considerable effort is being invested into uncovering the driving forces that enable the separation of macromolecular solutions into coexisting phases. At its heart, this process is governed by the balance of macromolecule-solvent, inter-macromolecule, and solvent-solvent interactions. We show that the driving forces for phase separation, including the coefficients that measure interaction strengths between macromolecules, can be extracted by titrating the concentrations of crowders that enable macromolecules to phase separate at lower concentrations. Our work paves the way to leverage specific categories of measurements for quantitative characterizations of driving forces for phase separation.
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30
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Vermeulen A, Takken FLW, Sánchez-Camargo VA. Translation Arrest: A Key Player in Plant Antiviral Response. Genes (Basel) 2023; 14:1293. [PMID: 37372472 DOI: 10.3390/genes14061293] [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: 05/22/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Plants evolved several mechanisms to protect themselves against viruses. Besides recessive resistance, where compatible host factors required for viral proliferation are absent or incompatible, there are (at least) two types of inducible antiviral immunity: RNA silencing (RNAi) and immune responses mounted upon activation of nucleotide-binding domain leucine-rich repeat (NLR) receptors. RNAi is associated with viral symptom recovery through translational repression and transcript degradation following recognition of viral double-stranded RNA produced during infection. NLR-mediated immunity is induced upon (in)direct recognition of a viral protein by an NLR receptor, triggering either a hypersensitive response (HR) or an extreme resistance response (ER). During ER, host cell death is not apparent, and it has been proposed that this resistance is mediated by a translational arrest (TA) of viral transcripts. Recent research indicates that translational repression plays a crucial role in plant antiviral resistance. This paper reviews current knowledge on viral translational repression during viral recovery and NLR-mediated immunity. Our findings are summarized in a model detailing the pathways and processes leading to translational arrest of plant viruses. This model can serve as a framework to formulate hypotheses on how TA halts viral replication, inspiring new leads for the development of antiviral resistance in crops.
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Affiliation(s)
- Annemarie Vermeulen
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Frank L W Takken
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Victor A Sánchez-Camargo
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
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31
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Pappu R, Farag M, Borcherds W, Bremer A, Mittag T. Phase Separation in Mixtures of Prion-Like Low Complexity Domains is Driven by the Interplay of Homotypic and Heterotypic Interactions. RESEARCH SQUARE 2023:rs.3.rs-2870258. [PMID: 37205474 PMCID: PMC10187436 DOI: 10.21203/rs.3.rs-2870258/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Prion-like low-complexity domains (PLCDs) are involved in the formation and regulation of distinct biomolecular condensates that form via coupled associative and segregative phase transitions. We previously deciphered how evolutionarily conserved sequence features drive phase separation of PLCDs through homotypic interactions. However, condensates typically encompass a diverse mixture of proteins with PLCDs. Here, we combine simulations and experiments to study mixtures of PLCDs from two RNA binding proteins namely, hnRNPA1 and FUS. We find that 1:1 mixtures of the A1-LCD and FUS-LCD undergo phase separation more readily than either of the PLCDs on their own. The enhanced driving forces for phase separation of mixtures of A1-LCD and FUS-LCD arise partly from complementary electrostatic interactions between the two proteins. This complex coacervation-like mechanism adds to complementary interactions among aromatic residues. Further, tie line analysis shows that stoichiometric ratios of different components and their sequence-encoded interactions jointly contribute to the driving forces for condensate formation. These results highlight how expression levels might be tuned to regulate the driving forces for condensate formation in vivo . Simulations also show that the organization of PLCDs within condensates deviates from expectations based on random mixture models. Instead, spatial organization within condensates will reflect the relative strengths of homotypic versus heterotypic interactions. We also uncover rules for how interaction strengths and sequence lengths modulate conformational preferences of molecules at interfaces of condensates formed by mixtures of proteins. Overall, our findings emphasize the network-like organization of molecules within multicomponent condensates, and the distinctive, composition-specific conformational features of condensate interfaces.
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32
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Zhang J, Huang Y, Bai F. Stochastic Monte Carlo Model for Simulating the Dynamic Liquid-Liquid Phase Separation in Bacterial Cells. J Phys Chem B 2023; 127:4145-4153. [PMID: 37130439 DOI: 10.1021/acs.jpcb.3c01696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
There is growing evidence showing that many critical biological processes are driven by biomolecule condensates through liquid-liquid phase separation (LLPS). Although the qualitative observation and description of LLPS have been well documented, quantitative simulations of the time-dependent progression of LLPS in live cells are generally lacking. In this work, we build a stochastic Monte Carlo model to simulate the dynamic LLPS process during the formation of bacterial aggresomes. We demonstrate that the size distribution of the protein condensates evolves from an exponential-like to a bimodal-like pattern, and the number of condensates increases at the beginning and then decreases after reaching a maximum. Incorporating diffusion and collision, our simplified model recapitulates the two-step LLPS process in which many smaller condensates are formed in the first step and then merged into a few larger ones. We further reveal that the condensation speed, which can be defined by the condensates formed in unit time during the first step, is mainly determined by both the collision energy barrier and the initial protein density, while the number of condensates at the equilibrium is mainly associated with the dissociation energy barrier. Moreover, the LLPS process is not sensitive to temperature changes ranging around physiological conditions. Additionally, we consider the effect of the nucleation energy barrier on LLPS. We find that a higher nucleation energy barrier brings a slower condensation speed. Overall, we simulate the spatiotemporal dynamics of the LLPS process and provide qualitative guidance for understanding the dynamics of LLPS in bacterial cells, which can faithfully recapitulate experimental observations and facilitate the design of future experimental tests.
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Affiliation(s)
- Jingpeng Zhang
- Biomedical Pioneering Innovation Center, Peking University, Beijing 100871, China
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Yanyi Huang
- Biomedical Pioneering Innovation Center, Peking University, Beijing 100871, China
- College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
- Institute for Cell Analysis, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Fan Bai
- Biomedical Pioneering Innovation Center, Peking University, Beijing 100871, China
- School of Life Sciences, Peking University, Beijing 100871, China
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33
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Qin S, Zhou HX. Atomistic Modeling of Liquid-Liquid Phase Equilibrium Explains Dependence of Critical Temperature on γ-Crystallin Sequence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.25.538329. [PMID: 37162827 PMCID: PMC10168431 DOI: 10.1101/2023.04.25.538329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Liquid-liquid phase separation of protein solutions has regained heightened attention for its biological importance and pathogenic relevance. Coarse-grained models are limited when explaining residue-level effects on phase equilibrium. Here we report phase diagrams for γ-crystallins using atomistic modeling. The calculations were made possible by combining our FMAP method for computing chemical potentials and Brownian dynamics simulations for configurational sampling of dense protein solutions, yielding the binodal and critic temperature ( T c ). We obtain a higher T c for a known high- T c γ-crystallin, γF, than for a low- T c paralog, γB. The difference in T c is corroborated by a gap in second virial coefficient. Decomposition of inter-protein interactions reveals one amino-acid substitution between γB and γF, from Ser to Trp at position 130, as the major contributor to the difference in T c . This type of analysis enables us to link phase equilibrium to amino-acid sequence and to design mutations for altering phase equilibrium.
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Affiliation(s)
- Sanbo Qin
- 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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34
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Kohler V, Andréasson C. Reversible protein assemblies in the proteostasis network in health and disease. Front Mol Biosci 2023; 10:1155521. [PMID: 37021114 PMCID: PMC10067754 DOI: 10.3389/fmolb.2023.1155521] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/09/2023] [Indexed: 04/07/2023] Open
Abstract
While proteins populating their native conformations constitute the functional entities of cells, protein aggregates are traditionally associated with cellular dysfunction, stress and disease. During recent years, it has become clear that large aggregate-like protein condensates formed via liquid-liquid phase separation age into more solid aggregate-like particles that harbor misfolded proteins and are decorated by protein quality control factors. The constituent proteins of the condensates/aggregates are disentangled by protein disaggregation systems mainly based on Hsp70 and AAA ATPase Hsp100 chaperones prior to their handover to refolding and degradation systems. Here, we discuss the functional roles that condensate formation/aggregation and disaggregation play in protein quality control to maintain proteostasis and why it matters for understanding health and disease.
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Affiliation(s)
- Verena Kohler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Claes Andréasson
- Department of Molecular Biosciences, Stockholm University, Stockholm, Sweden
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35
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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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36
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Farag M, Borcherds WM, Bremer A, Mittag T, Pappu RV. Phase Separation in Mixtures of Prion-Like Low Complexity Domains is Driven by the Interplay of Homotypic and Heterotypic Interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.15.532828. [PMID: 36993212 PMCID: PMC10055064 DOI: 10.1101/2023.03.15.532828] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Prion-like low-complexity domains (PLCDs) are involved in the formation and regulation of distinct biomolecular condensates that form via coupled associative and segregative phase transitions. We previously deciphered how evolutionarily conserved sequence features drive phase separation of PLCDs through homotypic interactions. However, condensates typically encompass a diverse mixture of proteins with PLCDs. Here, we combine simulations and experiments to study mixtures of PLCDs from two RNA binding proteins namely, hnRNPA1 and FUS. We find that 1:1 mixtures of the A1-LCD and FUS-LCD undergo phase separation more readily than either of the PLCDs on their own. The enhanced driving forces for phase separation of mixtures of A1-LCD and FUS-LCD arise partly from complementary electrostatic interactions between the two proteins. This complex coacervation-like mechanism adds to complementary interactions among aromatic residues. Further, tie line analysis shows that stoichiometric ratios of different components and their sequence-encoded interactions jointly contribute to the driving forces for condensate formation. These results highlight how expression levels might be tuned to regulate the driving forces for condensate formation in vivo . Simulations also show that the organization of PLCDs within condensates deviates from expectations based on random mixture models. Instead, spatial organization within condensates will reflect the relative strengths of homotypic versus heterotypic interactions. We also uncover rules for how interaction strengths and sequence lengths modulate conformational preferences of molecules at interfaces of condensates formed by mixtures of proteins. Overall, our findings emphasize the network-like organization of molecules within multicomponent condensates, and the distinctive, composition-specific conformational features of condensate interfaces. Significance Statement Biomolecular condensates are mixtures of different protein and nucleic acid molecules that organize biochemical reactions in cells. Much of what we know about how condensates form comes from studies of phase transitions of individual components of condensates. Here, we report results from studies of phase transitions of mixtures of archetypal protein domains that feature in distinct condensates. Our investigations, aided by a blend of computations and experiments, show that the phase transitions of mixtures are governed by a complex interplay of homotypic and heterotypic interactions. The results point to how expression levels of different protein components can be tuned in cells to modulate internal structures, compositions, and interfaces of condensates, thus affording distinct ways to control the functions of condensates.
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37
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Staples MI, Frazer C, Fawzi NL, Bennett RJ. Phase separation in fungi. Nat Microbiol 2023; 8:375-386. [PMID: 36782025 PMCID: PMC10081517 DOI: 10.1038/s41564-022-01314-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 12/16/2022] [Indexed: 02/15/2023]
Abstract
Phase separation, in which macromolecules partition into a concentrated phase that is immiscible with a dilute phase, is involved with fundamental cellular processes across the tree of life. We review the principles of phase separation and highlight how it impacts diverse processes in the fungal kingdom. These include the regulation of autophagy, cell signalling pathways, transcriptional circuits and the establishment of asymmetry in fungal cells. We describe examples of stable, phase-separated assemblies including membraneless organelles such as the nucleolus as well as transient condensates that also arise through phase separation and enable cells to rapidly and reversibly respond to important environmental cues. We showcase how research into phase separation in model yeasts, such as Saccharomyces cerevisiae and Schizosaccharomyces pombe, in conjunction with that in plant and human fungal pathogens, such as Ashbya gossypii and Candida albicans, is continuing to enrich our understanding of fundamental molecular processes.
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Affiliation(s)
- Mae I Staples
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA
| | - Corey Frazer
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA
| | - Nicolas L Fawzi
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Richard J Bennett
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA.
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38
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Chadwick BJ, Ross BE, Lin X. Molecular Dissection of Crz1 and Its Dynamic Subcellular Localization in Cryptococcus neoformans. J Fungi (Basel) 2023; 9:jof9020252. [PMID: 36836365 PMCID: PMC9963361 DOI: 10.3390/jof9020252] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/01/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
Across lower eukaryotes, the transcription factor Crz1 is dephosphorylated by calcineurin, which facilitates Crz1 translocation to the nucleus to regulate gene expression. In the fungal pathogen Cryptococcus neoformans, calcineurin-Crz1 signaling maintains calcium homeostasis, thermotolerance, cell wall integrity, and morphogenesis. How Crz1 distinguishes different stressors and differentially regulates cellular responses is poorly understood. Through monitoring Crz1 subcellular localization over time, we found that Crz1 transiently localizes to granules after exposure to high temperature or calcium. These granules also host the phosphatase calcineurin and Pub1, a ribonucleoprotein stress granule marker, suggesting a role of stress granules in modulating calcineurin-Crz1 signaling. Additionally, we constructed and analyzed an array of Crz1 truncation mutants. We identified the intrinsically disordered regions in Crz1 contribute to proper stress granule localization, nuclear localization, and function. Our results provide the groundwork for further determination of the mechanisms behind the complex regulation of Crz1.
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Affiliation(s)
| | | | - Xiaorong Lin
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
- Correspondence:
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39
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TFIID dependency of steady-state mRNA transcription altered epigenetically by simultaneous functional loss of Taf1 and Spt3 is Hsp104-dependent. PLoS One 2023; 18:e0281233. [PMID: 36757926 PMCID: PMC9910645 DOI: 10.1371/journal.pone.0281233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 01/18/2023] [Indexed: 02/10/2023] Open
Abstract
In Saccharomyces cerevisiae, class II gene promoters have been divided into two subclasses, TFIID- and SAGA-dominated promoters or TFIID-dependent and coactivator-redundant promoters, depending on the experimental methods used to measure mRNA levels. A prior study demonstrated that Spt3, a TBP-delivering subunit of SAGA, functionally regulates the PGK1 promoter via two mechanisms: by stimulating TATA box-dependent transcriptional activity and conferring Taf1/TFIID independence. However, only the former could be restored by plasmid-borne SPT3. In the present study, we sought to determine why ectopically expressed SPT3 is unable to restore Taf1/TFIID independence to the PGK1 promoter, identifying that this function was dependent on the construction protocol for the SPT3 taf1 strain. Specifically, simultaneous functional loss of Spt3 and Taf1 during strain construction was a prerequisite to render the PGK1 promoter Taf1/TFIID-dependent in this strain. Intriguingly, genetic approaches revealed that an as-yet unidentified trans-acting factor reprogrammed the transcriptional mode of the PGK1 promoter from the Taf1/TFIID-independent state to the Taf1/TFIID-dependent state. This factor was generated in the haploid SPT3 taf1 strain in an Hsp104-dependent manner and inherited meiotically in a non-Mendelian fashion. Furthermore, RNA-seq analyses demonstrated that this factor likely affects the transcription mode of not only the PGK1 promoter, but also of many other class II gene promoters. Collectively, these findings suggest that a prion or biomolecular condensate is generated in a Hsp104-dependent manner upon simultaneous functional loss of TFIID and SAGA, and could alter the roles of these transcription complexes on a wide variety of class II gene promoters without altering their primary sequences. Therefore, these findings could provide the first evidence that TFIID dependence of class II gene transcription can be altered epigenetically, at least in Saccharomyces cerevisiae.
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40
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Haghizadeh A, Iftikhar M, Dandpat SS, Simpson T. Looking at Biomolecular Interactions through the Lens of Correlated Fluorescence Microscopy and Optical Tweezers. Int J Mol Sci 2023; 24:2668. [PMID: 36768987 PMCID: PMC9916863 DOI: 10.3390/ijms24032668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/19/2022] [Accepted: 01/26/2023] [Indexed: 02/01/2023] Open
Abstract
Understanding complex biological events at the molecular level paves the path to determine mechanistic processes across the timescale necessary for breakthrough discoveries. While various conventional biophysical methods provide some information for understanding biological systems, they often lack a complete picture of the molecular-level details of such dynamic processes. Studies at the single-molecule level have emerged to provide crucial missing links to understanding complex and dynamic pathways in biological systems, which are often superseded by bulk biophysical and biochemical studies. Latest developments in techniques combining single-molecule manipulation tools such as optical tweezers and visualization tools such as fluorescence or label-free microscopy have enabled the investigation of complex and dynamic biomolecular interactions at the single-molecule level. In this review, we present recent advances using correlated single-molecule manipulation and visualization-based approaches to obtain a more advanced understanding of the pathways for fundamental biological processes, and how this combination technique is facilitating research in the dynamic single-molecule (DSM), cell biology, and nanomaterials fields.
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41
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Kulkarni A, Vidal-Henriquez E, Zwicker D. Effective simulations of interacting active droplets. Sci Rep 2023; 13:733. [PMID: 36639416 PMCID: PMC9839783 DOI: 10.1038/s41598-023-27630-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 01/04/2023] [Indexed: 01/15/2023] Open
Abstract
Droplets form a cornerstone of the spatiotemporal organization of biomolecules in cells. These droplets are controlled using physical processes like chemical reactions and imposed gradients, which are costly to simulate using traditional approaches, like solving the Cahn-Hilliard equation. To overcome this challenge, we here present an alternative, efficient method. The main idea is to focus on the relevant degrees of freedom, like droplet positions and sizes. We derive dynamical equations for these quantities using approximate analytical solutions obtained from a sharp interface limit and linearized equations in the bulk phases. We verify our method against fully-resolved simulations and show that it can describe interacting droplets under the influence of chemical reactions and external gradients using only a fraction of the computational costs of traditional methods. Our method can be extended to include other processes in the future and will thus serve as a relevant platform for understanding the dynamics of droplets in cells.
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Affiliation(s)
- Ajinkya Kulkarni
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077, Göttingen, Germany
| | | | - David Zwicker
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077, Göttingen, Germany.
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42
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Song X, Yang F, Yang T, Wang Y, Ding M, Li L, Xu P, Liu S, Dai M, Chi C, Xiang S, Xu C, Li D, Wang Z, Li L, Hill DL, Fu C, Yuan K, Li P, Zang J, Hou Z, Jiang K, Shi Y, Liu X, Yao X. Phase separation of EB1 guides microtubule plus-end dynamics. Nat Cell Biol 2023; 25:79-91. [PMID: 36536176 DOI: 10.1038/s41556-022-01033-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 10/21/2022] [Indexed: 12/24/2022]
Abstract
In eukaryotes, end-binding (EB) proteins serve as a hub for orchestrating microtubule dynamics and are essential for cellular dynamics and organelle movements. EB proteins modulate structural transitions at growing microtubule ends by recognizing and promoting an intermediate state generated during GTP hydrolysis. However, the molecular mechanisms and physiochemical properties of the EB1 interaction network remain elusive. Here we show that EB1 formed molecular condensates through liquid-liquid phase separation (LLPS) to constitute the microtubule plus-end machinery. EB1 LLPS is driven by multivalent interactions among different segments, which are modulated by charged residues in the linker region. Phase-separated EB1 provided a compartment for enriching tubulin dimers and other plus-end tracking proteins. Real-time imaging of chromosome segregation in HeLa cells expressing LLPS-deficient EB1 mutants revealed the importance of EB1 LLPS dynamics in mitotic chromosome movements. These findings demonstrate that EB1 forms a distinct physical and biochemical membraneless-organelle via multivalent interactions that guide microtubule dynamics.
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Affiliation(s)
- Xiaoyu Song
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA
| | - Fengrui Yang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA
| | - Tongtong Yang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Yong Wang
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Mingrui Ding
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA
| | - Linge Li
- Anhui Key Laboratory for Chemical Biology & Hefei National Center for Cross-disciplinary Sciences, Hefei, China
| | - Panpan Xu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Shuaiyu Liu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Anhui Key Laboratory for Chemical Biology & Hefei National Center for Cross-disciplinary Sciences, Hefei, China
| | - Ming Dai
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Changbiao Chi
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Shengqi Xiang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Chao Xu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Dong Li
- Institute of Biophysics, Beijing, China
| | - Zhikai Wang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA
| | - Lin Li
- CAS Center of Excellence in Molecular Cell Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Donald L Hill
- Department of Pathology, University of Alabama, Birmingham, AL, USA
| | - Chuanhai Fu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Kai Yuan
- Hunan Key Laboratory of Molecular Precision Medicine, Central South University School of Life Sciences, Changsha, China
| | - Pilong Li
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Jianye Zang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Zhonghuai Hou
- Anhui Key Laboratory for Chemical Biology & Hefei National Center for Cross-disciplinary Sciences, Hefei, China
| | - Kai Jiang
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Yunyu Shi
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Xing Liu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China. .,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA.
| | - Xuebiao Yao
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.
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43
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Brownsword MJ, Locker N. A little less aggregation a little more replication: Viral manipulation of stress granules. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1741. [PMID: 35709333 PMCID: PMC10078398 DOI: 10.1002/wrna.1741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/29/2022] [Accepted: 05/05/2022] [Indexed: 01/31/2023]
Abstract
Recent exciting studies have uncovered how membrane-less organelles, also known as biocondensates, are providing cells with rapid response pathways, allowing them to re-organize their cellular contents and adapt to stressful conditions. Their assembly is driven by the phase separation of their RNAs and intrinsically disordered protein components into condensed foci. Among these, stress granules (SGs) are dynamic cytoplasmic biocondensates that form in response to many stresses, including activation of the integrated stress response or viral infections. SGs sit at the crossroads between antiviral signaling and translation because they concentrate signaling proteins and components of the innate immune response, in addition to translation machinery and stalled mRNAs. Consequently, they have been proposed to contribute to antiviral activities, and therefore are targeted by viral countermeasures. Equally, SGs components can be commandeered by viruses for their own efficient replication. Phase separation processes are an important component of the viral life cycle, for example, driving the assembly of replication factories or inclusion bodies. Therefore, in this review, we will outline the recent understanding of this complex interplay and tug of war between viruses, SGs, and their components. This article is categorized under: RNA in Disease and Development > RNA in Disease Translation > Regulation RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
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Affiliation(s)
- Matthew J. Brownsword
- Faculty of Health and Medical Sciences, School of Biosciences and MedicineUniversity of SurreyGuildfordSurreyUK
| | - Nicolas Locker
- Faculty of Health and Medical Sciences, School of Biosciences and MedicineUniversity of SurreyGuildfordSurreyUK
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44
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Hall RA, Wallace EW. Post-transcriptional control of fungal cell wall synthesis. Cell Surf 2022; 8:100074. [PMID: 35097244 PMCID: PMC8783092 DOI: 10.1016/j.tcsw.2022.100074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/10/2022] [Accepted: 01/10/2022] [Indexed: 12/21/2022] Open
Abstract
Pathogenic fungi hide from their hosts by camouflage, obscuring immunogenic cell wall components such as beta-glucan with innocuous coverings such as mannoproteins and alpha-glucan that are less readily recognised by the host. Attempts to understand how such processes are regulated have met with varying success. Typically studies focus on understanding the transcriptional response of fungi to either their reservoir environment or the host. However, such approaches do not fully address this research question, due to the layers of post-transcriptional and post-translational regulation that occur within a cell. Although in animals the impact of post-transcriptional and post-translational regulation has been well characterised, our knowledge of these processes in the fungal kingdom is more limited. Mutations in RNA-binding proteins, like Ssd1 and Candida albicans Slr1, affect cell wall composition and fungal virulence indicating that post-transcriptional regulation plays a key role in these processes. Here, we review the current state of knowledge of fungal post-transcriptional regulation, and link this to potential mechanisms of immune evasion by drawing on studies from model yeast and plant pathogenic fungi. We highlight several RNA-binding proteins that regulate cell wall synthesis and could be involved in local translation of cell wall components. Expanding our knowledge on post-transcriptional regulation in human fungal pathogens is essential to fully comprehend fungal virulence strategies and for the design of novel antifungal therapies.
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Affiliation(s)
- Rebecca A. Hall
- Kent Fungal Group, Division of Natural Sciences, School of Biosciences, University of Kent, Canterbury CT2 7NJ, United Kingdom
| | - Edward W.J. Wallace
- Institute for Cell Biology and SynthSys, School of Biological Sciences, University of Edinburgh, EH9 3FF, United Kingdom
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45
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A brief guideline for studies of phase-separated biomolecular condensates. Nat Chem Biol 2022; 18:1307-1318. [DOI: 10.1038/s41589-022-01204-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 10/10/2022] [Indexed: 11/20/2022]
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46
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Different states and the associated fates of biomolecular condensates. Essays Biochem 2022; 66:849-862. [PMID: 36350032 DOI: 10.1042/ebc20220054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/20/2022] [Accepted: 10/07/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Biomolecular condensates are functional assemblies, which can enrich intrinsically disordered proteins (IDPs) and/or RNAs at concentrations that are orders of magnitude higher than the bulk. In their native functional state, these structures can exist in multiple physical states including liquid-droplet phase, hydrogels, and solid assemblies. On the other hand, an aberrant transition between these physical states can result in loss-of-function or a gain-of-toxic-function. A prime example of such an aberrant transition is droplet aging—a phenomenon where some condensates may progressively transition into less dynamic material states at biologically relevant timescales. In this essay, we review structural and viscoelastic roots of aberrant liquid–solid transitions. Also, we highlight the different checkpoints and experimentally tunable handles, both active (ATP-dependent enzymes, post-translational modifications) and passive (colocalization of RNA molecules), that could alter the material state of assemblies.
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47
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de Castro RJA, Rêgo MTAM, Brandão FS, Pérez ALA, De Marco JL, Poças-Fonseca MJ, Nichols C, Alspaugh JA, Felipe MSS, Alanio A, Bocca AL, Fernandes L. Engineered Fluorescent Strains of Cryptococcus neoformans: a Versatile Toolbox for Studies of Host-Pathogen Interactions and Fungal Biology, Including the Viable but Nonculturable State. Microbiol Spectr 2022; 10:e0150422. [PMID: 36005449 PMCID: PMC9603711 DOI: 10.1128/spectrum.01504-22] [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: 04/25/2022] [Accepted: 08/05/2022] [Indexed: 12/31/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen known for its remarkable ability to infect and subvert phagocytes. This ability provides survival and persistence within the host and relies on phenotypic plasticity. The viable but nonculturable (VBNC) phenotype was recently described in C. neoformans, whose study is promising in understanding the pathophysiology of cryptococcosis. The use of fluorescent strains is improving host interaction research, but it is still underexploited. Here, we fused histone H3 or the poly(A) binding protein (Pab) to enhanced green fluorescent protein (eGFP) or mCherry, obtaining a set of C. neoformans transformants with different colors, patterns of fluorescence, and selective markers (hygromycin B resistance [Hygr] or neomycin resistance [Neor]). We validated their similarity to the parental strain in the stress response, the expression of virulence-related phenotypes, mating, virulence in Galleria mellonella, and survival within murine macrophages. PAB-GFP, the brightest transformant, was successfully applied for the analysis of phagocytosis by flow cytometry and fluorescence microscopy. Moreover, we demonstrated that an engineered fluorescent strain of C. neoformans was able to generate VBNC cells. GFP-tagged Pab1, a key regulator of the stress response, evidenced nuclear retention of Pab1 and the assembly of cytoplasmic stress granules, unveiling posttranscriptional mechanisms associated with dormant C. neoformans cells. Our results support that the PAB-GFP strain is a useful tool for research on C. neoformans. IMPORTANCE Cryptococcus neoformans is a human-pathogenic yeast that can undergo a dormant state and is responsible for over 180,000 deaths annually worldwide. We engineered a set of fluorescent transformants to aid in research on C. neoformans. A mutant with GFP-tagged Pab1 improved fluorescence-based techniques used in host interaction studies. Moreover, this mutant induced a viable but nonculturable phenotype and uncovered posttranscriptional mechanisms associated with dormant C. neoformans. The experimental use of fluorescent mutants may shed light on C. neoformans-host interactions and fungal biology, including dormant phenotypes.
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Affiliation(s)
- Raffael Júnio Araújo de Castro
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
- CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses et Antifongiques, Institut Pasteur, Paris, France
| | - Marco Túlio Aidar Mariano Rêgo
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Fabiana S. Brandão
- Faculty of Health Science, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Ana Laura Alfonso Pérez
- Department of Cell Biology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasilia, Federal District, Brazil
| | - Janice Lisboa De Marco
- Department of Cell Biology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasilia, Federal District, Brazil
| | - Marcio José Poças-Fonseca
- Department of Genetics and Morphology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Connie Nichols
- Duke University School of Medicine, Department of Medicine, Durham, North Carolina, USA
| | - J. Andrew Alspaugh
- Duke University School of Medicine, Department of Medicine, Durham, North Carolina, USA
| | - Maria Sueli S. Felipe
- Catholic University of Brasilia, Campus Asa Norte, Asa Norte, Brasília, Federal District, Brazil
| | - Alexandre Alanio
- CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses et Antifongiques, Institut Pasteur, Paris, France
- Laboratoire de Mycologie et Parasitologie, AP-HP, Hôpital Saint Louis, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Anamélia Lorenzetti Bocca
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Larissa Fernandes
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
- Faculty of Ceilândia, Campus UnB Ceilândia, University of Brasília, Ceilândia Sul, Brasília, Federal District, Brazil
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48
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Chaves-Arquero B, Martínez-Lumbreras S, Sibille N, Camero S, Bernadó P, Jiménez MÁ, Zorrilla S, Pérez-Cañadillas JM. eIF4G1 N-terminal intrinsically disordered domain is a multi-docking station for RNA, Pab1, Pub1, and self-assembly. Front Mol Biosci 2022; 9:986121. [PMID: 36213119 PMCID: PMC9537944 DOI: 10.3389/fmolb.2022.986121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Yeast eIF4G1 interacts with RNA binding proteins (RBPs) like Pab1 and Pub1 affecting its function in translation initiation and stress granules formation. We present an NMR and SAXS study of the N-terminal intrinsically disordered region of eIF4G1 (residues 1-249) and its interactions with Pub1, Pab1 and RNA. The conformational ensemble of eIF4G11-249 shows an α-helix within the BOX3 conserved element and a dynamic network of fuzzy π-π and π-cation interactions involving arginine and aromatic residues. The Pab1 RRM2 domain interacts with eIF4G1 BOX3, the canonical interaction site, but also with BOX2, a conserved element of unknown function to date. The RNA1 region interacts with RNA through a new RNA interaction motif and with the Pub1 RRM3 domain. This later also interacts with eIF4G1 BOX1 modulating its intrinsic self-assembly properties. The description of the biomolecular interactions involving eIF4G1 to the residue detail increases our knowledge about biological processes involving this key translation initiation factor.
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Affiliation(s)
- Belén Chaves-Arquero
- Department of Biological Physical Chemistry, Institute of Physical-Chemistry “Rocasolano”, CSIC, Madrid, Spain
| | - Santiago Martínez-Lumbreras
- Department of Biological Physical Chemistry, Institute of Physical-Chemistry “Rocasolano”, CSIC, Madrid, Spain
| | - Nathalie Sibille
- Centre de Biochimie Structurale (CBS), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Sergio Camero
- Department of Biological Physical Chemistry, Institute of Physical-Chemistry “Rocasolano”, CSIC, Madrid, Spain
| | - Pau Bernadó
- Centre de Biochimie Structurale (CBS), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - M. Ángeles Jiménez
- Department of Biological Physical Chemistry, Institute of Physical-Chemistry “Rocasolano”, CSIC, Madrid, Spain
| | - Silvia Zorrilla
- Department of Cellular and Molecular Biology, Biological Research Center, CSIC, Madrid, Spain
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Palumbo RJ, McKean N, Leatherman E, Namitz KEW, Connell L, Wolfe A, Moody K, Gostinčar C, Gunde-Cimerman N, Bah A, Hanes SD. Coevolution of the Ess1-CTD axis in polar fungi suggests a role for phase separation in cold tolerance. SCIENCE ADVANCES 2022; 8:eabq3235. [PMID: 36070379 PMCID: PMC9451162 DOI: 10.1126/sciadv.abq3235] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/21/2022] [Indexed: 06/14/2023]
Abstract
Most of the world's biodiversity lives in cold (-2° to 4°C) and hypersaline environments. To understand how cells adapt to such conditions, we isolated two key components of the transcription machinery from fungal species that live in extreme polar environments: the Ess1 prolyl isomerase and its target, the carboxy-terminal domain (CTD) of RNA polymerase II. Polar Ess1 enzymes are conserved and functional in the model yeast, Saccharomyces cerevisiae. By contrast, polar CTDs diverge from the consensus (YSPTSPS)26 and are not fully functional in S. cerevisiae. These CTDs retain the critical Ess1 Ser-Pro target motifs, but substitutions at Y1, T4, and S7 profoundly affected their ability to undergo phase separation in vitro and localize in vivo. We propose that environmentally tuned phase separation by the CTD and other intrinsically disordered regions plays an adaptive role in cold tolerance by concentrating enzymes and substrates to overcome energetic barriers to metabolic activity.
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Affiliation(s)
- Ryan J. Palumbo
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Nathan McKean
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Erinn Leatherman
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Kevin E. W. Namitz
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Laurie Connell
- School of Marine Sciences and Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469, USA
| | - Aaron Wolfe
- Ichor Life Sciences Inc., 2651 US Route 11, LaFayette, NY 13084, USA
- Lewis School of Health Sciences, Clarkson University, 8 Clarkson Avenue, Potsdam, NY 13699, USA
- The BioInspired Institute, Syracuse University, Syracuse, NY 13244, USA
| | - Kelsey Moody
- Ichor Life Sciences Inc., 2651 US Route 11, LaFayette, NY 13084, USA
- Lewis School of Health Sciences, Clarkson University, 8 Clarkson Avenue, Potsdam, NY 13699, USA
- The BioInspired Institute, Syracuse University, Syracuse, NY 13244, USA
| | - Cene Gostinčar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
| | - Nina Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
| | - Alaji Bah
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Steven D. Hanes
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
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50
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Li Z, Liu X, Liu M. Stress Granule Homeostasis, Aberrant Phase Transition, and Amyotrophic Lateral Sclerosis. ACS Chem Neurosci 2022; 13:2356-2370. [PMID: 35905138 DOI: 10.1021/acschemneuro.2c00262] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. In recent years, a large number of ALS-related mutations have been discovered to have a strong link to stress granules (SGs). SGs are cytoplasmic ribonucleoprotein condensates mediated by liquid-liquid phase separation (LLPS) of biomacromolecules. They help cells cope with stress. The normal physiological functions of SGs are dependent on three key aspects of SG "homeostasis": SG assembly, disassembly, and SG components. Any of these three aspects can be disrupted, resulting in abnormalities in the cellular stress response and leading to cytotoxicity. Several ALS-related pathogenic mutants have abnormal LLPS abilities that disrupt SG homeostasis, and some of them can even cause aberrant phase transitions. As a result, ALS-related mutants may disrupt various aspects of SG homeostasis by directly disturbing the intermolecular interactions or affecting core SG components, thus disrupting the phase equilibrium of the cytoplasm during stress. Considering that the importance of the "global view" of SG homeostasis in ALS pathogenesis has not received enough attention, we first systematically summarize the physiological regulatory mechanism of SG homeostasis based on LLPS and then examine ALS pathogenesis from the perspective of disrupted SG homeostasis and aberrant phase transition of biomacromolecules.
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Affiliation(s)
- Zhanxu Li
- Xiangya School of Medicine, Central South University, Changsha 410078, Hunan, China
| | - Xionghao Liu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, Hunan, China
| | - Mujun Liu
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha 410078, Hunan, China
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