1
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Ambadi Thody S, Clements HD, Baniasadi H, Lyon AS, Sigman MS, Rosen MK. Small-molecule properties define partitioning into biomolecular condensates. Nat Chem 2024:10.1038/s41557-024-01630-w. [PMID: 39271915 DOI: 10.1038/s41557-024-01630-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 08/13/2024] [Indexed: 09/15/2024]
Abstract
Biomolecular condensates regulate cellular function by compartmentalizing molecules without a surrounding membrane. Condensate function arises from the specific exclusion or enrichment of molecules. Thus, understanding condensate composition is critical to characterizing condensate function. Whereas principles defining macromolecular composition have been described, understanding of small-molecule composition remains limited. Here we quantified the partitioning of ~1,700 biologically relevant small molecules into condensates composed of different macromolecules. Partitioning varied nearly a million-fold across compounds but was correlated among condensates, indicating that disparate condensates are physically similar. For one system, the enriched compounds did not generally bind macromolecules with high affinity under conditions where condensates do not form, suggesting that partitioning is not governed by site-specific interactions. Correspondingly, a machine learning model accurately predicts partitioning using only computed physicochemical features of the compounds, chiefly those related to solubility and hydrophobicity. These results suggest that a hydrophobic environment emerges upon condensate formation, driving the enrichment and exclusion of small molecules.
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Affiliation(s)
- Sabareesan Ambadi Thody
- Department of Biophysics, Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Hanna D Clements
- Department of Chemistry, University of Utah, Salt Lake City, UT, USA
| | - Hamid Baniasadi
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, USA
| | - Andrew S Lyon
- Department of Biophysics, Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX, USA
| | - Matthew S Sigman
- Department of Chemistry, University of Utah, Salt Lake City, UT, USA.
| | - Michael K Rosen
- Department of Biophysics, Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX, USA.
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2
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Guo L, Hong T, Lee YT, Hu X, Pan G, Zhao R, Yang Y, Yang J, Cai X, Rivera L, Liang J, Wang R, Dou Y, Kodali S, Li W, Han L, Di Stefano B, Zhou Y, Li J, Huang Y. Perturbing TET2 condensation promotes aberrant genome-wide DNA methylation and curtails leukaemia cell growth. Nat Cell Biol 2024:10.1038/s41556-024-01496-7. [PMID: 39251719 DOI: 10.1038/s41556-024-01496-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 08/01/2024] [Indexed: 09/11/2024]
Abstract
The ten-eleven translocation (TET) family of dioxygenases maintain stable local DNA demethylation during cell division and lineage specification. As the major catalytic product of TET enzymes, 5-hydroxymethylcytosine is selectively enriched at specific genomic regions, such as enhancers, in a tissue-dependent manner. However, the mechanisms underlying this selectivity remain unresolved. Here we unveil a low-complexity insert domain within TET2 that facilitates its biomolecular condensation with epigenetic modulators, such as UTX and MLL4. This co-condensation fosters a permissive chromatin environment for precise DNA demethylation. Disrupting low-complexity insert-mediated condensation alters the genomic binding of TET2 to cause promiscuous DNA demethylation and genome reorganization. These changes influence the expression of key genes implicated in leukaemogenesis to curtail leukaemia cell proliferation. Collectively, this study establishes the pivotal role of TET2 condensation in orchestrating precise DNA demethylation and gene transcription to support tumour cell growth.
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Affiliation(s)
- Lei Guo
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Tingting Hong
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Yi-Tsang Lee
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Xue Hu
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Guokai Pan
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Rongjie Zhao
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Yuhan Yang
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Jingwen Yang
- School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Xiaoli Cai
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Logan Rivera
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Jie Liang
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Rui Wang
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Yaling Dou
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA
| | - Srikanth Kodali
- Stem Cells and Regenerative Medicine Center, Center for Cell and Gene Therapy, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Wenbo Li
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
- The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Leng Han
- School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Bruno Di Stefano
- Stem Cells and Regenerative Medicine Center, Center for Cell and Gene Therapy, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yubin Zhou
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA.
- Department of Translational Medical Sciences, School of Medicine, Texas A&M University, Houston, TX, USA.
| | - Jia Li
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cancer Research, the Affiliated Cancer Hospital, Guangzhou Medical University, Guangzhou, China.
- Department of Laboratory Medicine, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China.
- Guangzhou National Laboratory, Guangzhou Medical University, Guangzhou, China.
| | - Yun Huang
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX, USA.
- Department of Translational Medical Sciences, School of Medicine, Texas A&M University, Houston, TX, USA.
- Department of Biomedical Engineering, College of Engineering, Texas A&M University, Houston, TX, USA.
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3
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Sun YC, Hsieh TL, Lin CI, Shao WY, Lin YH, Huang JR. A Few Charged Residues in Galectin-3's Folded and Disordered Regions Regulate Phase Separation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2402570. [PMID: 39248370 DOI: 10.1002/advs.202402570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 07/25/2024] [Indexed: 09/10/2024]
Abstract
Proteins with intrinsically disordered regions (IDRs) often undergo phase separation to control their functions spatiotemporally. Changing the pH alters the protonation levels of charged sidechains, which in turn affects the attractive or repulsive force for phase separation. In a cell, the rupture of membrane-bound compartments, such as lysosomes, creates an abrupt change in pH. However, how proteins' phase separation reacts to different pH environments remains largely unexplored. Here, using extensive mutagenesis, NMR spectroscopy, and biophysical techniques, it is shown that the assembly of galectin-3, a widely studied lysosomal damage marker, is driven by cation-π interactions between positively charged residues in its folded domain with aromatic residues in the IDR in addition to π-π interaction between IDRs. It is also found that the sole two negatively charged residues in its IDR sense pH changes for tuning the condensation tendency. Also, these two residues may prevent this prion-like IDR domain from forming rapid and extensive aggregates. These results demonstrate how cation-π, π-π, and electrostatic interactions can regulate protein condensation between disordered and structured domains and highlight the importance of sparse negatively charged residues in prion-like IDRs.
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Affiliation(s)
- Yung-Chen Sun
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Taipei, 112304, Taiwan
- Taiwan International Graduate Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei, Taiwan
| | - Tsung-Lun Hsieh
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Taipei, 112304, Taiwan
| | - Chia-I Lin
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Taipei, 112304, Taiwan
| | - Wan-Yu Shao
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Taipei, 112304, Taiwan
| | - Yu-Hao Lin
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Taipei, 112304, Taiwan
- Taiwan International Graduate Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei, Taiwan
| | - Jie-Rong Huang
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Taipei, 112304, Taiwan
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Taipei, 112304, Taiwan
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Taipei, 112304, Taiwan
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4
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Chen C, Ganar KA, de Haas RJ, Jarnot N, Hogeveen E, de Vries R, Deshpande S. Elastin-like polypeptide coacervates as reversibly triggerable compartments for synthetic cells. Commun Chem 2024; 7:198. [PMID: 39232074 PMCID: PMC11374812 DOI: 10.1038/s42004-024-01270-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 08/05/2024] [Indexed: 09/06/2024] Open
Abstract
Compartmentalization is a vital aspect of living cells to orchestrate intracellular processes. In a similar vein, constructing dynamic and responsive sub-compartments is key to synthetic cell engineering. In recent years, liquid-liquid phase separation via coacervation has offered an innovative avenue for creating membraneless organelles (MOs) within artificial cells. Here, we present a lab-on-a-chip system to reversibly trigger peptide-based coacervates within cell-mimicking confinements. We use double emulsion droplets (DEs) as our synthetic cell containers while pH-responsive elastin-like polypeptides (ELPs) act as the coacervate system. We first present a high-throughput microfluidic DE production enabling efficient encapsulation of the ELPs. The DEs are then harvested to perform multiple MO formation-dissolution cycles using pH as well as temperature variation. For controlled long-term visualization and modulation of the external environment, we developed an integrated microfluidic device for trapping and environmental stimulation of DEs, with negligible mechanical force, and demonstrated a proof-of-principle osmolyte-based triggering to induce multiple MO formation-dissolution cycles. In conclusion, our work showcases the use of DEs and ELPs in designing membraneless reversible compartmentalization within synthetic cells via physicochemical triggers. Additionally, presented on-chip platform can be applied over a wide range of phase separation and vesicle systems for applications in synthetic cells and beyond.
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Affiliation(s)
- Chang Chen
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Ketan A Ganar
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Robbert J de Haas
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Nele Jarnot
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Erwin Hogeveen
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Renko de Vries
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Siddharth Deshpande
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
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5
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Jo M, Kim S, Park J, Chang YT, Gwon Y. Reduced dynamicity and increased high-order protein assemblies in dense fibrillar component of the nucleolus under cellular senescence. Redox Biol 2024; 75:103279. [PMID: 39111063 PMCID: PMC11347067 DOI: 10.1016/j.redox.2024.103279] [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: 05/14/2024] [Revised: 06/27/2024] [Accepted: 07/20/2024] [Indexed: 08/23/2024] Open
Abstract
Cellular senescence, which is triggered by various stressors, manifests as irreversible cell cycle arrest, resulting in the disruption of multiple nuclear condensates. One of the affected structures is the nucleolus, whose tripartite layout, separated into distinct liquid phases, allows for the stepwise progression of ribosome biogenesis. The dynamic properties of dense fibrillar components, a sub-nucleolar phase, are crucial for mediating pre-rRNA processing. However, the mechanistic link between the material properties of dense fibrillar components and cellular senescence remains unclear. We established a significant association between cellular senescence and alterations in nucleolar materiality and characteristics, including the number, size, and sphericity of individual subphases of the nucleolus. Senescent cells exhibit reduced fibrillarin dynamics, aberrant accumulation of high-order protein assemblies, such as oligomers and fibrils, and increased dense fibrillar component density. Intriguingly, the addition of RNA-interacting entities mirrored the diminished diffusion of fibrillarin in the nucleolus during cellular senescence. Thus, our findings contribute to a broader understanding of the intricate changes in the materiality of the nucleolus associated with cellular senescence and shed light on nucleolar dynamics in the context of aging and cellular stress.
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Affiliation(s)
- Minjeong Jo
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
| | - Soomin Kim
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
| | - Jeongeun Park
- Department of MetaBioHealth, Sungkyunkwan University Institute for Convergence, Suwon, 16419, Republic of Korea
| | - Young-Tae Chang
- Department of Chemistry, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
| | - Youngdae Gwon
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea; Department of MetaBioHealth, Sungkyunkwan University Institute for Convergence, Suwon, 16419, Republic of Korea; KIST-SKKU Brain Research Center, Sungkyunkwan University Institute for Convergence, Suwon, 16419, Republic of Korea.
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6
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Zhang L, Hodgins L, Sakib S, Verbeem A, Mahmood A, Perez-Romero C, Marmion RA, Dostatni N, Fradin C. Both the transcriptional activator, Bcd, and repressor, Cic, form small mobile oligomeric clusters. Biophys J 2024:S0006-3495(24)00558-7. [PMID: 39164967 DOI: 10.1016/j.bpj.2024.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 07/11/2024] [Accepted: 08/15/2024] [Indexed: 08/22/2024] Open
Abstract
Transcription factors play an essential role in pattern formation during early embryo development, generating a strikingly fast and precise transcriptional response that results in sharp gene expression boundaries. To characterize the steps leading up to transcription, we performed a side-by-side comparison of the nuclear dynamics of two morphogens, a transcriptional activator, Bicoid (Bcd), and a transcriptional repressor, Capicua (Cic), both involved in body patterning along the anterior-posterior axis of the early Drosophila embryo. We used a combination of fluorescence recovery after photobleaching, fluorescence correlation spectroscopy, and single-particle tracking to access a wide range of dynamical timescales. Despite their opposite effects on gene transcription, we find that Bcd and Cic have very similar nuclear dynamics, characterized by the coexistence of a freely diffusing monomer population with a number of oligomeric clusters, which range from low stoichiometry and high mobility clusters to larger, DNA-bound hubs. Our observations are consistent with the inclusion of both Bcd and Cic into transcriptional hubs or condensates, while putting constraints on the mechanism by which these form. These results fit in with the recent proposal that many transcription factors might share a common search strategy for target gene regulatory regions that makes use of their large unstructured regions, and may eventually help explain how the transcriptional response they elicit can be at the same time so fast and so precise.
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Affiliation(s)
- Lili Zhang
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
| | - Lydia Hodgins
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
| | - Shariful Sakib
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Alexander Verbeem
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
| | - Ahmad Mahmood
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
| | - Carmina Perez-Romero
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Robert A Marmion
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey
| | - Nathalie Dostatni
- Institut Curie, PSL University, CNRS, Sorbonne University, Nuclear Dynamics, Paris, France
| | - Cécile Fradin
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada; Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada.
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7
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Kamano S, Ozawa D, Ikenaka K, Nagai Y. Role of Lipids in the Pathogenesis of Parkinson's Disease. Int J Mol Sci 2024; 25:8935. [PMID: 39201619 PMCID: PMC11354291 DOI: 10.3390/ijms25168935] [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: 07/08/2024] [Revised: 08/07/2024] [Accepted: 08/10/2024] [Indexed: 09/02/2024] Open
Abstract
Aggregation of α-synuclein (αSyn) and its accumulation as Lewy bodies play a central role in the pathogenesis of Parkinson's disease (PD). However, the mechanism by which αSyn aggregates in the brain remains unclear. Biochemical studies have demonstrated that αSyn interacts with lipids, and these interactions affect the aggregation process of αSyn. Furthermore, genetic studies have identified mutations in lipid metabolism-associated genes such as glucocerebrosidase 1 (GBA1) and synaptojanin 1 (SYNJ1) in sporadic and familial forms of PD, respectively. In this review, we focus on the role of lipids in triggering αSyn aggregation in the pathogenesis of PD and propose the possibility of modulating the interaction of lipids with αSyn as a potential therapy for PD.
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Grants
- 24H00630 Ministry of Education, Culture, Sports, Science and Technology
- 21H02840 Ministry of Education, Culture, Sports, Science and Technology
- 17K19658 Ministry of Education, Culture, Sports, Science and Technology
- 20H05927 Ministry of Education, Culture, Sports, Science and Technology
- JP16ek0109018 Japan Agency for Medical Research and Development
- JP19ek0109222 Japan Agency for Medical Research and Development
- 30-3 National Center of Neurology and Psychiatry
- 30-9 National Center of Neurology and Psychiatry
- 3-9 National Center of Neurology and Psychiatry
- 6-9 National Center of Neurology and Psychiatry
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Affiliation(s)
- Shumpei Kamano
- Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama 589-8511, Osaka, Japan; (S.K.); (D.O.)
| | - Daisaku Ozawa
- Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama 589-8511, Osaka, Japan; (S.K.); (D.O.)
| | - Kensuke Ikenaka
- Department of Neurology, Osaka University Graduate School of Medicine, Suita 565-0871, Osaka, Japan;
| | - Yoshitaka Nagai
- Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama 589-8511, Osaka, Japan; (S.K.); (D.O.)
- Life Science Research Institute, Kindai University, Osaka-Sayama 589-8511, Osaka, Japan
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8
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Yu Y, Liu Q, Zeng J, Tan Y, Tang Y, Wei G. Multiscale simulations reveal the driving forces of p53C phase separation accelerated by oncogenic mutations. Chem Sci 2024; 15:12806-12818. [PMID: 39148776 PMCID: PMC11323318 DOI: 10.1039/d4sc03645j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Accepted: 07/07/2024] [Indexed: 08/17/2024] Open
Abstract
Liquid-Liquid phase separation (LLPS) of p53 to form liquid condensates has been implicated in cellular functions and dysfunctions. The p53 condensates may serve as amyloid fibril precursors to initiate p53 aggregation, which is associated with oncogenic gain-of-function and various human cancers. M237I and R249S mutations located in p53 core domain (p53C) have been detected respectively in glioblastomas and hepatocellular carcinoma. Interestingly, these p53C mutants can also undergo LLPS and liquid-to-solid phase transition, which are faster than wild type p53C. However, the underlying molecular basis governing the accelerated LLPS and liquid-to-solid transition of p53C remain poorly understood. Herein, we explore the M237I/R249S mutation-induced structural alterations and phase separation behavior of p53C by employing multiscale molecular dynamics simulations. All-atom simulations revealed conformational disruptions in the zinc-binding domain of the M237I mutant and in both loop3 and zinc-binding domain of the R249S mutant. The two mutations enhance hydrophobic exposure of those regions and attenuate intramolecular interactions, which may hasten the LLPS and aggregation of p53C. Martini 3 coarse-grained simulations demonstrated spontaneous phase separation of p53C and accelerated effects of M237I/R249S mutations on the phase separation of p53C. Importantly, we find that the regions with enhanced intermolecular interactions observed in coarse-grained simulations coincide with the disrupted regions with weakened intramolecular interactions observed in all-atom simulations, indicating that M237I/R249S mutation-induced local structural disruptions expedite the LLPS of p53C. This study unveils the molecular mechanisms underlying the two cancer-associated mutation-accelerated LLPS and aggregation of p53C, providing avenues for anticancer therapy by targeting the phase separation process.
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Affiliation(s)
- Yawei Yu
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University Shanghai 200438 People's Republic of China
| | - Qian Liu
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University Shanghai 200438 People's Republic of China
| | - Jiyuan Zeng
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University Shanghai 200438 People's Republic of China
| | - Yuan Tan
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University Shanghai 200438 People's Republic of China
| | - Yiming Tang
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University Shanghai 200438 People's Republic of China
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University Shanghai 200438 People's Republic of China
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9
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Santamaria A, Hutin S, Doucet CM, Zubieta C, Milhiet PE, Costa L. Quantifying surface tension and viscosity in biomolecular condensates by FRAP-ID. Biophys J 2024:S0006-3495(24)00520-4. [PMID: 39113361 DOI: 10.1016/j.bpj.2024.07.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/01/2024] [Accepted: 07/31/2024] [Indexed: 08/22/2024] Open
Abstract
Many proteins with intrinsically disordered regions undergo liquid-liquid phase separation under specific conditions in vitro and in vivo. These complex biopolymers form a metastable phase with distinct mechanical properties defining the timescale of their biological functions. However, determining these properties is nontrivial, even in vitro, and often requires multiple techniques. Here we report the measurement of both viscosity and surface tension of biomolecular condensates via correlative fluorescence microscopy and atomic force microscopy (AFM) in a single experiment (fluorescence recovery after probe-induced dewetting, FRAP-ID). Upon surface tension evaluation via regular AFM-force spectroscopy, controlled AFM indentations induce dry spots in fluorescent condensates on a glass coverslip. The subsequent rewetting exhibits a contact line velocity that is used to quantify the condensed-phase viscosity. Therefore, in contrast with fluorescence recovery after photobleaching (FRAP), where molecular diffusion is observed, in FRAP-ID fluorescence recovery is obtained through fluid rewetting and the subsequent morphological relaxation. We show that the latter can be used to cross-validate viscosity values determined during the rewetting regime. Making use of fluid mechanics, FRAP-ID is a valuable tool to evaluate the mechanical properties that govern the dynamics of biomolecular condensates and determine how these properties impact the temporal aspects of condensate functionality.
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Affiliation(s)
- Andreas Santamaria
- Center for Structural Biology (CBS), CNRS, INSERM, Montpellier University, Montpellier, France
| | - Stephanie Hutin
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble-Alpes, CNRS, CEA, INRAE, IRIG-DBSCI, Grenoble, France
| | - Christine M Doucet
- Center for Structural Biology (CBS), CNRS, INSERM, Montpellier University, Montpellier, France
| | - Chloe Zubieta
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble-Alpes, CNRS, CEA, INRAE, IRIG-DBSCI, Grenoble, France
| | - Pierre-Emmanuel Milhiet
- Center for Structural Biology (CBS), CNRS, INSERM, Montpellier University, Montpellier, France
| | - Luca Costa
- Center for Structural Biology (CBS), CNRS, INSERM, Montpellier University, Montpellier, France.
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10
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Nicy, Morgan JWR, Wales DJ. Energy landscapes for clusters of hexapeptides. J Chem Phys 2024; 161:054112. [PMID: 39092941 DOI: 10.1063/5.0220652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Accepted: 07/17/2024] [Indexed: 08/04/2024] Open
Abstract
We present the results for energy landscapes of hexapeptides obtained using interfaces to the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) program. We have used basin-hopping global optimization and discrete path sampling to explore the landscapes of hexapeptide monomers, dimers, and oligomers containing 10, 100, and 200 monomers modeled using a residue-level coarse-grained potential, Mpipi, implemented in LAMMPS. We find that the dimers of peptides containing amino acid residues that are better at promoting phase separation, such as tyrosine and arginine, have melting peaks at higher temperature in their heat capacity compared to phenylalanine and lysine, respectively. This observation correlates with previous work on the same uncapped hexapeptide monomers modeled using atomistic potential. For oligomers, we compare the variation in monomer conformations with radial distance and observe trends for selected angles calculated for each monomer. The LAMMPS interfaces to the GMIN and OPTIM programs for landscape exploration offer new opportunities to investigate larger systems and provide access to the coarse-grained potentials implemented within LAMMPS.
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Affiliation(s)
- Nicy
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - John W R Morgan
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - David J Wales
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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11
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Barkley RJR, Crowley JC, Brodrick AJ, Zipfel WR, Parker JSL. Fluorescent protein tags affect the condensation properties of a phase-separating viral protein. Mol Biol Cell 2024; 35:ar100. [PMID: 38809580 PMCID: PMC11244164 DOI: 10.1091/mbc.e24-01-0013] [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: 01/16/2024] [Revised: 05/17/2024] [Accepted: 05/24/2024] [Indexed: 05/30/2024] Open
Abstract
Fluorescent protein (FP) tags are extensively used to visualize and characterize the properties of biomolecular condensates despite a lack of investigation into the effects of these tags on phase separation. Here, we characterized the dynamic properties of µNS, a viral protein hypothesized to undergo phase separation and the main component of mammalian orthoreovirus viral factories. Our interest in the sequence determinants and nucleation process of µNS phase separation led us to compare the size and density of condensates formed by FP::µNS to the untagged protein. We found an FP-dependent increase in droplet size and density, which suggests that FP tags can promote µNS condensation. To further assess the effect of FP tags on µNS droplet formation, we fused FP tags to µNS mutants to show that the tags could variably induce phase separation of otherwise noncondensing proteins. By comparing fluorescent constructs with untagged µNS, we identified mNeonGreen as the least artifactual FP tag that minimally perturbed µNS condensation. These results show that FP tags can promote phase separation and that some tags are more suitable for visualizing and characterizing biomolecular condensates with minimal experimental artifacts.
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Affiliation(s)
- Russell J. R. Barkley
- Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850
| | - Jack C. Crowley
- School of Applied and Engineering Physics, College of Engineering, Cornell University, Ithaca, NY 14850
| | - Andrew J. Brodrick
- Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850
| | - Warren R. Zipfel
- School of Applied and Engineering Physics, College of Engineering, Cornell University, Ithaca, NY 14850
- Meinig School of Biomedical Engineering, College of Engineering, Cornell University, Ithaca, NY 14850
| | - John S. L. Parker
- Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850
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12
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Fukata Y, Fukata M, MacGillavry HD, Nair D, Hosy E. Celebrating the Birthday of AMPA Receptor Nanodomains: Illuminating the Nanoscale Organization of Excitatory Synapses with 10 Nanocandles. J Neurosci 2024; 44:e2104232024. [PMID: 38839340 PMCID: PMC11154862 DOI: 10.1523/jneurosci.2104-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 06/07/2024] Open
Abstract
A decade ago, in 2013, and over the course of 4 summer months, three separate observations were reported that each shed light independently on a new molecular organization that fundamentally reshaped our perception of excitatory synaptic transmission (Fukata et al., 2013; MacGillavry et al., 2013; Nair et al., 2013). This discovery unveiled an intricate arrangement of AMPA-type glutamate receptors and their principal scaffolding protein PSD-95, at synapses. This breakthrough was made possible, thanks to advanced super-resolution imaging techniques. It fundamentally changed our understanding of excitatory synaptic architecture and paved the way for a brand-new area of research. In this Progressions article, the primary investigators of the nanoscale organization of synapses have come together to chronicle the tale of their discovery. We recount the initial inquiry that prompted our research, the preceding studies that inspired our work, the technical obstacles that were encountered, and the breakthroughs that were made in the subsequent decade in the realm of nanoscale synaptic transmission. We review the new discoveries made possible by the democratization of super-resolution imaging techniques in the field of excitatory synaptic physiology and architecture, first by the extension to other glutamate receptors and to presynaptic proteins and then by the notion of trans-synaptic organization. After describing the organizational modifications occurring in various pathologies, we discuss briefly the latest technical developments made possible by super-resolution imaging and emerging concepts in synaptic physiology.
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Affiliation(s)
- Yuko Fukata
- Division of Molecular and Cellular Pharmacology, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Division of Neuropharmacology, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
| | - Harold D MacGillavry
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, The Netherlands
| | - Deepak Nair
- Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, Karnataka, India
| | - Eric Hosy
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, CNRS UMR5297, Bordeaux F-33000, France
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13
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Bokros M, Balukoff NC, Grunfeld A, Sebastiao M, Beurel E, Bourgault S, Lee S. RNA tailing machinery drives amyloidogenic phase transition. Proc Natl Acad Sci U S A 2024; 121:e2316734121. [PMID: 38805292 PMCID: PMC11161805 DOI: 10.1073/pnas.2316734121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 04/18/2024] [Indexed: 05/30/2024] Open
Abstract
The RNA tailing machinery adds nucleotides to the 3'-end of RNA molecules that are implicated in various biochemical functions, including protein synthesis and RNA stability. Here, we report a role for the RNA tailing machinery as enzymatic modifiers of intracellular amyloidogenesis. A targeted RNA interference screen identified Terminal Nucleotidyl-transferase 4b (TENT4b/Papd5) as an essential participant in the amyloidogenic phase transition of nucleoli into solid-like Amyloid bodies. Full-length-and-mRNA sequencing uncovered starRNA, a class of unusually long untemplated RNA molecules synthesized by TENT4b. StarRNA consists of short rRNA fragments linked to long, linear mixed tails that operate as polyanionic stimulators of amyloidogenesis in cells and in vitro. Ribosomal intergenic spacer noncoding RNA (rIGSRNA) recruit TENT4b in intranucleolar foci to coordinate starRNA synthesis driving their amyloidogenic phase transition. The exoribonuclease RNA Exosome degrades starRNA and functions as a general suppressor of cellular amyloidogenesis. We propose that amyloidogenic phase transition is under tight enzymatic control by the RNA tailing and exosome axis.
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Affiliation(s)
- Michael Bokros
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL33136
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, Cancer Epigenetics Program, University of Miami, Miami, FL33136
| | - Nathan C. Balukoff
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL33136
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, Cancer Epigenetics Program, University of Miami, Miami, FL33136
| | - Alex Grunfeld
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL33136
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, Cancer Epigenetics Program, University of Miami, Miami, FL33136
| | - Mathew Sebastiao
- Department of Chemistry, Université du Québec à Montréal, MontrealQCH3C 3P8, Canada
- Quebec Network for Research on Protein Function, Engineering, and Applications, PROTEO, Montreal, QCH3C 3P8, Canada
| | - Eléonore Beurel
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL33136
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL33136
| | - Steve Bourgault
- Department of Chemistry, Université du Québec à Montréal, MontrealQCH3C 3P8, Canada
- Quebec Network for Research on Protein Function, Engineering, and Applications, PROTEO, Montreal, QCH3C 3P8, Canada
| | - Stephen Lee
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL33136
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, Cancer Epigenetics Program, University of Miami, Miami, FL33136
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14
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Chew PY, Joseph JA, Collepardo-Guevara R, Reinhardt A. Aromatic and arginine content drives multiphasic condensation of protein-RNA mixtures. Biophys J 2024; 123:1342-1355. [PMID: 37408305 PMCID: PMC11163273 DOI: 10.1016/j.bpj.2023.06.024] [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: 04/16/2023] [Revised: 06/20/2023] [Accepted: 06/30/2023] [Indexed: 07/07/2023] Open
Abstract
Multiphasic architectures are found ubiquitously in biomolecular condensates and are thought to have important implications for the organization of multiple chemical reactions within the same compartment. Many of these multiphasic condensates contain RNA in addition to proteins. Here, we investigate the importance of different interactions in multiphasic condensates comprising two different proteins and RNA using computer simulations with a residue-resolution coarse-grained model of proteins and RNA. We find that in multilayered condensates containing RNA in both phases, protein-RNA interactions dominate, with aromatic residues and arginine forming the key stabilizing interactions. The total aromatic and arginine content of the two proteins must be appreciably different for distinct phases to form, and we show that this difference increases as the system is driven toward greater multiphasicity. Using the trends observed in the different interaction energies of this system, we demonstrate that we can also construct multilayered condensates with RNA preferentially concentrated in one phase. The "rules" identified can thus enable the design of synthetic multiphasic condensates to facilitate further study of their organization and function.
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Affiliation(s)
- Pin Yu Chew
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Jerelle A Joseph
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey
| | - Rosana Collepardo-Guevara
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom; Department of Physics, University of Cambridge, Cambridge, United Kingdom; Department of Genetics, University of Cambridge, Cambridge, United Kingdom.
| | - Aleks Reinhardt
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom.
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15
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Zhang M, Zhang Z, Niu X, Ti H, Zhou Y, Gao B, Li Y, Liu J, Chen X, Li H. Interplay Between Intracellular Transport Dynamics and Liquid‒Liquid Phase Separation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308338. [PMID: 38447188 PMCID: PMC11109639 DOI: 10.1002/advs.202308338] [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: 11/02/2023] [Revised: 01/22/2024] [Indexed: 03/08/2024]
Abstract
Liquid‒liquid phase separation (LLPS) is a ubiquitous process in which proteins, RNA, and biomolecules assemble into membrane-less compartments, playing important roles in many biological functions and diseases. The current knowledge on the biophysical and biochemical principles of LLPS is largely from in vitro studies; however, the physiological environment in living cells is complex and not at equilibrium. The characteristics of intracellular dynamics and their roles in physiological LLPS remain to be resolved. Here, by using single-particle tracking of quantum dots and dynamic monitoring of the formation of stress granules (SGs) in single cells, the spatiotemporal dynamics of intracellular transport in cells undergoing LLPS are quantified. It is shown that intracellular diffusion and active transport are both reduced. Furthermore, the formation of SG droplets contributes to increased spatial heterogeneity within the cell. More importantly, the study demonstrated that the LLPS of SGs can be regulated by intracellular dynamics in two stages: the reduced intracellular diffusion promotes SG assembly and the microtubule-associated transport facilitates SG coalescences. The work on intracellular dynamics not only improves the understanding of the mechanism of physiology phase separations occurring in nonequilibrium environments but also reveals an interplay between intracellular dynamics and LLPS.
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Affiliation(s)
- Ming‐Li Zhang
- School of Systems Science and Institute of Nonequilibrium SystemsBeijing Normal UniversityBeijing100875China
| | - Ziheng Zhang
- School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Xue‐Zhi Niu
- School of Systems Science and Institute of Nonequilibrium SystemsBeijing Normal UniversityBeijing100875China
| | - Hui‐Ying Ti
- School of Systems Science and Institute of Nonequilibrium SystemsBeijing Normal UniversityBeijing100875China
| | - Yu‐Xuan Zhou
- School of Systems Science and Institute of Nonequilibrium SystemsBeijing Normal UniversityBeijing100875China
| | - Bo Gao
- School of Systems Science and Institute of Nonequilibrium SystemsBeijing Normal UniversityBeijing100875China
| | - Yiwei Li
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics – Hubei Bioinformatics and Molecular Imaging Key LaboratoryDepartment of Biomedical EngineeringCollege of Life Science and TechnologyHuazhong University of Science and TechnologyWuhan430074China
| | - Ji‐Long Liu
- School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Xiaosong Chen
- School of Systems Science and Institute of Nonequilibrium SystemsBeijing Normal UniversityBeijing100875China
| | - Hui Li
- School of Systems Science and Institute of Nonequilibrium SystemsBeijing Normal UniversityBeijing100875China
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16
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Ye G, Tang Y, Yang Q, Zhang C, Shi H, Wang J, Hu X, Wan X, Xu Z, Liang J, Yang Y, Yang M, Liu Y. A peptide derived from SARS-CoV-2 nucleocapsid protein with broad-spectrum anti-coronavirus activity. J Med Virol 2024; 96:e29492. [PMID: 38587139 DOI: 10.1002/jmv.29492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/29/2024] [Accepted: 02/13/2024] [Indexed: 04/09/2024]
Affiliation(s)
- Guoguo Ye
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Yimin Tang
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
| | - Qin Yang
- College of Life Sciences, Wuhan University, Wuhan, China
| | - Chenhui Zhang
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Huiping Shi
- School of Life Science, Key Laboratory of Molecular Medicine and Biotherapy, Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Advanced Research Institute of Multidisciplinary Sciences, Beijing Institute of Technology, Beijing, China
| | - Jun Wang
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
| | - Xiao Hu
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Xiaofu Wan
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
- National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, Guangdong Province, China
| | - Zhixiang Xu
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
| | - Jinhu Liang
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Yang Yang
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Minghui Yang
- School of Life Science, Key Laboratory of Molecular Medicine and Biotherapy, Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Advanced Research Institute of Multidisciplinary Sciences, Beijing Institute of Technology, Beijing, China
| | - Yingxia Liu
- Shenzhen Key Laboratory of Pathogen and Immunity, National Clinical Research Center for Infectious Disease, Division of Infectious Disease, The Third People's Hospital of Shenzhen, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
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17
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Gan P, Eppert M, De La Cruz N, Lyons H, Shah AM, Veettil RT, Chen K, Pradhan P, Bezprozvannaya S, Xu L, Liu N, Olson EN, Sabari BR. Coactivator condensation drives cardiovascular cell lineage specification. SCIENCE ADVANCES 2024; 10:eadk7160. [PMID: 38489358 PMCID: PMC10942106 DOI: 10.1126/sciadv.adk7160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 02/12/2024] [Indexed: 03/17/2024]
Abstract
During development, cells make switch-like decisions to activate new gene programs specifying cell lineage. The mechanisms underlying these decisive choices remain unclear. Here, we show that the cardiovascular transcriptional coactivator myocardin (MYOCD) activates cell identity genes by concentration-dependent and switch-like formation of transcriptional condensates. MYOCD forms such condensates and activates cell identity genes at critical concentration thresholds achieved during smooth muscle cell and cardiomyocyte differentiation. The carboxyl-terminal disordered region of MYOCD is necessary and sufficient for condensate formation. Disrupting this region's ability to form condensates disrupts gene activation and smooth muscle cell reprogramming. Rescuing condensate formation by replacing this region with disordered regions from functionally unrelated proteins rescues gene activation and smooth muscle cell reprogramming. Our findings demonstrate that MYOCD condensate formation is required for gene activation during cardiovascular differentiation. We propose that the formation of transcriptional condensates at critical concentrations of cell type-specific regulators provides a molecular switch underlying the activation of key cell identity genes during development.
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Affiliation(s)
- Peiheng Gan
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Mikayla Eppert
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Nancy De La Cruz
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Heankel Lyons
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Akansha M. Shah
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Reshma T. Veettil
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kenian Chen
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Prashant Pradhan
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Svetlana Bezprozvannaya
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lin Xu
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ning Liu
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Eric N. Olson
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Benjamin R. Sabari
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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18
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Thirumalai D, Kumar A, Chakraborty D, Straub JE, Mugnai ML. Conformational fluctuations and phases in fused in sarcoma (FUS) low-complexity domain. Biopolymers 2024; 115:e23558. [PMID: 37399327 PMCID: PMC10831756 DOI: 10.1002/bip.23558] [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: 03/02/2023] [Revised: 05/30/2023] [Accepted: 06/15/2023] [Indexed: 07/05/2023]
Abstract
The well-known phenomenon of phase separation in synthetic polymers and proteins has become a major topic in biophysics because it has been invoked as a mechanism of compartment formation in cells, without the need for membranes. Most of the coacervates (or condensates) are composed of Intrinsically Disordered Proteins (IDPs) or regions that are structureless, often in interaction with RNA and DNA. One of the more intriguing IDPs is the 526-residue RNA-binding protein, Fused in Sarcoma (FUS), whose monomer conformations and condensates exhibit unusual behavior that are sensitive to solution conditions. By focussing principally on the N-terminus low-complexity domain (FUS-LC comprising residues 1-214) and other truncations, we rationalize the findings of solid-state NMR experiments, which show that FUS-LC adopts a non-polymorphic fibril structure (core-1) involving residues 39-95, flanked by fuzzy coats on both the N- and C-terminal ends. An alternate structure (core-2), whose free energy is comparable to core-1, emerges only in the truncated construct (residues 110-214). Both core-1 and core-2 fibrils are stabilized by a Tyrosine ladder as well as hydrophilic interactions. The morphologies (gels, fibrils, and glass-like) adopted by FUS seem to vary greatly, depending on the experimental conditions. The effect of phosphorylation is site-specific. Simulations show that phosphorylation of residues within the fibril has a greater destabilization effect than residues that are outside the fibril region, which accords well with experiments. Many of the peculiarities associated with FUS may also be shared by other IDPs, such as TDP43 and hnRNPA2. We outline a number of problems for which there is no clear molecular explanation.
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Affiliation(s)
- D Thirumalai
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
- Department of Physics, The University of Texas at Austin, Austin, Texas, USA
| | - Abhinaw Kumar
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - Debayan Chakraborty
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - John E Straub
- Department of Chemistry, Boston University, Boston, Massachusetts, USA
| | - Mauro L Mugnai
- Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC, USA
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19
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Li S, Zhang Y, Chen J. Backbone interactions and secondary structures in phase separation of disordered proteins. Biochem Soc Trans 2024; 52:319-329. [PMID: 38348795 DOI: 10.1042/bst20230618] [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: 11/29/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/29/2024]
Abstract
Intrinsically disordered proteins (IDPs) are one of the major drivers behind the formation and characteristics of biomolecular condensates. Due to their inherent flexibility, the backbones of IDPs are significantly exposed, rendering them highly influential and susceptible to biomolecular phase separation. In densely packed condensates, exposed backbones have a heightened capacity to interact with neighboring protein chains, which might lead to strong coupling between the secondary structures and phase separation and further modulate the subsequent transitions of the condensates, such as aging and fibrillization. In this mini-review, we provide an overview of backbone-mediated interactions and secondary structures within biomolecular condensates to underscore the importance of protein backbones in phase separation. We further focus on recent advances in experimental techniques and molecular dynamics simulation methods for probing and exploring the roles of backbone interactions and secondary structures in biomolecular phase separation involving IDPs.
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Affiliation(s)
- Shanlong Li
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Yumeng Zhang
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, U.S.A
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20
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Chattaraj A, Baltaci Z, Mayer BJ, Loew LM, Ditlev JA. Measurement of solubility product in a model condensate reveals the interplay of small oligomerization and self-association. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.23.576869. [PMID: 38328089 PMCID: PMC10849621 DOI: 10.1101/2024.01.23.576869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Cellular condensates often consist of 10s to 100s of distinct interacting molecular species. Because of the complexity of these interactions, predicting the point at which they will undergo phase separation into discrete compartments is daunting. Using experiments and computation, we therefore studied a simple model system consisting of 2 proteins, polySH3 and polyPRM, designed for pentavalent heterotypic binding. We tested whether the peak solubility product, the product of dilute phase monomer concentrations, is a predictive parameter for the onset of phase separation. Titrating up equal total concentrations of each component showed that the maximum solubility product does approximately coincide with the threshold for phase separation in both the experiments and models. However, we found that measurements of dilute phase concentration include contributions from small oligomers, not just monomers; therefore, a quantitative comparison of the experiments and models required inclusion of small oligomers in the model analysis. We also examined full phase diagrams where the model results were almost symmetric along the diagonal, but the experimental results were highly asymmetric. This led us to perform dynamic light scattering experiments, where we discovered a weak homotypic interaction for polyPRM; when this was added to the computational model, it was able to recapitulate the experimentally observed asymmetry. Thus, comparing experiments to simulation reveals that the solubility product can be predictive of phase separation, even if small oligomers and low affinity homotypic interactions preclude experimental measurement of monomer concentration.
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Affiliation(s)
- Aniruddha Chattaraj
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut, United States of America
| | - Zeynep Baltaci
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Bruce J. Mayer
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut, United States of America
- Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, Connecticut, United States of America
| | - Leslie M. Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut, United States of America
| | - Jonathon A. Ditlev
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
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21
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Zhang Y, Li S, Gong X, Chen J. Toward Accurate Simulation of Coupling between Protein Secondary Structure and Phase Separation. J Am Chem Soc 2024; 146:342-357. [PMID: 38112495 PMCID: PMC10842759 DOI: 10.1021/jacs.3c09195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Intrinsically disordered proteins (IDPs) frequently mediate phase separation that underlies the formation of a biomolecular condensate. Together with theory and experiment, efficient coarse-grained (CG) simulations have been instrumental in understanding the sequence-specific phase separation of IDPs. However, the widely used Cα-only models are limited in capturing the peptide nature of IDPs, particularly backbone-mediated interactions and effects of secondary structures, in phase separation. Here, we describe a hybrid resolution (HyRes) protein model toward a more accurate description of the backbone and transient secondary structures in phase separation. With an atomistic backbone and coarse-grained side chains, HyRes can semiquantitatively capture the residue helical propensity and overall chain dimension of monomeric IDPs. Using GY-23 as a model system, we show that HyRes is efficient enough for the direct simulation of spontaneous phase separation and, at the same time, appears accurate enough to resolve the effects of single His to Lys mutations. HyRes simulations also successfully predict increased β-structure formation in the condensate, consistent with available experimental CD data. We further utilize HyRes to study the phase separation of TPD-43, where several disease-related mutants in the conserved region (CR) have been shown to affect residual helicities and modulate the phase separation propensity as measured by the saturation concentration. The simulations successfully recapitulate the effect of these mutants on the helicity and phase separation propensity of TDP-43 CR. Analyses reveal that the balance between backbone and side chain-mediated interactions, but not helicity itself, actually determines phase separation propensity. These results support that HyRes represents an effective protein model for molecular simulation of IDP phase separation and will help to elucidate the coupling between transient secondary structures and phase separation.
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Affiliation(s)
| | | | - Xiping Gong
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
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22
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Chakraborty A, Dutta A, Dettori LG, Daoud R, Li J, Gonzalez L, Xue X, Hehnly H, Sung P, Bah A, Feng W. Complex interplay between FMRP and DHX9 during DNA replication stress. J Biol Chem 2024; 300:105572. [PMID: 38110032 PMCID: PMC10825048 DOI: 10.1016/j.jbc.2023.105572] [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: 06/07/2023] [Revised: 11/28/2023] [Accepted: 12/06/2023] [Indexed: 12/20/2023] Open
Abstract
Mutations in, or deficiency of, fragile X messenger ribonucleoprotein (FMRP) is responsible for the Fragile X syndrome (FXS), the most common cause for inherited intellectual disability. FMRP is a nucleocytoplasmic protein, primarily characterized as a translation repressor with poorly understood nuclear function(s). We recently reported that FXS patient cells lacking FMRP sustain higher level of DNA double-strand breaks (DSBs) than normal cells, specifically at sequences prone to forming R-loops, a phenotype further exacerbated by DNA replication stress. Moreover, expression of FMRP, and not an FMRPI304N mutant known to cause FXS, reduced R-loop-associated DSBs. We subsequently reported that recombinant FMRP directly binds R-loops, primarily through the carboxyl terminal intrinsically disordered region. Here, we show that FMRP directly interacts with an RNA helicase, DHX9. This interaction, which is mediated by the amino terminal structured domain of FMRP, is reduced with FMRPI304N. We also show that FMRP inhibits DHX9 helicase activity on RNA:DNA hybrids and the inhibition is also dependent on the amino terminus. Furthermore, the FMRPI304N mutation causes both FMRP and DHX9 to persist on the chromatin in replication stress. These results suggest an antagonistic relationship between FMRP and DHX9 at the chromatin, where their proper interaction leads to dissociation of both proteins from the fully resolved R-loop. We propose that the absence or the loss of function of FMRP leads to persistent presence of DHX9 or both proteins, respectively, on the unresolved R-loop, ultimately leading to DSBs. Our study sheds new light on our understanding of the genome functions of FMRP.
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Affiliation(s)
- Arijita Chakraborty
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Arijit Dutta
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center San Antonio, San Antonio, Texas, USA
| | - Leonardo G Dettori
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Rosemarie Daoud
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Jing Li
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Leticia Gonzalez
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas, USA
| | - Xiaoyu Xue
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas, USA
| | - Heidi Hehnly
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center San Antonio, San Antonio, Texas, USA
| | - Alaji Bah
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Wenyi Feng
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA.
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23
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Grams N, Charman M, Halko E, Lauman R, Garcia BA, Weitzman MD. Phosphorylation regulates viral biomolecular condensates to promote infectious progeny production. EMBO J 2024; 43:277-303. [PMID: 38177504 PMCID: PMC10897327 DOI: 10.1038/s44318-023-00021-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 01/06/2024] Open
Abstract
Biomolecular condensates (BMCs) play important roles in diverse biological processes. Many viruses form BMCs which have been implicated in various functions critical for the productive infection of host cells. The adenovirus L1-52/55 kilodalton protein (52K) was recently shown to form viral BMCs that coordinate viral genome packaging and capsid assembly. Although critical for packaging, we do not know how viral condensates are regulated during adenovirus infection. Here we show that phosphorylation of serine residues 28 and 75 within the N-terminal intrinsically disordered region of 52K modulates viral condensates in vitro and in cells, promoting liquid-like properties. Furthermore, we demonstrate that phosphorylation of 52K promotes viral genome packaging and the production of infectious progeny particles. Collectively, our findings provide insights into how viral condensate properties are regulated and maintained in a state conducive to their function in viral progeny production. In addition, our findings have implications for antiviral strategies aimed at targeting the regulation of viral BMCs to limit viral multiplication.
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Affiliation(s)
- Nicholas Grams
- Division of Protective Immunity and Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Cell & Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Matthew Charman
- Division of Protective Immunity and Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
| | - Edwin Halko
- Division of Protective Immunity and Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Richard Lauman
- Division of Protective Immunity and Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - Matthew D Weitzman
- Division of Protective Immunity and Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
- Penn Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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24
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Mann R, Notani D. Transcription factor condensates and signaling driven transcription. Nucleus 2023; 14:2205758. [PMID: 37129580 PMCID: PMC10155639 DOI: 10.1080/19491034.2023.2205758] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 04/10/2023] [Accepted: 04/19/2023] [Indexed: 05/03/2023] Open
Abstract
Transcription Factor (TF) condensates are a heterogenous mix of RNA, DNA, and multiple co-factor proteins capable of modulating the transcriptional response of the cell. The dynamic nature and the spatial location of TF-condensates in the 3D nuclear space is believed to provide a fast response, which is on the same pace as the signaling cascade and yet ever-so-specific in the crowded environment of the nucleus. However, the current understanding of how TF-condensates can achieve these feet so quickly and efficiently is still unclear. In this review, we draw parallels with other protein condensates and share our speculations on how the nucleus uses these TF-condensates to achieve high transcriptional specificity and fidelity. We discuss the various constituents of TF-condensates, their properties, and the known and unknown functions of TF-condensates with a particular focus on steroid signaling-induced transcriptional programs.
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Affiliation(s)
- Rajat Mann
- National Centre for Biological Sciences, TIFR, Bangalore, India
| | - Dimple Notani
- National Centre for Biological Sciences, TIFR, Bangalore, India
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25
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Galagedera SKK, Dao TP, Enos SE, Chaudhuri A, Schmit JD, Castañeda CA. Polyubiquitin ligand-induced phase transitions are optimized by spacing between ubiquitin units. Proc Natl Acad Sci U S A 2023; 120:e2306638120. [PMID: 37824531 PMCID: PMC10589717 DOI: 10.1073/pnas.2306638120] [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: 04/25/2023] [Accepted: 09/01/2023] [Indexed: 10/14/2023] Open
Abstract
Biomolecular condensates form via multivalent interactions among key macromolecules and are regulated through ligand binding and/or posttranslational modifications. One such modification is ubiquitination, the covalent addition of ubiquitin (Ub) or polyubiquitin chains to target macromolecules. Specific interactions between polyubiquitin chains and partner proteins, including hHR23B, NEMO, and UBQLN2, regulate condensate assembly or disassembly. Here, we used a library of designed polyubiquitin hubs and UBQLN2 as model systems for determining the driving forces of ligand-mediated phase transitions. Perturbations to either the UBQLN2-binding surface of Ub or the spacing between Ub units reduce the ability of hubs to modulate UBQLN2 phase behavior. By developing an analytical model based on polyphasic linkage principles that accurately described the effects of different hubs on UBQLN2 phase separation, we determined that introduction of Ub to UBQLN2 condensates incurs a significant inclusion energetic penalty. This penalty antagonizes the ability of polyUb hubs to scaffold multiple UBQLN2 molecules and cooperatively amplify phase separation. The extent to which polyubiquitin hubs promote UBQLN2 phase separation is encoded in the spacings between Ub units. This spacing is modulated by chains of different linkages and designed chains of different architectures, thus illustrating how the ubiquitin code regulates functionality via the emergent properties of the condensate. The spacing in naturally occurring linear polyubiquitin chains is already optimized to promote phase separation with UBQLN2. We expect our findings to extend to other condensates, emphasizing the importance of ligand properties, including concentration, valency, affinity, and spacing between binding sites in studies and designs of condensates.
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Affiliation(s)
- Sarasi K. K. Galagedera
- Department of Biology, Syracuse University, Syracuse, NY13244
- Department of Chemistry, Syracuse University, Syracuse, NY13244
| | - Thuy P. Dao
- Department of Biology, Syracuse University, Syracuse, NY13244
- Department of Chemistry, Syracuse University, Syracuse, NY13244
| | - Suzanne E. Enos
- Department of Biology, Syracuse University, Syracuse, NY13244
- Department of Chemistry, Syracuse University, Syracuse, NY13244
| | - Antara Chaudhuri
- Department of Biology, Syracuse University, Syracuse, NY13244
- Department of Chemistry, Syracuse University, Syracuse, NY13244
| | - Jeremy D. Schmit
- Department of Physics, Kansas State University, Manhattan, KS66506
| | - Carlos A. Castañeda
- Department of Biology, Syracuse University, Syracuse, NY13244
- Department of Chemistry, Syracuse University, Syracuse, NY13244
- Interdisciplinary Neuroscience Program, Syracuse University, Syracuse, NY13244
- BioInspired Institute, Syracuse University, Syracuse, NY13244
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26
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Williamson I, Boyle S, Grimes GR, Friman ET, Bickmore WA. Dispersal of PRC1 condensates disrupts polycomb chromatin domains and loops. Life Sci Alliance 2023; 6:e202302101. [PMID: 37487640 PMCID: PMC10366532 DOI: 10.26508/lsa.202302101] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/10/2023] [Accepted: 07/12/2023] [Indexed: 07/26/2023] Open
Abstract
Polycomb repressive complex 1 (PRC1) strongly influences 3D genome organization, mediating local chromatin compaction and clustering of target loci. Several PRC1 subunits have the capacity to form biomolecular condensates through liquid-liquid phase separation in vitro and when tagged and over-expressed in cells. Here, we use 1,6-hexanediol, which can disrupt liquid-like condensates, to examine the role of endogenous PRC1 biomolecular condensates on local and chromosome-wide clustering of PRC1-bound loci. Using imaging and chromatin immunoprecipitation, we show that PRC1-mediated chromatin compaction and clustering of targeted genomic loci-at different length scales-can be reversibly disrupted by the addition and subsequent removal of 1,6-hexanediol to mouse embryonic stem cells. Decompaction and dispersal of polycomb domains and clusters cannot be solely attributable to reduced PRC1 occupancy detected by chromatin immunoprecipitation following 1,6-hexanediol treatment as the addition of 2,5-hexanediol has similar effects on binding despite this alcohol not perturbing PRC1-mediated 3D clustering, at least at the sub-megabase and megabase scales. These results suggest that weak hydrophobic interactions between PRC1 molecules may have a role in polycomb-mediated genome organization.
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Affiliation(s)
- Iain Williamson
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Shelagh Boyle
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Graeme R Grimes
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Elias T Friman
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
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27
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Nicy, Collepardo-Guevara R, Joseph JA, Wales DJ. Energy landscapes and heat capacity signatures for peptides correlate with phase separation propensity. QRB DISCOVERY 2023; 4:e7. [PMID: 37771761 PMCID: PMC10523320 DOI: 10.1017/qrd.2023.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/09/2023] [Accepted: 07/17/2023] [Indexed: 09/30/2023] Open
Abstract
Phase separation plays an important role in the formation of membraneless compartments within the cell and intrinsically disordered proteins with low-complexity sequences can drive this compartmentalisation. Various intermolecular forces, such as aromatic-aromatic and cation-aromatic interactions, promote phase separation. However, little is known about how the ability of proteins to phase separate under physiological conditions is encoded in their energy landscapes and this is the focus of the present investigation. Our results provide a first glimpse into how the energy landscapes of minimal peptides that contain - and cation- interactions differ from the peptides that lack amino acids with such interactions. The peaks in the heat capacity () as a function of temperature report on alternative low-lying conformations that differ significantly in terms of their enthalpic and entropic contributions. The analysis and subsequent quantification of frustration of the energy landscape suggest that the interactions that promote phase separation lead to features (peaks or inflection points) at low temperatures in . More features may occur for peptides containing residues with better phase separation propensity and the energy landscape is more frustrated for such peptides. Overall, this work links the features in the underlying single-molecule potential energy landscapes to their collective phase separation behaviour and identifies quantities ( and frustration metric) that can be utilised in soft material design.
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Affiliation(s)
- Nicy
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Rosana Collepardo-Guevara
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Department of Physics, University of Cambridge, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Jerelle A. Joseph
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA
| | - David J. Wales
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
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28
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Ray S, Mason TO, Boyens-Thiele L, Farzadfard A, Larsen JA, Norrild RK, Jahnke N, Buell AK. Mass photometric detection and quantification of nanoscale α-synuclein phase separation. Nat Chem 2023; 15:1306-1316. [PMID: 37337111 DOI: 10.1038/s41557-023-01244-8] [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: 07/11/2022] [Accepted: 05/19/2023] [Indexed: 06/21/2023]
Abstract
Protein liquid-liquid phase separation can lead to disease-related amyloid fibril formation. The mechanisms of conversion of monomeric protein into condensate droplets and of the latter into fibrils remain elusive. Here, using mass photometry, we demonstrate that the Parkinson's disease-related protein, α-synuclein, can form dynamic nanoscale clusters at physiologically relevant, sub-saturated concentrations. Nanoclusters nucleate in bulk solution and promote amyloid fibril formation of the dilute-phase monomers upon ageing. Their formation is instantaneous, even under conditions where macroscopic assemblies appear only after several days. The slow growth of the nanoclusters can be attributed to a kinetic barrier, probably due to an interfacial penalty from the charged C terminus of α-synuclein. Our findings reveal that α-synuclein phase separation occurs at much wider ranges of solution conditions than reported so far. Importantly, we establish mass photometry as a promising methodology to detect and quantify nanoscale precursors of phase separation. We also demonstrate its general applicability by probing the existence of nanoclusters of a non-amyloidogenic protein, Ddx4n1.
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Affiliation(s)
- Soumik Ray
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Thomas O Mason
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Lars Boyens-Thiele
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Azad Farzadfard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Jacob Aunstrup Larsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Rasmus K Norrild
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Nadin Jahnke
- Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark
| | - Alexander K Buell
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark.
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29
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Zhang Y, Li S, Gong X, Chen J. Accurate Simulation of Coupling between Protein Secondary Structure and Liquid-Liquid Phase Separation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.22.554378. [PMID: 37662293 PMCID: PMC10473686 DOI: 10.1101/2023.08.22.554378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Intrinsically disordered proteins (IDPs) frequently mediate liquid-liquid phase separation (LLPS) that underlies the formation of membraneless organelles. Together with theory and experiment, efficient coarse-grained (CG) simulations have been instrumental in understanding sequence-specific phase separation of IDPs. However, the widely-used Cα-only models are severely limited in capturing the peptide nature of IDPs, including backbone-mediated interactions and effects of secondary structures, in LLPS. Here, we describe a hybrid resolution (HyRes) protein model for accurate description of the backbone and transient secondary structures in LLPS. With an atomistic backbone and coarse-grained side chains, HyRes accurately predicts the residue helical propensity and chain dimension of monomeric IDPs. Using GY-23 as a model system, we show that HyRes is efficient enough for direct simulation of spontaneous phase separation, and at the same time accurate enough to resolve the effects of single mutations. HyRes simulations also successfully predict increased beta-sheet formation in the condensate, consistent with available experimental data. We further utilize HyRes to study the phase separation of TPD-43, where several disease-related mutants in the conserved region (CR) have been shown to affect residual helicities and modulate LLPS propensity. The simulations successfully recapitulate the effect of these mutants on the helicity and LLPS propensity of TDP-43 CR. Analyses reveal that the balance between backbone and sidechain-mediated interactions, but not helicity itself, actually determines LLPS propensity. We believe that the HyRes model represents an important advance in the molecular simulation of LLPS and will help elucidate the coupling between IDP transient secondary structures and phase separation.
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Affiliation(s)
| | | | - Xiping Gong
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
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30
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Lan C, Kim J, Ulferts S, Aprile-Garcia F, Weyrauch S, Anandamurugan A, Grosse R, Sawarkar R, Reinhardt A, Hugel T. Quantitative real-time in-cell imaging reveals heterogeneous clusters of proteins prior to condensation. Nat Commun 2023; 14:4831. [PMID: 37582808 PMCID: PMC10427612 DOI: 10.1038/s41467-023-40540-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 07/26/2023] [Indexed: 08/17/2023] Open
Abstract
Our current understanding of biomolecular condensate formation is largely based on observing the final near-equilibrium condensate state. Despite expectations from classical nucleation theory, pre-critical protein clusters were recently shown to form under subsaturation conditions in vitro; if similar long-lived clusters comprising more than a few molecules are also present in cells, our understanding of the physical basis of biological phase separation may fundamentally change. Here, we combine fluorescence microscopy with photobleaching analysis to quantify the formation of clusters of NELF proteins in living, stressed cells. We categorise small and large clusters based on their dynamics and their response to p38 kinase inhibition. We find a broad distribution of pre-condensate cluster sizes and show that NELF protein cluster formation can be explained as non-classical nucleation with a surprisingly flat free-energy landscape for a wide range of sizes and an inhibition of condensation in unstressed cells.
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Affiliation(s)
- Chenyang Lan
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
- BIOSS and CIBSS Signalling Research Centres, University of Freiburg, Freiburg, Germany
- PicoQuant GmbH, Rudower Chaussee 29, 12489, Berlin, Germany
| | - Juhyeong Kim
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Svenja Ulferts
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
| | | | - Sophie Weyrauch
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
- Faculty of Chemistry and Pharmacology, University of Freiburg, Freiburg, Germany
| | | | - Robert Grosse
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
| | - Ritwick Sawarkar
- Medical Research Council (MRC), University of Cambridge, Cambridge, CB2 1QR, United Kingdom
| | - Aleks Reinhardt
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, United Kingdom.
| | - Thorsten Hugel
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany.
- BIOSS and CIBSS Signalling Research Centres, University of Freiburg, Freiburg, Germany.
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31
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Toledo PL, Gianotti AR, Vazquez DS, Ermácora MR. Protein nanocondensates: the next frontier. Biophys Rev 2023; 15:515-530. [PMID: 37681092 PMCID: PMC10480383 DOI: 10.1007/s12551-023-01105-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 07/21/2023] [Indexed: 09/09/2023] Open
Abstract
Over the past decade, myriads of studies have highlighted the central role of protein condensation in subcellular compartmentalization and spatiotemporal organization of biological processes. Conceptually, protein condensation stands at the highest level in protein structure hierarchy, accounting for the assembly of bodies ranging from thousands to billions of molecules and for densities ranging from dense liquids to solid materials. In size, protein condensates range from nanocondensates of hundreds of nanometers (mesoscopic clusters) to phase-separated micron-sized condensates. In this review, we focus on protein nanocondensation, a process that can occur in subsaturated solutions and can nucleate dense liquid phases, crystals, amorphous aggregates, and fibers. We discuss the nanocondensation of proteins in the light of general physical principles and examine the biophysical properties of several outstanding examples of nanocondensation. We conclude that protein nanocondensation cannot be fully explained by the conceptual framework of micron-scale biomolecular condensation. The evolution of nanocondensates through changes in density and order is currently under intense investigation, and this should lead to the development of a general theoretical framework, capable of encompassing the full range of sizes and densities found in protein condensates.
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Affiliation(s)
- Pamela L. Toledo
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, 1876, Bernal, Buenos Aires, Argentina
- Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Bernal, Argentina
| | - Alejo R. Gianotti
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, 1876, Bernal, Buenos Aires, Argentina
- Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Bernal, Argentina
| | - Diego S. Vazquez
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, 1876, Bernal, Buenos Aires, Argentina
- Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Bernal, Argentina
| | - Mario R. Ermácora
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, 1876, Bernal, Buenos Aires, Argentina
- Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Bernal, Argentina
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32
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Thirumalai D, Kumar A, Chakraborty D, Straub JE, Mugnai ML. Conformational Fluctuations and Phases in Fused in Sarcoma (FUS) Low-Complexity Domain. ARXIV 2023:arXiv:2303.04215v2. [PMID: 36945688 PMCID: PMC10029050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
The well known phenomenon of phase separation in synthetic polymers and proteins has become a major topic in biophysics because it has been invoked as a mechanism of compartment formation in cells, without the need for membranes. Most of the coacervates (or condensates) are composed of Intrinsically Disordered Proteins (IDPs) or regions that are structureless, often in interaction with RNA and DNA. One of the more intriguing IDPs is the 526-residue RNA binding protein, Fused In Sarcoma (FUS), whose monomer conformations and condensates exhibit unusual behavior that are sensitive to solution conditions. By focussing principally on the N-terminus low complexity domain (FUS-LC comprising residues 1-214) and other truncations, we rationalize the findings of solid state NMR experiments, which show that FUS-LC adopts a non-polymorphic fibril (core-1) involving residues 39-95, flanked by fuzzy coats on both the N- and C- terminal ends. An alternate structure (core-2), whose free energy is comparable to core-1, emerges only in the truncated construct (residues 110-214). Both core-1 and core-2 fibrils are stabilized by a Tyrosine ladder as well as hydrophilic interactions. The morphologies (gels, fibrils, and glass-like behavior) adopted by FUS seem to vary greatly, depending on the experimental conditions. The effect of phosphorylation is site specific and affects the stability of the fibril depending on the sites that are phosphorylated. Many of the peculiarities associated with FUS may also be shared by other IDPs, such as TDP43 and hnRNPA2. We outline a number of problems for which there is no clear molecular understanding.
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Affiliation(s)
- D Thirumalai
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712
- Department of Physics, The University of Texas at Austin, Austin, TX 78712
| | - Abhinaw Kumar
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712
| | - Debayan Chakraborty
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712
| | - John E Straub
- Department of Chemistry, Boston University, Boston, MA 78712
| | - Mauro L Mugnai
- Institute of Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057
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Galagedera SKK, Dao TP, Enos SE, Chaudhuri A, Schmit JD, Castañeda CA. Decoding optimal ligand design for multicomponent condensates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.13.532222. [PMID: 36993708 PMCID: PMC10054939 DOI: 10.1101/2023.03.13.532222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Biomolecular condensates form via multivalent interactions among key macromolecules and are regulated through ligand binding and/or post-translational modifications. One such modification is ubiquitination, the covalent addition of ubiquitin (Ub) or polyubiquitin chains to target macromolecules for various cellular processes. Specific interactions between polyubiquitin chains and partner proteins, including hHR23B, NEMO, and UBQLN2, regulate condensate assembly or disassembly. Here, we used a library of designed polyubiquitin hubs and UBQLN2 as model systems for determining the driving forces of ligand-mediated phase transitions. Perturbations to the UBQLN2-binding surface of Ub or deviations from the optimal spacing between Ub units reduce the ability of hubs to modulate UBQLN2 phase behavior. By developing an analytical model that accurately described the effects of different hubs on UBQLN2 phase diagrams, we determined that introduction of Ub to UBQLN2 condensates incurs a significant inclusion energetic penalty. This penalty antagonizes the ability of polyUb hubs to scaffold multiple UBQLN2 molecules and cooperatively amplify phase separation. Importantly, the extent to which polyubiquitin hubs can promote UBQLN2 phase separation are encoded in the spacings between Ub units as found for naturally-occurring chains of different linkages and designed chains of different architectures, thus illustrating how the ubiquitin code regulates functionality via the emergent properties of the condensate. We expect our findings to extend to other condensates necessitating the consideration of ligand properties, including concentration, valency, affinity, and spacing between binding sites in studies and designs of condensates.
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Affiliation(s)
| | - Thuy P. Dao
- Departments of Biology and Chemistry, Syracuse University, Syracuse, NY 13244, USA
| | - Suzanne E. Enos
- Departments of Biology and Chemistry, Syracuse University, Syracuse, NY 13244, USA
| | - Antara Chaudhuri
- Departments of Biology and Chemistry, Syracuse University, Syracuse, NY 13244, USA
| | - Jeremy D. Schmit
- Department of Physics, Kansas State University, Manhattan, KS 66506, USA
| | - Carlos A. Castañeda
- Departments of Biology and Chemistry, Syracuse University, Syracuse, NY 13244, USA
- Interdisciplinary Neuroscience Program, Syracuse University, Syracuse, NY 13244, USA
- BioInspired Institute, Syracuse University, Syracuse, NY 13244, USA
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Charman M, Grams N, Kumar N, Halko E, Dybas JM, Abbott A, Lum KK, Blumenthal D, Tsopurashvili E, Weitzman MD. A viral biomolecular condensate coordinates assembly of progeny particles. Nature 2023; 616:332-338. [PMID: 37020020 DOI: 10.1038/s41586-023-05887-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 02/24/2023] [Indexed: 04/07/2023]
Abstract
Biomolecular condensates formed by phase separation can compartmentalize and regulate cellular processes1,2. Emerging evidence has suggested that membraneless subcellular compartments in virus-infected cells form by phase separation3-8. Although linked to several viral processes3-5,9,10, evidence that phase separation contributes functionally to the assembly of progeny particles in infected cells is lacking. Here we show that phase separation of the human adenovirus 52-kDa protein has a critical role in the coordinated assembly of infectious progeny particles. We demonstrate that the 52-kDa protein is essential for the organization of viral structural proteins into biomolecular condensates. This organization regulates viral assembly such that capsid assembly is coordinated with the provision of viral genomes needed to produce complete packaged particles. We show that this function is governed by the molecular grammar of an intrinsically disordered region of the 52-kDa protein, and that failure to form condensates or to recruit viral factors that are critical for assembly results in failed packaging and assembly of only non-infectious particles. Our findings identify essential requirements for coordinated assembly of progeny particles and demonstrate that phase separation of a viral protein is critical for production of infectious progeny during adenovirus infection.
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Affiliation(s)
- Matthew Charman
- Division of Protective Immunity, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
- Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - Nicholas Grams
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Namrata Kumar
- Division of Protective Immunity, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Edwin Halko
- Division of Protective Immunity, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Joseph M Dybas
- Division of Protective Immunity, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Biomedical and Health Informatics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Amber Abbott
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Krystal K Lum
- Division of Protective Immunity, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Daniel Blumenthal
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Division of Cell Pathology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - Matthew D Weitzman
- Division of Protective Immunity, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
- Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Penn Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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35
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Digby ZA, Chen Y, Akkaoui K, Schlenoff JB. Bulk Biopolyelectrolyte Complexes from Homopolypeptides: Solid "Salt Bridges". Biomacromolecules 2023; 24:1453-1462. [PMID: 36753621 DOI: 10.1021/acs.biomac.2c01456] [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: 02/10/2023]
Abstract
Salt bridges, pairings between oppositely charged amino acids, are dispersed throughout proteins to assist folding and interactions. Biopolyelectrolyte complexes (BioPECs) were made between the homopolypeptides poly-l-arginine (PLR) and poly-l-lysine (PLK) with sodium triphosphate (STPP), as well as from polypeptide-only combinations. Viscoelastic measurements on these high salt bridge density materials showed many were solid, even glassy, in nature. Although the polypeptide-phosphate complexes had similar moduli at room temperature, the PLR-STPP complex displayed an unusual melting event above 70 °C not seen in PLK-STPP. This event was supported with differential scanning calorimetry. Infrared spectroscopy showed the PLK-STPP system contained β-sheets, while PLR-STPP did not. Stoichiometric, macroscopic BioPECs of PLR and PLK with poly-l-aspartic acid (PLD) and poly-l-glutamic acid (PLE) were made. PLR-PLD was found to undergo a melting event similar to that in PLR-STPP. ATR-FTIR studies showed that BioPECs made with PLD do not contain β-sheets, while those composed of PLE do. This work illustrates an expanded palette of unique properties from these biomaterials, such as strong viscoelastic differences between PECs containing PLE and PLD, even though they differ by only one carbon on the side chain.
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Affiliation(s)
- Zachary A Digby
- Department of Chemistry and Biochemistry The Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Yuhui Chen
- Department of Chemistry and Biochemistry The Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Khalil Akkaoui
- Department of Chemistry and Biochemistry The Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Joseph B Schlenoff
- Department of Chemistry and Biochemistry The Florida State University, Tallahassee, Florida 32306-4390, United States
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Escudero-Pérez B, Lalande A, Mathieu C, Lawrence P. Host–Pathogen Interactions Influencing Zoonotic Spillover Potential and Transmission in Humans. Viruses 2023; 15:v15030599. [PMID: 36992308 PMCID: PMC10060007 DOI: 10.3390/v15030599] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/13/2023] [Accepted: 02/20/2023] [Indexed: 02/24/2023] Open
Abstract
Emerging infectious diseases of zoonotic origin are an ever-increasing public health risk and economic burden. The factors that determine if and when an animal virus is able to spill over into the human population with sufficient success to achieve ongoing transmission in humans are complex and dynamic. We are currently unable to fully predict which pathogens may appear in humans, where and with what impact. In this review, we highlight current knowledge of the key host–pathogen interactions known to influence zoonotic spillover potential and transmission in humans, with a particular focus on two important human viruses of zoonotic origin, the Nipah virus and the Ebola virus. Namely, key factors determining spillover potential include cellular and tissue tropism, as well as the virulence and pathogenic characteristics of the pathogen and the capacity of the pathogen to adapt and evolve within a novel host environment. We also detail our emerging understanding of the importance of steric hindrance of host cell factors by viral proteins using a “flytrap”-type mechanism of protein amyloidogenesis that could be crucial in developing future antiviral therapies against emerging pathogens. Finally, we discuss strategies to prepare for and to reduce the frequency of zoonotic spillover occurrences in order to minimize the risk of new outbreaks.
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Affiliation(s)
- Beatriz Escudero-Pérez
- WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Luebeck-Borstel-Reims, 38124 Braunschweig, Germany
| | - Alexandre Lalande
- CIRI (Centre International de Recherche en Infectiologie), Team Neuro-Invasion, TROpism and VIRal Encephalitis, INSERM U1111, CNRS UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France
| | - Cyrille Mathieu
- CIRI (Centre International de Recherche en Infectiologie), Team Neuro-Invasion, TROpism and VIRal Encephalitis, INSERM U1111, CNRS UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France
| | - Philip Lawrence
- CONFLUENCE: Sciences et Humanités (EA 1598), Université Catholique de Lyon (UCLy), 69002 Lyon, France
- Correspondence:
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Chew PY, Joseph JA, Collepardo-Guevara R, Reinhardt A. Thermodynamic origins of two-component multiphase condensates of proteins. Chem Sci 2023; 14:1820-1836. [PMID: 36819870 PMCID: PMC9931050 DOI: 10.1039/d2sc05873a] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/06/2023] [Indexed: 01/26/2023] Open
Abstract
Intracellular condensates are highly multi-component systems in which complex phase behaviour can ensue, including the formation of architectures comprising multiple immiscible condensed phases. Relying solely on physical intuition to manipulate such condensates is difficult because of the complexity of their composition, and systematically learning the underlying rules experimentally would be extremely costly. We address this challenge by developing a computational approach to design pairs of protein sequences that result in well-separated multilayered condensates and elucidate the molecular origins of these compartments. Our method couples a genetic algorithm to a residue-resolution coarse-grained protein model. We demonstrate that we can design protein partners to form multiphase condensates containing naturally occurring proteins, such as the low-complexity domain of hnRNPA1 and its mutants, and show how homo- and heterotypic interactions must differ between proteins to result in multiphasicity. We also show that in some cases the specific pattern of amino-acid residues plays an important role. Our findings have wide-ranging implications for understanding and controlling the organisation, functions and material properties of biomolecular condensates.
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Affiliation(s)
- Pin Yu Chew
- Yusuf Hamied Department of Chemistry, University of Cambridge Cambridge CB2 1EW UK
| | - Jerelle A Joseph
- Yusuf Hamied Department of Chemistry, University of Cambridge Cambridge CB2 1EW UK
- Department of Physics, University of Cambridge Cambridge CB3 0HE UK
- Department of Genetics, University of Cambridge Cambridge CB2 3EH UK
| | - Rosana Collepardo-Guevara
- Yusuf Hamied Department of Chemistry, University of Cambridge Cambridge CB2 1EW UK
- Department of Physics, University of Cambridge Cambridge CB3 0HE UK
- Department of Genetics, University of Cambridge Cambridge CB2 3EH UK
| | - Aleks Reinhardt
- Yusuf Hamied Department of Chemistry, University of Cambridge Cambridge CB2 1EW UK
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Duan G, Li Y, Ye M, Liu H, Wang N, Luo S. The Regulatory Mechanism of Transthyretin Irreversible Aggregation through Liquid-to-Solid Phase Transition. Int J Mol Sci 2023; 24:ijms24043729. [PMID: 36835140 PMCID: PMC9960511 DOI: 10.3390/ijms24043729] [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: 12/30/2022] [Revised: 02/05/2023] [Accepted: 02/07/2023] [Indexed: 02/17/2023] Open
Abstract
Transthyretin (TTR) aggregation and amyloid formation are associated with several ATTR diseases, such as senile systemic amyloidosis (SSA) and familial amyloid polyneuropathy (FAP). However, the mechanism that triggers the initial pathologic aggregation process of TTR remains largely elusive. Lately, increasing evidence has suggested that many proteins associated with neurodegenerative diseases undergo liquid-liquid phase separation (LLPS) and subsequent liquid-to-solid phase transition before the formation of amyloid fibrils. Here, we demonstrate that electrostatic interactions mediate LLPS of TTR, followed by a liquid-solid phase transition, and eventually the formation of amyloid fibrils under a mildly acidic pH in vitro. Furthermore, pathogenic mutations (V30M, R34T, and K35T) of TTR and heparin promote the process of phase transition and facilitate the formation of fibrillar aggregates. In addition, S-cysteinylation, which is a kind of post-translational modification of TTR, reduces the kinetic stability of TTR and increases the propensity for aggregation, while another modification, S-sulfonation, stabilizes the TTR tetramer and reduces the aggregation rate. Once TTR was S-cysteinylated or S-sulfonated, they dramatically underwent the process of phase transition, providing a foundation for post-translational modifications that could modulate TTR LLPS in the context of pathological interactions. These novel findings reveal molecular insights into the mechanism of TTR from initial LLPS and subsequent liquid-to-solid phase transition to amyloid fibrils, providing a new dimension for ATTR therapy.
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Shillcock JC, Thomas DB, Ipsen JH, Brown AD. Macromolecular Crowding Is Surprisingly Unable to Deform the Structure of a Model Biomolecular Condensate. BIOLOGY 2023; 12:181. [PMID: 36829460 PMCID: PMC9952705 DOI: 10.3390/biology12020181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/27/2023]
Abstract
The crowded interior of a living cell makes performing experiments on simpler in vitro systems attractive. Although these reveal interesting phenomena, their biological relevance can be questionable. A topical example is the phase separation of intrinsically disordered proteins into biomolecular condensates, which is proposed to underlie the membrane-less compartmentalization of many cellular functions. How a cell reliably controls biochemical reactions in compartments open to the compositionally-varying cytoplasm is an important question for understanding cellular homeostasis. Computer simulations are often used to study the phase behavior of model biomolecular condensates, but the number of relevant parameters increases as the number of protein components increases. It is unfeasible to exhaustively simulate such models for all parameter combinations, although interesting phenomena are almost certainly hidden in their high-dimensional parameter space. Here, we have studied the phase behavior of a model biomolecular condensate in the presence of a polymeric crowding agent. We used a novel compute framework to execute dozens of simultaneous simulations spanning the protein/crowder concentration space. We then combined the results into a graphical representation for human interpretation, which provided an efficient way to search the model's high-dimensional parameter space. We found that steric repulsion from the crowder drives a near-critical system across the phase boundary, but the molecular arrangement within the resulting biomolecular condensate is rather insensitive to the crowder concentration and molecular weight. We propose that a cell may use the local cytoplasmic concentration to assist the formation of biomolecular condensates, while relying on the dense phase to reliably provide a stable, structured, fluid milieu for cellular biochemistry despite being open to its changing environment.
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Affiliation(s)
- Julian C. Shillcock
- Blue Brain Project and Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - David B. Thomas
- Department of Electronics and Computer Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - John H. Ipsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Andrew D. Brown
- Department of Electronics and Computer Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK
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Chew PY, Reinhardt A. Phase diagrams-Why they matter and how to predict them. J Chem Phys 2023; 158:030902. [PMID: 36681642 DOI: 10.1063/5.0131028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Understanding the thermodynamic stability and metastability of materials can help us to, for example, gauge whether crystalline polymorphs in pharmaceutical formulations are likely to be durable. It can also help us to design experimental routes to novel phases with potentially interesting properties. In this Perspective, we provide an overview of how thermodynamic phase behavior can be quantified both in computer simulations and machine-learning approaches to determine phase diagrams, as well as combinations of the two. We review the basic workflow of free-energy computations for condensed phases, including some practical implementation advice, ranging from the Frenkel-Ladd approach to thermodynamic integration and to direct-coexistence simulations. We illustrate the applications of such methods on a range of systems from materials chemistry to biological phase separation. Finally, we outline some challenges, questions, and practical applications of phase-diagram determination which we believe are likely to be possible to address in the near future using such state-of-the-art free-energy calculations, which may provide fundamental insight into separation processes using multicomponent solvents.
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Affiliation(s)
- Pin Yu Chew
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Aleks Reinhardt
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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Ginell GM, Holehouse AS. An Introduction to the Stickers-and-Spacers Framework as Applied to Biomolecular Condensates. Methods Mol Biol 2023; 2563:95-116. [PMID: 36227469 DOI: 10.1007/978-1-0716-2663-4_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Cellular organization is determined by a combination of membrane-bound and membrane-less biomolecular assemblies that range from clusters of tens of molecules to micrometer-sized cellular bodies. Over the last decade, membrane-less assemblies have come to be referred to as biomolecular condensates, reflecting their ability to condense specific molecules with respect to the remainder of the cell. In many cases, the physics of phase transitions provides a conceptual framework and a mathematical toolkit to describe the assembly, maintenance, and dissolution of biomolecular condensates. Among the various quantitative and qualitative models applied to understand intracellular phase transitions, the stickers-and-spacers framework offers an intuitive yet rigorous means to map biomolecular sequences and structure to the driving forces needed for higher-order assembly. This chapter introduces the fundamental concepts behind the stickers-and-spacers model, considers its application to different biological systems, and discusses limitations and misconceptions around the model.
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Affiliation(s)
- Garrett M Ginell
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
- Center for Science & Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, MO, USA
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA.
- Center for Science & Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, MO, USA.
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42
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Laghmach R, Malhotra I, Potoyan DA. Multiscale Modeling of Protein-RNA Condensation in and Out of Equilibrium. Methods Mol Biol 2023; 2563:117-133. [PMID: 36227470 PMCID: PMC11186142 DOI: 10.1007/978-1-0716-2663-4_5] [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] [Indexed: 06/16/2023]
Abstract
A vast number of intracellular membraneless bodies also known as biomolecular condensates form through a liquid-liquid phase separation (LLPS) of biomolecules. To date, phase separation has been identified as the main driving force for a membraneless organelles such as nucleoli, Cajal bodies, stress granules, and chromatin compartments. Recently, the protein-RNA condensation is receiving increased attention, because it is closely related to the biological function of cells such as transcription, translation, and RNA metabolism. Despite the multidisciplinary efforts put forth to study the biophysical properties of protein-RNA condensates, there are many fundamental unanswered questions regarding the mechanism of formation and regulation of protein-RNA condensates in eukaryotic cells. Major challenges in studying protein-RNA condensation stem from (i) the molecular heterogeneity and conformational flexibility of RNA and protein chains and (ii) the nonequilibrium nature of transcription and cellular environment. Computer simulations, bioinformatics, and mathematical models are uniquely positioned for shedding light on the microscopic nature of protein-RNA phase separation. To this end, there is an urgent need for innovative models with the right spatiotemporal resolution for confronting the experimental observables in a comprehensive and physics-based manner. In this chapter, we will summarize the currently emerging research efforts, which employ atomistic and coarse-grained molecular models and field theoretical models to understand equilibrium and nonequilibrium aspects of protein-RNA condensation.
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Affiliation(s)
- Rabia Laghmach
- Department of Chemistry, Iowa State University, Ames, IA, USA
| | - Isha Malhotra
- Department of Chemistry, Iowa State University, Ames, IA, USA
| | - Davit A Potoyan
- Department of Chemistry, Iowa State University, Ames, IA, USA.
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43
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Mahato J, Ray S, Maji SK, Chowdhury A. Spectrally Resolved FRET Microscopy of α-Synuclein Phase-Separated Liquid Droplets. Methods Mol Biol 2023; 2551:425-447. [PMID: 36310218 DOI: 10.1007/978-1-0716-2597-2_27] [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] [Indexed: 06/16/2023]
Abstract
Liquid-liquid phase separation (LLPS) has emerged as an important phenomenon associated with formation of membraneless organelles. Recently, LLPS has been shown to act as nucleation centers for disease-associated protein aggregation and amyloid fibril formation. Phase-separated α-synuclein droplets gradually rigidify during the course of protein aggregation, and it is very challenging to understand the biomolecular interactions that lead to liquid-like to solid-like transition using conventional ensemble measurements. Here, we describe a spectrally-resolved fluorescence microscopy based Förster resonance energy transfer (FRET) imaging to probe interactions of α-synuclein in individual droplets during LLPS-mediated aggregation. By acquiring entire emission spectral profiles of individual droplets upon sequential excitation of acceptors and donors therein, this technique allows for the quantification of sensitized emission proportional to the extent of FRET, which enables interrogation of the evolution of local interactions of donor-/acceptor-labeled α-synuclein molecules within each droplet. The present study on single droplets is not only an important development for studying LLPS but can also be used to investigate self-assembly or aggregation in biomolecular systems and soft materials.
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Affiliation(s)
| | - Soumik Ray
- Department of Biosciences and Bioengineering, IIT Bombay, Mumbai, India
| | - Samir K Maji
- Department of Biosciences and Bioengineering, IIT Bombay, Mumbai, India.
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Ray S, Singh N, Patel K, Krishnamoorthy G, Maji SK. FRAP and FRET Investigation of α-Synuclein Fibrillization via Liquid-Liquid Phase Separation In Vitro and in HeLa Cells. Methods Mol Biol 2023; 2551:395-423. [PMID: 36310217 DOI: 10.1007/978-1-0716-2597-2_26] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Liquid-liquid phase separation (LLPS) acts as an important biological phenomenon in membraneless organelle formation. These phase-separated bodies can also act as nucleation centers for disease-associated amyloid formation. Fluorescence recovery after photobleaching (FRAP) is a crucial technique to analyze the material property (liquid or solid) of protein LLPS. On the other hand, Förster resonance energy transfer (FRET) is used to understand the domain-specific involvement (intermolecular interactions) of protein molecules inside the phase-separated droplets. In this protocol, we delineate mechanisms of liquid-to-solid transition of α-synuclein LLPS by using in vitro and in cell FRAP as well as in vitro FRET techniques.
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Affiliation(s)
- Soumik Ray
- Department of Biosciences and Bioengineering, IIT Bombay, Mumbai, India
| | - Nitu Singh
- Department of Biosciences and Bioengineering, IIT Bombay, Mumbai, India
| | - Komal Patel
- Department of Biosciences and Bioengineering, IIT Bombay, Mumbai, India
| | | | - Samir K Maji
- Department of Biosciences and Bioengineering, IIT Bombay, Mumbai, India.
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Functional benefit of structural disorder for the replication of measles, Nipah and Hendra viruses. Essays Biochem 2022; 66:915-934. [PMID: 36148633 DOI: 10.1042/ebc20220045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/18/2022] [Accepted: 08/25/2022] [Indexed: 12/24/2022]
Abstract
Measles, Nipah and Hendra viruses are severe human pathogens within the Paramyxoviridae family. Their non-segmented, single-stranded, negative-sense RNA genome is encapsidated by the nucleoprotein (N) within a helical nucleocapsid that is the substrate used by the viral RNA-dependent-RNA-polymerase (RpRd) for transcription and replication. The RpRd is a complex made of the large protein (L) and of the phosphoprotein (P), the latter serving as an obligate polymerase cofactor and as a chaperon for N. Both the N and P proteins are enriched in intrinsically disordered regions (IDRs), i.e. regions devoid of stable secondary and tertiary structure. N possesses a C-terminal IDR (NTAIL), while P consists of a large, intrinsically disordered N-terminal domain (NTD) and a C-terminal domain (CTD) encompassing alternating disordered and ordered regions. The V and W proteins, two non-structural proteins that are encoded by the P gene via a mechanism of co-transcriptional edition of the P mRNA, are prevalently disordered too, sharing with P the disordered NTD. They are key players in the evasion of the host antiviral response and were shown to phase separate and to form amyloid-like fibrils in vitro. In this review, we summarize the available information on IDRs within the N, P, V and W proteins from these three model paramyxoviruses and describe their molecular partnership. We discuss the functional benefit of disorder to virus replication in light of the critical role of IDRs in affording promiscuity, multifunctionality, fine regulation of interaction strength, scaffolding functions and in promoting liquid-liquid phase separation and fibrillation.
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Rajeev P, Singh N, Kechkar A, Butler C, Ramanan N, Sibarita JB, Jose M, Nair D. Nanoscale regulation of Ca2+ dependent phase transitions and real-time dynamics of SAP97/hDLG. Nat Commun 2022; 13:4236. [PMID: 35869063 PMCID: PMC9307800 DOI: 10.1038/s41467-022-31912-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 07/08/2022] [Indexed: 11/20/2022] Open
Abstract
Synapse associated protein-97/Human Disk Large (SAP97/hDLG) is a conserved, alternatively spliced, modular, scaffolding protein critical in regulating the molecular organization of cell-cell junctions in vertebrates. We confirm that the molecular determinants of first order phase transition of SAP97/hDLG is controlled by morpho-functional changes in its nanoscale organization. Furthermore, the nanoscale molecular signatures of these signalling islands and phase transitions are altered in response to changes in cytosolic Ca2+. Additionally, exchange kinetics of alternatively spliced isoforms of the intrinsically disordered region in SAP97/hDLG C-terminus shows differential sensitivities to Ca2+ bound Calmodulin, affirming that the molecular signatures of local phase transitions of SAP97/hDLG depends on their nanoscale heterogeneity and compositionality of isoforms. SAP97/hDLG is a ubiquitous, alternatively spliced, and conserved modular scaffolding protein involved in the organization cell junctions and excitatory synapses. Here, authors confirm that SAP97/hDLG condenses in to nanosized molecular domains in both heterologous cells and hippocampal pyramidal neurons. Authors demonstrate that in vivo and in vitro condensation, molecular signatures of nanoscale condensates and exchange kinetics of SAP97/hDLG is modulated by the local availability of alternatively spliced isoforms. Additionally, SAP97/hDLG isoforms exhibits a differential sensitivity to Ca2+ bound Calmodulin, resulting in altered properties of nanocondensates and their real-time regulation
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Murata Y, Niina T, Takada S. The stoichiometric interaction model for mesoscopic MD simulations of liquid-liquid phase separation. Biophys J 2022; 121:4382-4393. [PMID: 36199253 PMCID: PMC9703007 DOI: 10.1016/j.bpj.2022.10.001] [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: 03/11/2022] [Revised: 06/28/2022] [Accepted: 09/30/2022] [Indexed: 12/14/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) has received considerable attention in recent years for explaining the formation of cellular biomolecular condensates. The fluidity and the complexity of their components make molecular simulation approaches indispensable for gaining structural insights. Domain-resolution mesoscopic model simulations have been explored for cases in which condensates are formed by multivalent proteins with tandem domains. One problem with this approach is that interdomain pairwise interactions cannot regulate the valency of the binding domains. To overcome this problem, we propose a new potential, the stoichiometric interaction (SI) potential. First, we verified that the SI potential maintained the valency of the interacting domains for the test systems. We then examined a well-studied LLPS model system containing tandem repeats of SH3 domains and proline-rich motifs. We found that the SI potential alone cannot reproduce the phase diagram of LLPS quantitatively. We had to combine the SI and a pairwise interaction; the former and the latter represent the specific and nonspecific interactions, respectively. Biomolecular condensates with the mixed SI and pairwise interaction exhibited fluidity, whereas those with the pairwise interaction alone showed no detectable diffusion. We also compared the phase diagrams of the systems containing different numbers of tandem domains with those obtained from the experiments and found quantitative agreement in all but one case.
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Affiliation(s)
- Yutaka Murata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Toru Niina
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.
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Mitrea DM, Mittasch M, Gomes BF, Klein IA, Murcko MA. Modulating biomolecular condensates: a novel approach to drug discovery. Nat Rev Drug Discov 2022; 21:841-862. [PMID: 35974095 PMCID: PMC9380678 DOI: 10.1038/s41573-022-00505-4] [Citation(s) in RCA: 89] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2022] [Indexed: 12/12/2022]
Abstract
In the past decade, membraneless assemblies known as biomolecular condensates have been reported to play key roles in many cellular functions by compartmentalizing specific proteins and nucleic acids in subcellular environments with distinct properties. Furthermore, growing evidence supports the view that biomolecular condensates often form by phase separation, in which a single-phase system demixes into a two-phase system consisting of a condensed phase and a dilute phase of particular biomolecules. Emerging understanding of condensate function in normal and aberrant cellular states, and of the mechanisms of condensate formation, is providing new insights into human disease and revealing novel therapeutic opportunities. In this Perspective, we propose that such insights could enable a previously unexplored drug discovery approach based on identifying condensate-modifying therapeutics (c-mods), and we discuss the strategies, techniques and challenges involved.
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Bremer A, Posey AE, Borgia MB, Borcherds WM, Farag M, Pappu RV, Mittag T. Quantifying Coexistence Concentrations in Multi-Component Phase-Separating Systems Using Analytical HPLC. Biomolecules 2022; 12:biom12101480. [PMID: 36291688 PMCID: PMC9599810 DOI: 10.3390/biom12101480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 09/30/2022] [Accepted: 10/03/2022] [Indexed: 11/28/2022] Open
Abstract
Over the last decade, evidence has accumulated to suggest that numerous instances of cellular compartmentalization can be explained by the phenomenon of phase separation. This is a process by which a macromolecular solution separates spontaneously into dense and dilute coexisting phases. Semi-quantitative, in vitro approaches for measuring phase boundaries have proven very useful in determining some key features of biomolecular condensates, but these methods often lack the precision necessary for generating quantitative models. Therefore, there is a clear need for techniques that allow quantitation of coexisting dilute and dense phase concentrations of phase-separating biomolecules, especially in systems with more than one type of macromolecule. Here, we report the design and deployment of analytical High-Performance Liquid Chromatography (HPLC) for in vitro separation and quantification of distinct biomolecules that allows us to measure dilute and dense phase concentrations needed to reconstruct coexistence curves in multicomponent mixtures. This approach is label-free, detects lower amounts of material than is accessible with classic UV-spectrophotometers, is applicable to a broad range of macromolecules of interest, is a semi-high-throughput technique, and if needed, the macromolecules can be recovered for further use. The approach promises to provide quantitative insights into the balance of homotypic and heterotypic interactions in multicomponent phase-separating systems.
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Affiliation(s)
- Anne Bremer
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Ammon E. Posey
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Madeleine B. Borgia
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Wade M. Borcherds
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Mina Farag
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Rohit V. Pappu
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
- Correspondence: (R.V.P.); (T.M.)
| | - Tanja Mittag
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
- Correspondence: (R.V.P.); (T.M.)
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Zhang Y, Liu X, Chen J. Toward Accurate Coarse-Grained Simulations of Disordered Proteins and Their Dynamic Interactions. J Chem Inf Model 2022; 62:4523-4536. [PMID: 36083825 PMCID: PMC9910785 DOI: 10.1021/acs.jcim.2c00974] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intrinsically disordered proteins (IDPs) play crucial roles in cellular regulatory networks and are now recognized to often remain highly dynamic even in specific interactions and assemblies. Accurate description of these dynamic interactions is extremely challenging using atomistic simulations because of the prohibitive computational cost. Efficient coarse-grained approaches could offer an effective solution to overcome this bottleneck if they could provide an accurate description of key local and global properties of IDPs in both unbound and bound states. The recently developed hybrid-resolution (HyRes) protein model has been shown to be capable of providing a semiquantitative description of the secondary structure propensities of IDPs. Here, we show that greatly improved description of global structures and transient interactions can be achieved by introducing a solvent-accessible surface area-based implicit solvent term followed by reoptimization of effective interaction strengths. The new model, termed HyRes II, can semiquantitatively reproduce a wide range of local and global structural properties of a set of IDPs of various lengths and complexities. It can also distinguish the level of compaction between folded proteins and IDPs. In particular, applied to the disordered N-terminal transactivation domain (TAD) of tumor suppressor p53, HyRes II is able to recapitulate various nontrivial structural properties compared to experimental results, some of them to a level of accuracy that is almost comparable to results from atomistic explicit solvent simulations. Furthermore, we demonstrate that HyRes II can be used to simulate the dynamic interactions of TAD with the DNA-binding domain of p53, generating structural ensembles that are highly consistent with existing NMR data. We anticipate that HyRes II will provide an efficient and relatively reliable tool toward accurate coarse-grained simulations of dynamic protein interactions.
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Affiliation(s)
- Yumeng Zhang
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Xiaorong Liu
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
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