1
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Kang HW, Nguyen L, An S, Kyoung M. Mechanistic insights into condensate formation of human liver-type phosphofructokinase by stochastic modeling approaches. Sci Rep 2024; 14:19011. [PMID: 39152221 PMCID: PMC11329711 DOI: 10.1038/s41598-024-69534-w] [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: 10/05/2023] [Accepted: 08/06/2024] [Indexed: 08/19/2024] Open
Abstract
Human liver-type phosphofructokinase 1 (PFKL) has been shown to regulate glucose flux as a scaffolder arranging glycolytic and gluconeogenic enzymes into a multienzyme metabolic condensate, the glucosome. However, it has remained elusive of how phase separation of PFKL is governed and initiates glucosome formation in living cells, thus hampering to understand a mechanism of glucosome formation and its functional contribution to human cells. In this work, we developed a stochastic model in silico using the principle of Langevin dynamics to investigate how biological properties of PFKL contribute to the condensate formation. The significance of an intermolecular interaction between PFKLs, an effective concentration of PFKL at a region of interest, and its own self-assembled filaments in formation of PFKL condensates and control of their sizes were demonstrated by molecular dynamics simulation using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). Such biological properties that define intracellular dynamics of PFKL appear to be essential for phase separation of PFKL, which may represent an initiation step for the formation of glucosome condensates. Collectively, our computational study provides mechanistic insights of glucosome formation, particularly an initial stage through the formation of PFKL condensates in living human cells.
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Affiliation(s)
- Hye-Won Kang
- Department of Mathematics and Statistics, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD, 21250, USA.
| | - Luan Nguyen
- Department of Mathematics and Statistics, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD, 21250, USA
| | - Songon An
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD, 21250, USA
- Program in Oncology, Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland, Baltimore, MD, 21201, USA
| | - Minjoung Kyoung
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD, 21250, USA.
- Program in Oncology, Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland, Baltimore, MD, 21201, USA.
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2
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Geng Q, Keya JJ, Hotta T, Verhey KJ. The kinesin-3 KIF1C undergoes liquid-liquid phase separation for accumulation of specific transcripts at the cell periphery. EMBO J 2024; 43:3192-3213. [PMID: 38898313 PMCID: PMC11294625 DOI: 10.1038/s44318-024-00147-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/30/2024] [Accepted: 05/17/2024] [Indexed: 06/21/2024] Open
Abstract
In cells, mRNAs are transported to and positioned at subcellular areas to locally regulate protein production. Recent studies have identified the kinesin-3 family member motor protein KIF1C as an RNA transporter. However, it is not clear how KIF1C interacts with RNA molecules. Here, we show that the KIF1C C-terminal tail domain contains an intrinsically disordered region (IDR) that drives liquid-liquid phase separation (LLPS). KIF1C forms dynamic puncta in cells that display physical properties of liquid condensates and incorporate RNA molecules in a sequence-selective manner. Endogenous KIF1C forms condensates in cellular protrusions, where mRNAs are enriched in an IDR-dependent manner. Purified KIF1C tail constructs undergo LLPS in vitro at near-endogenous nM concentrations and in the absence of crowding agents and can directly recruit RNA molecules. Overall, our work uncovers an intrinsic correlation between the LLPS activity of KIF1C and its role in mRNA positioning. In addition, the LLPS activity of KIF1C's tail represents a new mode of motor-cargo interaction that extends our current understanding of cytoskeletal motor proteins.
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Affiliation(s)
- Qi Geng
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Jakia Jannat Keya
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Takashi Hotta
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA.
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3
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Zheng LW, Liu CC, Yu KD. Phase separations in oncogenesis, tumor progressions and metastasis: a glance from hallmarks of cancer. J Hematol Oncol 2023; 16:123. [PMID: 38110976 PMCID: PMC10726551 DOI: 10.1186/s13045-023-01522-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 12/12/2023] [Indexed: 12/20/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) is a novel principle for interpreting precise spatiotemporal coordination in living cells through biomolecular condensate (BMC) formation via dynamic aggregation. LLPS changes individual molecules into membrane-free, droplet-like BMCs with specific functions, which coordinate various cellular activities. The formation and regulation of LLPS are closely associated with oncogenesis, tumor progressions and metastasis, the specific roles and mechanisms of LLPS in tumors still need to be further investigated at present. In this review, we comprehensively summarize the conditions of LLPS and identify mechanisms involved in abnormal LLPS in cancer processes, including tumor growth, metastasis, and angiogenesis from the perspective of cancer hallmarks. We have also reviewed the clinical applications of LLPS in oncologic areas. This systematic summary of dysregulated LLPS from the different dimensions of cancer hallmarks will build a bridge for determining its specific functions to further guide basic research, finding strategies to intervene in LLPS, and developing relevant therapeutic approaches.
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Affiliation(s)
- Le-Wei Zheng
- Department of Breast Surgery, Department of Oncology, Key Laboratory of Breast Cancer in Shanghai, Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Cui-Cui Liu
- Department of Breast Surgery, Department of Oncology, Key Laboratory of Breast Cancer in Shanghai, Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Ke-Da Yu
- Department of Breast Surgery, Department of Oncology, Key Laboratory of Breast Cancer in Shanghai, Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
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4
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Geng Q, Keya JJ, Hotta T, Verhey KJ. KIF1C, an RNA transporting kinesin-3, undergoes liquid-liquid phase separation through its C-terminal disordered domain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.23.563538. [PMID: 37961614 PMCID: PMC10634753 DOI: 10.1101/2023.10.23.563538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The spatial distribution of mRNA is critical for local control of protein production. Recent studies have identified the kinesin-3 family member KIF1C as an RNA transporter. However, it is not clear how KIF1C interacts with RNA molecules. Here, we show that KIF1C's C-terminal tail domain is an intrinsically disordered region (IDR) containing a prion-like domain (PLD) that is unique compared to the C-terminal tails of other kinesin family members. In cells, KIF1C constructs undergo reversible formation of dynamic puncta that display physical properties of liquid condensates and incorporate RNA molecules in a sequence-selective manner. The IDR is necessary and sufficient for driving liquid-liquid phase separation (LLPS) but the condensate properties can be modulated by adjacent coiled-coil segments. The purified KIF1C IDR domain undergoes LLPS in vitro at near-endogenous nM concentrations in a salt-dependent manner. Deletion of the IDR abolished the ability of KIF1C to undergo LLPS and disrupted the distribution of mRNA cargoes to the cell periphery. Our work thus uncovers an intrinsic correlation between the LLPS activity of KIF1C and its role as an RNA transporter. In addition, as the first kinesin motor reported to undergo LLPS, our work reveals a previously uncharacterized mode of motor-cargo interaction that extends our understanding of the behavior of cytoskeletal motor proteins.
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Affiliation(s)
- Qi Geng
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Jakia Jannat Keya
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Takashi Hotta
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
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5
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Jiao S, Li C, Guo F, Zhang J, Zhang H, Cao Z, Wang W, Bu W, Lin M, Lü J, Zhou Z. SUN1/2 controls macrophage polarization via modulating nuclear size and stiffness. Nat Commun 2023; 14:6416. [PMID: 37828059 PMCID: PMC10570371 DOI: 10.1038/s41467-023-42187-5] [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: 09/17/2022] [Accepted: 10/03/2023] [Indexed: 10/14/2023] Open
Abstract
Alteration of the size and stiffness of the nucleus triggered by environmental cues are thought to be important for eukaryotic cell fate and function. However, it remains unclear how context-dependent nuclear remodeling occurs and reprograms gene expression. Here we identify the nuclear envelope proteins SUN1/2 as mechano-regulators of the nucleus during M1 polarization of the macrophage. Specifically, we show that LPS treatment decreases the protein levels of SUN1/2 in a CK2-βTrCP-dependent manner to shrink and soften the nucleus, therefore altering the chromatin accessibility for M1-associated gene expression. Notably, the transmembrane helix of SUN1/2 is solely required and sufficient for the nuclear mechano-remodeling. Consistently, SUN1/2 depletion in macrophages facilitates their phagocytosis, tissue infiltration, and proinflammatory cytokine production, thereby boosting the antitumor immunity in mice. Thus, our study demonstrates that, in response to inflammatory cues, SUN1/2 proteins act as mechano-regulators to remodel the nucleus and chromatin for M1 polarization of the macrophage.
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Affiliation(s)
- Shi Jiao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China.
| | - Chuanchuan Li
- CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, 417 E 68th St, New York, NY, 10065, USA
| | - Fenghua Guo
- Department of General Surgery, Hua'shan Hospital, Fudan University Shanghai Medical College, Shanghai, 200040, China
| | - Jinjin Zhang
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Hui Zhang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China
| | - Zhifa Cao
- Department of Stomatology, Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Department of Biochemistry and Molecular Biology, Tongji University School of Medicine, Shanghai, 200072, China
| | - Wenjia Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China
| | - Wenbo Bu
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China
| | - Mobin Lin
- Department of General Surgery, Yangpu Hospital, Tongji University School of Medicine, Shanghai, 200090, China.
| | - Junhong Lü
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201203, China.
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, China.
| | - Zhaocai Zhou
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China.
- Department of Stomatology, Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Department of Biochemistry and Molecular Biology, Tongji University School of Medicine, Shanghai, 200072, China.
- Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, 211166, China.
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6
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Wang T, Shi S, Shi Y, Jiang P, Hu G, Ye Q, Shi Z, Yu K, Wang C, Fan G, Zhao S, Ma H, Chang ACY, Li Z, Bian Q, Lin CP. Chemical-induced phase transition and global conformational reorganization of chromatin. Nat Commun 2023; 14:5556. [PMID: 37689690 PMCID: PMC10492836 DOI: 10.1038/s41467-023-41340-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 08/29/2023] [Indexed: 09/11/2023] Open
Abstract
Chemicals or drugs can accumulate within biomolecular condensates formed through phase separation in cells. Here, we use super-resolution imaging to search for chemicals that induce phase transition within chromatin at the microscale. This microscopic screening approach reveals that adriamycin (doxorubicin) - a widely used anticancer drug that is known to interact with chromatin - specifically induces visible local condensation and global conformational change of chromatin in cancer and primary cells. Hi-C and ATAC-seq experiments systematically and quantitatively demonstrate that adriamycin-induced chromatin condensation is accompanied by weakened chromatin interaction within topologically associated domains, compartment A/B switching, lower chromatin accessibility, and corresponding transcriptomic changes. Mechanistically, adriamycin complexes with histone H1 and induces phase transition of H1, forming fibrous aggregates in vitro. These results reveal a phase separation-driven mechanism for a chemotherapeutic drug.
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Affiliation(s)
- Tengfei Wang
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Shuxiang Shi
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
- Lingang Laboratory, 200031, Shanghai, China
| | - Yuanyuan Shi
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200125, Shanghai, China
- Shanghai Key Laboratory of Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China
| | - Peipei Jiang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200125, Shanghai, China
- Shanghai Key Laboratory of Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China
| | - Ganlu Hu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210, Shanghai, China
| | - Qinying Ye
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Zhan Shi
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Kexin Yu
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
- iHuman Institute, ShanghaiTech University, 201010, Shanghai, China
| | - Chenguang Wang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200125, Shanghai, China
- Shanghai Key Laboratory of Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Guoping Fan
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210, Shanghai, China
| | - Suwen Zhao
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
- iHuman Institute, ShanghaiTech University, 201010, Shanghai, China
| | - Hanhui Ma
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Alex C Y Chang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200125, Shanghai, China
- Shanghai Key Laboratory of Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhi Li
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Qian Bian
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 200125, Shanghai, China.
- Shanghai Key Laboratory of Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China.
| | - Chao-Po Lin
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
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7
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Bai Q, Liu Z, Chen J, Liang D. Crowded Environment Regulates the Coacervation of Biopolymers via Nonspecific Interactions. Biomacromolecules 2023; 24:283-293. [PMID: 36511362 DOI: 10.1021/acs.biomac.2c01129] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The membrane-less organelles (MLOs) with subcompartments are formed via liquid-liquid phase separation (LLPS) in the crowded cell interior whose background molecules are up to 400 mg/mL. It is still a puzzle how the background molecules regulate the formation, dynamics, and functions of MLOs. Using biphasic coacervate droplets formed by poly(l-lysine) (PLL), quaternized dextran (Q-dextran), and single-stranded oligonucleotides (ss-oligo) as a model of MLO, we online monitored the LLPS process in Bovine Serine Albumin (BSA) solution up to 200.0 mg/mL. Negatively charged BSA is able to form complex or coacervate with positively charged PLL and Q-dextran and thus participates in the LLPS via nonspecific interactions. Results show that BSA effectively regulates the LLPS by controlling the phase distribution, morphologies, and kinetics. With increasing BSA concentration, the spherical biphasic droplets evolve in sequence into phase-inverted flower-like structure, worm-like chains, network structures, and confined coacervates. Each kind of morphology is formed via its own specific growth and fusion pathway. Our work suggests that MLOs could be controlled solely by the crowded environment and provides a further step toward understanding the life process in cell.
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Affiliation(s)
- Qingwen Bai
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, China
| | - Zhijun Liu
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, China
| | - Jiaxin Chen
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, China
| | - Dehai Liang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, China
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8
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Efremov AK, Hovan L, Yan J. Nucleus size and its effect on nucleosome stability in living cells. Biophys J 2022; 121:4189-4204. [PMID: 36146936 PMCID: PMC9675033 DOI: 10.1016/j.bpj.2022.09.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/15/2022] [Accepted: 09/16/2022] [Indexed: 11/25/2022] Open
Abstract
DNA architectural proteins play a major role in organization of chromosomal DNA in living cells by packaging it into chromatin, whose spatial conformation is determined by an intricate interplay between the DNA-binding properties of architectural proteins and physical constraints applied to the DNA by a tight nuclear space. Yet, the exact effects of the nucleus size on DNA-protein interactions and chromatin structure currently remain obscure. Furthermore, there is even no clear understanding of molecular mechanisms responsible for the nucleus size regulation in living cells. To find answers to these questions, we developed a general theoretical framework based on a combination of polymer field theory and transfer-matrix calculations, which showed that the nucleus size is mainly determined by the difference between the surface tensions of the nuclear envelope and the endoplasmic reticulum membrane as well as the osmotic pressure exerted by cytosolic macromolecules on the nucleus. In addition, the model demonstrated that the cell nucleus functions as a piezoelectric element, changing its electrostatic potential in a size-dependent manner. This effect has been found to have a profound impact on stability of nucleosomes, revealing a previously unknown link between the nucleus size and chromatin structure. Overall, our study provides new insights into the molecular mechanisms responsible for regulation of the nucleus size, as well as the potential role of nuclear organization in shaping the cell response to environmental cues.
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Affiliation(s)
- Artem K Efremov
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China; Mechanobiology Institute, National University of Singapore, Singapore, Singapore.
| | - Ladislav Hovan
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - Jie Yan
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
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9
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Liebl MC, Hofmann TG. Regulating the p53 Tumor Suppressor Network at PML Biomolecular Condensates. Cancers (Basel) 2022; 14:4549. [PMID: 36230470 PMCID: PMC9558958 DOI: 10.3390/cancers14194549] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/13/2022] [Accepted: 09/16/2022] [Indexed: 11/16/2022] Open
Abstract
By forming specific functional entities, nuclear biomolecular condensates play an important function in guiding biological processes. PML biomolecular condensates, also known as PML nuclear bodies (NBs), are macro-molecular sub-nuclear organelles involved in central biological processes, including anti-viral response and cell fate control upon genotoxic stress. PML condensate formation is stimulated upon cellular stress, and relies on protein-protein interactions establishing a PML protein meshwork capable of recruiting the tumor suppressor p53, along with numerous modifiers of p53, thus balancing p53 posttranslational modifications and activity. This stress-regulated process appears to be controlled by liquid-liquid phase separation (LLPS), which may facilitate regulated protein-unmixing of p53 and its regulators into PML nuclear condensates. In this review, we summarize and discuss the molecular mechanisms underlying PML nuclear condensate formation, and how these impact the biological function of p53 in driving the cell death and senescence responses. In addition, by using an in silico approach, we identify 299 proteins which share PML and p53 as binding partners, thus representing novel candidate proteins controlling p53 function and cell fate decision-making at the level of PML nuclear biocondensates.
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Affiliation(s)
| | - Thomas G. Hofmann
- Institute of Toxicology, University Medical Center Mainz, Johannes Gutenberg University, 55131 Mainz, Germany
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10
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Biological colloids: Unique properties of membranelles organelles in the cell. Adv Colloid Interface Sci 2022; 310:102777. [DOI: 10.1016/j.cis.2022.102777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 11/24/2022]
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11
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AFM imaging of the transcriptionally active chromatin in mammalian cells' nuclei. Biochim Biophys Acta Gen Subj 2022; 1866:130234. [PMID: 36007722 DOI: 10.1016/j.bbagen.2022.130234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 07/21/2022] [Accepted: 08/18/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND Nuclear rigidity is traditionally associated with lamina and densely packed heterochromatin. Actively transcribed DNA is thought to be less densely packed. Currently, approaches for direct measurements of the transcriptionally active chromatin rigidity are quite limited. METHODS Isolated nuclei were subjected to mechanical stress at 60 g and analyzed by Atomic Force Microscopy (AFM). RESULTS Nuclei of the normal fibroblast cells were completely flattened under mechanical stress, whereas nuclei of the cancerous HeLa were extremely resistant. In the deformed HeLa nuclei, AFM revealed a highly-branched landscape assembled of ~400 nm closed-packed globules and their structure was changing in response to external influence. Normal and cancerous cells' isolated nuclei were strikingly different by DNA resistance to applied mechanical stress. Paradoxically, more transcriptionally active and less optically dense chromatin of the nuclei of the cancerous cells demonstrated higher physical rigidity. A high concentration of the transcription inhibitor actinomycin D led to complete flattening of HeLa nuclei, that might be related to the relaxation of supercoiled DNA tending to deformation. At a low concentration of actinomycin D, we observed the intermediary formation of stochastically distributed nanoloops and nanofilaments with different shapes but constant width ~ 180 nm. We related this phenomenon with partial DNA relaxation, while non-relaxed DNA still remained rigid. CONCLUSIONS The resistance to deformation of nuclear chromatin correlates with fundamental biological processes in the cell nucleus, such as transcription, as assessed by AFM. GENERAL SIGNIFICANCE A new outlook to studying internal nuclei structure is proposed.
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12
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Liquid-liquid phase separation in tumor biology. Signal Transduct Target Ther 2022; 7:221. [PMID: 35803926 PMCID: PMC9270353 DOI: 10.1038/s41392-022-01076-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/16/2022] [Accepted: 06/21/2022] [Indexed: 12/12/2022] Open
Abstract
Liquid–liquid phase separation (LLPS) is a novel principle for explaining the precise spatial and temporal regulation in living cells. LLPS compartmentalizes proteins and nucleic acids into micron-scale, liquid-like, membraneless bodies with specific functions, which were recently termed biomolecular condensates. Biomolecular condensates are executors underlying the intracellular spatiotemporal coordination of various biological activities, including chromatin organization, genomic stability, DNA damage response and repair, transcription, and signal transduction. Dysregulation of these cellular processes is a key event in the initiation and/or evolution of cancer, and emerging evidence has linked the formation and regulation of LLPS to malignant transformations in tumor biology. In this review, we comprehensively summarize the detailed mechanisms of biomolecular condensate formation and biophysical function and review the recent major advances toward elucidating the multiple mechanisms involved in cancer cell pathology driven by aberrant LLPS. In addition, we discuss the therapeutic perspectives of LLPS in cancer research and the most recently developed drug candidates targeting LLPS modulation that can be used to combat tumorigenesis.
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13
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Pack CG. Application of quantitative cell imaging using label-free optical diffraction tomography. Biophys Physicobiol 2021; 18:244-253. [PMID: 34745809 PMCID: PMC8550874 DOI: 10.2142/biophysico.bppb-v18.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/11/2021] [Indexed: 12/01/2022] Open
Abstract
The cell is three-dimensionally and dynamically organized into cellular compartments, including the endoplasmic reticulum, mitochondria, vesicles, and nucleus, which have high relative molecular density. The structure and functions of these compartments and organelles may be deduced from the diffusion and interaction of related biomolecules. Among these cellular components, various protein molecules can freely access the nucleolus or mitotic chromosome through Brownian diffusion, even though they have a densely packed structure. However, physicochemical properties of the nucleolus and chromosomes, such as molecular density and volume, are not yet fully understood under changing cellular conditions. Many studies have been conducted based on high-resolution imaging and analysis techniques using fluorescence. However, there are limitations in imaging only fluorescently labeled molecules, and cytotoxicity occurs during three-dimensional imaging. Alternatively, the recently developed label-free three-dimensional optical diffraction tomography (ODT) imaging technique can divide various organelles in cells into volumes and analyze them by refractive index, although specific molecules cannot be observed. A previous study established an analytical method that provides comprehensive insights into the physical properties of the nucleolus and mitotic chromosome by utilizing the advantages of ODT and fluorescence techniques, such as fluorescence correlation spectroscopy and confocal laser scanning microscopy. This review article summarizes a recent study and discusses the future aspects of the ODT for cellular compartments.
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Affiliation(s)
- Chan-Gi Pack
- Convergence Medicine Research Center (CREDIT), Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
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14
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Zannino L, Casali C, Siciliani S, Biggiogera M. The dynamics of the nuclear environment and their impact on gene function. J Biochem 2021; 169:259-264. [PMID: 32745171 DOI: 10.1093/jb/mvaa091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/15/2020] [Indexed: 01/04/2023] Open
Abstract
In the last decades, it has become increasingly clear how the modulation of spatial organization of chromatin over time and through the cell cycle is closely connected to gene function regulation. Different physicochemical stimuli contribute to the realization of specific transcriptional programs and finally to a specific cellular phenotype. In this review, we aim to describe the current knowledge about the dynamics regulating the movements and the interactions of molecules within the nucleus and their impact on gene functions. In particular, taking into account that these forces exert their effect in a nuclear environment characterized by a high concentration of molecules, we will discuss the role of proteins and structures that regulate these movements and transduce physicochemical signals acting on the cell to the nucleus.
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Affiliation(s)
- Lorena Zannino
- Laboratory of Cell Biology and Neurobiology, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | | | - Stella Siciliani
- Laboratory of Cell Biology and Neurobiology, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
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15
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Fonin AV, Silonov SA, Shpironok OG, Antifeeva IA, Petukhov AV, Romanovich AE, Kuznetsova IM, Uversky VN, Turoverov KK. The Role of Non-Specific Interactions in Canonical and ALT-Associated PML-Bodies Formation and Dynamics. Int J Mol Sci 2021; 22:ijms22115821. [PMID: 34072343 PMCID: PMC8198325 DOI: 10.3390/ijms22115821] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 04/30/2021] [Accepted: 05/22/2021] [Indexed: 12/19/2022] Open
Abstract
In this work, we put forward a hypothesis about the decisive role of multivalent nonspecific interactions in the early stages of PML body formation. Our analysis of the PML isoform sequences showed that some of the PML isoforms, primarily PML-II, are prone to phase separation due to their polyampholytic properties and the disordered structure of their C-terminal domains. The similarity of the charge properties of the C-terminal domains of PML-II and PML-VI isoforms made it possible for the first time to detect migration of PML-VI from PML bodies to the periphery of the cell nucleus, similar to the migration of PML-II isoforms. We found a population of “small” (area less than 1 µm2) spherical PML bodies with high dynamics of PML isoforms exchange with nucleoplasm and a low fraction of immobilized proteins, which indicates their liquid state properties. Such structures can act as “seeds” of functionally active PML bodies, providing the necessary concentration of PML isoforms for the formation of intermolecular disulfide bonds between PML monomers. FRAP analysis of larger bodies of toroidal topology showed the existence of an insoluble scaffold in their structure. The hypothesis about the role of nonspecific multiple weak interactions in the formation of PML bodies is further supported by the change in the composition of the scaffold proteins of PML bodies, but not their solidification, under conditions of induction of dimerization of PML isoforms under oxidative stress. Using the colocalization of ALT-associated PML bodies (APBs) with TRF1, we identified APBs and showed the difference in the dynamic properties of APBs and canonical PML bodies.
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Affiliation(s)
- Alexander V. Fonin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064 St. Petersburg, Russia; (S.A.S.); (O.G.S.); (I.A.A.); (I.M.K.)
- Correspondence: (A.V.F.); (V.N.U.); (K.K.T.); Tel.: +7-812-2971957 (K.K.T.); Fax: +7-812-2970341(K.K.T.)
| | - Sergey A. Silonov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064 St. Petersburg, Russia; (S.A.S.); (O.G.S.); (I.A.A.); (I.M.K.)
| | - Olesya G. Shpironok
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064 St. Petersburg, Russia; (S.A.S.); (O.G.S.); (I.A.A.); (I.M.K.)
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
| | - Iuliia A. Antifeeva
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064 St. Petersburg, Russia; (S.A.S.); (O.G.S.); (I.A.A.); (I.M.K.)
| | - Alexey V. Petukhov
- Institute of Hematology, Almazov National Medical Research Centre, 197341 St. Petersburg, Russia;
| | - Anna E. Romanovich
- St-Petersburg State University Science Park, Resource Center of Molecular and Cell Technologies, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia;
| | - Irina M. Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064 St. Petersburg, Russia; (S.A.S.); (O.G.S.); (I.A.A.); (I.M.K.)
| | - Vladimir N. Uversky
- Department of Molecular Medicine and Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
- Correspondence: (A.V.F.); (V.N.U.); (K.K.T.); Tel.: +7-812-2971957 (K.K.T.); Fax: +7-812-2970341(K.K.T.)
| | - Konstantin K. Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064 St. Petersburg, Russia; (S.A.S.); (O.G.S.); (I.A.A.); (I.M.K.)
- Peter the Great St.-Petersburg Polytechnic University, Polytechnicheskaya 29, 195251 St. Petersburg, Russia
- Correspondence: (A.V.F.); (V.N.U.); (K.K.T.); Tel.: +7-812-2971957 (K.K.T.); Fax: +7-812-2970341(K.K.T.)
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16
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Suda K, Suematsu A, Akiyama R. Lateral depletion effect on two-dimensional ordering of bacteriorhodopsins in a lipid bilayer: A theoretical study based on a binary hard-disk model. J Chem Phys 2021; 154:204904. [PMID: 34241177 DOI: 10.1063/5.0044399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The 2D ordering of bacteriorhodopsins in a lipid bilayer was studied using a binary hard-disk model. The phase diagrams were calculated taking into account the lateral depletion effects. The critical concentrations of the protein ordering for monomers and trimers were obtained from the phase diagrams. The critical concentration ratio agreed well with the experiment when the repulsive core interaction between the depletants, namely, lipids, was taken into account. The results suggest that the depletion effect plays an important role in the association behaviors of transmembrane proteins.
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Affiliation(s)
- Keiju Suda
- Department of Chemistry, Graduate School of Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Ayumi Suematsu
- Faculty of Science and Engineering, Kyushu Sangyo University, Fukuoka 813-8503, Japan
| | - Ryo Akiyama
- Department of Chemistry, Graduate School of Science, Kyushu University, Fukuoka 819-0395, Japan
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17
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Landman J, Schelling MPM, Tuinier R, Vis M. Repulsive and attractive depletion forces mediated by nonadsorbing polyelectrolytes in the Donnan limit. J Chem Phys 2021; 154:164904. [PMID: 33940853 DOI: 10.1063/5.0044749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In mixtures of colloids and nonadsorbing polyelectrolytes, a Donnan potential arises across the region between surfaces that are depleted of the polyelectrolyte and the rest of the system. This Donnan potential tends to shift the polyelectrolyte density profile toward the colloidal surface and leads to the local accumulation of polyelectrolytes. We derive a zero-field theory for the disjoining pressure between two parallel flat plates. The polyelectrolyte is allowed to enter the confined interplate region at the cost of a conformational free energy penalty. The resulting disjoining pressure shows a crossover to a repulsive regime when the interplate separation gets smaller than the size of the polyelectrolyte chain, followed by an attractive part. We find a quantitative match between the model and self-consistent field computations that take into account the full Poisson-Boltzmann electrostatics.
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Affiliation(s)
- Jasper Landman
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Max P M Schelling
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Remco Tuinier
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Mark Vis
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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18
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Li J, Zhang Y, Chen X, Ma L, Li P, Yu H. Protein phase separation and its role in chromatin organization and diseases. Biomed Pharmacother 2021; 138:111520. [PMID: 33765580 DOI: 10.1016/j.biopha.2021.111520] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 03/04/2021] [Accepted: 03/14/2021] [Indexed: 12/25/2022] Open
Abstract
In the physical sciences, solid, liquid, and gas are the most familiar phase states, whose essence is their existence reflecting the different spatial distribution of molecular components. The biological molecules in the living cell also have differences in spatial distribution. The molecules organized in the form of membrane-bound organelles are well recognized. However, the biomolecules organized in membraneless compartments called biomolecular condensates remain elusive. The liquid-liquid phase separation (LLPS), as a new emerging scientific breakthrough, describes the biomolecules assembled in special distribution and appeared as membraneless condensates in the form of a new "phase" compared with the surrounding liquid milieu. LLPS provides an important theoretical basis for explaining the composition of biological molecules and related biological reactions. Mounting evidence has emerged recently that phase-separated condensates participate in various biological activities. This article reviews the occurrence of LLPS and underlying regulatory mechanisms for understanding how multivalent molecules drive phase transitions to form the biomolecular condensates. And, it also summarizes recent major progress in elucidating the roles of LLPS in chromatin organization and provides clues for the development of new innovative therapeutic strategies for related diseases.
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Affiliation(s)
- Jiaqi Li
- Dr. Neher's Laboratory for innovative Drug Discovery, Macau University of Science and Technology, Macao, China; State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macao, China
| | - Yao Zhang
- Dr. Neher's Laboratory for innovative Drug Discovery, Macau University of Science and Technology, Macao, China; State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macao, China
| | - Xi Chen
- Dr. Neher's Laboratory for innovative Drug Discovery, Macau University of Science and Technology, Macao, China; State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macao, China
| | - Lijuan Ma
- Dr. Neher's Laboratory for innovative Drug Discovery, Macau University of Science and Technology, Macao, China; State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macao, China
| | - Pilong Li
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Haijie Yu
- Dr. Neher's Laboratory for innovative Drug Discovery, Macau University of Science and Technology, Macao, China; State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macao, China.
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19
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Bai Q, Zhang Q, Jing H, Chen J, Liang D. Liquid-Liquid Phase Separation of Peptide/Oligonucleotide Complexes in Crowded Macromolecular Media. J Phys Chem B 2020; 125:49-57. [PMID: 33373232 DOI: 10.1021/acs.jpcb.0c09225] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The membraneless organelles (MLOs) and coacervates of oppositely charged polyelectrolytes are both formed by liquid-liquid phase separation. To reveal how the crowded cell interior regulates the MLOs, we chose the coacervates formed by peptide S5 and single-stranded oligonucleotide (ss-oligo) at 1:1 charge ratio and investigated the phase separation processes in polyacrylamide (PAM) and poly(ethylene oxide) (PEO) media at varying concentrations. Results show that the droplet formation unit is the neutral primary complex, instead of individual S5 or ss-oligo. Therefore, the coacervation process can be described by the classic theory of nucleation and growth. The dynamic scaling relationships show that S5/ss-oligo coacervation undergoes in sequence the heterogeneous nucleation, diffusion-limited growth, and Brownian motion coalescence with time. The inert crowders generate multiple effects, including accelerating the growth of droplets, weakening the electrostatic attraction, and slowing down or even trapping the droplets in the crowder network. The overall effect is that both the size and size distribution of the droplets decrease with increasing crowder concentration, and the effect of PEO is stronger than that of PAM. Our study provides a further step toward a deeper understanding of the kinetics of MLOs in crowded living cells.
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Affiliation(s)
- Qingwen Bai
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Qiufen Zhang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Hairong Jing
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Jiaxin Chen
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Dehai Liang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
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20
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Corpet A, Kleijwegt C, Roubille S, Juillard F, Jacquet K, Texier P, Lomonte P. PML nuclear bodies and chromatin dynamics: catch me if you can! Nucleic Acids Res 2020; 48:11890-11912. [PMID: 33068409 PMCID: PMC7708061 DOI: 10.1093/nar/gkaa828] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 12/17/2022] Open
Abstract
Eukaryotic cells compartmentalize their internal milieu in order to achieve specific reactions in time and space. This organization in distinct compartments is essential to allow subcellular processing of regulatory signals and generate specific cellular responses. In the nucleus, genetic information is packaged in the form of chromatin, an organized and repeated nucleoprotein structure that is a source of epigenetic information. In addition, cells organize the distribution of macromolecules via various membrane-less nuclear organelles, which have gathered considerable attention in the last few years. The macromolecular multiprotein complexes known as Promyelocytic Leukemia Nuclear Bodies (PML NBs) are an archetype for nuclear membrane-less organelles. Chromatin interactions with nuclear bodies are important to regulate genome function. In this review, we will focus on the dynamic interplay between PML NBs and chromatin. We report how the structure and formation of PML NBs, which may involve phase separation mechanisms, might impact their functions in the regulation of chromatin dynamics. In particular, we will discuss how PML NBs participate in the chromatinization of viral genomes, as well as in the control of specific cellular chromatin assembly pathways which govern physiological mechanisms such as senescence or telomere maintenance.
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Affiliation(s)
- Armelle Corpet
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, LabEx DEVweCAN, Institut NeuroMyoGène (INMG), team Chromatin Dynamics, Nuclear Domains, Virus F-69008, Lyon, France
| | - Constance Kleijwegt
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, LabEx DEVweCAN, Institut NeuroMyoGène (INMG), team Chromatin Dynamics, Nuclear Domains, Virus F-69008, Lyon, France
| | - Simon Roubille
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, LabEx DEVweCAN, Institut NeuroMyoGène (INMG), team Chromatin Dynamics, Nuclear Domains, Virus F-69008, Lyon, France
| | - Franceline Juillard
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, LabEx DEVweCAN, Institut NeuroMyoGène (INMG), team Chromatin Dynamics, Nuclear Domains, Virus F-69008, Lyon, France
| | - Karine Jacquet
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, LabEx DEVweCAN, Institut NeuroMyoGène (INMG), team Chromatin Dynamics, Nuclear Domains, Virus F-69008, Lyon, France
| | - Pascale Texier
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, LabEx DEVweCAN, Institut NeuroMyoGène (INMG), team Chromatin Dynamics, Nuclear Domains, Virus F-69008, Lyon, France
| | - Patrick Lomonte
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, LabEx DEVweCAN, Institut NeuroMyoGène (INMG), team Chromatin Dynamics, Nuclear Domains, Virus F-69008, Lyon, France
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21
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A biomimetic model of 3D fluid extracellular macromolecular crowding microenvironment fine-tunes ovarian cancer cells dissemination phenotype. Biomaterials 2020; 269:120610. [PMID: 33388691 DOI: 10.1016/j.biomaterials.2020.120610] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 10/21/2020] [Accepted: 12/14/2020] [Indexed: 12/15/2022]
Abstract
An early fundamental step in ovarian cancer progression is the dissemination of cancer cells through liquid environments, one of them being cancer ascites accumulated in the peritoneal cavity. These biological fluids are highly crowded with a high total macromolecule concentration. This biophysical property of fluids is widely used in tissue engineering for a few decades now, yet is largely underrated in cancer biomimetic models. To unravel the role of fluids extracellular macromolecular crowding (MMC), we exposed ovarian cancer cells (OCC) to high molecular weight inert polymer solutions. High macromolecular composition of extracellular liquid presented a differential effect: i) it impeded non-adherent OCC aggregation in suspension and, decreased their adhesion; ii) it promoted adherent OCC migration by decreasing extracellular matrix deposition. Besides, there seemed to be a direct link between the extracellular MMC and intracellular processes, especially the actin cytoskeleton organization and the nucleus morphology. In conclusion, extracellular fluid MMC orients OCC dissemination phenotype. Integrating MMC seems crucial to produce more relevant mimetic 3D in vitro fluid models to study ovarian dissemination but also to screen drugs.
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22
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Jalihal AP, Pitchiaya S, Xiao L, Bawa P, Jiang X, Bedi K, Parolia A, Cieslik M, Ljungman M, Chinnaiyan AM, Walter NG. Multivalent Proteins Rapidly and Reversibly Phase-Separate upon Osmotic Cell Volume Change. Mol Cell 2020; 79:978-990.e5. [PMID: 32857953 PMCID: PMC7502480 DOI: 10.1016/j.molcel.2020.08.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 06/11/2020] [Accepted: 08/05/2020] [Indexed: 12/12/2022]
Abstract
Processing bodies (PBs) and stress granules (SGs) are prominent examples of subcellular, membraneless compartments that are observed under physiological and stress conditions, respectively. We observe that the trimeric PB protein DCP1A rapidly (within ∼10 s) phase-separates in mammalian cells during hyperosmotic stress and dissolves upon isosmotic rescue (over ∼100 s) with minimal effect on cell viability even after multiple cycles of osmotic perturbation. Strikingly, this rapid intracellular hyperosmotic phase separation (HOPS) correlates with the degree of cell volume compression, distinct from SG assembly, and is exhibited broadly by homo-multimeric (valency ≥ 2) proteins across several cell types. Notably, HOPS sequesters pre-mRNA cleavage factor components from actively transcribing genomic loci, providing a mechanism for hyperosmolarity-induced global impairment of transcription termination. Our data suggest that the multimeric proteome rapidly responds to changes in hydration and molecular crowding, revealing an unexpected mode of globally programmed phase separation and sequestration.
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Affiliation(s)
- Ameya P Jalihal
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA; Cell and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sethuramasundaram Pitchiaya
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-1055, USA; Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA; Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Lanbo Xiao
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-1055, USA; Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Pushpinder Bawa
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-1055, USA
| | - Xia Jiang
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-1055, USA
| | - Karan Bedi
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Abhijit Parolia
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-1055, USA; Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Marcin Cieslik
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-1055, USA; Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mats Ljungman
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA; Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA; Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA; Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI 48109, USA
| | - Arul M Chinnaiyan
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-1055, USA; Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA; Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Urology, University of Michigan, Ann Arbor, MI 48109, USA; Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA; Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Nils G Walter
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA; Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA; Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA.
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23
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Kantidze OL, Razin SV. Weak interactions in higher-order chromatin organization. Nucleic Acids Res 2020; 48:4614-4626. [PMID: 32313950 PMCID: PMC7229822 DOI: 10.1093/nar/gkaa261] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/30/2020] [Accepted: 04/03/2020] [Indexed: 12/20/2022] Open
Abstract
The detailed principles of the hierarchical folding of eukaryotic chromosomes have been revealed during the last two decades. Along with structures composing three-dimensional (3D) genome organization (chromatin compartments, topologically associating domains, chromatin loops, etc.), the molecular mechanisms that are involved in their establishment and maintenance have been characterized. Generally, protein-protein and protein-DNA interactions underlie the spatial genome organization in eukaryotes. However, it is becoming increasingly evident that weak interactions, which exist in biological systems, also contribute to the 3D genome. Here, we provide a snapshot of our current understanding of the role of the weak interactions in the establishment and maintenance of the 3D genome organization. We discuss how weak biological forces, such as entropic forces operating in crowded solutions, electrostatic interactions of the biomolecules, liquid-liquid phase separation, DNA supercoiling, and RNA environment participate in chromosome segregation into structural and functional units and drive intranuclear functional compartmentalization.
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Affiliation(s)
- Omar L Kantidze
- Institute of Gene Biology Russian Academy of Sciences, 119334 Moscow, Russia
| | - Sergey V Razin
- Institute of Gene Biology Russian Academy of Sciences, 119334 Moscow, Russia
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24
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Razin SV, Gavrilov AA. The Role of Liquid–Liquid Phase Separation in the Compartmentalization of Cell Nucleus and Spatial Genome Organization. BIOCHEMISTRY (MOSCOW) 2020; 85:643-650. [DOI: 10.1134/s0006297920060012] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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25
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González García Á, Ianiro A, Beljon R, Leermakers FAM, Tuinier R. (Homo)polymer-mediated colloidal stability of micellar solutions. SOFT MATTER 2020; 16:1560-1571. [PMID: 31950966 DOI: 10.1039/c9sm01665a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Despite their wide range of applications, there is a remarkable lack of fundamental understanding about how micelles respond to other components in solution. The colloidal stability of micellar solutions in presence of (homo)polymers is investigated here following a theoretical bottom-up approach. A polymer-mediated micelle-micelle interaction is extracted from changes in the micelle-unimer equilibrium as a function of the inter-micelle distance. The homopolymer-mediated diblock copolymer micelle-micelle interaction is studied both for depletion and adsorption of the homopolymer. The fluffy nature of the solvophilic domain (corona) of the micelle weakens the depletion-induced destabilization. Accumulation of polymers into the corona induces bridging attraction between micelles. In fact, both depletion and adsorption phenomena are regulated by the coronal thickness relative to the size of the added polymer. Penetration of guest compounds into the coronal domain of crew-cut micelles, with a narrower yet denser corona, is less pronounced as for starlike micelles (with a more diffuse corona). Therefore, crew-cut micelles are less sensitive to the effect of added compounds, and hence more suitable for applications in multicomponent systems, such as industrial formulations or biological fluids. The trends observed for the colloidal stability of crew-cut micelles qualitatively match with our experimental observations on aqueous dispersions of polycaprolactone-polyethylene glycol (PCL-PEO) micellar suspensions with added PEO chains.
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Affiliation(s)
- Álvaro González García
- Van't Hoff Laboratory for Physical and Colloid Chemistry, Department of Chemistry & Debye Institute, Utrecht University, Padualaan 8, 3584 CH, The Netherlands.
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26
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Zhang Q, Bai Q, Zhu L, Hou T, Zhao J, Liang D. Macromolecular Crowding and Confinement Effect on the Growth of DNA Nanotubes in Dextran and Hyaluronic Acid Media. ACS APPLIED BIO MATERIALS 2019; 3:412-420. [DOI: 10.1021/acsabm.9b00892] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qiufen Zhang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Qingwen Bai
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Lin Zhu
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Tianhao Hou
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiang Zhao
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Dehai Liang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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27
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Mudogo CN, Falke S, Brognaro H, Duszenko M, Betzel C. Protein phase separation and determinants of in cell crystallization. Traffic 2019; 21:220-230. [DOI: 10.1111/tra.12711] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 10/21/2019] [Accepted: 10/27/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Celestin N. Mudogo
- Laboratory for Structural Biology of Infection and InflammationInstitute of Biochemistry and Molecular Biology, University of Hamburg Hamburg Germany
- Department of Basic Sciences, School of MedicineUniversity of Kinshasa Kinshasa Democratic Republic of Congo
| | - Sven Falke
- Laboratory for Structural Biology of Infection and InflammationInstitute of Biochemistry and Molecular Biology, University of Hamburg Hamburg Germany
| | - Hévila Brognaro
- Laboratory for Structural Biology of Infection and InflammationInstitute of Biochemistry and Molecular Biology, University of Hamburg Hamburg Germany
- Centre for Free‐Electron‐Laser Science Hamburg Germany
| | - Michael Duszenko
- Institute of Neurophysiology, University of Tübingen Tübingen Germany
| | - Christian Betzel
- Laboratory for Structural Biology of Infection and InflammationInstitute of Biochemistry and Molecular Biology, University of Hamburg Hamburg Germany
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28
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Shim AR, Nap RJ, Huang K, Almassalha LM, Matusda H, Backman V, Szleifer I. Dynamic Crowding Regulates Transcription. Biophys J 2019; 118:2117-2129. [PMID: 31818468 DOI: 10.1016/j.bpj.2019.11.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/26/2019] [Accepted: 11/11/2019] [Indexed: 02/01/2023] Open
Abstract
The nuclear environment is highly crowded by biological macromolecules, including chromatin and mobile proteins, which alter the kinetics and efficiency of transcriptional machinery. These alterations have been described, both theoretically and experimentally, for steady-state crowding densities; however, temporal changes in crowding density ("dynamic crowding") have yet to be integrated with gene expression. Dynamic crowding is pertinent to nuclear biology because processes such as chromatin translocation and protein diffusion lend to highly mobile biological crowders. Therefore, to capture such dynamic crowding and investigate its influence on transcription, we employ a three-pronged, systems-molecular approach. A system of chemical reactions represents the transcription pathway, the rates of which are determined by molecular-scale simulations; Brownian dynamics and Monte Carlo simulations quantify protein diffusion and DNA-protein binding affinity, dependent on macromolecular density. Altogether, this approach shows that transcription depends critically on dynamic crowding as the gene expression resultant from dynamic crowding can be profoundly different than that of steady-state crowding. In fact, expression levels can display both amplification and suppression and are notably different for genes or gene populations with different chemical and structural properties. These properties can be exploited to impose circadian expression, which is asymmetric and varies in strength, or to explain expression in cells under biomechanical stress. Therefore, this work demonstrates that dynamic crowding nontrivially alters transcription kinetics and presents dynamic crowding within the bulk nuclear nanoenvironment as a novel regulatory framework for gene expression.
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Affiliation(s)
- Anne R Shim
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois; Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois
| | - Rikkert J Nap
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois; Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois
| | - Kai Huang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois; Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois
| | - Luay M Almassalha
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Hiroaki Matusda
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois; Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois
| | - Igal Szleifer
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois; Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois; Department of Chemistry, Northwestern University, Evanston, Illinois.
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29
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Razin SV, Ulianov SV, Gavrilov AA. 3D Genomics. Mol Biol 2019; 53:802-812. [DOI: 10.1134/s0026893319060153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/01/2019] [Accepted: 06/03/2019] [Indexed: 08/30/2023]
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30
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Kim TK, Lee BW, Fujii F, Lee KH, Lee S, Park Y, Kim JK, Lee SW, Pack CG. Mitotic Chromosomes in Live Cells Characterized Using High-Speed and Label-Free Optical Diffraction Tomography. Cells 2019; 8:cells8111368. [PMID: 31683735 PMCID: PMC6912651 DOI: 10.3390/cells8111368] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/21/2019] [Accepted: 10/30/2019] [Indexed: 12/16/2022] Open
Abstract
The cell nucleus is a three-dimensional, dynamic organelle organized into subnuclear compartments such as chromatin and nucleoli. The structure and function of these compartments are maintained by diffusion and interactions between related factors as well as by dynamic and structural changes. Recent studies using fluorescent microscopic techniques suggest that protein factors can access and are freely mobile in heterochromatin and in mitotic chromosomes, despite their densely packed structure. However, the physicochemical properties of the chromosome during cell division are not fully understood. In the present study, characteristic properties such as the refractive index (RI), volume of the mitotic chromosomes, and diffusion coefficient (D) of fluorescent probes inside the chromosome were quantified using an approach combining label-free optical diffraction tomography with complementary confocal laser-scanning microscopy and fluorescence correlation spectroscopy. Variations in these parameters correlated with osmotic conditions, suggesting that changes in RI are consistent with those of the diffusion coefficient for mitotic chromosomes and cytosol. Serial RI tomography images of chromosomes in live cells during mitosis were compared with three-dimensional confocal micrographs to demonstrate that compaction and decompaction of chromosomes induced by osmotic change were characterized by linked changes in chromosome RI, volume, and the mobilities of fluorescent proteins.
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Affiliation(s)
- Tae-Keun Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
| | - Byong-Wook Lee
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
| | - Fumihiko Fujii
- Division of Physical Pharmacy, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Kobe 650-8586, Japan.
| | | | - Sanghwa Lee
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
| | - YongKeun Park
- Tomocube Inc., Daejeon 34051, Korea.
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.
| | - Jun Ki Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Korea.
| | - Sang-Wook Lee
- Department of Radiation Oncology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
| | - Chan-Gi Pack
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Korea.
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31
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Do Cellular Condensates Accelerate Biochemical Reactions? Lessons from Microdroplet Chemistry. Biophys J 2019; 115:3-8. [PMID: 29972809 DOI: 10.1016/j.bpj.2018.05.023] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/03/2018] [Accepted: 05/23/2018] [Indexed: 01/20/2023] Open
Abstract
Cellular condensates-phase-separated concentrates of proteins and nucleic acids-provide organizational structure for biochemistry that is distinct from membrane-bound compartments. It has been suggested that one major function of cellular condensates is to accelerate biochemical processes that are normally slow or thermodynamically unfavorable. Yet, the mechanisms leading to increased reaction rates within cellular condensates remain poorly understood. In this article, we highlight recent advances in microdroplet chemistry that accelerate reaction rates by many orders of magnitude as compared to bulk and suggest that similar mechanisms may also affect reaction kinetics in cellular condensates.
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32
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Novikova SE, Vakhrushev IV, Tsvetkova AV, Shushkova NA, Farafonova TE, Yarygin KN, Zgoda VG. [Proteomics of transcription factors: identification of pool of HL-60 cell line-specific regulatory proteins]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2019; 65:294-305. [PMID: 31436170 DOI: 10.18097/pbmc20196504294] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
HL-60 promyelocytic cells are a widely used as a model for studying induced granulocytic differentiation. Investigation of proteins of the nuclear fraction, particularly transcription factors, is necessary for a better understanding of molecular mechanisms of cell maturation. Mass spectrometry is a powerful tool for analyzing a proteome due to its high sensitivity, specificity and performance. In this paper, using the selected reaction monitoring (SRM) method, we have assessed the levels of RBPJ, STAT1, CEBPB, CASP3, VAV1, PRKDC, PARP1 and UBC9 nuclear proteins isolated using hypertonic buffer, detergents (sodium dodecyl sulfate (SDS), sodium deoxycholate (DOC) and fissionable detergent ProteaseMAX™) and using centrifugation in a sucrose density gradient. The minimum and maximum protein content was 1.13±0.28 and 14.34±1.63 fmol/mkg of total protein for the transcription factor RBPJ and ubiquitin-protein ligase type I UBC9, respectively. According to the results of shotgun mass spectrometric analysis of nuclear fractions, 2356 proteins were identified, of which 106 proteins were annotated as transcription factors. 37 transcription factors were uniquely identified in the fraction obtained by centrifugation in a sucrose density gradient, while only 9 and 8 transcription factors were uniquely identified in the nuclear fractions obtained using hypertonic buffer and detergents, respectively. The transcription factors identified in the HL-60 cell line represent regulatory molecules; their directed profiling under the influence of differentiation inducers, will shed light on the mechanism of granulocyte maturation.
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Affiliation(s)
- S E Novikova
- Institute of Biomedical Chemistry, Moscow, Russia
| | | | | | | | | | - K N Yarygin
- Institute of Biomedical Chemistry, Moscow, Russia
| | - V G Zgoda
- Institute of Biomedical Chemistry, Moscow, Russia
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33
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Kim TK, Lee BW, Fujii F, Kim JK, Pack CG. Physicochemical Properties of Nucleoli in Live Cells Analyzed by Label-Free Optical Diffraction Tomography. Cells 2019; 8:cells8070699. [PMID: 31295945 PMCID: PMC6679011 DOI: 10.3390/cells8070699] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/27/2019] [Accepted: 07/09/2019] [Indexed: 12/15/2022] Open
Abstract
The cell nucleus is three-dimensionally and dynamically organized by nuclear components with high molecular density, such as chromatin and nuclear bodies. The structure and functions of these components are represented by the diffusion and interaction of related factors. Recent studies suggest that the nucleolus can be assessed using various protein probes, as the probes are highly mobile in this organelle, although it is known that they have a densely packed structure. However, physicochemical properties of the nucleolus itself, such as molecular density and volume when cellular conditions are changed, are not yet fully understood. In this study, physical parameters such as the refractive index (RI) and volume of the nucleoli in addition to the diffusion coefficient (D) of fluorescent probe protein inside the nucleolus are quantified and compared by combining label-free optical diffraction tomography (ODT) with confocal laser scanning microscopy (CLSM)-based fluorescence correlation spectroscopy (FCS). 3D evaluation of RI values and corresponding RI images of nucleoli in live HeLa cells successfully demonstrated varying various physiological conditions. Our complimentary method suggests that physical property of the nucleolus in live cell is sensitive to ATP depletion and transcriptional inhibition, while it is insensitive to hyper osmotic pressure when compared with the cytoplasm and nucleoplasm. The result demonstrates that the nucleolus has unique physicochemical properties when compared with other cellular components.
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Affiliation(s)
- Tae-Keun Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea
| | - Byong-Wook Lee
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea
| | - Fumihiko Fujii
- Division of Physical Pharmacy, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Kobe 650-8586, Japan
| | - Jun Ki Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Korea.
| | - Chan-Gi Pack
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Korea.
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34
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Son HN, Chi HNQ, Chung DC, Long LT. Morphological changes during replicative senescence in bovine ovarian granulosa cells. Cell Cycle 2019; 18:1490-1497. [PMID: 31131697 DOI: 10.1080/15384101.2019.1624108] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The objective of this study was to evaluate replicative senescence of bovine granulosa cells (bGCs) during in vitro long-term culture. WST-1 assay analysis showed that bGCs proliferation was reduced from primary culture to 14th passage. The several bGCs from the 3rd passage and 7th passage exposed the weak activity of beta-galactosidase, while a strongly positive staining of beta-galactosidase was observed in bGCs from 14th passage. Flow cytometry analysis showed that bGCs were induced to cell cycle arrest at G0/G1 phase through in vitro expansion. TERT transcript expression of bGCs was downregulated from primary culture to 14th passage. The cell and nuclear area of bGCs were dramatically increased from 14th passage to 25th passage. The nucleocytoplasmic ratio of bGCs was dramatically reduced in 22th passage (4.32%) and 25th passage (2.45%), comparing to previous passages: primary culture (10.67%), 7th passage (9.21%), or 14th passage (10.33%). The number of microfilament bundle of bGCs was increased in 22nd passage (67.42 ± 17.76) and 25th passage (56.31 ± 22.45). The diameter of microfilament bundle of bGCs in 25th passage was dramatically increased to 1.88 ± 0.32 µm comparing to the primary culture (1.15 ± 0.03 µm). In this study, we also assessed the nuclear form factor which illustrates the level of nuclear circular form. A reduction of nuclear form factor was observed in bGCs during long-term in vitro expansion. The changes of nuclear form factor were correlated to other senescent characteristics, especially the nucleocytoplasmic ratio.
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Affiliation(s)
- Hoang Nghia Son
- a Animal Biotechnology Department , Institute of Tropical Biology, Vietnam Academy of Science and Technology , Ho Chi Minh City , Vietnam.,b Biotechnology Department , Graduate University of Science and Technology, Vietnam Academy of Science and Technology , Ha Noi , Vietnam
| | - Ho Nguyen Quynh Chi
- a Animal Biotechnology Department , Institute of Tropical Biology, Vietnam Academy of Science and Technology , Ho Chi Minh City , Vietnam.,b Biotechnology Department , Graduate University of Science and Technology, Vietnam Academy of Science and Technology , Ha Noi , Vietnam
| | - Doan Chinh Chung
- a Animal Biotechnology Department , Institute of Tropical Biology, Vietnam Academy of Science and Technology , Ho Chi Minh City , Vietnam.,b Biotechnology Department , Graduate University of Science and Technology, Vietnam Academy of Science and Technology , Ha Noi , Vietnam
| | - Le Thanh Long
- a Animal Biotechnology Department , Institute of Tropical Biology, Vietnam Academy of Science and Technology , Ho Chi Minh City , Vietnam.,b Biotechnology Department , Graduate University of Science and Technology, Vietnam Academy of Science and Technology , Ha Noi , Vietnam
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35
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Lemetti L, Hirvonen SP, Fedorov D, Batys P, Sammalkorpi M, Tenhu H, Linder MB, Aranko AS. Molecular crowding facilitates assembly of spidroin-like proteins through phase separation. Eur Polym J 2019. [DOI: 10.1016/j.eurpolymj.2018.10.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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36
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Falahati H, Haji-Akbari A. Thermodynamically driven assemblies and liquid-liquid phase separations in biology. SOFT MATTER 2019; 15:1135-1154. [PMID: 30672955 DOI: 10.1039/c8sm02285b] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The sustenance of life depends on the high degree of organization that prevails through different levels of living organisms, from subcellular structures such as biomolecular complexes and organelles to tissues and organs. The physical origin of such organization is not fully understood, and even though it is clear that cells and organisms cannot maintain their integrity without consuming energy, there is growing evidence that individual assembly processes can be thermodynamically driven and occur spontaneously due to changes in thermodynamic variables such as intermolecular interactions and concentration. Understanding the phase separation in vivo requires a multidisciplinary approach, integrating the theory and physics of phase separation with experimental and computational techniques. This paper aims at providing a brief overview of the physics of phase separation and its biological implications, with a particular focus on the assembly of membraneless organelles. We discuss the underlying physical principles of phase separation from its thermodynamics to its kinetics. We also overview the wide range of methods utilized for experimental verification and characterization of phase separation of membraneless organelles, as well as the utility of molecular simulations rooted in thermodynamics and statistical physics in understanding the governing principles of thermodynamically driven biological self-assembly processes.
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Affiliation(s)
- Hanieh Falahati
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA.
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37
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Razin SV. Structural-Functional Organization of the Eukaryotic Cell Nucleus and Transcription Regulation: Introduction to This Special Issue of Biochemistry (Moscow). BIOCHEMISTRY (MOSCOW) 2018; 83:299-301. [PMID: 29626917 DOI: 10.1134/s0006297918040016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This issue of Biochemistry (Moscow) is devoted to the cell nucleus and mechanisms of transcription regulation. Over the years, biochemical processes in the cell nucleus have been studied in isolation, outside the context of their spatial organization. Now it is clear that segregation of functional processes within a compartmentalized cell nucleus is very important for the implementation of basic genetic processes. The functional compartmentalization of the cell nucleus is closely related to the spatial organization of the genome, which in turn plays a key role in the operation of epigenetic mechanisms. In this issue of Biochemistry (Moscow), we present a selection of review articles covering the functional architecture of the eukaryotic cell nucleus, the mechanisms of genome folding, the role of stochastic processes in establishing 3D architecture of the genome, and the impact of genome spatial organization on transcription regulation.
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Affiliation(s)
- S V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
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38
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Hancock R. Crowding, Entropic Forces, and Confinement: Crucial Factors for Structures and Functions in the Cell Nucleus. BIOCHEMISTRY (MOSCOW) 2018; 83:326-337. [PMID: 29626920 DOI: 10.1134/s0006297918040041] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The view of the cell nucleus as a crowded system of colloid particles and that chromosomes are giant self-avoiding polymers is stimulating rapid advances in our understanding of its structure and activities, thanks to concepts and experimental methods from colloid, polymer, soft matter, and nano sciences and to increased computational power for simulating macromolecules and polymers. This review summarizes current understanding of some characteristics of the molecular environment in the nucleus, of how intranuclear compartments are formed, and of how the genome is highly but precisely compacted, and underlines the crucial, subtle, and sometimes unintuitive effects on structures and reactions of entropic forces caused by the high concentration of macromolecules in the nucleus.
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Affiliation(s)
- R Hancock
- Biosystems Group, Biotechnology Centre, Silesian University of Technology, Poland and Laval University Cancer Research Centre, Québec, G1R2J6, Canada.
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39
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Fernández-Ponce C, Durán-Ruiz MC, Narbona-Sánchez I, Muñoz-Miranda JP, Arbulo-Echevarria MM, Serna-Sanz A, Baumann C, Litrán R, Aguado E, Bloch W, García-Cozar F. Ultrastructural Localization and Molecular Associations of HCV Capsid Protein in Jurkat T Cells. Front Microbiol 2018; 8:2595. [PMID: 29354102 PMCID: PMC5758585 DOI: 10.3389/fmicb.2017.02595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 12/12/2017] [Indexed: 12/24/2022] Open
Abstract
Hepatitis C virus core protein is a highly basic viral protein that multimerizes with itself to form the viral capsid. When expressed in CD4+ T lymphocytes, it can induce modifications in several essential cellular and biological networks. To shed light on the mechanisms underlying the alterations caused by the viral protein, we have analyzed HCV-core subcellular localization and its associations with host proteins in Jurkat T cells. In order to investigate the intracellular localization of Hepatitis C virus core protein, we have used a lentiviral system to transduce Jurkat T cells and subsequently localize the protein using immunoelectron microscopy techniques. We found that in Jurkat T cells, Hepatitis C virus core protein mostly localizes in the nucleus and specifically in the nucleolus. In addition, we performed pull-down assays combined with Mass Spectrometry Analysis, to identify proteins that associate with Hepatitis C virus core in Jurkat T cells. We found proteins such as NOLC1, PP1γ, ILF3, and C1QBP implicated in localization and/or traffic to the nucleolus. HCV-core associated proteins are implicated in RNA processing and RNA virus infection as well as in functions previously shown to be altered in Hepatitis C virus core expressing CD4+ T cells, such as cell cycle delay, decreased proliferation, and induction of a regulatory phenotype. Thus, in the current work, we show the ultrastructural localization of Hepatitis C virus core and the first profile of HCV core associated proteins in T cells, and we discuss the functions and interconnections of these proteins in molecular networks where relevant biological modifications have been described upon the expression of Hepatitis C virus core protein. Thereby, the current work constitutes a necessary step toward understanding the mechanisms underlying HCV core mediated alterations that had been described in relevant biological processes in CD4+ T cells.
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Affiliation(s)
- Cecilia Fernández-Ponce
- Department of Biomedicine, Biotechnology and Public Health, University of Cadiz and Institute of Biomedical Research Cádiz (INIBICA), Cadiz, Spain
| | - Maria C Durán-Ruiz
- Department of Biomedicine, Biotechnology and Public Health, University of Cadiz and Institute of Biomedical Research Cádiz (INIBICA), Cadiz, Spain
| | - Isaac Narbona-Sánchez
- Department of Biomedicine, Biotechnology and Public Health, University of Cadiz and Institute of Biomedical Research Cádiz (INIBICA), Cadiz, Spain
| | - Juan P Muñoz-Miranda
- Department of Biomedicine, Biotechnology and Public Health, University of Cadiz and Institute of Biomedical Research Cádiz (INIBICA), Cadiz, Spain
| | - Mikel M Arbulo-Echevarria
- Department of Biomedicine, Biotechnology and Public Health, University of Cadiz and Institute of Biomedical Research Cádiz (INIBICA), Cadiz, Spain
| | | | | | - Rocío Litrán
- Department of Condensed Matter Physics, University of Cádiz, Puerto Real, Spain
| | - Enrique Aguado
- Department of Biomedicine, Biotechnology and Public Health, University of Cadiz and Institute of Biomedical Research Cádiz (INIBICA), Cadiz, Spain
| | - Wilhelm Bloch
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany
| | - Francisco García-Cozar
- Department of Biomedicine, Biotechnology and Public Health, University of Cadiz and Institute of Biomedical Research Cádiz (INIBICA), Cadiz, Spain
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40
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Vargas-Lara F, Starr FW, Douglas JF. Molecular rigidity and enthalpy-entropy compensation in DNA melting. SOFT MATTER 2017; 13:8309-8330. [PMID: 29057399 DOI: 10.1039/c7sm01220a] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Enthalpy-entropy compensation (EEC) is observed in diverse molecular binding processes of importance to living systems and manufacturing applications, but this widely occurring phenomenon is not sufficiently understood from a molecular physics standpoint. To gain insight into this fundamental problem, we focus on the melting of double-stranded DNA (dsDNA) since measurements exhibiting EEC are extensive for nucleic acid complexes and existing coarse-grained models of DNA allow us to explore the influence of changes in molecular parameters on the energetic parameters by using molecular dynamics simulations. Previous experimental and computational studies have indicated a correlation between EEC and changes in molecular rigidity in certain binding-unbinding processes, and, correspondingly, we estimate measures of DNA molecular rigidity under a wide range of conditions, along with resultant changes in the enthalpy and entropy of binding. In particular, we consider variations in dsDNA rigidity that arise from changes of intrinsic molecular rigidity such as varying the associative interaction strength between the DNA bases, the length of the DNA chains, and the bending stiffness of the individual DNA chains. We also consider extrinsic changes of molecular rigidity arising from the addition of polymer additives and geometrical confinement of DNA between parallel plates. All our computations confirm EEC and indicate that this phenomenon is indeed highly correlated with changes in molecular rigidity. However, two distinct patterns relating to how DNA rigidity influences the entropy of association emerge from our analysis. Increasing the intrinsic DNA rigidity increases the entropy of binding, but increases in molecular rigidity from external constraints decreases the entropy of binding. EEC arises in numerous synthetic and biological binding processes and we suggest that changes in molecular rigidity might provide a common origin of this ubiquitous phenomenon in the mutual binding and unbinding of complex molecules.
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Affiliation(s)
- Fernando Vargas-Lara
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
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41
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Nakano SI, Sugimoto N. Model studies of the effects of intracellular crowding on nucleic acid interactions. MOLECULAR BIOSYSTEMS 2017; 13:32-41. [PMID: 27819369 DOI: 10.1039/c6mb00654j] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Molecular interactions and reactions in living cells occur with high concentrations of background molecules and ions. Many research studies have shown that intracellular molecules have characteristics different from those obtained using simple aqueous solutions. To better understand the behavior of biomolecules in intracellular environments, biophysical experiments were conducted under cell-mimicking conditions in a test tube. It has been shown that the molecular environments at the physiological level of macromolecular crowding, spatial confinement, water activity and dielectric constant, have significant effects on the interactions of DNA and RNA for hybridization, higher-order folding, and catalytic activity. The experimental approaches using in vitro model systems are useful to reveal the origin of the environmental effects and to bridge the gap between the behaviors of nucleic acids in vitro and in vivo. This paper highlights the model experiments used to evaluate the influences of intracellular environment on nucleic acid interactions.
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Affiliation(s)
- Shu-Ichi Nakano
- Department of Nanobiochemistry, Faculty of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan.
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan. and Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
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42
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Abstract
Molecular self-assembly is the dominant form of chemical reaction in living systems, yet efforts at systems biology modeling are only beginning to appreciate the need for and challenges to accurate quantitative modeling of self-assembly. Self-assembly reactions are essential to nearly every important process in cell and molecular biology and handling them is thus a necessary step in building comprehensive models of complex cellular systems. They present exceptional challenges, however, to standard methods for simulating complex systems. While the general systems biology world is just beginning to deal with these challenges, there is an extensive literature dealing with them for more specialized self-assembly modeling. This review will examine the challenges of self-assembly modeling, nascent efforts to deal with these challenges in the systems modeling community, and some of the solutions offered in prior work on self-assembly specifically. The review concludes with some consideration of the likely role of self-assembly in the future of complex biological system models more generally.
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Affiliation(s)
- Marcus Thomas
- Computational Biology Department, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States of America. Joint Carnegie Mellon University/University of Pittsburgh Ph.D. Program in Computational Biology, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States of America
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43
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Caudron-Herger M, Pankert T, Rippe K. Regulation of nucleolus assembly by non-coding RNA polymerase II transcripts. Nucleus 2017; 7:308-18. [PMID: 27416361 DOI: 10.1080/19491034.2016.1190890] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The nucleolus is a nuclear subcompartment for tightly regulated rRNA production and ribosome subunit biogenesis. It also acts as a cellular stress sensor and can release enriched factors in response to cellular stimuli. Accordingly, the content and structure of the nucleolus change dynamically, which is particularly evident during cell cycle progression: the nucleolus completely disassembles during mitosis and reassembles in interphase. Although the mechanisms that drive nucleolar (re)organization have been the subject of a number of studies, they are only partly understood. Recently, we identified Alu element-containing RNA polymerase II transcripts (aluRNAs) as important for nucleolar structure and rRNA synthesis. Integrating these findings with studies on the liquid droplet-like nature of the nucleolus leads us to propose a model on how RNA polymerase II transcripts could regulate the assembly of the nucleolus in response to external stimuli and during cell cycle progression.
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Affiliation(s)
- Maïwen Caudron-Herger
- a RNA Biology and Cancer, German Cancer Research Center (DKFZ) , Heidelberg , Germany
| | - Teresa Pankert
- b Genome Organization & Function, German Cancer Research Center (DKFZ) and BioQuant Center , Heidelberg , Germany
| | - Karsten Rippe
- b Genome Organization & Function, German Cancer Research Center (DKFZ) and BioQuant Center , Heidelberg , Germany
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44
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Banani SF, Lee HO, Hyman AA, Rosen MK. Biomolecular condensates: organizers of cellular biochemistry. Nat Rev Mol Cell Biol 2017; 18:285-298. [PMID: 28225081 PMCID: PMC7434221 DOI: 10.1038/nrm.2017.7] [Citation(s) in RCA: 3162] [Impact Index Per Article: 451.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Biomolecular condensates are micron-scale compartments in eukaryotic cells that lack surrounding membranes but function to concentrate proteins and nucleic acids. These condensates are involved in diverse processes, including RNA metabolism, ribosome biogenesis, the DNA damage response and signal transduction. Recent studies have shown that liquid-liquid phase separation driven by multivalent macromolecular interactions is an important organizing principle for biomolecular condensates. With this physical framework, it is now possible to explain how the assembly, composition, physical properties and biochemical and cellular functions of these important structures are regulated.
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Affiliation(s)
- Salman F. Banani
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Hyun O. Lee
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Anthony A. Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Michael K. Rosen
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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45
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Stroberg W, Schnell S. On the origin of non-membrane-bound organelles, and their physiological function. J Theor Biol 2017; 434:42-49. [PMID: 28392184 DOI: 10.1016/j.jtbi.2017.04.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 03/29/2017] [Accepted: 04/05/2017] [Indexed: 12/28/2022]
Abstract
The origin of cellular compartmentalization has long been viewed as paralleling the origin of life. Historically, membrane-bound organelles have been presented as the canonical examples of compartmentalization. However, recent interest in cellular compartments that lack encompassing membranes has forced biologists to reexamine the form and function of cellular organization. The intracellular environment is now known to be full of transient macromolecular structures that are essential to cellular function, especially in relation to RNA regulation. Here we discuss key findings regarding the physicochemical principles governing the formation and function of non-membrane-bound organelles. Particularly, we focus how the physiological function of non-membrane-bound organelles depends on their molecular structure. We also present a potential mechanism for the formation of non-membrane-bound organelles. We conclude with suggestions for future inquiry into the diversity of roles played by non-membrane bound organelles.
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Affiliation(s)
- Wylie Stroberg
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Santiago Schnell
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Computational Medicine & Bioinformatics, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Brehm Center for Diabetes Research, University of Michigan Medical School, Ann Arbor, MI 48105, USA.
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46
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Mourão MA, Hakim JB, Schnell S. Connecting the dots: the effects of macromolecular crowding on cell physiology. Biophys J 2016; 107:2761-2766. [PMID: 25517143 DOI: 10.1016/j.bpj.2014.10.051] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/17/2014] [Accepted: 10/23/2014] [Indexed: 10/25/2022] Open
Abstract
The physicochemical properties of cellular environments with a high macromolecular content have been systematically characterized to explain differences observed in the diffusion coefficients, kinetics parameters, and thermodynamic properties of proteins inside and outside of cells. However, much less attention has been given to the effects of macromolecular crowding on cell physiology. Here, we review recent findings that shed some light on the role of crowding in various cellular processes, such as reduction of biochemical activities, structural reorganization of the cytoplasm, cytoplasm fluidity, and cellular dormancy. We conclude by presenting some unresolved problems that require the attention of biophysicists, biochemists, and cell physiologists. Although it is still underappreciated, macromolecular crowding plays a critical role in life as we know it.
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Affiliation(s)
- Márcio A Mourão
- Mathematical Biosciences Institute, Ohio State University, Columbus, Ohio
| | - Joe B Hakim
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Santiago Schnell
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan; Department of Computational Medicine & Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan; Brehm Center for Diabetes Research, University of Michigan Medical School, Ann Arbor, Michigan.
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47
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Golov AK, Gavrilov AA, Razin SV. The Role of Crowding Forces in Juxtaposing β-Globin Gene Domain Remote Regulatory Elements in Mouse Erythroid Cells. PLoS One 2015; 10:e0139855. [PMID: 26436546 PMCID: PMC4593578 DOI: 10.1371/journal.pone.0139855] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/11/2015] [Indexed: 01/03/2023] Open
Abstract
The extremely high concentration of macromolecules in a eukaryotic cell nucleus indicates that the nucleoplasm is a crowded macromolecular solution in which large objects tend to gather together due to crowding forces. It has been shown experimentally that crowding forces support the integrity of various nuclear compartments. However, little is known about their role in control of chromatin dynamics in vivo. Here, we experimentally addressed the possible role of crowding forces in spatial organization of the eukaryotic genome. Using the mouse β-globin domain as a model, we demonstrated that spatial juxtaposition of the remote regulatory elements of this domain in globin-expressing cells may be lost and restored by manipulation of the level of macromolecular crowding. In addition to proving the role of crowding forces in shaping interphase chromatin, our results suggest that the folding of the chromatin fiber is a major determinant in juxtaposing remote genomic elements.
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Affiliation(s)
- Arkadiy K. Golov
- Institute of Gene Biology of the Russian Academy of Sciences, Vavilov Street 34/5, 119334, Moscow, Russia
| | - Alexey A. Gavrilov
- Institute of Gene Biology of the Russian Academy of Sciences, Vavilov Street 34/5, 119334, Moscow, Russia
| | - Sergey V. Razin
- Institute of Gene Biology of the Russian Academy of Sciences, Vavilov Street 34/5, 119334, Moscow, Russia
- Molecular Biology Department, Biological Faculty, Lomonosov Moscow State University, 119992, Moscow, Russia
- * E-mail:
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48
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Oh I, Choi S, Jung Y, Kim JS. Phase separation of a Lennard-Jones fluid interacting with a long, condensed polymer chain: implications for the nuclear body formation near chromosomes. SOFT MATTER 2015; 11:6450-6459. [PMID: 26179211 DOI: 10.1039/c5sm01096a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Phase separation in a biological cell nucleus occurs in a heterogeneous environment filled with a high density of chromatins and thus it is inevitably influenced by interactions with chromatins. As a model system of nuclear body formation in a cell nucleus filled with chromatins, we simulate the phase separation of a low-density Lennard-Jones (LJ) fluid interacting with a long, condensed polymer chain. The influence of the density variation of LJ particles above and below the phase boundary and the role of attractive interactions between LJ particles and polymer segments are investigated at a fixed value of strong self-interaction between LJ particles. For a density of LJ particles above the phase boundary, phase separation occurs and a dense domain of LJ particles forms irrespective of interactions with the condensed polymer chain whereas its localization relative to the polymer chain is determined by the LJ-polymer attraction strength. Especially, in the case of moderately weak attractions, the domain forms separately from the polymer chain and subsequently associates with the polymer chain. When the density is below the phase boundary, however, the formation of a dense domain is possible only when the LJ-polymer attraction is strong enough, for which the domain grows in direct contact with the interacting polymer chain. In this work, different growth behaviors of LJ particles result from the differences in the density of LJ particles and in the LJ-polymer interaction, and this work suggests that the distinct formation of activity-dependent and activity-independent nuclear bodies (NBs) in a cell nucleus may originate from the differences in the concentrations of body-specific NB components and in their interaction with chromatins.
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Affiliation(s)
- Inrok Oh
- Department of Chemistry, Seoul National University, Seoul 151-747, Republic of Korea.
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Pliss A, Peng X, Liu L, Kuzmin A, Wang Y, Qu J, Li Y, Prasad PN. Single Cell Assay for Molecular Diagnostics and Medicine: Monitoring Intracellular Concentrations of Macromolecules by Two-photon Fluorescence Lifetime Imaging. Theranostics 2015; 5:919-30. [PMID: 26155309 PMCID: PMC4493531 DOI: 10.7150/thno.11863] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/03/2015] [Indexed: 02/01/2023] Open
Abstract
Molecular organization of a cell is dynamically transformed along the course of cellular physiological processes, pathologic developments or derived from interactions with drugs. The capability to measure and monitor concentrations of macromolecules in a single cell would greatly enhance studies of cellular processes in heterogeneous populations. In this communication, we introduce and experimentally validate a bio-analytical single-cell assay, wherein the overall concentration of macromolecules is estimated in specific subcellular domains, such as structure-function compartments of the cell nucleus as well as in nucleoplasm. We describe quantitative mapping of local biomolecular concentrations, either intrinsic relating to the functional and physiological state of a cell, or altered by a therapeutic drug action, using two-photon excited fluorescence lifetime imaging (FLIM). The proposed assay utilizes a correlation between the fluorescence lifetime of fluorophore and the refractive index of its microenvironment varying due to changes in the concentrations of macromolecules, mainly proteins. Two-photon excitation in Near-Infra Red biological transparency window reduced the photo-toxicity in live cells, as compared with a conventional single-photon approach. Using this new assay, we estimated average concentrations of proteins in the compartments of nuclear speckles and in the nucleoplasm at ~150 mg/ml, and in the nucleolus at ~284 mg/ml. Furthermore, we show a profound influence of pharmaceutical inhibitors of RNA synthesis on intracellular protein density. The approach proposed here will significantly advance theranostics, and studies of drug-cell interactions at the single-cell level, aiding development of personal molecular medicine.
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50
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Efremov AK, Qu Y, Maruyama H, Lim CJ, Takeyasu K, Yan J. Transcriptional Repressor TrmBL2 from Thermococcus kodakarensis Forms Filamentous Nucleoprotein Structures and Competes with Histones for DNA Binding in a Salt- and DNA Supercoiling-dependent Manner. J Biol Chem 2015; 290:15770-15784. [PMID: 25931116 DOI: 10.1074/jbc.m114.626705] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Indexed: 11/06/2022] Open
Abstract
Architectural DNA proteins play important roles in the chromosomal DNA organization and global gene regulation in living cells. However, physiological functions of some DNA-binding proteins from archaea remain unclear. Recently, several abundant DNA-architectural proteins including histones, Alba, and TrmBL2 have been identified in model euryarchaeon Thermococcus kodakarensis. Although histones and Alba proteins have been previously characterized, the DNA binding properties of TrmBL2 and its interplay with the other major architectural proteins in the chromosomal DNA organization and gene transcription regulation remain largely unexplored. Here, we report single-DNA studies showing that at low ionic strength (<300 mM KCl), TrmBL2 binds to DNA largely in non-sequence-specific manner with positive cooperativity, resulting in formation of stiff nucleoprotein filamentous patches, whereas at high ionic strength (>300 mM KCl) TrmBL2 switches to more sequence-specific interaction, suggesting the presence of high affinity TrmBL2-filament nucleation sites. Furthermore, in vitro assays indicate the existence of DNA binding competition between TrmBL2 and archaeal histones B from T. kodakarensis, which can be strongly modulated by DNA supercoiling and ionic strength of surrounding solution. Overall, these results advance our understanding of TrmBL2 DNA binding properties and provide important insights into potential functions of architectural proteins in nucleoid organization and gene regulation in T. kodakarensis.
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Affiliation(s)
- Artem K Efremov
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore 117546, Singapore
| | - Yuanyuan Qu
- Centre for Bioimaging Sciences, National University of Singapore, Singapore 117546, Singapore; Department of Physics, National University of Singapore, Singapore 117542, Singapore; School of Physics, Shandong University, Jinan 250100, China
| | - Hugo Maruyama
- Department of Bacteriology, Osaka Dental University, Hirakata 573-1121, Japan
| | - Ci J Lim
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore 117546, Singapore; National University of Singapore Graduate School for Integrative Sciences and Engineering, Singapore 119077
| | - Kunio Takeyasu
- Laboratory of Plasma Membrane and Nuclear Signaling, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan.
| | - Jie Yan
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore 117546, Singapore; Department of Physics, National University of Singapore, Singapore 117542, Singapore; National University of Singapore Graduate School for Integrative Sciences and Engineering, Singapore 119077.
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