1
|
Eltayeb A, Al-Sarraj F, Alharbi M, Albiheyri R, Mattar EH, Abu Zeid IM, Bouback TA, Bamagoos A, Uversky VN, Rubio-Casillas A, Redwan EM. Intrinsic factors behind long COVID: IV. Hypothetical roles of the SARS-CoV-2 nucleocapsid protein and its liquid-liquid phase separation. J Cell Biochem 2024; 125:e30530. [PMID: 38349116 DOI: 10.1002/jcb.30530] [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: 09/09/2023] [Revised: 01/10/2024] [Accepted: 01/24/2024] [Indexed: 03/12/2024]
Abstract
When the SARS-CoV-2 virus infects humans, it leads to a condition called COVID-19 that has a wide spectrum of clinical manifestations, from no symptoms to acute respiratory distress syndrome. The virus initiates damage by attaching to the ACE-2 protein on the surface of endothelial cells that line the blood vessels and using these cells as hosts for replication. Reactive oxygen species levels are increased during viral replication, which leads to oxidative stress. About three-fifths (~60%) of the people who get infected with the virus eradicate it from their body after 28 days and recover their normal activity. However, a large fraction (~40%) of the people who are infected with the virus suffer from various symptoms (anosmia and/or ageusia, fatigue, cough, myalgia, cognitive impairment, insomnia, dyspnea, and tachycardia) beyond 12 weeks and are diagnosed with a syndrome called long COVID. Long-term clinical studies in a group of people who contracted SARS-CoV-2 have been contrasted with a noninfected matched group of people. A subset of infected people can be distinguished by a set of cytokine markers to have persistent, low-grade inflammation and often self-report two or more bothersome symptoms. No medication can alleviate their symptoms efficiently. Coronavirus nucleocapsid proteins have been investigated extensively as potential drug targets due to their key roles in virus replication, among which is their ability to bind their respective genomic RNAs for incorporation into emerging virions. This review highlights basic studies of the nucleocapsid protein and its ability to undergo liquid-liquid phase separation. We hypothesize that this ability of the nucleocapsid protein for phase separation may contribute to long COVID. This hypothesis unlocks new investigation angles and could potentially open novel avenues for a better understanding of long COVID and treating this condition.
Collapse
Affiliation(s)
- Ahmed Eltayeb
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Faisal Al-Sarraj
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mona Alharbi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Raed Albiheyri
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Centre of Excellence in Bionanoscience Research, King Abdulaziz University, Jeddah, Saudi Arabia
- Immunology Unit, King Fahad Medical Research Centre, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ehab H Mattar
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Isam M Abu Zeid
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Thamer A Bouback
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Atif Bamagoos
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
- Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Moscow Region, Russia
| | - Alberto Rubio-Casillas
- Autlan Regional Hospital, Health Secretariat, Autlan, Jalisco, Mexico
- Biology Laboratory, Autlan Regional Preparatory School, University of Guadalajara, Autlan, Jalisco, Mexico
| | - Elrashdy M Redwan
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Centre of Excellence in Bionanoscience Research, King Abdulaziz University, Jeddah, Saudi Arabia
| |
Collapse
|
2
|
Stortz M, Presman DM, Levi V. Transcriptional condensates: a blessing or a curse for gene regulation? Commun Biol 2024; 7:187. [PMID: 38365945 PMCID: PMC10873363 DOI: 10.1038/s42003-024-05892-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 02/06/2024] [Indexed: 02/18/2024] Open
Abstract
Whether phase-separation is involved in the organization of the transcriptional machinery and if it aids or inhibits the transcriptional process is a matter of intense debate. In this Mini Review, we will cover the current knowledge regarding the role of transcriptional condensates on gene expression regulation. We will summarize the latest discoveries on the relationship between condensate formation, genome organization, and transcriptional activity, focusing on the strengths and weaknesses of the experimental approaches used to interrogate these aspects of transcription in living cells. Finally, we will discuss the challenges for future research.
Collapse
Grants
- PICT 2020-00818 Ministry of Science, Technology and Productive Innovation, Argentina | Agencia Nacional de Promoción Científica y Tecnológica (National Agency for Science and Technology, Argentina)
- PICT-2018-1921 Ministry of Science, Technology and Productive Innovation, Argentina | Agencia Nacional de Promoción Científica y Tecnológica (National Agency for Science and Technology, Argentina)
- PICT 2019-0397 Ministry of Science, Technology and Productive Innovation, Argentina | Agencia Nacional de Promoción Científica y Tecnológica (National Agency for Science and Technology, Argentina)
- 20020190100101BA University of Buenos Aires | Secretaría de Ciencia y Técnica, Universidad de Buenos Aires (Secretaría de Ciencia y Técnica de la Universidad de Buenos Aires)
- 2022-11220210100212CO Consejo Nacional de Investigaciones Científicas y Técnicas (National Scientific and Technical Research Council)
Collapse
Affiliation(s)
- Martin Stortz
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Diego M Presman
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, C1428EGA, Argentina.
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina.
| | - Valeria Levi
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina.
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina.
| |
Collapse
|
3
|
Mann R, Notani D. Transcription factor condensates and signaling driven transcription. Nucleus 2023; 14:2205758. [PMID: 37129580 PMCID: PMC10155639 DOI: 10.1080/19491034.2023.2205758] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 04/10/2023] [Accepted: 04/19/2023] [Indexed: 05/03/2023] Open
Abstract
Transcription Factor (TF) condensates are a heterogenous mix of RNA, DNA, and multiple co-factor proteins capable of modulating the transcriptional response of the cell. The dynamic nature and the spatial location of TF-condensates in the 3D nuclear space is believed to provide a fast response, which is on the same pace as the signaling cascade and yet ever-so-specific in the crowded environment of the nucleus. However, the current understanding of how TF-condensates can achieve these feet so quickly and efficiently is still unclear. In this review, we draw parallels with other protein condensates and share our speculations on how the nucleus uses these TF-condensates to achieve high transcriptional specificity and fidelity. We discuss the various constituents of TF-condensates, their properties, and the known and unknown functions of TF-condensates with a particular focus on steroid signaling-induced transcriptional programs.
Collapse
Affiliation(s)
- Rajat Mann
- National Centre for Biological Sciences, TIFR, Bangalore, India
| | - Dimple Notani
- National Centre for Biological Sciences, TIFR, Bangalore, India
| |
Collapse
|
4
|
Abstract
The human genome is organized into multiple structural layers, ranging from chromosome territories to progressively smaller substructures, such as topologically associating domains (TADs) and chromatin loops. These substructures, collectively referred to as long-range chromatin interactions (LRIs), have a significant role in regulating gene expression. TADs are regions of the genome that harbour groups of genes and regulatory elements that frequently interact with each other and are insulated from other regions, thereby preventing widespread uncontrolled DNA contacts. Chromatin loops formed within TADs through enhancer and promoter interactions are elastic, allowing transcriptional heterogeneity and stochasticity. Over the past decade, it has become evident that the 3D genome structure, also referred to as the chromatin architecture, is central to many transcriptional cellular decisions. In this Review, we delve into the intricate relationship between steroid receptors and LRIs, discussing how steroid receptors interact with and modulate these chromatin interactions. Genetic alterations in the many processes involved in organizing the nuclear architecture are often associated with the development of hormone-dependent cancers. A better understanding of the interplay between architectural proteins and hormone regulatory networks can ultimately be exploited to develop improved approaches for cancer treatment.
Collapse
Affiliation(s)
- Theophilus T Tettey
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Lorenzo Rinaldi
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, MD, USA.
| |
Collapse
|
5
|
Tav C, Fournier É, Fournier M, Khadangi F, Baguette A, Côté MC, Silveira MAD, Bérubé-Simard FA, Bourque G, Droit A, Bilodeau S. Glucocorticoid stimulation induces regionalized gene responses within topologically associating domains. Front Genet 2023; 14:1237092. [PMID: 37576549 PMCID: PMC10413275 DOI: 10.3389/fgene.2023.1237092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/07/2023] [Indexed: 08/15/2023] Open
Abstract
Transcription-factor binding to cis-regulatory regions regulates the gene expression program of a cell, but occupancy is often a poor predictor of the gene response. Here, we show that glucocorticoid stimulation led to the reorganization of transcriptional coregulators MED1 and BRD4 within topologically associating domains (TADs), resulting in active or repressive gene environments. Indeed, we observed a bias toward the activation or repression of a TAD when their activities were defined by the number of regions gaining and losing MED1 and BRD4 following dexamethasone (Dex) stimulation. Variations in Dex-responsive genes at the RNA levels were consistent with the redistribution of MED1 and BRD4 at the associated cis-regulatory regions. Interestingly, Dex-responsive genes without the differential recruitment of MED1 and BRD4 or binding by the glucocorticoid receptor were found within TADs, which gained or lost MED1 and BRD4, suggesting a role of the surrounding environment in gene regulation. However, the amplitude of the response of Dex-regulated genes was higher when the differential recruitment of the glucocorticoid receptor and transcriptional coregulators was observed, reaffirming the role of transcription factor-driven gene regulation and attributing a lesser role to the TAD environment. These results support a model where a signal-induced transcription factor induces a regionalized effect throughout the TAD, redefining the notion of direct and indirect effects of transcription factors on target genes.
Collapse
Affiliation(s)
- Christophe Tav
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
| | - Éric Fournier
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
| | - Michèle Fournier
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Fatemeh Khadangi
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Audrey Baguette
- Department of Human Genetics, Faculty of Medicine, McGill University, Montréal, QC, Canada
| | - Maxime C. Côté
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Maruhen A. D. Silveira
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Félix-Antoine Bérubé-Simard
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Guillaume Bourque
- Department of Human Genetics, Faculty of Medicine, McGill University, Montréal, QC, Canada
- Canadian Center for Computational Genomics, McGill University, Montréal, QC, Canada
| | - Arnaud Droit
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
- Centre de Recherche du CHU de Québec—Université Laval, Axe Endocrinologie et Néphrologie, Québec, QC, Canada
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Steve Bilodeau
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
- Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| |
Collapse
|
6
|
Guo G, Wang X, Zhang Y, Li T. Sequence variations of phase-separating proteins and resources for studying biomolecular condensates. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1119-1132. [PMID: 37464880 PMCID: PMC10423696 DOI: 10.3724/abbs.2023131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 06/06/2023] [Indexed: 07/20/2023] Open
Abstract
Phase separation (PS) is an important mechanism underlying the formation of biomolecular condensates. Physiological condensates are associated with numerous biological processes, such as transcription, immunity, signaling, and synaptic transmission. Changes in particular amino acids or segments can disturb the protein's phase behavior and interactions with other biomolecules in condensates. It is thus presumed that variations in the phase-separating-prone domains can significantly impact the properties and functions of condensates. The dysfunction of condensates contributes to a number of pathological processes. Pharmacological perturbation of these condensates is proposed as a promising way to restore physiological states. In this review, we characterize the variations observed in PS proteins that lead to aberrant biomolecular compartmentalization. We also showcase recent advancements in bioinformatics of membraneless organelles (MLOs), focusing on available databases useful for screening PS proteins and describing endogenous condensates, guiding researchers to seek the underlying pathogenic mechanisms of biomolecular condensates.
Collapse
Affiliation(s)
- Gaigai Guo
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
| | - Xinxin Wang
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
| | - Yi Zhang
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
| | - Tingting Li
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
- Key Laboratory for NeuroscienceMinistry of Education/National Health Commission of ChinaPeking UniversityBeijing100191China
| |
Collapse
|
7
|
Meeussen JVW, Pomp W, Brouwer I, de Jonge WJ, Patel HP, Lenstra TL. Transcription factor clusters enable target search but do not contribute to target gene activation. Nucleic Acids Res 2023; 51:5449-5468. [PMID: 36987884 PMCID: PMC10287935 DOI: 10.1093/nar/gkad227] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 03/06/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Many transcription factors (TFs) localize in nuclear clusters of locally increased concentrations, but how TF clustering is regulated and how it influences gene expression is not well understood. Here, we use quantitative microscopy in living cells to study the regulation and function of clustering of the budding yeast TF Gal4 in its endogenous context. Our results show that Gal4 forms clusters that overlap with the GAL loci. Cluster number, density and size are regulated in different growth conditions by the Gal4-inhibitor Gal80 and Gal4 concentration. Gal4 truncation mutants reveal that Gal4 clustering is facilitated by, but does not completely depend on DNA binding and intrinsically disordered regions. Moreover, we discover that clustering acts as a double-edged sword: self-interactions aid TF recruitment to target genes, but recruited Gal4 molecules that are not DNA-bound do not contribute to, and may even inhibit, transcription activation. We propose that cells need to balance the different effects of TF clustering on target search and transcription activation to facilitate proper gene expression.
Collapse
Affiliation(s)
- Joseph V W Meeussen
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, The Netherlands
| | - Wim Pomp
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, The Netherlands
| | - Ineke Brouwer
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, The Netherlands
| | - Wim J de Jonge
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, The Netherlands
| | - Heta P Patel
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, The Netherlands
| | - Tineke L Lenstra
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, The Netherlands
| |
Collapse
|
8
|
van Staalduinen J, van Staveren T, Grosveld F, Wendt KS. Live-cell imaging of chromatin contacts opens a new window into chromatin dynamics. Epigenetics Chromatin 2023; 16:27. [PMID: 37349773 PMCID: PMC10288748 DOI: 10.1186/s13072-023-00503-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 06/15/2023] [Indexed: 06/24/2023] Open
Abstract
Our understanding of the organization of the chromatin fiber within the cell nucleus has made great progress in the last few years. High-resolution techniques based on next-generation sequencing as well as optical imaging that can investigate chromatin conformations down to the single cell level have revealed that chromatin structure is highly heterogeneous at the level of the individual allele. While TAD boundaries and enhancer-promoter pairs emerge as hotspots of 3D proximity, the spatiotemporal dynamics of these different types of chromatin contacts remain largely unexplored. Investigation of chromatin contacts in live single cells is necessary to close this knowledge gap and further enhance the current models of 3D genome organization and enhancer-promoter communication. In this review, we first discuss the potential of single locus labeling to study architectural and enhancer-promoter contacts and provide an overview of the available single locus labeling techniques such as FROS, TALE, CRISPR-dCas9 and ANCHOR, and discuss the latest developments and applications of these systems.
Collapse
Affiliation(s)
- Jente van Staalduinen
- Department of Cell Biology, Erasmus MC, Dr. Molewaterplein 50, 3015 GE, Rotterdam, The Netherlands
| | - Thomas van Staveren
- Department of Cell Biology, Erasmus MC, Dr. Molewaterplein 50, 3015 GE, Rotterdam, The Netherlands
| | - Frank Grosveld
- Department of Cell Biology, Erasmus MC, Dr. Molewaterplein 50, 3015 GE, Rotterdam, The Netherlands
| | - Kerstin S Wendt
- Department of Cell Biology, Erasmus MC, Dr. Molewaterplein 50, 3015 GE, Rotterdam, The Netherlands.
| |
Collapse
|
9
|
Sołtys K, Ożyhar A. Phase separation propensity of the intrinsically disordered AB region of human RXRβ. Cell Commun Signal 2023; 21:92. [PMID: 37143076 PMCID: PMC10157963 DOI: 10.1186/s12964-023-01113-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 03/25/2023] [Indexed: 05/06/2023] Open
Abstract
RXRβ is one of three subtypes of human retinoid X receptor (RXR), a transcription factor that belongs to the nuclear receptor superfamily. Its expression can be detected in almost all tissues. In contrast to other subtypes - RXRα and RXRγ - RXRβ has the longest and unique N-terminal sequence called the AB region, which harbors a ligand-independent activation function. In contrast to the functional properties of this sequence, the molecular properties of the AB region of human RXRβ (AB_hRXRB) have not yet been characterized. Here, we present a systematic biochemical and biophysical analysis of recombinant AB_hRXRB, along with in silico examinations, which demonstrate that AB_hRXRB exhibits properties of a coil-like intrinsically disordered region. AB_hRXRB possesses a flexible structure that is able to adopt a more ordered conformation under the influence of different environmental factors. Interestingly, AB_hRXRB promotes the formation of liquid-liquid phase separation (LLPS), a phenomenon previously observed for the AB region of another human subtype of RXR - RXRγ (AB_hRXRG). Although both AB regions seem to be similar in terms of their ability to induce phase separation, they clearly differ in the sensitivity to factors driving and regulating LLPS. This distinct LLPS response to environmental factors driven by the unique amino acid compositions of AB_hRXRB and AB_hRXRG can be significant for the specific modulation of the transcriptional activation of target genes by different subtypes of RXR. Video Abstract.
Collapse
Affiliation(s)
- Katarzyna Sołtys
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
| | - Andrzej Ożyhar
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland
| |
Collapse
|
10
|
Oses C, Francia MG, Verneri P, Vazquez Echegaray C, Guberman AS, Levi V. The dynamical organization of the core pluripotency transcription factors responds to differentiation cues in early S-phase. Front Cell Dev Biol 2023; 11:1125015. [PMID: 37215075 PMCID: PMC10192714 DOI: 10.3389/fcell.2023.1125015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 04/21/2023] [Indexed: 05/24/2023] Open
Abstract
DNA replication in stem cells is a major challenge for pluripotency preservation and cell fate decisions. This process involves massive changes in the chromatin architecture and the reorganization of many transcription-related molecules in different spatial and temporal scales. Pluripotency is controlled by the master transcription factors (TFs) OCT4, SOX2 and NANOG that partition into condensates in the nucleus of embryonic stem cells. These condensates are proposed to play relevant roles in the regulation of gene expression and the maintenance of pluripotency. Here, we asked whether the dynamical distribution of the pluripotency TFs changes during the cell cycle, particularly during DNA replication. Since the S phase is considered to be a window of opportunity for cell fate decisions, we explored if differentiation cues in G1 phase trigger changes in the distribution of these TFs during the subsequent S phase. Our results show a spatial redistribution of TFs condensates during DNA replication which was not directly related to chromatin compaction. Additionally, fluorescence fluctuation spectroscopy revealed TF-specific, subtle changes in the landscape of TF-chromatin interactions, consistent with their particularities as key players of the pluripotency network. Moreover, we found that differentiation stimuli in the preceding G1 phase triggered a relatively fast and massive reorganization of pluripotency TFs in early-S phase. Particularly, OCT4 and SOX2 condensates dissolved whereas the lifetimes of TF-chromatin interactions increased suggesting that the reorganization of condensates is accompanied with a change in the landscape of TF-chromatin interactions. Notably, NANOG showed impaired interactions with chromatin in stimulated early-S cells in line with its role as naïve pluripotency TF. Together, these findings provide new insights into the regulation of the core pluripotency TFs during DNA replication of embryonic stem cells and highlight their different roles at early differentiation stages.
Collapse
Affiliation(s)
- Camila Oses
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Marcos Gabriel Francia
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Paula Verneri
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Camila Vazquez Echegaray
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alejandra Sonia Guberman
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Valeria Levi
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| |
Collapse
|
11
|
Di Nunzio F, Uversky VN, Mouland AJ. Biomolecular condensates: insights into early and late steps of the HIV-1 replication cycle. Retrovirology 2023; 20:4. [PMID: 37029379 PMCID: PMC10081342 DOI: 10.1186/s12977-023-00619-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/16/2023] [Indexed: 04/09/2023] Open
Abstract
A rapidly evolving understanding of phase separation in the biological and physical sciences has led to the redefining of virus-engineered replication compartments in many viruses with RNA genomes. Condensation of viral, host and genomic and subgenomic RNAs can take place to evade the innate immunity response and to help viral replication. Divergent viruses prompt liquid-liquid phase separation (LLPS) to invade the host cell. During HIV replication there are several steps involving LLPS. In this review, we characterize the ability of individual viral and host partners that assemble into biomolecular condensates (BMCs). Of note, bioinformatic analyses predict models of phase separation in line with several published observations. Importantly, viral BMCs contribute to function in key steps retroviral replication. For example, reverse transcription takes place within nuclear BMCs, called HIV-MLOs while during late replication steps, retroviral nucleocapsid acts as a driver or scaffold to recruit client viral components to aid the assembly of progeny virions. Overall, LLPS during viral infections represents a newly described biological event now appreciated in the virology field, that can also be considered as an alternative pharmacological target to current drug therapies especially when viruses become resistant to antiviral treatment.
Collapse
Affiliation(s)
- Francesca Di Nunzio
- Advanced Molecular Virology Unit, Department of Virology, Institut Pasteur, Université Paris Cité, 75015, Paris, France
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Andrew J Mouland
- Lady Davis Institute at the Jewish General Hospital, Montréal, QC, H3T 1E2, Canada.
- Department of Microbiology and Immunology, McGill University, Montréal, QC, H3A 2B4, Canada.
- Department of Medicine, McGill University, Montréal, QC, H4A 3J1, Canada.
| |
Collapse
|
12
|
Chau BA, Chen V, Cochrane AW, Parent LJ, Mouland AJ. Liquid-liquid phase separation of nucleocapsid proteins during SARS-CoV-2 and HIV-1 replication. Cell Rep 2023; 42:111968. [PMID: 36640305 PMCID: PMC9790868 DOI: 10.1016/j.celrep.2022.111968] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 10/27/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
The leap of retroviruses and coronaviruses from animal hosts to humans has led to two ongoing pandemics and tens of millions of deaths worldwide. Retrovirus and coronavirus nucleocapsid proteins have been studied extensively as potential drug targets due to their central roles in virus replication, among which is their capacity to bind their respective genomic RNAs for packaging into nascent virions. This review focuses on fundamental studies of these nucleocapsid proteins and how their intrinsic abilities to condense through liquid-liquid phase separation (LLPS) contribute to viral replication. Therapeutic targeting of these condensates and methodological advances are also described to address future questions on how phase separation contributes to viral replication.
Collapse
Affiliation(s)
- Bao-An Chau
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Venessa Chen
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Alan W Cochrane
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Leslie J Parent
- Division of Infectious Diseases and Epidemiology, Departments of Medicine and Microbiology and Immunology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada; Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada.
| |
Collapse
|
13
|
Zogopoulos VL, Malatras A, Kyriakidis K, Charalampous C, Makrygianni EA, Duguez S, Koutsi MA, Pouliou M, Vasileiou C, Duddy WJ, Agelopoulos M, Chrousos GP, Iconomidou VA, Michalopoulos I. HGCA2.0: An RNA-Seq Based Webtool for Gene Coexpression Analysis in Homo sapiens. Cells 2023; 12:cells12030388. [PMID: 36766730 PMCID: PMC9913097 DOI: 10.3390/cells12030388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/09/2023] [Accepted: 01/19/2023] [Indexed: 01/24/2023] Open
Abstract
Genes with similar expression patterns in a set of diverse samples may be considered coexpressed. Human Gene Coexpression Analysis 2.0 (HGCA2.0) is a webtool which studies the global coexpression landscape of human genes. The website is based on the hierarchical clustering of 55,431 Homo sapiens genes based on a large-scale coexpression analysis of 3500 GTEx bulk RNA-Seq samples of healthy individuals, which were selected as the best representative samples of each tissue type. HGCA2.0 presents subclades of coexpressed genes to a gene of interest, and performs various built-in gene term enrichment analyses on the coexpressed genes, including gene ontologies, biological pathways, protein families, and diseases, while also being unique in revealing enriched transcription factors driving coexpression. HGCA2.0 has been successful in identifying not only genes with ubiquitous expression patterns, but also tissue-specific genes. Benchmarking showed that HGCA2.0 belongs to the top performing coexpression webtools, as shown by STRING analysis. HGCA2.0 creates working hypotheses for the discovery of gene partners or common biological processes that can be experimentally validated. It offers a simple and intuitive website design and user interface, as well as an API endpoint.
Collapse
Affiliation(s)
- Vasileios L. Zogopoulos
- Centre of Systems Biology, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
- Section of Cell Biology and Biophysics, Department of Biology, National and Kapodistrian University of Athens, 15701 Athens, Greece
| | - Apostolos Malatras
- Biobank.cy Center of Excellence in Biobanking and Biomedical Research, University of Cyprus, 2029 Nicosia, Cyprus
| | - Konstantinos Kyriakidis
- Centre of Systems Biology, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
- School of Pharmacy, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Chrysanthi Charalampous
- Centre of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
| | - Evanthia A. Makrygianni
- University Research Institute of Maternal and Child Health and Precision Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Stéphanie Duguez
- Personalised Medicine Centre, School of Medicine, Ulster University, Derry-Londonderry BT47 6SB, UK
| | - Marianna A. Koutsi
- Centre of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
| | - Marialena Pouliou
- Centre of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
| | - Christos Vasileiou
- Centre of Systems Biology, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
- Engineering Design and Computing Laboratory, ETH Zurich, 8092 Zurich, Switzerland
| | - William J. Duddy
- Personalised Medicine Centre, School of Medicine, Ulster University, Derry-Londonderry BT47 6SB, UK
| | - Marios Agelopoulos
- Centre of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
| | - George P. Chrousos
- University Research Institute of Maternal and Child Health and Precision Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Vassiliki A. Iconomidou
- Section of Cell Biology and Biophysics, Department of Biology, National and Kapodistrian University of Athens, 15701 Athens, Greece
| | - Ioannis Michalopoulos
- Centre of Systems Biology, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
- Correspondence:
| |
Collapse
|
14
|
Lambert É, Puwakdandawa K, Tao YF, Robert F. From structure to molecular condensates: emerging mechanisms for Mediator function. FEBS J 2023; 290:286-309. [PMID: 34698446 DOI: 10.1111/febs.16250] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/15/2021] [Accepted: 10/25/2021] [Indexed: 02/05/2023]
Abstract
Mediator is a large modular protein assembly whose function as a coactivator of transcription is conserved in all eukaryotes. The Mediator complex can integrate and relay signals from gene-specific activators bound at enhancers to activate the general transcription machinery located at promoters. It has thus been described as a bridge between these elements during initiation of transcription. Here, we review recent studies on Mediator relating to its structure, gene specificity and general requirement, roles in chromatin architecture as well as novel concepts involving phase separation and transcriptional bursting. We revisit the mechanism of action of Mediator and ultimately put forward models for its mode of action in gene activation.
Collapse
Affiliation(s)
- Élie Lambert
- Institut de recherches cliniques de Montréal, Canada
| | | | - Yi Fei Tao
- Institut de recherches cliniques de Montréal, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, Canada.,Département de Médecine, Faculté de Médecine, Université de Montréal, Canada
| |
Collapse
|
15
|
Pinheiro EDS, Preato AM, Petrucci TVB, dos Santos LS, Glezer I. Phase-separation: a possible new layer for transcriptional regulation by glucocorticoid receptor. Front Endocrinol (Lausanne) 2023; 14:1160238. [PMID: 37124728 PMCID: PMC10145926 DOI: 10.3389/fendo.2023.1160238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/20/2023] [Indexed: 05/02/2023] Open
Abstract
Glucocorticoids (GCs) are hormones involved in circadian adaptation and stress response, and it is also noteworthy that these steroidal molecules present potent anti-inflammatory action through GC receptors (GR). Upon ligand-mediated activation, GR translocates to the nucleus, and regulates gene expression related to metabolism, acute-phase response and innate immune response. GR field of research has evolved considerably in the last decades, providing varied mechanisms that contributed to the understanding of transcriptional regulation and also impacted drug design for treating inflammatory diseases. Liquid-liquid phase separation (LLPS) in cellular processes represents a recent topic in biology that conceptualizes membraneless organelles and microenvironments that promote, or inhibit, chemical reactions and interactions of protein or nucleic acids. The formation of these molecular condensates has been implicated in gene expression control, and recent evidence shows that GR and other steroid receptors can nucleate phase separation (PS). Here we briefly review the varied mechanisms of transcriptional control by GR, which are largely studied in the context of inflammation, and further present how PS can be involved in the control of gene expression. Lastly, we consider how the reported advances on LLPS during transcription control, specially for steroid hormone receptors, could impact the different modalities of GR action on gene expression, adding a new plausible molecular event in glucocorticoid signal transduction.
Collapse
|
16
|
Akter S, Shimba A, Ikuta K, Mahmud MRA, Yamada S, Sasanuma H, Tsuda M, Sone M, Ago Y, Murai K, Tanaka H, Takeda S. Physiological concentrations of glucocorticoids induce pathological DNA double-strand breaks. Genes Cells 2023; 28:53-67. [PMID: 36415926 DOI: 10.1111/gtc.12993] [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: 10/03/2022] [Revised: 11/15/2022] [Accepted: 11/15/2022] [Indexed: 11/24/2022]
Abstract
Steroid hormones induce the transcription of target genes by activating nuclear receptors. Early transcriptional response to various stimuli, including hormones, involves the active catalysis of topoisomerase II (TOP2) at transcription regulatory sequences. TOP2 untangles DNAs by transiently generating double-strand breaks (DSBs), where TOP2 covalently binds to DSB ends. When TOP2 fails to rejoin, called "abortive" catalysis, the resulting DSBs are repaired by tyrosyl-DNA phosphodiesterase 2 (TDP2) and non-homologous end-joining (NHEJ). A steroid, cortisol, is the most important glucocorticoid, and dexamethasone (Dex), a synthetic glucocorticoid, is widely used for suppressing inflammation in clinics. We here revealed that clinically relevant concentrations of Dex and physiological concentrations of cortisol efficiently induce DSBs in G1 phase cells deficient in TDP2 and NHEJ. The DSB induction depends on glucocorticoid receptor (GR) and TOP2. Considering the specific role of TDP2 in removing TOP2 adducts from DSB ends, induced DSBs most likely represent stalled TOP2-DSB complexes. Inhibition of RNA polymerase II suppressed the DSBs formation only modestly in the G1 phase. We propose that cortisol and Dex frequently generate DSBs through the abortive catalysis of TOP2 at transcriptional regulatory sequences, including promoters or enhancers, where active TOP2 catalysis occurs during early transcriptional response.
Collapse
Affiliation(s)
- Salma Akter
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akihiro Shimba
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Koichi Ikuta
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Md Rasel Al Mahmud
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shintaro Yamada
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Sasanuma
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masataka Tsuda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masakatsu Sone
- Department of Metabolic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Division of Metabolism and Endocrinology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Yukio Ago
- Department of Cellular and Molecular Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kenichi Murai
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Hisashi Tanaka
- Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Shenzhen University School of Medicine, Shenzhen University, Shenzhen, Guangdong, China
| |
Collapse
|
17
|
SOX2 Modulates the Nuclear Organization and Transcriptional Activity of the Glucocorticoid Receptor. J Mol Biol 2022; 434:167869. [PMID: 36309135 DOI: 10.1016/j.jmb.2022.167869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 10/07/2022] [Accepted: 10/19/2022] [Indexed: 11/07/2022]
Abstract
Steroid receptors (SRs) are ligand-dependent transcription factors (TFs) relevant to key cellular processes in both physiology and pathology, including some types of cancer. SOX2 is a master TF of pluripotency and self-renewal of embryonic stem cells, and its dysregulation is also associated with various types of human cancers. A potential crosstalk between these TFs could be relevant in malignant cells yet, to the best of our knowledge, no formal study has been performed thus far. Here we show, by quantitative live-cell imaging microscopy, that ectopic expression of SOX2 disrupts the formation of hormone-dependent intranuclear condensates of many steroid receptors (SRs), including those formed by the glucocorticoid receptor (GR). SOX2 also reduces GR's binding to specific DNA targets and modulates its transcriptional activity. SOX2-driven effects on GR condensates do not require the intrinsically disordered N-terminal domain of the receptor and, surprisingly, neither relies on GR/SOX2 interactions. SOX2 also alters the intranuclear dynamics and compartmentalization of the SR coactivator NCoA-2 and impairs GR/NCoA-2 interactions. These results suggest an indirect mechanism underlying SOX2-driven effects on SRs involving this coactivator. Together, these results highlight that the transcriptional program elicited by GR relies on its nuclear organization and is intimately linked to the distribution of other GR partners, such as the NCoA-2 coactivator. Abnormal expression of SOX2, commonly observed in many tumors, may alter the biological action of GR and, probably, other SRs as well. Understanding this crosstalk may help to improve steroid hormone-based therapies in cancers with elevated SOX2 expression.
Collapse
|
18
|
Zhang F, Biswas M, Massah S, Lee J, Lingadahalli S, Wong S, Wells C, Foo J, Khan N, Morin H, Saxena N, Kung SY, Sun B, Parra Nuñez A, Sanchez C, Chan N, Ung L, Altıntaş U, Bui J, Wang Y, Fazli L, Oo H, Rennie P, Lack N, Cherkasov A, Gleave M, Gsponer J, Lallous N. Dynamic phase separation of the androgen receptor and its coactivators key to regulate gene expression. Nucleic Acids Res 2022; 51:99-116. [PMID: 36535377 PMCID: PMC9841400 DOI: 10.1093/nar/gkac1158] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 10/27/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022] Open
Abstract
Numerous cancers, including prostate cancer (PCa), are addicted to transcription programs driven by specific genomic regions known as super-enhancers (SEs). The robust transcription of genes at such SEs is enabled by the formation of phase-separated condensates by transcription factors and coactivators with intrinsically disordered regions. The androgen receptor (AR), the main oncogenic driver in PCa, contains large disordered regions and is co-recruited with the transcriptional coactivator mediator complex subunit 1 (MED1) to SEs in androgen-dependent PCa cells, thereby promoting oncogenic transcriptional programs. In this work, we reveal that full-length AR forms foci with liquid-like properties in different PCa models. We demonstrate that foci formation correlates with AR transcriptional activity, as this activity can be modulated by changing cellular foci content chemically or by silencing MED1. AR ability to phase separate was also validated in vitro by using recombinant full-length AR protein. We also demonstrate that AR antagonists, which suppress transcriptional activity by targeting key regions for homotypic or heterotypic interactions of this receptor, hinder foci formation in PCa cells and phase separation in vitro. Our results suggest that enhanced compartmentalization of AR and coactivators may play an important role in the activation of oncogenic transcription programs in androgen-dependent PCa.
Collapse
Affiliation(s)
- Fan Zhang
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | | | | | - Joseph Lee
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Shreyas Lingadahalli
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Samantha Wong
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Christopher Wells
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Jane Foo
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Nabeel Khan
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Helene Morin
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Neetu Saxena
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Sonia H Y Kung
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Bei Sun
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Ana Karla Parra Nuñez
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Christophe Sanchez
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Novia Chan
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Lauren Ung
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Umut Berkay Altıntaş
- School of Medicine, Koç University, Rumelifeneri Yolu, Istanbul 34450, Turkey,Koç University Research Centre for Translational Medicine (KUTTAM), Koç University, Rumelifeneri Yolu, Istanbul 34450, Turkey
| | - Jennifer M Bui
- Michael Smith Laboratories, Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Yuzhuo Wang
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Ladan Fazli
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Htoo Zarni Oo
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Paul S Rennie
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Nathan A Lack
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada,School of Medicine, Koç University, Rumelifeneri Yolu, Istanbul 34450, Turkey,Koç University Research Centre for Translational Medicine (KUTTAM), Koç University, Rumelifeneri Yolu, Istanbul 34450, Turkey
| | - Artem Cherkasov
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Martin E Gleave
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, 2660 Oak St., Vancouver, BC V6H 3Z6, Canada
| | - Jörg Gsponer
- Correspondence may also be addressed to Jörg Gsponer.
| | - Nada Lallous
- To whom correspondence should be addressed. Tel: +1 604 875 4111; Fax: +1 604 875 5654;
| |
Collapse
|
19
|
Meszaros A, Ahmed J, Russo G, Tompa P, Lazar T. The evolution and polymorphism of mono-amino acid repeats in androgen receptor and their regulatory role in health and disease. Front Med (Lausanne) 2022; 9:1019803. [PMID: 36388907 PMCID: PMC9642029 DOI: 10.3389/fmed.2022.1019803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/30/2022] [Indexed: 12/24/2022] Open
Abstract
Androgen receptor (AR) is a key member of nuclear hormone receptors with the longest intrinsically disordered N-terminal domain (NTD) in its protein family. There are four mono-amino acid repeats (polyQ1, polyQ2, polyG, and polyP) located within its NTD, of which two are polymorphic (polyQ1 and polyG). The length of both polymorphic repeats shows clinically important correlations with disease, especially with cancer and neurodegenerative diseases, as shorter and longer alleles exhibit significant differences in expression, activity and solubility. Importantly, AR has also been shown to undergo condensation in the nucleus by liquid-liquid phase separation, a process highly sensitive to protein solubility and concentration. Nonetheless, in prostate cancer cells, AR variants also partition into transcriptional condensates, which have been shown to alter the expression of target gene products. In this review, we summarize current knowledge on the link between AR repeat polymorphisms and cancer types, including mechanistic explanations and models comprising the relationship between condensate formation, polyQ1 length and transcriptional activity. Moreover, we outline the evolutionary paths of these recently evolved amino acid repeats across mammalian species, and discuss new research directions with potential breakthroughs and controversies in the literature.
Collapse
Affiliation(s)
- Attila Meszaros
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Junaid Ahmed
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Giorgio Russo
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Peter Tompa
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Research Centre for Natural Sciences (RCNS), ELKH, Budapest, Hungary
- *Correspondence: Peter Tompa,
| | - Tamas Lazar
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Tamas Lazar,
| |
Collapse
|
20
|
Stochastic particle unbinding modulates growth dynamics and size of transcription factor condensates in living cells. Proc Natl Acad Sci U S A 2022; 119:e2200667119. [PMID: 35881789 PMCID: PMC9351496 DOI: 10.1073/pnas.2200667119] [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] [Indexed: 11/25/2022] Open
Abstract
Living cells organize internal compartments by forming molecular condensates that operate as versatile biochemical “hubs.” Their occurrence is particularly relevant in the nucleus where they regulate, amongst others, gene transcription. However, the biophysics of transcription factor (TF) condensation remains highly unexplored. Through single-molecule experiments in living cells, theory, and simulations, we assessed the diffusion, growth dynamics, and sizes of TF condensates of the nuclear progesterone receptor (PR). Interestingly, PR condensates obey classical growth dynamics at shorter times but deviate at longer times, reaching finite sizes at steady-state. We demonstrate that condensate growth dynamics and nanoscale-size arrested growth is regulated by molecular escaping from condensates, providing an exquisite control of condensate size in nonequilibrium systems such as living cells. Liquid–liquid phase separation (LLPS) is emerging as a key physical principle for biological organization inside living cells, forming condensates that play important regulatory roles. Inside living nuclei, transcription factor (TF) condensates regulate transcriptional initiation and amplify the transcriptional output of expressed genes. However, the biophysical parameters controlling TF condensation are still poorly understood. Here we applied a battery of single-molecule imaging, theory, and simulations to investigate the physical properties of TF condensates of the progesterone receptor (PR) in living cells. Analysis of individual PR trajectories at different ligand concentrations showed marked signatures of a ligand-tunable LLPS process. Using a machine learning architecture, we found that receptor diffusion within condensates follows fractional Brownian motion resulting from viscoelastic interactions with chromatin. Interestingly, condensate growth dynamics at shorter times is dominated by Brownian motion coalescence (BMC), followed by a growth plateau at longer timescales that result in nanoscale condensate sizes. To rationalize these observations, we extended on the BMC model by including the stochastic unbinding of particles within condensates. Our model reproduced the BMC behavior together with finite condensate sizes at the steady state, fully recapitulating our experimental data. Overall, our results are consistent with condensate growth dynamics being regulated by the escaping probability of PR molecules from condensates. The interplay between condensation assembly and molecular escaping maintains an optimum physical condensate size. Such phenomena must have implications for the biophysical regulation of other nuclear condensates and could also operate in multiple biological scenarios.
Collapse
|
21
|
Zhou T, Feng Q. Androgen receptor signaling and spatial chromatin organization in castration-resistant prostate cancer. Front Med (Lausanne) 2022; 9:924087. [PMID: 35966880 PMCID: PMC9372301 DOI: 10.3389/fmed.2022.924087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 07/12/2022] [Indexed: 12/03/2022] Open
Abstract
Prostate cancer is one of the leading causes of cancer death and affects millions of men in the world. The American Cancer Society estimated about 34,500 deaths from prostate cancer in the United States in year 2022. The Androgen receptor (AR) signaling is a major pathway that sustains local and metastatic prostate tumor growth. Androgen-deprivation therapy (ADT) is the standard of care for metastatic prostate cancer patient and can suppress the tumor growth for a median of 2–3 years. Unfortunately, the malignancy inevitably progresses to castration-resistant prostate cancer (CRPC) which is more aggressive and no longer responsive to ADT. Surprisingly, for most of the CPRC patients, cancer growth still depends on androgen receptor signaling. Accumulating evidence suggests that CRPC cells have rewired their transcriptional program to retain AR signaling in the absence of androgens. Besides AR, other transcription factors also contribute to the resistance mechanism through multiple pathways including enhancing AR signaling pathway and activating other complementary signaling pathways for the favor of AR downstream genes expression. More recent studies have shown the role of transcription factors in reconfiguring chromatin 3D structure and regulating topologically associating domains (TADs). Pioneer factors, transcription factors and coactivators form liquid-liquid phase separation compartment that can modulate transcriptional events along with configuring TADs. The role of AR and other transcription factors on chromatin structure change and formation of condensate compartment in prostate cancer cells has only been recently investigated and appreciated. This review intends to provide an overview of transcription factors that contribute to AR signaling through activation of gene expression, governing 3D chromatin structure and establishing phase to phase separation. A more detailed understanding of the spatial role of transcription factors in CRPC might provide novel therapeutic targets for the treatment of CRPC.
Collapse
|
22
|
Strickland BA, Ansari SA, Dantoft W, Uhlenhaut NH. How to tame your genes: mechanisms of inflammatory gene repression by glucocorticoids. FEBS Lett 2022; 596:2596-2616. [PMID: 35612756 DOI: 10.1002/1873-3468.14409] [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: 12/23/2021] [Revised: 04/24/2022] [Accepted: 05/18/2022] [Indexed: 01/08/2023]
Abstract
Glucocorticoids (GCs) are widely used therapeutic agents to treat a broad range of inflammatory conditions. Their functional effects are elicited by binding to the glucocorticoid receptor (GR), which regulates transcription of distinct gene networks in response to ligand. However, the mechanisms governing various aspects of undesired side effects versus beneficial immunomodulation upon GR activation remain complex and incompletely understood. In this review, we discuss emerging models of inflammatory gene regulation by GR, highlighting GR's regulatory specificity conferred by context-dependent changes in chromatin architecture and transcription factor or co-regulator dynamics. GR controls both gene activation and repression, with the repression mechanism being central to favorable clinical outcomes. We describe current knowledge about 3D genome organization and its role in spatiotemporal transcriptional control by GR. Looking beyond, we summarize the evidence for dynamics in gene regulation by GR through cooperative convergence of epigenetic modifications, transcription factor crosstalk, molecular condensate formation and chromatin looping. Further characterizing these genomic events will reframe our understanding of mechanisms of transcriptional repression by GR.
Collapse
Affiliation(s)
- Benjamin A Strickland
- Metabolic Programming, Technische Universitaet Muenchen (TUM), School of Life Sciences Weihenstephan, ZIEL - Institute for Food and Health, Gregor-Mendel-Str. 2, 85354, Freising, Germany
| | - Suhail A Ansari
- Institute for Diabetes and Endocrinology (IDE), Helmholtz Center Munich (HMGU) and German Center for Diabetes Research (DZD), Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany
| | - Widad Dantoft
- Institute for Diabetes and Endocrinology (IDE), Helmholtz Center Munich (HMGU) and German Center for Diabetes Research (DZD), Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany
| | - N Henriette Uhlenhaut
- Metabolic Programming, Technische Universitaet Muenchen (TUM), School of Life Sciences Weihenstephan, ZIEL - Institute for Food and Health, Gregor-Mendel-Str. 2, 85354, Freising, Germany.,Institute for Diabetes and Endocrinology (IDE), Helmholtz Center Munich (HMGU) and German Center for Diabetes Research (DZD), Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany
| |
Collapse
|
23
|
PPARγ phase separates with RXRα at PPREs to regulate target gene expression. Cell Discov 2022; 8:37. [PMID: 35473936 PMCID: PMC9043196 DOI: 10.1038/s41421-022-00388-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 02/22/2022] [Indexed: 12/16/2022] Open
Abstract
Peroxisome proliferator-activated receptor (PPAR)-γ is a key transcription activator controlling adipogenesis and lipid metabolism. PPARγ binds PPAR response elements (PPREs) as the obligate heterodimer with retinoid X receptor (RXR) α, but exactly how PPARγ orchestrates the transcriptional response is unknown. This study demonstrates that PPARγ forms phase-separated droplets in vitro and solid-like nuclear condensates in cell, which is intriguingly mediated by its DNA binding domain characterized by the zinc finger motif. Furthermore, PPARγ forms nuclear condensates at PPREs sites through phase separation to compartmentalize its heterodimer partner RXRα to initiate PPARγ-specific transcriptional activation. Finally, using an optogenetic approach, the enforced formation of PPARγ/RXRα condensates leads to preferential enrichment at PPREs sites and significantly promotes the expression of PPARγ target genes. These results define a novel mechanism by which PPARγ engages the phase separation principles for efficient and specific transcriptional activation.
Collapse
|
24
|
Appelman MD, Hollaar EE, Schuijers J, van Mil SWC. Protein Condensation in the Nuclear Receptor Family; Implications for Transcriptional Output. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1390:243-253. [DOI: 10.1007/978-3-031-11836-4_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
|
25
|
Pluripotency transcription factors at the focus: the phase separation paradigm in stem cells. Biochem Soc Trans 2021; 49:2871-2878. [PMID: 34812855 DOI: 10.1042/bst20210856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 12/13/2022]
Abstract
The transcription factors (TFs) OCT4, SOX2 and NANOG are key players of the gene regulatory network of pluripotent stem cells. Evidence accumulated in recent years shows that even small imbalances in the expression levels or relative concentrations of these TFs affect both, the maintenance of pluripotency and cell fate decisions. In addition, many components of the transcriptional machinery including RNA polymerases, cofactors and TFs such as those required for pluripotency, do not distribute homogeneously in the nucleus but concentrate in multiple foci influencing the delivery of these molecules to their DNA-targets. How cells control strict levels of available pluripotency TFs in this heterogeneous space and the biological role of these foci remain elusive. In recent years, a wealth of evidence led to propose that many of the nuclear compartments are formed through a liquid-liquid phase separation process. This new paradigm early penetrated the stem cells field since many key players of the pluripotency circuitry seem to phase-separate. Overall, the formation of liquid compartments may modulate the kinetics of biochemical reactions and consequently regulate many nuclear processes. Here, we review the state-of-the-art knowledge of compartmentalization in the cell nucleus and the relevance of this process for transcriptional regulation, particularly in pluripotent stem cells. We also highlight the recent advances and new ideas in the field showing how compartmentalization may affect pluripotency preservation and cell fate decisions.
Collapse
|
26
|
Sołtys K, Ożyhar A. Transcription Regulators and Membraneless Organelles Challenges to Investigate Them. Int J Mol Sci 2021; 22:12758. [PMID: 34884563 PMCID: PMC8657783 DOI: 10.3390/ijms222312758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/19/2021] [Accepted: 11/23/2021] [Indexed: 12/13/2022] Open
Abstract
Eukaryotic cells are composed of different bio-macromolecules that are divided into compartments called organelles providing optimal microenvironments for many cellular processes. A specific type of organelles is membraneless organelles. They are formed via a process called liquid-liquid phase separation that is driven by weak multivalent interactions between particular bio-macromolecules. In this review, we gather crucial information regarding different classes of transcription regulators with the propensity to undergo liquid-liquid phase separation and stress the role of intrinsically disordered regions in this phenomenon. We also discuss recently developed experimental systems for studying formation and properties of membraneless organelles.
Collapse
Affiliation(s)
- Katarzyna Sołtys
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland;
| | | |
Collapse
|
27
|
Structural insights into glucocorticoid receptor function. Biochem Soc Trans 2021; 49:2333-2343. [PMID: 34709368 DOI: 10.1042/bst20210419] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 09/30/2021] [Accepted: 10/04/2021] [Indexed: 01/02/2023]
Abstract
The glucocorticoid receptor (GR) is a steroid hormone-activated transcription factor that binds to various glucocorticoid response elements to up- or down- regulate the transcription of thousands of genes involved in metabolism, development, stress and inflammatory responses. GR consists of two domains enabling interaction with glucocorticoids, DNA response elements and coregulators, as well as a large intrinsically disordered region that mediates condensate formation. A growing body of structural studies during the past decade have shed new light on GR interactions, providing a new understanding of the mechanisms driving context-specific GR activity. Here, we summarize the established and emerging mechanisms of action of GR, primarily from a structural perspective. This minireview also discusses how the current state of knowledge of GR function may guide future glucocorticoid design with an improved therapeutic index for different inflammatory disorders.
Collapse
|
28
|
Garcia DA, Fettweis G, Presman DM, Paakinaho V, Jarzynski C, Upadhyaya A, Hager GL. Power-law behavior of transcription factor dynamics at the single-molecule level implies a continuum affinity model. Nucleic Acids Res 2021; 49:6605-6620. [PMID: 33592625 DOI: 10.1093/nar/gkab072] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/13/2021] [Accepted: 02/11/2021] [Indexed: 12/11/2022] Open
Abstract
Single-molecule tracking (SMT) allows the study of transcription factor (TF) dynamics in the nucleus, giving important information regarding the diffusion and binding behavior of these proteins in the nuclear environment. Dwell time distributions obtained by SMT for most TFs appear to follow bi-exponential behavior. This has been ascribed to two discrete populations of TFs-one non-specifically bound to chromatin and another specifically bound to target sites, as implied by decades of biochemical studies. However, emerging studies suggest alternate models for dwell-time distributions, indicating the existence of more than two populations of TFs (multi-exponential distribution), or even the absence of discrete states altogether (power-law distribution). Here, we present an analytical pipeline to evaluate which model best explains SMT data. We find that a broad spectrum of TFs (including glucocorticoid receptor, oestrogen receptor, FOXA1, CTCF) follow a power-law distribution of dwell-times, blurring the temporal line between non-specific and specific binding, suggesting that productive binding may involve longer binding events than previously believed. From these observations, we propose a continuum of affinities model to explain TF dynamics, that is consistent with complex interactions of TFs with multiple nuclear domains as well as binding and searching on the chromatin template.
Collapse
Affiliation(s)
- David A Garcia
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA.,Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Gregory Fettweis
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA
| | - Diego M Presman
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA.,Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA, Buenos Aires, Argentina
| | - Ville Paakinaho
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA.,Institute of Biomedicine, University of Eastern Finland, Kuopio, PO Box 1627, FI-70211 Kuopio, Finland
| | - Christopher Jarzynski
- Department of Physics, University of Maryland, College Park, MD 20742, USA.,Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.,Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
| | - Arpita Upadhyaya
- Department of Physics, University of Maryland, College Park, MD 20742, USA.,Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA
| |
Collapse
|
29
|
Frank F, Liu X, Ortlund EA. Glucocorticoid receptor condensates link DNA-dependent receptor dimerization and transcriptional transactivation. Proc Natl Acad Sci U S A 2021; 118:e2024685118. [PMID: 34285072 PMCID: PMC8325269 DOI: 10.1073/pnas.2024685118] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The glucocorticoid receptor (GR) is a ligand-regulated transcription factor (TF) that controls the tissue- and gene-specific transactivation and transrepression of thousands of target genes. Distinct GR DNA-binding sequences with activating or repressive activities have been identified, but how they modulate transcription in opposite ways is not known. We show that GR forms phase-separated condensates that specifically concentrate known coregulators via their intrinsically disordered regions (IDRs) in vitro. A combination of dynamic, multivalent (between IDRs) and specific, stable interactions (between LxxLL motifs and the GR ligand-binding domain) control the degree of recruitment. Importantly, GR DNA binding directs the selective partitioning of coregulators within GR condensates such that activating DNAs cause enhanced recruitment of coactivators. Our work shows that condensation controls GR function by modulating coregulator recruitment and provides a mechanism for the up- and down-regulation of GR target genes controlled by distinct DNA recognition elements.
Collapse
Affiliation(s)
- Filipp Frank
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Xu Liu
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| |
Collapse
|
30
|
Wagh K, Garcia DA, Upadhyaya A. Phase separation in transcription factor dynamics and chromatin organization. Curr Opin Struct Biol 2021; 71:148-155. [PMID: 34303933 DOI: 10.1016/j.sbi.2021.06.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 06/16/2021] [Indexed: 02/07/2023]
Abstract
Studies over the past decade have highlighted the key role of liquid-liquid phase separation in cellular organization and function. Dynamic compartmentalization of transcription factors and coactivators by such phase-separated condensates regulates the assembly of transcriptional machinery at genomic loci. Although rapid advances in microscopy have demonstrated the ubiquity of such condensates, a rigorous characterization of the physics of phase separation in transcription remains to be carried out. In this review, we discuss theoretical and experimental evidence for biomolecular condensates as dynamic regulators of transcription. Looking beyond, we highlight functional consequences for transcription factor dynamics and gene expression and discuss potential pitfalls of misclassifying biomolecular condensates as liquid droplets in the absence of a rigorous physical description.
Collapse
Affiliation(s)
- Kaustubh Wagh
- Department of Physics, University of Maryland, College Park, MD, 20742, USA; Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - David A Garcia
- Department of Physics, University of Maryland, College Park, MD, 20742, USA; Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Arpita Upadhyaya
- Department of Physics, University of Maryland, College Park, MD, 20742, USA; Institute for Physical Science and Technology, University of Maryland, College Park, MD, 20742, USA.
| |
Collapse
|
31
|
Sołtys K, Wycisk K, Ożyhar A. Liquid-liquid phase separation of the intrinsically disordered AB region of hRXRγ is driven by hydrophobic interactions. Int J Biol Macromol 2021; 183:936-949. [PMID: 33971237 DOI: 10.1016/j.ijbiomac.2021.05.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/29/2021] [Accepted: 05/04/2021] [Indexed: 12/22/2022]
Abstract
Nuclear receptors (NRs) are a family of transcription factors that are regulated endogenously by small lipophilic ligands. Recently, liquid-liquid phase separation (LLPS) has appeared as a new aspect of NR function. In the human retinoid X receptor γ (hRXRγ), the inherently disordered AB region undergoes LLPS via homotypic multivalent interactions. To better understand the functions of liquid condensates, a clear view of the molecular interactions underlying the LLPS are required. The phase separation propensity of the AB region of hRXRγ (AB_hRXG) at a high NaCl concentration, a lower critical solution temperature behavior, and also sensitivity to kosmotropic salts and 1,6-hexanediol, which all indicate the importance of hydrophobic interactions in the formation of AB_hRXG liquid condensates, is presented in the paper. Additionally, molecular crowding agents and TMAO shift the equilibrium, in turn enabling phase transition at lower AB_hRXG concentrations. Although the LLPS of the proteins can lead to aggregation, AB_hRXG liquid condensates are not aggregation prone. Interestingly, the formation of AB_hRXG liquid condensates has an impact on the rest of the receptor, as AB_hRXG liquid condensates recruit the remaining fragment of hRXRγ into the droplets. The ability of AB_hRXG to undergo LLPS might be important for gene expression regulation.
Collapse
Affiliation(s)
- Katarzyna Sołtys
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland.
| | - Krzysztof Wycisk
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland
| | - Andrzej Ożyhar
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland
| |
Collapse
|
32
|
Sabari BR. Biomolecular Condensates and Gene Activation in Development and Disease. Dev Cell 2021; 55:84-96. [PMID: 33049213 DOI: 10.1016/j.devcel.2020.09.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/18/2020] [Accepted: 09/04/2020] [Indexed: 01/04/2023]
Abstract
Activating the right gene at the right time and place is essential for development. Emerging evidence suggests that this process is regulated by the mesoscale compartmentalization of the gene-control machinery, RNA polymerase II and its cofactors, within biomolecular condensates. Coupling gene activity to the reversible and dynamic process of condensate formation is proposed to enable the robust and precise changes in gene-regulatory programs during signaling and development. The macromolecular features that enable condensates and the regulatory pathways that control them are dysregulated in disease, highlighting their importance for normal physiology. In this review, we will discuss the role of condensates in gene activation; the multivalent features of protein, RNA, and DNA that enable reversible condensate formation; and how these processes are utilized in normal and disease biology. Understanding the regulation of condensates promises to provide novel insights into how organization of the gene-control machinery regulates development and disease.
Collapse
Affiliation(s)
- Benjamin R Sabari
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
33
|
Więch A, Tarczewska A, Ożyhar A, Orłowski M. Metal Ions Induce Liquid Condensate Formation by the F Domain of Aedes aegypti Ecdysteroid Receptor. New Perspectives of Nuclear Receptor Studies. Cells 2021; 10:cells10030571. [PMID: 33807814 PMCID: PMC7999165 DOI: 10.3390/cells10030571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 11/16/2022] Open
Abstract
The superfamily of nuclear receptors (NRs), composed of ligand-activated transcription factors, is responsible for gene expression as a reaction to physiological and environmental changes. Transcriptional machinery may require phase separation to fulfil its role. Although NRs have a similar canonical structure, their C-terminal domains (F domains) are considered the least conserved and known regions. This article focuses on the peculiar molecular properties of the intrinsically disordered F domain of the ecdysteroid receptor from the Aedes aegypti mosquito (AaFEcR), the vector of the world's most devastating human diseases such as dengue and Zika. The His-Pro-rich segment of AaFEcR was recently shown to form the unique poly-proline helix II (PPII) in the presence of Cu2+. Here, using widefield microscopy of fluorescently labeled AaFEcR, Zn2+- and Cu2+-induced liquid-liquid phase separation (LLPS) was observed for the first time for the members of NRs. The perspectives of this finding on future research on the F domain are discussed, especially in relation to other NR members.
Collapse
|
34
|
Garcia-Cabau C, Salvatella X. Regulation of biomolecular condensate dynamics by signaling. Curr Opin Cell Biol 2021; 69:111-119. [PMID: 33578289 DOI: 10.1016/j.ceb.2021.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/24/2020] [Accepted: 01/04/2021] [Indexed: 12/16/2022]
Abstract
Biomolecular condensates are mesoscopic biomolecular assemblies devoid of long range order that contribute to important cellular functions. They form reversibly, are stabilized by numerous but relatively weak intermolecular interactions, and their formation can be regulated by various cellular signals including changes in local concentration, post-translational modifications, energy-consuming processes, and biomolecular interactions. Condensates formed by liquid-liquid phase separation are initially liquid but are metastable relative to hydrogels or irreversible solids that have been associated with protein aggregation diseases and are stabilized by stronger, more permanent interactions. As a consequence of this, a series of cellular mechanisms are available to regulate not only biomolecular condensation but also the physical properties of the condensates.
Collapse
Affiliation(s)
- Carla Garcia-Cabau
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain; Joint BSC-IRB Research Programme in Computational Biology, Baldiri Reixac 10, 08028, Barcelona, Spain
| | - Xavier Salvatella
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain; Joint BSC-IRB Research Programme in Computational Biology, Baldiri Reixac 10, 08028, Barcelona, Spain; ICREA, Passeig Lluís Companys 23, 08010, Barcelona, Spain.
| |
Collapse
|
35
|
Garcia DA, Johnson TA, Presman DM, Fettweis G, Wagh K, Rinaldi L, Stavreva DA, Paakinaho V, Jensen RAM, Mandrup S, Upadhyaya A, Hager GL. An intrinsically disordered region-mediated confinement state contributes to the dynamics and function of transcription factors. Mol Cell 2021; 81:1484-1498.e6. [PMID: 33561389 DOI: 10.1016/j.molcel.2021.01.013] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/08/2020] [Accepted: 01/08/2021] [Indexed: 02/06/2023]
Abstract
Transcription factors (TFs) regulate gene expression by binding to specific consensus motifs within the local chromatin context. The mechanisms by which TFs navigate the nuclear environment as they search for binding sites remain unclear. Here, we used single-molecule tracking and machine-learning-based classification to directly measure the nuclear mobility of the glucocorticoid receptor (GR) in live cells. We revealed two distinct and dynamic low-mobility populations. One accounts for specific binding to chromatin, while the other represents a confinement state that requires an intrinsically disordered region (IDR), implicated in liquid-liquid condensate subdomains. Further analysis showed that the dwell times of both subpopulations follow a power-law distribution, consistent with a broad distribution of affinities on the GR cistrome and interactome. Together, our data link IDRs with a confinement state that is functionally distinct from specific chromatin binding and modulates the transcriptional output by increasing the local concentration of TFs at specific sites.
Collapse
Affiliation(s)
- David A Garcia
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA; Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Thomas A Johnson
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA
| | - Diego M Presman
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA Buenos Aires, Argentina
| | - Gregory Fettweis
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA
| | - Kaustubh Wagh
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA; Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Lorenzo Rinaldi
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA
| | - Diana A Stavreva
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA
| | - Ville Paakinaho
- Institute of Biomedicine, University of Eastern Finland, Kuopio, P.O. Box 1627, 70211 Kuopio, Finland
| | - Rikke A M Jensen
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA; Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Susanne Mandrup
- Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
| | - Arpita Upadhyaya
- Department of Physics, University of Maryland, College Park, MD 20742, USA; Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA.
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20893, USA.
| |
Collapse
|
36
|
Phasing the intranuclear organization of steroid hormone receptors. Biochem J 2021; 478:443-461. [DOI: 10.1042/bcj20200883] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/28/2020] [Accepted: 01/07/2021] [Indexed: 12/15/2022]
Abstract
Steroid receptors (SRs) encompass a family of transcription factors that regulate the expression of thousands of genes upon binding to steroid hormones and include the glucocorticoid, androgen, progesterone, estrogen and mineralocorticoid receptors. SRs control key physiological and pathological processes, thus becoming relevant drug targets. As with many other nuclear proteins, hormone-activated SRs concentrate in multiple discrete foci within the cell nucleus. Even though these foci were first observed ∼25 years ago, their exact structure and function remained elusive. In the last years, new imaging methodologies and theoretical frameworks improved our understanding of the intranuclear organization. These studies led to a new paradigm stating that many membraneless nuclear compartments, including transcription-related foci, form through a liquid–liquid phase separation process. These exciting ideas impacted the SR field by raising the hypothesis of SR foci as liquid condensates involved in transcriptional regulation. In this work, we review the current knowledge about SR foci formation under the light of the condensate model, analyzing how these structures may impact SR function. These new ideas, combined with state-of-the-art techniques, may shed light on the biophysical mechanisms governing the formation of SR foci and the biological function of these structures in normal physiology and disease.
Collapse
|
37
|
Præstholm SM, Correia CM, Grøntved L. Multifaceted Control of GR Signaling and Its Impact on Hepatic Transcriptional Networks and Metabolism. Front Endocrinol (Lausanne) 2020; 11:572981. [PMID: 33133019 PMCID: PMC7578419 DOI: 10.3389/fendo.2020.572981] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/03/2020] [Indexed: 12/14/2022] Open
Abstract
Glucocorticoids (GCs) and the glucocorticoid receptor (GR) are important regulators of development, inflammation, stress response and metabolism, demonstrated in various diseases including Addison's disease, Cushing's syndrome and by the many side effects of prolonged clinical administration of GCs. These conditions include severe metabolic challenges in key metabolic organs like the liver. In the liver, GR is known to regulate the transcription of key enzymes in glucose and lipid metabolism and contribute to the regulation of circadian-expressed genes. Insights to the modes of GR regulation and the underlying functional mechanisms are key for understanding diseases and for the development of improved clinical uses of GCs. The activity and function of GR is regulated at numerous levels including ligand availability, interaction with heat shock protein (HSP) complexes, expression of GR isoforms and posttranslational modifications. Moreover, recent genomics studies show functional interaction with multiple transcription factors (TF) and coregulators in complex transcriptional networks controlling cell type-specific gene expression by GCs. In this review we describe the different regulatory steps important for GR activity and discuss how different TF interaction partners of GR selectively control hepatic gene transcription and metabolism.
Collapse
Affiliation(s)
| | | | - Lars Grøntved
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| |
Collapse
|