1
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Montoya-Garcia A, Guerrero-Fonseca IM, Chanez-Paredes SD, Hernandez-Almaraz KB, Leon-Vega II, Silva-Olivares A, Betanzos A, Mondragon-Castelan M, Mondragon-Flores R, Salinas-Lara C, Vargas-Robles H, Schnoor M. Arpin deficiency increases actomyosin contractility and vascular permeability. eLife 2024; 12:RP90692. [PMID: 39298260 PMCID: PMC11412691 DOI: 10.7554/elife.90692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2024] Open
Abstract
Arpin was discovered as an inhibitor of the Arp2/3 complex localized at the lamellipodial tip of fibroblasts, where it regulated migration steering. Recently, we showed that arpin stabilizes the epithelial barrier in an Arp2/3-dependent manner. However, the expression and functions of arpin in endothelial cells (EC) have not yet been described. Arpin mRNA and protein are expressed in EC and downregulated by pro-inflammatory cytokines. Arpin depletion in Human Umbilical Vein Endothelial Cells causes the formation of actomyosin stress fibers leading to increased permeability in an Arp2/3-independent manner. Instead, inhibitors of ROCK1 and ZIPK, kinases involved in the generation of stress fibers, normalize the loss-of-arpin effects on actin filaments and permeability. Arpin-deficient mice are viable but show a characteristic vascular phenotype in the lung including edema, microhemorrhage, and vascular congestion, increased F-actin levels, and vascular permeability. Our data show that, apart from being an Arp2/3 inhibitor, arpin is also a regulator of actomyosin contractility and endothelial barrier integrity.
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Affiliation(s)
| | | | | | | | | | | | - Abigail Betanzos
- Department of Infectomics and Molecular Pathogenesis, CINVESTAV-IPN, Mexico City, Mexico
| | | | | | - Citlaltepetl Salinas-Lara
- Laboratorio de Patogénesis Molecular, Facultad de Estudios Superiores de Iztacala, Tlalnepantla de Baz, Mexico
| | | | - Michael Schnoor
- Department of Molecular Biomedicine, CINVESTAV-IPN, Mexico City, Mexico
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2
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Shokrollahi M, Stanic M, Hundal A, Chan JNY, Urman D, Jordan CA, Hakem A, Espin R, Hao J, Krishnan R, Maass PG, Dickson BC, Hande MP, Pujana MA, Hakem R, Mekhail K. DNA double-strand break-capturing nuclear envelope tubules drive DNA repair. Nat Struct Mol Biol 2024; 31:1319-1330. [PMID: 38632359 DOI: 10.1038/s41594-024-01286-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Accepted: 03/25/2024] [Indexed: 04/19/2024]
Abstract
Current models suggest that DNA double-strand breaks (DSBs) can move to the nuclear periphery for repair. It is unclear to what extent human DSBs display such repositioning. Here we show that the human nuclear envelope localizes to DSBs in a manner depending on DNA damage response (DDR) kinases and cytoplasmic microtubules acetylated by α-tubulin acetyltransferase-1 (ATAT1). These factors collaborate with the linker of nucleoskeleton and cytoskeleton complex (LINC), nuclear pore complex (NPC) protein NUP153, nuclear lamina and kinesins KIF5B and KIF13B to generate DSB-capturing nuclear envelope tubules (dsbNETs). dsbNETs are partly supported by nuclear actin filaments and the circadian factor PER1 and reversed by kinesin KIFC3. Although dsbNETs promote repair and survival, they are also co-opted during poly(ADP-ribose) polymerase (PARP) inhibition to restrain BRCA1-deficient breast cancer cells and are hyper-induced in cells expressing the aging-linked lamin A mutant progerin. In summary, our results advance understanding of nuclear structure-function relationships, uncover a nuclear-cytoplasmic DDR and identify dsbNETs as critical factors in genome organization and stability.
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Affiliation(s)
- Mitra Shokrollahi
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Mia Stanic
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Anisha Hundal
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Princess Margaret Cancer Research Centre, University Health Network, Toronto, Ontario, Canada
| | - Janet N Y Chan
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Defne Urman
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Chris A Jordan
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Anne Hakem
- Princess Margaret Cancer Research Centre, University Health Network, Toronto, Ontario, Canada
| | - Roderic Espin
- ProCURE, Catalan Institute of Oncology, Oncobell, Bellvitge Institute for Biomedical Research (IDIBELL), L'Hospitalet del Llobregat, Barcelona, Spain
- Biomedical Research Network Centre in Respiratory Diseases (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Jun Hao
- Princess Margaret Cancer Research Centre, University Health Network, Toronto, Ontario, Canada
| | - Rehna Krishnan
- Princess Margaret Cancer Research Centre, University Health Network, Toronto, Ontario, Canada
| | - Philipp G Maass
- Department of Molecular Genetics, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Brendan C Dickson
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Manoor P Hande
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Miquel A Pujana
- ProCURE, Catalan Institute of Oncology, Oncobell, Bellvitge Institute for Biomedical Research (IDIBELL), L'Hospitalet del Llobregat, Barcelona, Spain
- Biomedical Research Network Centre in Respiratory Diseases (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Razqallah Hakem
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
- Princess Margaret Cancer Research Centre, University Health Network, Toronto, Ontario, Canada.
- Department of Medical Biophysics, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
| | - Karim Mekhail
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
- Temerty Centre for AI Research and Education in Medicine, University of Toronto, Toronto, Ontario, Canada.
- College of New Scholars, Artists and Scientists, Royal Society of Canada, Ottawa, Ontario, Canada.
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3
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Du WW, Zhou C, Yang H, Wen S, Chen Y, Chen EX, Yang XH, Li F, Du KY, Yuan H, Ye T, Qadir J, Yang BB. Aggravated Ulcerative Colitis via circNlgn-Mediated Suppression of Nuclear Actin Polymerization. RESEARCH (WASHINGTON, D.C.) 2024; 7:0441. [PMID: 39183944 PMCID: PMC11342054 DOI: 10.34133/research.0441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Accepted: 07/12/2024] [Indexed: 08/27/2024]
Abstract
Colitis is a chronic bowel disease characterized by damage to the lining of the large intestine, with its precise underlying causes remaining incompletely understood. In this study, we provide evidence that circular RNA circNlgn plays a pivotal role in promoting the development of colitis. Colitis patients produce significant higher levels of circNlgn. Transgenic mice expressing circNlgn exhibit heightened susceptibility to colitis development and progression, primarily attributed to the presence of the protein isoform Nlgn173 encoded by circNlgn. Nlgn173 undergoes translocation into cell nuclei, where it interacts with actin, impeding the binding of actin-related protein 2 and 3 (Arp2/3) complex to actin molecules. Consequently, this leads to a reduction in actin polymerization. Mechanistically, Nlgn173 enhances tyrosine-53 phosphorylation of nuclear actin, diminishing its capacity to interact with the Arp2/3 complex and causing a decrease in filamentous actin levels. These alterations in actin dynamics result in inhibited cell cycle progression, increased apoptosis, and decreased proliferation of colonic epithelial cells, thereby exacerbating colitis development and progression. In contrast, the silencing of circNlgn or the targeted inhibition of Nlgn173 translation and nuclear translocation leads to the promotion of nuclear actin polymerization, enhanced cell survival, and reduced apoptosis and ultimately improves the outcome of colitis in vivo. Interestingly, nuclear actin polymerization is highly related with expression of PIAS3, which modulates signal transducer and activator of transcription 3 and NF-κB activity in colitis. Strategies such as circNlgn knockdown and targeting nuclear actin polymerization of the colonic epithelium may explore a novel avenue for acute ulcerative colitis clinical intervention.
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Affiliation(s)
- William W. Du
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
| | - Chi Zhou
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
- Department of Colorectal Surgery,
Sun Yat-sen University Cancer Center, Guangzhou, China
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine,
Sun Yat-sen University Cancer Center, Guangzhou, China
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer,
Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Hui Yang
- The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Shuoyang Wen
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
| | - Yu Chen
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
| | - Eric X. Chen
- Princess Margaret Cancer Centre, Toronto, ON, Canada
| | - Xiuwei H. Yang
- Department of Pharmacology and Nutritional Sciences, College of Medicine,
University of Kentucky, Lexington, KY, USA
| | - Feiya Li
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
| | - Kevin Y. Du
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
| | - Hui Yuan
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
| | - Ting Ye
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
| | - Javeria Qadir
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
| | - Burton B. Yang
- Sunnybrook Research Institute,
Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology,
University of Toronto, Toronto, ON, Canada
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4
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Mao YX, Li Y, Yang Z, Xu N, Zhang S, Wang X, Yang X, Sun Q, Mao Y. Comparative transcriptome analysis between rhesus macaques ( Macaca mulatta) and crab-eating macaques ( M. fascicularis). Zool Res 2024; 45:299-310. [PMID: 38485500 PMCID: PMC11017088 DOI: 10.24272/j.issn.2095-8137.2023.322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/28/2023] [Indexed: 03/19/2024] Open
Abstract
Understanding gene expression variations between species is pivotal for deciphering the evolutionary diversity in phenotypes. Rhesus macaques ( Macaca mulatta, MMU) and crab-eating macaques ( M. fascicularis, MFA) serve as crucial nonhuman primate biomedical models with different phenotypes. To date, however, large-scale comparative transcriptome research between these two species has not yet been fully explored. Here, we conducted systematic comparisons utilizing newly sequenced RNA-seq data from 84 samples (41 MFA samples and 43 MMU samples) encompassing 14 common tissues. Our findings revealed a small fraction of genes (3.7%) with differential expression between the two species, as well as 36.5% of genes with tissue-specific expression in both macaques. Comparison of gene expression between macaques and humans indicated that 22.6% of orthologous genes displayed differential expression in at least two tissues. Moreover, 19.41% of genes that overlapped with macaque-specific structural variants showed differential expression between humans and macaques. Of these, the FAM220A gene exhibited elevated expression in humans compared to macaques due to lineage-specific duplication. In summary, this study presents a large-scale transcriptomic comparison between MMU and MFA and between macaques and humans. The discovery of gene expression variations not only enhances the biomedical utility of macaque models but also contributes to the wider field of primate genomics.
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Affiliation(s)
- Yu-Xiang Mao
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Key Laboratory of Genetic Evolution & Animal Models, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
| | - Yamei Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai 201210, China
- Key Laboratory of Genetic Evolution & Animal Models, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
| | - Zikun Yang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ning Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Key Laboratory of Genetic Evolution & Animal Models, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
| | - Shilong Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Xuankai Wang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Xiangyu Yang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Qiang Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai 201210, China
- Key Laboratory of Genetic Evolution & Animal Models, Chinese Academy of Sciences, Kunming, Yunnan 650201, China. E-mail:
| | - Yafei Mao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
- Center for Genomic Research, International Institutes of Medicine, Fourth Affiliated Hospital, Zhejiang University, Yiwu, Zhejiang 322000, China. E-mail:
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5
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Kyheröinen S, Prajapati B, Sokolova M, Schmitz M, Viita T, Geyer M, Vartiainen MK. Actin associates with actively elongating genes and binds directly to the Cdk9 subunit of P-TEFb. J Biol Chem 2024; 300:105698. [PMID: 38301887 PMCID: PMC10891344 DOI: 10.1016/j.jbc.2024.105698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/08/2024] [Accepted: 01/21/2024] [Indexed: 02/03/2024] Open
Abstract
Nuclear actin has been demonstrated to be essential for optimal transcription, but the molecular mechanisms and direct binding partner for actin in the RNA polymerase complex have remained unknown. By using purified proteins in a variety of biochemical assays, we demonstrate a direct and specific interaction between monomeric actin and Cdk9, the kinase subunit of the positive transcription elongation factor b required for RNA polymerase II pause-release. This interaction efficiently prevents actin polymerization, is not dependent on kinase activity of Cdk9, and is not involved with releasing positive transcription elongation factor b from its inhibitor 7SK snRNP complex. Supporting the specific role for actin in the elongation phase of transcription, chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) reveals that actin interacts with genes only upon their active transcription elongation. This study therefore provides novel insights into the mechanisms by which actin facilitates the transcription process.
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Affiliation(s)
- Salla Kyheröinen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Bina Prajapati
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Maria Sokolova
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | | | - Tiina Viita
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, Bonn, Germany
| | - Maria K Vartiainen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.
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6
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Alteen MG, Deme JC, Alvarez CP, Loppnau P, Hutchinson A, Seitova A, Chandrasekaran R, Silva Ramos E, Secker C, Alqazzaz M, Wanker EE, Lea SM, Arrowsmith CH, Harding RJ. Delineation of functional subdomains of Huntingtin protein and their interaction with HAP40. Structure 2023; 31:1121-1131.e6. [PMID: 37390814 PMCID: PMC10527579 DOI: 10.1016/j.str.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/14/2023] [Accepted: 06/05/2023] [Indexed: 07/02/2023]
Abstract
The huntingtin (HTT) protein plays critical roles in numerous cellular pathways by functioning as a scaffold for its many interaction partners and HTT knock out is embryonic lethal. Interrogation of HTT function is complicated by the large size of this protein so we studied a suite of structure-rationalized subdomains to investigate the structure-function relationships within the HTT-HAP40 complex. Protein samples derived from the subdomain constructs were validated using biophysical methods and cryo-electron microscopy, revealing they are natively folded and can complex with validated binding partner, HAP40. Derivatized versions of these constructs enable protein-protein interaction assays in vitro, with biotin tags, and in cells, with luciferase two-hybrid assay-based tags, which we use in proof-of-principle analyses to further interrogate the HTT-HAP40 interaction. These open-source biochemical tools enable studies of fundamental HTT biochemistry and biology, will aid the discovery of macromolecular or small-molecule binding partners and help map interaction sites across this large protein.
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Affiliation(s)
- Matthew G Alteen
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada; POINT Biopharma, 22 St Clair Avenue E Suite 1201, Toronto, ON M4T 2S3, Canada
| | - Justin C Deme
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Claudia P Alvarez
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada; SCIEX, 71 Four Valley Dr, Vaughan, ON L4K 4V8, Canada
| | - Peter Loppnau
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Ashley Hutchinson
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Alma Seitova
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Renu Chandrasekaran
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Eduardo Silva Ramos
- Neuroproteomics, Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Christopher Secker
- Neuroproteomics, Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Mona Alqazzaz
- Princess Margaret Cancer Centre and Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Erich E Wanker
- Neuroproteomics, Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Susan M Lea
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Cheryl H Arrowsmith
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada; Princess Margaret Cancer Centre and Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada.
| | - Rachel J Harding
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada.
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7
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Rubio LS, Gross DS. Dynamic coalescence of yeast Heat Shock Protein genes bypasses the requirement for actin. Genetics 2023; 223:iyad006. [PMID: 36659814 PMCID: PMC10319981 DOI: 10.1093/genetics/iyad006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 07/22/2022] [Accepted: 01/03/2023] [Indexed: 01/21/2023] Open
Abstract
Nuclear actin has been implicated in dynamic chromatin rearrangements in diverse eukaryotes. In mammalian cells, it is required to reposition double-strand DNA breaks to enable homologous recombination repair and to enhance transcription by facilitating RNA Pol II recruitment to gene promoters. In the yeast Saccharomyces cerevisiae, nuclear actin modulates interphase chromosome dynamics and is required to reposition the induced INO1 gene to the nuclear periphery. Here, we have investigated the role of actin in driving intergenic interactions between Heat Shock Factor 1 (Hsf1)-regulated Heat Shock Protein (HSP) genes in budding yeast. These genes, dispersed on multiple chromosomes, dramatically reposition following exposure of cells to acute thermal stress, leading to their clustering within dynamic biomolecular condensates. Using an auxin-induced degradation strategy, we found that conditional depletion of nucleators of either linear or branched F-actin (Bni1/Bnr1 and Arp2, respectively) had little or no effect on heat shock-induced HSP gene coalescence or transcription. In addition, we found that pretreatment of cells with latrunculin A, an inhibitor of both filamentous and monomeric actin, failed to affect intergenic interactions between activated HSP genes and their heat shock-induced intragenic looping and folding. Moreover, latrunculin A pretreatment had little effect on HSP gene expression at either RNA or protein levels. In notable contrast, we confirmed that repositioning of activated INO1 to the nuclear periphery and its proper expression do require actin. Collectively, our work suggests that transcriptional activation and 3D genome restructuring of thermally induced, Hsf1-regulated genes can occur in the absence of actin.
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Affiliation(s)
- Linda S Rubio
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - David S Gross
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
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8
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Balaban C, Sztacho M, Antiga L, Miladinović A, Harata M, Hozák P. PIP2-Effector Protein MPRIP Regulates RNA Polymerase II Condensation and Transcription. Biomolecules 2023; 13:biom13030426. [PMID: 36979361 PMCID: PMC10046169 DOI: 10.3390/biom13030426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/17/2023] [Accepted: 02/21/2023] [Indexed: 03/02/2023] Open
Abstract
The specific post-translational modifications of the C-terminal domain (CTD) of the Rpb1 subunit of RNA polymerase II (RNAPII) correlate with different stages of transcription. The phosphorylation of the Ser5 residues of this domain associates with the initiation condensates, which are formed through liquid-liquid phase separation (LLPS). The subsequent Tyr1 phosphorylation of the CTD peaks at the promoter-proximal region and is involved in the pause-release of RNAPII. By implementing super-resolution microscopy techniques, we previously reported that the nuclear Phosphatidylinositol 4,5-bisphosphate (PIP2) associates with the Ser5-phosphorylated-RNAPII complex and facilitates the RNAPII transcription. In this study, we identified Myosin Phosphatase Rho-Interacting Protein (MPRIP) as a novel regulator of the RNAPII transcription that recruits Tyr1-phosphorylated CTD (Tyr1P-CTD) to nuclear PIP2-containing structures. The depletion of MPRIP increases the number of the initiation condensates, indicating a defect in the transcription. We hypothesize that MPRIP regulates the condensation and transcription through affecting the association of the RNAPII complex with nuclear PIP2-rich structures. The identification of Tyr1P-CTD as an interactor of PIP2 and MPRIP further points to a regulatory role in RNAPII pause-release, where the susceptibility of the transcriptional complex to leave the initiation condensate depends on its association with nuclear PIP2-rich structures. Moreover, the N-terminal domain of MPRIP, which is responsible for the interaction with the Tyr1P-CTD, contains an F-actin binding region that offers an explanation of how nuclear F-actin formations can affect the RNAPII transcription and condensation. Overall, our findings shed light on the role of PIP2 in RNAPII transcription through identifying the F-actin binding protein MPRIP as a transcription regulator and a determinant of the condensation of RNAPII.
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Affiliation(s)
- Can Balaban
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Martin Sztacho
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
- Correspondence: (M.S.); (P.H.)
| | - Ludovica Antiga
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Ana Miladinović
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Masahiko Harata
- Laboratory of Molecular Biochemistry, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
| | - Pavel Hozák
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
- Correspondence: (M.S.); (P.H.)
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9
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Talbot DE, Vormezeele BJ, Kimble GC, Wineland DM, Kelpsch DJ, Giedt MS, Tootle TL. Prostaglandins limit nuclear actin to control nucleolar function during oogenesis. Front Cell Dev Biol 2023; 11:1072456. [PMID: 36875757 PMCID: PMC9981675 DOI: 10.3389/fcell.2023.1072456] [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: 10/17/2022] [Accepted: 02/06/2023] [Indexed: 02/19/2023] Open
Abstract
Prostaglandins (PGs), locally acting lipid signals, regulate female reproduction, including oocyte development. However, the cellular mechanisms of PG action remain largely unknown. One cellular target of PG signaling is the nucleolus. Indeed, across organisms, loss of PGs results in misshapen nucleoli, and changes in nucleolar morphology are indicative of altered nucleolar function. A key role of the nucleolus is to transcribe ribosomal RNA (rRNA) to drive ribosomal biogenesis. Here we take advantage of the robust, in vivo system of Drosophila oogenesis to define the roles and downstream mechanisms whereby PGs regulate the nucleolus. We find that the altered nucleolar morphology due to PG loss is not due to reduced rRNA transcription. Instead, loss of PGs results in increased rRNA transcription and overall protein translation. PGs modulate these nucleolar functions by tightly regulating nuclear actin, which is enriched in the nucleolus. Specifically, we find that loss of PGs results in both increased nucleolar actin and changes in its form. Increasing nuclear actin, by either genetic loss of PG signaling or overexpression of nuclear targeted actin (NLS-actin), results in a round nucleolar morphology. Further, loss of PGs, overexpression of NLS-actin or loss of Exportin 6, all manipulations that increase nuclear actin levels, results in increased RNAPI-dependent transcription. Together these data reveal PGs carefully balance the level and forms of nuclear actin to control the level of nucleolar activity required for producing fertilization competent oocytes.
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Affiliation(s)
| | | | | | | | | | | | - Tina L. Tootle
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
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10
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Mahmood SR, Said NHE, Gunsalus KC, Percipalle P. β-actin mediated H3K27ac changes demonstrate the link between compartment switching and enhancer-dependent transcriptional regulation. Genome Biol 2023; 24:18. [PMID: 36698204 PMCID: PMC9875490 DOI: 10.1186/s13059-023-02853-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Recent work has demonstrated that three-dimensional genome organization is directly affected by changes in the levels of nuclear cytoskeletal proteins such as β-actin. The mechanisms which translate changes in 3D genome structure into changes in transcription, however, are not fully understood. Here, we use a comprehensive genomic analysis of cells lacking nuclear β-actin to investigate the mechanistic links between compartment organization, enhancer activity, and gene expression. RESULTS Using HiC-Seq, ATAC-Seq, and RNA-Seq, we first demonstrate that transcriptional and chromatin accessibility changes observed upon β-actin loss are highly enriched in compartment-switching regions. Accessibility changes within compartment switching genes, however, are mainly observed in non-promoter regions which potentially represent distal regulatory elements. Our results also show that β-actin loss induces widespread accumulation of the enhancer-specific epigenetic mark H3K27ac. Using the ABC model of enhancer annotation, we then establish that these epigenetic changes have a direct impact on enhancer activity and underlie transcriptional changes observed upon compartment switching. A complementary analysis of fibroblasts undergoing reprogramming into pluripotent stem cells further confirms that this relationship between compartment switching and enhancer-dependent transcriptional change is not specific to β-actin knockout cells but represents a general mechanism linking compartment-level genome organization to gene expression. CONCLUSIONS We demonstrate that enhancer-dependent transcriptional regulation plays a crucial role in driving gene expression changes observed upon compartment-switching. Our results also reveal a novel function of nuclear β-actin in regulating enhancer function by influencing H3K27 acetylation levels.
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Affiliation(s)
- Syed Raza Mahmood
- grid.440573.10000 0004 1755 5934Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates ,grid.137628.90000 0004 1936 8753Department of Biology, New York University, New York, NY 10003 USA
| | - Nadine Hosny El Said
- grid.440573.10000 0004 1755 5934Program in Biology, Division of Science and Mathematics, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Kristin C. Gunsalus
- grid.440573.10000 0004 1755 5934Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates ,grid.137628.90000 0004 1936 8753Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003 USA
| | - Piergiorgio Percipalle
- grid.440573.10000 0004 1755 5934Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates ,grid.440573.10000 0004 1755 5934Program in Biology, Division of Science and Mathematics, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates ,grid.10548.380000 0004 1936 9377Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
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11
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Sheu SH, Upadhyayula S, Dupuy V, Pang S, Deng F, Wan J, Walpita D, Pasolli HA, Houser J, Sanchez-Martinez S, Brauchi SE, Banala S, Freeman M, Xu CS, Kirchhausen T, Hess HF, Lavis L, Li Y, Chaumont-Dubel S, Clapham DE. A serotonergic axon-cilium synapse drives nuclear signaling to alter chromatin accessibility. Cell 2022; 185:3390-3407.e18. [PMID: 36055200 PMCID: PMC9789380 DOI: 10.1016/j.cell.2022.07.026] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 05/16/2022] [Accepted: 07/25/2022] [Indexed: 12/27/2022]
Abstract
Chemical synapses between axons and dendrites mediate neuronal intercellular communication. Here, we describe a synapse between axons and primary cilia: the axo-ciliary synapse. Using enhanced focused ion beam-scanning electron microscopy on samples with optimally preserved ultrastructure, we discovered synapses between brainstem serotonergic axons and the primary cilia of hippocampal CA1 pyramidal neurons. Functionally, these cilia are enriched in a ciliary-restricted serotonin receptor, the 5-hydroxytryptamine receptor 6 (5-HTR6). Using a cilia-targeted serotonin sensor, we show that opto- and chemogenetic stimulation of serotonergic axons releases serotonin onto cilia. Ciliary 5-HTR6 stimulation activates a non-canonical Gαq/11-RhoA pathway, which modulates nuclear actin and increases histone acetylation and chromatin accessibility. Ablation of this pathway reduces chromatin accessibility in CA1 pyramidal neurons. As a signaling apparatus with proximity to the nucleus, axo-ciliary synapses short circuit neurotransmission to alter the postsynaptic neuron's epigenetic state.
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Affiliation(s)
- Shu-Hsien Sheu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA; Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Department of Pathology, Boston, MA, USA; Howard Huges Medical Institute, Boston Children's Hospital, Department of Cardiology, Boston, MA, USA.
| | - Srigokul Upadhyayula
- Advanced Bioimaging Center, University of California at Berkeley, Berkeley, CA, USA; Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Vincent Dupuy
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Song Pang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Fei Deng
- School of Life Sciences, Peking University, Beijing, China
| | - Jinxia Wan
- School of Life Sciences, Peking University, Beijing, China
| | - Deepika Walpita
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - H Amalia Pasolli
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Justin Houser
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | | | - Sebastian E Brauchi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA; Department of Physiology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile; Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Valdivia, Chile
| | - Sambashiva Banala
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Melanie Freeman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - C Shan Xu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Tom Kirchhausen
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA; Department of Cell Biology, Harvard Medical School, 200 Longwood Ave, Boston, MA, USA; Department of Pediatrics, Harvard Medical School, 200 Longwood Ave, Boston, MA, USA
| | - Harald F Hess
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Luke Lavis
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Yulong Li
- School of Life Sciences, Peking University, Beijing, China
| | - Séverine Chaumont-Dubel
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - David E Clapham
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA; Harvard Medical School, Boston, MA, USA; Howard Huges Medical Institute, Boston Children's Hospital, Department of Cardiology, Boston, MA, USA.
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12
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Dupont S, Wickström SA. Mechanical regulation of chromatin and transcription. Nat Rev Genet 2022; 23:624-643. [DOI: 10.1038/s41576-022-00493-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2022] [Indexed: 01/14/2023]
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13
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Abstract
Actin is a highly conserved protein in mammals. The actin dynamics is regulated by actin-binding proteins and actin-related proteins. Nuclear actin and these regulatory proteins participate in multiple nuclear processes, including chromosome architecture organization, chromatin remodeling, transcription machinery regulation, and DNA repair. It is well known that the dysfunctions of these processes contribute to the development of cancer. Moreover, emerging evidence has shown that the deregulated actin dynamics is also related to cancer. This chapter discusses how the deregulation of nuclear actin dynamics contributes to tumorigenesis via such various nuclear events.
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Affiliation(s)
- Yuanjian Huang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Shengzhe Zhang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jae-Il Park
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
- Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center and Health Science Center, Houston, TX, USA.
- Program in Genetics and Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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14
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Casadonte R, Kriegsmann M, Kriegsmann K, Hauk I, Meliß RR, Müller CSL, Kriegsmann J. Imaging Mass Spectrometry-Based Proteomic Analysis to Differentiate Melanocytic Nevi and Malignant Melanoma. Cancers (Basel) 2021; 13:3197. [PMID: 34206844 PMCID: PMC8267712 DOI: 10.3390/cancers13133197] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 12/15/2022] Open
Abstract
The discrimination of malignant melanoma from benign nevi may be difficult in some cases. For this reason, immunohistological and molecular techniques are included in the differential diagnostic toolbox for these lesions. These methods are time consuming when applied subsequently and, in some cases, no definitive diagnosis can be made. We studied both lesions by imaging mass spectrometry (IMS) in a large cohort (n = 203) to determine a different proteomic profile between cutaneous melanomas and melanocytic nevi. Sample preparation and instrument setting were tested to obtain optimal results in term of data quality and reproducibility. A proteomic signature was found by linear discriminant analysis to discern malignant melanoma from benign nevus (n = 113) with an overall accuracy of >98%. The prediction model was tested in an independent set (n = 90) reaching an overall accuracy of 93% in classifying melanoma from nevi. Statistical analysis of the IMS data revealed mass-to-charge ratio (m/z) peaks which varied significantly (Area under the receiver operating characteristic curve > 0.7) between the two tissue types. To our knowledge, this is the largest IMS study of cutaneous melanoma and nevi performed up to now. Our findings clearly show that discrimination of melanocytic nevi from melanoma is possible by IMS.
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Affiliation(s)
| | - Mark Kriegsmann
- Institute of Pathology, University Hospital Heidelberg, 69120 Heidelberg, Germany;
| | - Katharina Kriegsmann
- Department of Hematology Oncology and Rheumatology, University Hospital Heidelberg, 69120 Heidelberg, Germany;
| | - Isabella Hauk
- Faculty of Medicine/Dentistry, Danube Private University, 3500 Krems-Stein, Austria;
| | - Rolf R. Meliß
- Institute für Dermatopathologie, 30519 Hannover, Germany;
| | - Cornelia S. L. Müller
- MVZ für Histologie, Zytologie und Molekulare Diagnostik Trier, 54296 Trier, Germany;
| | - Jörg Kriegsmann
- Proteopath GmbH, 54926 Trier, Germany; or
- Faculty of Medicine/Dentistry, Danube Private University, 3500 Krems-Stein, Austria;
- MVZ für Histologie, Zytologie und Molekulare Diagnostik Trier, 54296 Trier, Germany;
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15
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Erenpreisa J, Krigerts J, Salmina K, Gerashchenko BI, Freivalds T, Kurg R, Winter R, Krufczik M, Zayakin P, Hausmann M, Giuliani A. Heterochromatin Networks: Topology, Dynamics, and Function (a Working Hypothesis). Cells 2021; 10:1582. [PMID: 34201566 PMCID: PMC8304199 DOI: 10.3390/cells10071582] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 12/21/2022] Open
Abstract
Open systems can only exist by self-organization as pulsing structures exchanging matter and energy with the outer world. This review is an attempt to reveal the organizational principles of the heterochromatin supra-intra-chromosomal network in terms of nonlinear thermodynamics. The accessibility of the linear information of the genetic code is regulated by constitutive heterochromatin (CHR) creating the positional information in a system of coordinates. These features include scale-free splitting-fusing of CHR with the boundary constraints of the nucleolus and nuclear envelope. The analysis of both the literature and our own data suggests a radial-concentric network as the main structural organization principle of CHR regulating transcriptional pulsing. The dynamic CHR network is likely created together with nucleolus-associated chromatin domains, while the alveoli of this network, including springy splicing speckles, are the pulsing transcription hubs. CHR contributes to this regulation due to the silencing position variegation effect, stickiness, and flexible rigidity determined by the positioning of nucleosomes. The whole system acts in concert with the elastic nuclear actomyosin network which also emerges by self-organization during the transcriptional pulsing process. We hypothesize that the the transcriptional pulsing, in turn, adjusts its frequency/amplitudes specified by topologically associating domains to the replication timing code that determines epigenetic differentiation memory.
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Affiliation(s)
- Jekaterina Erenpreisa
- Latvian Biomedicine Research and Study Centre, LV-1067 Riga, Latvia; (J.K.); (K.S.); (P.Z.)
| | - Jekabs Krigerts
- Latvian Biomedicine Research and Study Centre, LV-1067 Riga, Latvia; (J.K.); (K.S.); (P.Z.)
| | - Kristine Salmina
- Latvian Biomedicine Research and Study Centre, LV-1067 Riga, Latvia; (J.K.); (K.S.); (P.Z.)
| | - Bogdan I. Gerashchenko
- R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, National Academy of Sciences of Ukraine, 03022 Kyiv, Ukraine;
| | - Talivaldis Freivalds
- Institute of Cardiology and Regenerative Medicine, University of Latvia, LV-1004 Riga, Latvia;
| | - Reet Kurg
- Institute of Technology, University of Tartu, 50411 Tartu, Estonia;
| | - Ruth Winter
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany; (R.W.); (M.K.); (M.H.)
| | - Matthias Krufczik
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany; (R.W.); (M.K.); (M.H.)
| | - Pawel Zayakin
- Latvian Biomedicine Research and Study Centre, LV-1067 Riga, Latvia; (J.K.); (K.S.); (P.Z.)
| | - Michael Hausmann
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany; (R.W.); (M.K.); (M.H.)
| | - Alessandro Giuliani
- Istituto Superiore di Sanita Environment and Health Department, 00161 Roma, Italy
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16
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The F-Actin-Binding MPRIP Forms Phase-Separated Condensates and Associates with PI(4,5)P2 and Active RNA Polymerase II in the Cell Nucleus. Cells 2021; 10:cells10040848. [PMID: 33918018 PMCID: PMC8068864 DOI: 10.3390/cells10040848] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/25/2021] [Accepted: 04/06/2021] [Indexed: 12/14/2022] Open
Abstract
Here, we provide evidence for the presence of Myosin phosphatase rho-interacting protein (MPRIP), an F-actin-binding protein, in the cell nucleus. The MPRIP protein binds to Phosphatidylinositol 4,5-bisphosphate (PIP2) and localizes to the nuclear speckles and nuclear lipid islets which are known to be involved in transcription. We identified MPRIP as a component of RNA Polymerase II/Nuclear Myosin 1 complex and showed that MPRIP forms phase-separated condensates which are able to bind nuclear F-actin fibers. Notably, the fibrous MPRIP preserves its liquid-like properties and reforms the spherical shaped condensates when F-actin is disassembled. Moreover, we show that the phase separation of MPRIP is driven by its long intrinsically disordered region at the C-terminus. We propose that the PIP2/MPRIP association might contribute to the regulation of RNAPII transcription via phase separation and nuclear actin polymerization.
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17
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Kumar D, Lak B, Suntio T, Vihinen H, Belevich I, Viita T, Xiaonan L, Vartiainen A, Vartiainen M, Varjosalo M, Jokitalo E. RTN4B interacting protein FAM134C promotes ER membrane curvature and has a functional role in autophagy. Mol Biol Cell 2021; 32:1158-1170. [PMID: 33826365 PMCID: PMC8351555 DOI: 10.1091/mbc.e20-06-0409] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The endoplasmic reticulum (ER) is composed of a controlled ratio of sheets and tubules, which are maintained by several proteins with multiple functions. Reticulons (RTNs), especially RTN4, and DP1/Yop1p family members are known to induce ER membrane curvature. RTN4B is the main RTN4 isoform expressed in nonneuronal cells. In this study, we identified FAM134C as a RTN4B interacting protein in mammalian, nonneuronal cells. FAM134C localized specifically to the ER tubules and sheet edges. Ultrastructural analysis revealed that overexpression of FAM134C induced the formation of unbranched, long tubules or dense globular structures composed of heavily branched narrow tubules. In both cases, tubules were nonmotile. ER tubulation was dependent on the reticulon homology domain (RHD) close to the N-terminus. FAM134C plays a role in the autophagy pathway as its level elevated significantly upon amino acid starvation but not during ER stress. Moreover, FAM134C depletion reduced the number and size of autophagic structures and the amount of ER as a cargo within autophagic structures under starvation conditions. Dominant-negative expression of FAM134C forms with mutated RHD or LC3 interacting region also led to a reduced number of autophagic structures. Our results suggest that FAM134C provides a link between regulation of ER architecture and ER turnover by promoting ER tubulation required for subsequent ER fragmentation and engulfment into autophagosomes.
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Affiliation(s)
| | - Behnam Lak
- Cell and Tissue Dynamics Research Program
| | | | - Helena Vihinen
- Cell and Tissue Dynamics Research Program.,Electron Microscopy Unit, and
| | - Ilya Belevich
- Cell and Tissue Dynamics Research Program.,Electron Microscopy Unit, and
| | | | - Liu Xiaonan
- Molecular Systems Biology Research Group and Proteomics Unit, Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | | | | | - Markku Varjosalo
- Molecular Systems Biology Research Group and Proteomics Unit, Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Eija Jokitalo
- Cell and Tissue Dynamics Research Program.,Electron Microscopy Unit, and
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18
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Roggenkamp HG, Khansahib I, Hernandez C LC, Zhang Y, Lodygin D, Krüger A, Gu F, Möckl F, Löhndorf A, Wolters V, Woike D, Rosche A, Bauche A, Schetelig D, Werner R, Schlüter H, Failla AV, Meier C, Fliegert R, Walseth TF, Flügel A, Diercks BP, Guse AH. HN1L/JPT2: A signaling protein that connects NAADP generation to Ca 2+ microdomain formation. Sci Signal 2021; 14:14/675/eabd5647. [PMID: 33758062 DOI: 10.1126/scisignal.abd5647] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
NAADP-evoked Ca2+ release through type 1 ryanodine receptors (RYR1) is a major mechanism underlying the earliest signals in T cell activation, which are the formation of Ca2+ microdomains. In our characterization of the molecular machinery underlying NAADP action, we identified an NAADP-binding protein, called hematological and neurological expressed 1-like protein (HN1L) [also known as Jupiter microtubule-associated homolog 2 (JPT2)]. Gene deletion of Hn1l/Jpt2 in human Jurkat and primary rat T cells resulted in decreased numbers of initial Ca2+ microdomains and delayed the onset and decreased the amplitude of global Ca2+ signaling. Photoaffinity labeling demonstrated direct binding of NAADP to recombinant HN1L/JPT2. T cell receptor/CD3-dependent coprecipitation of HN1L/JPT2 with RYRs and colocalization of these proteins suggest that HN1L/JPT2 connects NAADP formation with the activation of RYR channels within the first seconds of T cell activation. Thus, HN1L/JPT2 enables NAADP to activate Ca2+ release from the endoplasmic reticulum through RYR.
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Affiliation(s)
- Hannes G Roggenkamp
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Imrankhan Khansahib
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Lola C Hernandez C
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Yunpeng Zhang
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Dmitri Lodygin
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Centre Göttingen, 37075 Göttingen, Germany
| | - Aileen Krüger
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Feng Gu
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Franziska Möckl
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Anke Löhndorf
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Valerie Wolters
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Daniel Woike
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Anette Rosche
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Andreas Bauche
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Daniel Schetelig
- Department of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - René Werner
- Department of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Hartmut Schlüter
- Mass Spectrometric Proteomics Group, Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Antonio V Failla
- Microscopy Imaging Facility (UMIF), University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Chris Meier
- Organic Chemistry, University of Hamburg, 20146 Hamburg, Germany
| | - Ralf Fliegert
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Timothy F Walseth
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455-0217, USA
| | - Alexander Flügel
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Centre Göttingen, 37075 Göttingen, Germany
| | - Björn-Philipp Diercks
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
| | - Andreas H Guse
- The Ca Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
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19
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Ulferts S, Prajapati B, Grosse R, Vartiainen MK. Emerging Properties and Functions of Actin and Actin Filaments Inside the Nucleus. Cold Spring Harb Perspect Biol 2021; 13:cshperspect.a040121. [PMID: 33288541 PMCID: PMC7919393 DOI: 10.1101/cshperspect.a040121] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent years have provided considerable insights into the dynamic nature of the cell nucleus, which is constantly reorganizing its genome, controlling its size and shape, as well as spatiotemporally orchestrating chromatin remodeling and transcription. Remarkably, it has become clear that the ancient and highly conserved cytoskeletal protein actin plays a crucial part in these processes. However, the underlying mechanisms, regulations, and properties of actin functions inside the nucleus are still not well understood. Here we summarize the diverse and distinct roles of monomeric and filamentous actin as well as the emerging roles for actin dynamics inside the nuclear compartment for genome organization and nuclear architecture.
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Affiliation(s)
- Svenja Ulferts
- Institute for Clinical and Experimental Pharmacology and Toxicology I, University of Freiburg, 79104 Freiburg, Germany
| | - Bina Prajapati
- Institute of Biotechnology, Helsinki Institute for Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Robert Grosse
- Institute for Clinical and Experimental Pharmacology and Toxicology I, University of Freiburg, 79104 Freiburg, Germany,Centre for Integrative Biological Signalling Studies (CIBSS), 79104 Freiburg, Germany
| | - Maria K. Vartiainen
- Institute of Biotechnology, Helsinki Institute for Life Science, University of Helsinki, 00014 Helsinki, Finland
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Limited Proteolysis-Coupled Mass Spectrometry Identifies Phosphatidylinositol 4,5-Bisphosphate Effectors in Human Nuclear Proteome. Cells 2021; 10:cells10010068. [PMID: 33406800 PMCID: PMC7824793 DOI: 10.3390/cells10010068] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/23/2020] [Accepted: 12/29/2020] [Indexed: 12/20/2022] Open
Abstract
Specific nuclear sub-compartments that are regions of fundamental processes such as gene expression or DNA repair, contain phosphoinositides (PIPs). PIPs thus potentially represent signals for the localization of specific proteins into different nuclear functional domains. We performed limited proteolysis followed by label-free quantitative mass spectrometry and identified nuclear protein effectors of the most abundant PIP—phosphatidylinositol 4,5-bisphosphate (PIP2). We identified 515 proteins with PIP2-binding capacity of which 191 ‘exposed’ proteins represent a direct PIP2 interactors and 324 ‘hidden’ proteins, where PIP2 binding was increased upon trypsin treatment. Gene ontology analysis revealed that ‘exposed’ proteins are involved in the gene expression as regulators of Pol II, mRNA splicing, and cell cycle. They localize mainly to non-membrane bound organelles—nuclear speckles and nucleolus and are connected to the actin nucleoskeleton. ‘Hidden’ proteins are linked to the gene expression, RNA splicing and transport, cell cycle regulation, and response to heat or viral infection. These proteins localize to the nuclear envelope, nuclear pore complex, or chromatin. Bioinformatic analysis of peptides bound in both groups revealed that PIP2-binding motifs are in general hydrophilic. Our data provide an insight into the molecular mechanism of nuclear PIP2 protein interaction and advance the methodology applicable for further studies of PIPs or other protein ligands.
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A M, Latario CJ, Pickrell LE, Higgs HN. Lysine acetylation of cytoskeletal proteins: Emergence of an actin code. J Biophys Biochem Cytol 2020; 219:211455. [PMID: 33044556 PMCID: PMC7555357 DOI: 10.1083/jcb.202006151] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/26/2020] [Accepted: 09/02/2020] [Indexed: 02/06/2023] Open
Abstract
Reversible lysine acetylation of nuclear proteins such as histones is a long-established important regulatory mechanism for chromatin remodeling and transcription. In the cytoplasm, acetylation of a number of cytoskeletal proteins, including tubulin, cortactin, and the formin mDia2, regulates both cytoskeletal assembly and stability. More recently, acetylation of actin itself was revealed to regulate cytoplasmic actin polymerization through the formin INF2, with downstream effects on ER-to-mitochondrial calcium transfer, mitochondrial fission, and vesicle transport. This finding raises the possibility that actin acetylation, along with other post-translational modifications to actin, might constitute an "actin code," similar to the "histone code" or "tubulin code," controlling functional shifts to these central cellular proteins. Given the multiple roles of actin in nuclear functions, its modifications might also have important roles in gene expression.
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Abstract
The presence of actin in the nucleus has been a matter of debate for many years. In recent years many important roles of actin in the nucleus (transcriptional regulation, chromatin remodeling, DNA repair, cell division, maintenance of nuclear architecture) have been identified, and the precise control of nuclear actin levels has been demonstrated. The vital importance of the actin driven processes in the cell make it highly likely that dysregulation of nuclear actin dynamics and structure can be linked to tumor induction and -progression. In this chapter I summarize our current knowledge about nuclear actin in the cancer context.
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What do the structures of GCN5-containing complexes teach us about their function? BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194614. [PMID: 32739556 DOI: 10.1016/j.bbagrm.2020.194614] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022]
Abstract
Transcription initiation is a major regulatory step in eukaryotic gene expression. It involves the assembly of general transcription factors and RNA polymerase II into a functional pre-initiation complex at core promoters. The degree of chromatin compaction controls the accessibility of the transcription machinery to template DNA. Co-activators have critical roles in this process by actively regulating chromatin accessibility. Many transcriptional coactivators are multisubunit complexes, organized into distinct structural and functional modules and carrying multiple regulatory activities. The first nuclear histone acetyltransferase (HAT) characterized was General Control Non-derepressible 5 (Gcn5). Gcn5 was subsequently identified as a subunit of the HAT module of the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex, which is an experimental paradigm for multifunctional co-activators. We know today that Gcn5 is the catalytic subunit of multiple distinct co-activator complexes with specific functions. In this review, we summarize recent advances in the structure of Gcn5-containing co-activator complexes, most notably SAGA, and discuss how these new structural insights contribute to better understand their functions.
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Abstract
The presence of actin in the nucleus has historically been a highly contentious issue. It is now, however, well accepted that actin has physiologically important roles in the nucleus. In this Review, we describe the evolution of our thinking about actin in the nucleus starting with evidence supporting its involvement in transcription, chromatin remodeling and intranuclear movements. We also review the growing literature on the mechanisms that regulate the import and export of actin and how post-translational modifications of actin could regulate nuclear actin. We end with an extended discussion of the role of nuclear actin in the repair of DNA double stranded breaks.
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Affiliation(s)
- Leonid Serebryannyy
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612, United States
| | - Primal de Lanerolle
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612, United States.
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25
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Nuclear actin dynamics in gene expression and genome organization. Semin Cell Dev Biol 2020; 102:105-112. [DOI: 10.1016/j.semcdb.2019.10.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/28/2019] [Accepted: 10/24/2019] [Indexed: 11/19/2022]
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Ummethum H, Hamperl S. Proximity Labeling Techniques to Study Chromatin. Front Genet 2020; 11:450. [PMID: 32477404 PMCID: PMC7235407 DOI: 10.3389/fgene.2020.00450] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 04/14/2020] [Indexed: 12/19/2022] Open
Abstract
Mammals contain over 200 different cell types, yet nearly all have the same genomic DNA sequence. It is a key question in biology how the genetic instructions in DNA are selectively interpreted by cells to specify various transcriptional programs and therefore cellular identity. The structural and functional organization of chromatin governs the transcriptional state of individual genes. To understand how genomic loci adopt different levels of gene expression, it is critical to characterize all local chromatin factors as well as long-range interactions in the 3D nuclear compartment. Much of our current knowledge regarding protein interactions in a chromatin context is based on affinity purification of chromatin components coupled to mass spectrometry (AP-MS). AP-MS has been invaluable to map strong protein-protein interactions in the nucleus. However, the interaction is detected after cell lysis and biochemical enrichment, allowing for loss or gain of false positive or negative interaction partners. Recently, proximity-dependent labeling methods have emerged as powerful tools for studying chromatin in its native context. These methods take advantage of engineered enzymes that are fused to a chromatin factor of interest and can directly label all factors in proximity. Subsequent pull-down assays followed by mass spectrometry or sequencing approaches provide a comprehensive snapshot of the proximal chromatin interactome. By combining this method with dCas9, this approach can also be extended to study chromatin at specific genomic loci. Here, we review and compare current proximity-labeling approaches available for studying chromatin, with a particular focus on new emerging technologies that can provide important insights into the transcriptional and chromatin interaction networks essential for cellular identity.
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Affiliation(s)
- Henning Ummethum
- Chromosome Dynamics and Genome Stability, Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Munich, Germany
| | - Stephan Hamperl
- Chromosome Dynamics and Genome Stability, Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Munich, Germany
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Bullock SL, Visa N, Pederson T. Meeting report - Nuclear and cytoplasmic molecular machines at work. J Cell Sci 2020; 133:133/7/jcs245134. [PMID: 32253357 DOI: 10.1242/jcs.245134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This report summarizes an international conference on molecular machines convened at New York University, Abu Dhabi by Piergiorgio Percipalle, George Shubeita and Serdal Kirmizialtin. The meeting was conceived around the epistemological question of what do we understand, or not understand (if we have open minds), about the degree to which cells operate by the individual actions of single enzymes or non-catalytic protein effectors, versus combinations of these in which their heterotypic association creates an entity that is more finely tuned and efficient - a machine. This theme was explored through a vivid series of talks, summarizing the latest findings on macromolecular complexes that operate in the nucleus or cytoplasm.
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Affiliation(s)
| | - Neus Visa
- Department of Molecular Biosciences, Wenner Gren Institute, Stockholm University, Stockholm 10 691, Sweden
| | - Thoru Pederson
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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Hyrskyluoto A, Vartiainen MK. Regulation of nuclear actin dynamics in development and disease. Curr Opin Cell Biol 2020; 64:18-24. [PMID: 32088545 DOI: 10.1016/j.ceb.2020.01.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/17/2020] [Accepted: 01/22/2020] [Indexed: 12/21/2022]
Abstract
Actin has essential functions both in the cytoplasm and in the nucleus, where it has been linked to key nuclear processes, from transcription to DNA damage response. The multifunctional nature of actin suggests that the cell must contain mechanisms to accurately control the cellular actin balance. Indeed, recent results have demonstrated that nuclear actin levels fluctuate to regulate the transcriptional activity of the cell and that controlled nuclear actin polymerization is required for transcription activation, cell cycle progression, and DNA repair. Intriguingly, aberrant nuclear actin regulation has been observed, for example, in cancer, signifying the importance of this process for cellular homeostasis. This review discussed the latest research on how nuclear actin is regulated, and how this influences actin-dependent nuclear processes.
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Affiliation(s)
- Alise Hyrskyluoto
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014, Helsinki, Finland
| | - Maria K Vartiainen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014, Helsinki, Finland.
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Tamura T, Takato M, Shiono K, Hamachi I. Development of a Photoactivatable Proximity Labeling Method for the Identification of Nuclear Proteins. CHEM LETT 2020. [DOI: 10.1246/cl.190804] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Tomonori Tamura
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Mikiko Takato
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Keiya Shiono
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Itaru Hamachi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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Percipalle P, Vartiainen M. Cytoskeletal proteins in the cell nucleus: a special nuclear actin perspective. Mol Biol Cell 2020; 30:1781-1785. [PMID: 31306096 PMCID: PMC6727747 DOI: 10.1091/mbc.e18-10-0645] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The emerging role of cytoskeletal proteins in the cell nucleus has become a new frontier in cell biology. Actin and actin-binding proteins regulate chromatin and gene expression, but importantly they are beginning to be essential players in genome organization. These actin-based functions contribute to genome stability and integrity while affecting DNA replication and global transcription patterns. This is likely to occur through interactions of actin with nuclear components including nuclear lamina and subnuclear organelles. An exciting future challenge is to understand how these actin-based genome-wide mechanisms may regulate development and differentiation by interfering with the mechanical properties of the cell nucleus and how regulated actin polymerization plays a role in maintaining nuclear architecture. With a special focus on actin, here we summarize how cytoskeletal proteins operate in the nucleus and how they may be important to consolidate nuclear architecture for sustained gene expression or silencing.
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Affiliation(s)
- Piergiorgio Percipalle
- Biology Program, Science Division, New York University Abu Dhabi, 12988 Abu Dhabi, United Arab Emirates.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Maria Vartiainen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
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First person – Tiina Viita. J Cell Sci 2019. [DOI: 10.1242/jcs.232520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Tiina Viita is first author on ‘Nuclear actin interactome analysis links actin to KAT14 histone acetyl transferase and mRNA splicing’, published in JCS. Tiina is a PhD Student in the lab of Maria Vartiainen at the Institute of Biotechnology, University of Helsinki, Finland, investigating the nucleus, proteomics, chromatin remodeling, actin and post-transitional modifications of histones.
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