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Tamura I, Miyamoto K, Hatanaka C, Shiroshita A, Fujimura T, Shirafuta Y, Mihara Y, Maekawa R, Taketani T, Sato S, Matsumoto K, Tamura H, Sugino N. Nuclear actin assembly is an integral part of decidualization in human endometrial stromal cells. Commun Biol 2024; 7:830. [PMID: 38992143 PMCID: PMC11239864 DOI: 10.1038/s42003-024-06492-z] [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: 11/19/2022] [Accepted: 06/21/2024] [Indexed: 07/13/2024] Open
Abstract
Decidualization of the human endometrium is critical for establishing pregnancy and is entailed by differentiation of endometrial stromal cells (ESCs) into decidual cells. During decidualization, the actin cytoskeleton is dynamically reorganized for the ESCs' morphological and functional changes. Although actin dynamically alters its polymerized state upon external stimuli not only in the cytoplasm, but also in the nucleus, nuclear actin dynamics during decidualization have not been elucidated. Here, we show that nuclear actin was specifically assembled during decidualization of human ESCs. This decidualization-specific formation of nuclear actin filaments was disassembled following the withdrawal of the decidualization stimulus, suggesting its reversible process. Mechanistically, RNA-seq analyses revealed that the forced disassembly of nuclear actin resulted in the suppression of decidualization, accompanied with the abnormal upregulation of cell proliferation genes, leading to incomplete cell cycle arrest. CCAAT/enhancer-binding protein beta (C/EBPβ), an important regulator for decidualization, was responsible for downregulation of the nuclear actin exporter, thus accelerating nuclear actin accumulation and its assembly for decidualization. Taken together, we demonstrate that decidualization-specific nuclear actin assembly induces cell cycle arrest for establishing the decidualized state of ESCs. We propose that not only the cytoplasmic actin, but also nuclear actin dynamics profoundly affect decidualization process in humans for ensuring pregnancy.
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Affiliation(s)
- Isao Tamura
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan.
| | - Kei Miyamoto
- Laboratory of Molecular Developmental Biology, Faculty of Biology-Oriented Science and Technology, Kindai University, Wakayama, 649-6493, Japan.
- Laboratory of Animal Reproductive Physiology, Faculty of Agriculture, Kyushu University, Fukuoka, 819-0395, Japan.
| | - Chiharu Hatanaka
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
| | - Amon Shiroshita
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
| | - Taishi Fujimura
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
| | - Yuichiro Shirafuta
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
| | - Yumiko Mihara
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
| | - Ryo Maekawa
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
| | - Toshiaki Taketani
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
| | - Shun Sato
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
| | - Kazuya Matsumoto
- Laboratory of Molecular Developmental Biology, Faculty of Biology-Oriented Science and Technology, Kindai University, Wakayama, 649-6493, Japan
| | - Hiroshi Tamura
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
| | - Norihiro Sugino
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505, Japan
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Galbraith CG, English BP, Boehm U, Galbraith JA. Compartmentalized Cytoplasmic Flows Direct Protein Transport to the Cell's Leading Edge. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.12.593794. [PMID: 38798549 PMCID: PMC11118383 DOI: 10.1101/2024.05.12.593794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Inside the cell, proteins essential for signaling, morphogenesis, and migration navigate complex pathways, typically via vesicular trafficking or microtubule-driven mechanisms 1-3 . However, the process by which soluble cytoskeletal monomers maneuver through the cytoplasm's ever-changing environment to reach their destinations without using these pathways remains unknown. 4-6 Here, we show that actin cytoskeletal treadmilling leads to the formation of a semi-permeable actin-myosin barrier, creating a specialized compartment separated from the rest of the cell body that directs proteins toward the cell edge by advection, diffusion facilitated by fluid flow. Contraction at this barrier generates a molecularly non-specific fluid flow that transports actin, actin-binding proteins, adhesion proteins, and even inert proteins forward. The local curvature of the barrier specifically targets these proteins toward protruding edges of the leading edge, sites of new filament growth, effectively coordinating protein distribution with cellular dynamics. Outside this compartment, diffusion remains the primary mode of protein transport, contrasting sharply with the directed advection within. This discovery reveals a novel protein transport mechanism that redefines the front of the cell as a pseudo-organelle, actively orchestrating protein mobilization for cellular front activities such as protrusion and adhesion. By elucidating a new model of protein dynamics at the cellular front, this work contributes a critical piece to the puzzle of how cells adapt their internal structures for targeted and rapid response to extracellular cues. The findings challenge the current understanding of intracellular transport, suggesting that cells possess highly specialized and previously unrecognized organizational strategies for managing protein distribution efficiently, providing a new framework for understanding the cellular architecture's role in rapid response and adaptation to environmental changes.
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3
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Khudayberdiev S, Weiss K, Heinze A, Colombaretti D, Trausch N, Linne U, Rust MB. The actin-binding protein CAP1 represses MRTF-SRF-dependent gene expression in mouse cerebral cortex. Sci Signal 2024; 17:eadj0032. [PMID: 38713765 DOI: 10.1126/scisignal.adj0032] [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: 05/31/2023] [Accepted: 04/15/2024] [Indexed: 05/09/2024]
Abstract
Serum response factor (SRF) is an essential transcription factor for brain development and function. Here, we explored how an SRF cofactor, the actin monomer-sensing myocardin-related transcription factor MRTF, is regulated in mouse cortical neurons. We found that MRTF-dependent SRF activity in vitro and in vivo was repressed by cyclase-associated protein CAP1. Inactivation of the actin-binding protein CAP1 reduced the amount of actin monomers in the cytoplasm, which promoted nuclear MRTF translocation and MRTF-SRF activation. This function was independent of cofilin1 and actin-depolymerizing factor, and CAP1 loss of function in cortical neurons was not compensated by endogenous CAP2. Transcriptomic and proteomic analyses of cerebral cortex lysates from wild-type and Cap1 knockout mice supported the role of CAP1 in repressing MRTF-SRF-dependent signaling in vivo. Bioinformatic analysis identified likely MRTF-SRF target genes, which aligned with the transcriptomic and proteomic results. Together with our previous studies that implicated CAP1 in axonal growth cone function as well as the morphology and plasticity of excitatory synapses, our findings establish CAP1 as a crucial actin regulator in the brain relevant for formation of neuronal networks.
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Affiliation(s)
- Sharof Khudayberdiev
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, Hans-Meerwein-Strasse 6, 35032 Marburg, Germany
| | - Kerstin Weiss
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany
| | - Anika Heinze
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany
| | - Dalila Colombaretti
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany
| | - Nathan Trausch
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany
| | - Uwe Linne
- Department of Chemistry, Philipps-University Marburg, 35032 Marburg, Germany
| | - Marco B Rust
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, Hans-Meerwein-Strasse 6, 35032 Marburg, Germany
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Ulferts S, Lopes M, Miyamoto K, Grosse R. Nuclear actin dynamics and functions at a glance. J Cell Sci 2024; 137:jcs261630. [PMID: 38563209 DOI: 10.1242/jcs.261630] [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: 04/04/2024] Open
Abstract
Actin is well known for its cytoskeletal functions, where it helps to control and maintain cell shape and architecture, as well as regulating cell migration and intracellular cargo transport, among others. However, actin is also prevalent in the nucleus, where genome-regulating roles have been described, including it being part of chromatin-remodeling complexes. More recently, with the help of advances in microscopy techniques and specialized imaging probes, direct visualization of nuclear actin filament dynamics has helped elucidate new roles for nuclear actin, such as in cell cycle regulation, DNA replication and repair, chromatin organization and transcriptional condensate formation. In this Cell Science at a Glance article, we summarize the known signaling events driving the dynamic assembly of actin into filaments of various structures within the nuclear compartment for essential genome functions. Additionally, we highlight the physiological role of nuclear F-actin in meiosis and early embryonic development.
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Affiliation(s)
- Svenja Ulferts
- Institute for Clinical and Experimental Pharmacology and Toxicology I, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland
| | - Kei Miyamoto
- Faculty of Biology-Oriented Science and Technology, Kindai University, Wakayama 649-6493, Japan
| | - Robert Grosse
- Institute for Clinical and Experimental Pharmacology and Toxicology I, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany
- Centre for Integrative Biological Signalling Studies (CIBSS), 79104 Freiburg, Germany
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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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Palumbieri MD, Merigliano C, González-Acosta D, Kuster D, Krietsch J, Stoy H, von Känel T, Ulferts S, Welter B, Frey J, Doerdelmann C, Sanchi A, Grosse R, Chiolo I, Lopes M. Nuclear actin polymerization rapidly mediates replication fork remodeling upon stress by limiting PrimPol activity. Nat Commun 2023; 14:7819. [PMID: 38016948 PMCID: PMC10684888 DOI: 10.1038/s41467-023-43183-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/02/2023] [Indexed: 11/30/2023] Open
Abstract
Cells rapidly respond to replication stress actively slowing fork progression and inducing fork reversal. How replication fork plasticity is achieved in the context of nuclear organization is currently unknown. Using nuclear actin probes in living and fixed cells, we visualized nuclear actin filaments in unperturbed S phase and observed their rapid extension in number and length upon genotoxic treatments, frequently taking contact with replication factories. Chemically or genetically impairing nuclear actin polymerization shortly before these treatments prevents active fork slowing and abolishes fork reversal. Defective fork remodeling is linked to deregulated chromatin loading of PrimPol, which promotes unrestrained and discontinuous DNA synthesis and limits the recruitment of RAD51 and SMARCAL1 to nascent DNA. Moreover, defective nuclear actin polymerization upon mild replication interference induces chromosomal instability in a PRIMPOL-dependent manner. Hence, by limiting PrimPol activity, nuclear F-actin orchestrates replication fork plasticity and is a key molecular determinant in the rapid cellular response to genotoxic treatments.
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Affiliation(s)
| | - Chiara Merigliano
- Molecular and Computational Biology Department, University of Southern California, Los Angeles, CA, USA
| | | | - Danina Kuster
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Jana Krietsch
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Henriette Stoy
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Department of Cellular and Molecular Medicine, Copenhagen University, Copenhagen, Denmark
| | - Thomas von Känel
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Svenja Ulferts
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Freiburg im Breisgau, Germany
| | - Bettina Welter
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Joël Frey
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Cyril Doerdelmann
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Andrea Sanchi
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Robert Grosse
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Freiburg im Breisgau, Germany
- CIBSS - Centre for Integrative Biological Signaling Studies, University of Freiburg, Freiburg im Breisgau, Germany
| | - Irene Chiolo
- Molecular and Computational Biology Department, University of Southern California, Los Angeles, CA, USA.
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland.
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7
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Itoh K, Ossipova O, Matsuda M, Sokol SY. Myocardin-related transcription factors regulate morphogenetic events in vertebrate embryos by controlling F-actin organization and apical constriction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.27.559818. [PMID: 37808688 PMCID: PMC10557707 DOI: 10.1101/2023.09.27.559818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Myocardin-related transcription factors (Mrtfa and Mrtfb), also known as megakaryoblastic leukemia proteins (Mkl1/MAL and Mkl2), associate with serum response factor (Srf) to regulate transcription in response to actin dynamics, however, the functions of Mrtfs in early vertebrate embryos remain largely unknown. Here we document the requirement of Mrtfs for blastopore closure at gastrulation and neural plate folding in Xenopus early embryos. Both stimulation and inhibition of Mrtf activity caused similar gross morphological phenotypes, yet the effects on F-actin distribution and cell behavior were different. Suppressing Mrtf-dependent transcription reduced overall F-actin levels and inhibited apical constriction during gastrulation and neurulation. By contrast, constitutively active Mrtf caused tricellular junction remodeling and induced apical constriction in superficial ectoderm. The underlying mechanism appeared distinct from the one utilized by known apical constriction inducers. We propose that the regulation of apical constriction is among the primary cellular responses to Mrtf. Our findings highlight a dedicated role of specific transcription factors, Mrtfs, in early morphogenetic processes.
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8
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Angelini A, Trial J, Saltzman AB, Malovannaya A, Cieslik KA. A defective mechanosensing pathway affects fibroblast-to-myofibroblast transition in the old male mouse heart. iScience 2023; 26:107283. [PMID: 37520701 PMCID: PMC10372839 DOI: 10.1016/j.isci.2023.107283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/12/2023] [Accepted: 06/30/2023] [Indexed: 08/01/2023] Open
Abstract
The cardiac fibroblast interacts with an extracellular matrix (ECM), enabling myofibroblast maturation via a process called mechanosensing. Although in the aging male heart, ECM is stiffer than in the young mouse, myofibroblast development is impaired, as demonstrated in 2-D and 3-D experiments. In old male cardiac fibroblasts, we found a decrease in actin polymerization, α-smooth muscle actin (α-SMA), and Kindlin-2 expressions, the latter an effector of the mechanosensing. When Kindlin-2 levels were manipulated via siRNA interference, young fibroblasts developed an old-like fibroblast phenotype, whereas Kindlin-2 overexpression in old fibroblasts reversed the defective phenotype. Finally, inhibition of overactivated extracellular regulated kinases 1 and 2 (ERK1/2) in the old male fibroblasts rescued actin polymerization and α-SMA expression. Pathological ERK1/2 overactivation was also attenuated by Kindlin-2 overexpression. In contrast, old female cardiac fibroblasts retained an operant mechanosensing pathway. In conclusion, we identified defective components of the Kindlin/ERK/actin/α-SMA mechanosensing axis in aged male fibroblasts.
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Affiliation(s)
- Aude Angelini
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - JoAnn Trial
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Alexander B. Saltzman
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
- Mass Spectrometry Proteomics Core, Baylor College of Medicine, Houston, TX, USA
| | - Anna Malovannaya
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
- Mass Spectrometry Proteomics Core, Baylor College of Medicine, Houston, TX, USA
| | - Katarzyna A. Cieslik
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
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9
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Nieminuszczy J, Martin PR, Broderick R, Krwawicz J, Kanellou A, Mocanu C, Bousgouni V, Smith C, Wen KK, Woodward B, Bakal C, Shackley F, Aguilera A, Stewart G, Vyas Y, Niedzwiedz W. Actin nucleators safeguard replication forks by limiting nascent strand degradation. Nucleic Acids Res 2023; 51:6337-6354. [PMID: 37224534 PMCID: PMC10325910 DOI: 10.1093/nar/gkad369] [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: 10/13/2022] [Revised: 04/17/2023] [Accepted: 05/11/2023] [Indexed: 05/26/2023] Open
Abstract
Accurate genome replication is essential for all life and a key mechanism of disease prevention, underpinned by the ability of cells to respond to replicative stress (RS) and protect replication forks. These responses rely on the formation of Replication Protein A (RPA)-single stranded (ss) DNA complexes, yet this process remains largely uncharacterized. Here, we establish that actin nucleation-promoting factors (NPFs) associate with replication forks, promote efficient DNA replication and facilitate association of RPA with ssDNA at sites of RS. Accordingly, their loss leads to deprotection of ssDNA at perturbed forks, impaired ATR activation, global replication defects and fork collapse. Supplying an excess of RPA restores RPA foci formation and fork protection, suggesting a chaperoning role for actin nucleators (ANs) (i.e. Arp2/3, DIAPH1) and NPFs (i.e, WASp, N-WASp) in regulating RPA availability upon RS. We also discover that β-actin interacts with RPA directly in vitro, and in vivo a hyper-depolymerizing β-actin mutant displays a heightened association with RPA and the same dysfunctional replication phenotypes as loss of ANs/NPFs, which contrasts with the phenotype of a hyper-polymerizing β-actin mutant. Thus, we identify components of actin polymerization pathways that are essential for preventing ectopic nucleolytic degradation of perturbed forks by modulating RPA activity.
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Affiliation(s)
- Jadwiga Nieminuszczy
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Peter R Martin
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Ronan Broderick
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Joanna Krwawicz
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Alexandra Kanellou
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Camelia Mocanu
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Vicky Bousgouni
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Charlotte Smith
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Kuo-Kuang Wen
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, Penn State College of Medicine, Penn State Health Children's Hospital, Hershey, PA 17033, USA
| | - Beth L Woodward
- Genome Stability and Human Disease Laboratory, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Chris Bakal
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Fiona Shackley
- Paediatric Immunology, Allergy and Infectious Diseases, Sheffield Children's Hospital NHS Foundation Trust, Sheffield, UK
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Grant S Stewart
- Genome Stability and Human Disease Laboratory, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Yatin M Vyas
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, Penn State College of Medicine, Penn State Health Children's Hospital, Hershey, PA 17033, USA
| | - Wojciech Niedzwiedz
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
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10
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Wagner EL, Im JS, Sala S, Nakahata MI, Imbery TE, Li S, Chen D, Nimchuk K, Noy Y, Archer DW, Xu W, Hashisaki G, Avraham KB, Oakes PW, Shin JB. Repair of noise-induced damage to stereocilia F-actin cores is facilitated by XIRP2 and its novel mechanosensor domain. eLife 2023; 12:e72681. [PMID: 37294664 PMCID: PMC10259482 DOI: 10.7554/elife.72681] [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: 08/01/2021] [Accepted: 05/17/2023] [Indexed: 06/11/2023] Open
Abstract
Prolonged exposure to loud noise has been shown to affect inner ear sensory hair cells in a variety of deleterious manners, including damaging the stereocilia core. The damaged sites can be visualized as 'gaps' in phalloidin staining of F-actin, and the enrichment of monomeric actin at these sites, along with an actin nucleator and crosslinker, suggests that localized remodeling occurs to repair the broken filaments. Herein, we show that gaps in mouse auditory hair cells are largely repaired within 1 week of traumatic noise exposure through the incorporation of newly synthesized actin. We provide evidence that Xin actin binding repeat containing 2 (XIRP2) is required for the repair process and facilitates the enrichment of monomeric γ-actin at gaps. Recruitment of XIRP2 to stereocilia gaps and stress fiber strain sites in fibroblasts is force-dependent, mediated by a novel mechanosensor domain located in the C-terminus of XIRP2. Our study describes a novel process by which hair cells can recover from sublethal hair bundle damage and which may contribute to recovery from temporary hearing threshold shifts and the prevention of age-related hearing loss.
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Affiliation(s)
- Elizabeth L Wagner
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
- Department of Biochemistry & Molecular Genetics, University of VirginiaCharlottesvilleUnited States
| | - Jun-Sub Im
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Stefano Sala
- Department of Cell & Molecular Physiology, Stritch School of Medicine, Loyola University ChicagoChicagoUnited States
| | - Maura I Nakahata
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Terence E Imbery
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
- Department of Otolaryngology-Head & Neck Surgery, University of VirginiaCharlottesvilleUnited States
| | - Sihan Li
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
- Department of Biochemistry & Molecular Genetics, University of VirginiaCharlottesvilleUnited States
| | - Daniel Chen
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Katherine Nimchuk
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Yael Noy
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv UniversityTel AvivIsrael
| | - David W Archer
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Wenhao Xu
- Genetically Engineered Murine Model (GEMM) Core, University of VirginiaCharlottesvilleUnited States
| | - George Hashisaki
- Department of Otolaryngology-Head & Neck Surgery, University of VirginiaCharlottesvilleUnited States
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv UniversityTel AvivIsrael
| | - Patrick W Oakes
- Department of Cell & Molecular Physiology, Stritch School of Medicine, Loyola University ChicagoChicagoUnited States
| | - Jung-Bum Shin
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
- Department of Biochemistry & Molecular Genetics, University of VirginiaCharlottesvilleUnited States
- Department of Otolaryngology-Head & Neck Surgery, University of VirginiaCharlottesvilleUnited States
- Department of Cell Biology, University of VirginiaCharlottesvilleUnited States
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11
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Palumbieri MD, Merigliano C, Acosta DG, von Känel T, Welter B, Stoy H, Krietsch J, Ulferts S, Sanchi A, Grosse R, Chiolo I, Lopes M. Replication fork plasticity upon replication stress requires rapid nuclear actin polymerization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.24.534097. [PMID: 36993227 PMCID: PMC10055433 DOI: 10.1101/2023.03.24.534097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Cells rapidly respond to replication stress actively slowing fork progression and inducing fork reversal. How replication fork plasticity is achieved in the context of nuclear organization is currently unknown. Using nuclear actin probes in living and fixed cells, we visualized nuclear actin filaments in unperturbed S phase, rapidly extending in number and thickness upon genotoxic treatments, and taking frequent contact with replication factories. Chemically or genetically impairing nuclear actin polymerization shortly before these treatments prevents active fork slowing and abolishes fork reversal. Defective fork plasticity is linked to reduced recruitment of RAD51 and SMARCAL1 to nascent DNA. Conversely, PRIMPOL gains access to replicating chromatin, promoting unrestrained and discontinuous DNA synthesis, which is associated with increased chromosomal instability and decreased cellular resistance to replication stress. Hence, nuclear F-actin orchestrates replication fork plasticity and is a key molecular determinant in the rapid cellular response to genotoxic treatments.
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12
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Faria L, Canato S, Jesus TT, Gonçalves M, Guerreiro PS, Lopes CS, Meireles I, Morais-de-Sá E, Paredes J, Janody F. Activation of an actin signaling pathway in pre-malignant mammary epithelial cells by P-cadherin is essential for transformation. Dis Model Mech 2023; 16:dmm049652. [PMID: 36808468 PMCID: PMC9983776 DOI: 10.1242/dmm.049652] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 01/19/2023] [Indexed: 02/23/2023] Open
Abstract
Alterations in the expression or function of cell adhesion molecules have been implicated in all steps of tumor progression. Among those, P-cadherin is highly enriched in basal-like breast carcinomas, playing a central role in cancer cell self-renewal, collective cell migration and invasion. To establish a clinically relevant platform for functional exploration of P-cadherin effectors in vivo, we generated a humanized P-cadherin Drosophila model. We report that actin nucleators, Mrtf and Srf, are main P-cadherin effectors in fly. We validated these findings in a human mammary epithelial cell line with conditional activation of the SRC oncogene. We show that, prior to promoting malignant phenotypes, SRC induces a transient increase in P-cadherin expression, which correlates with MRTF-A accumulation, its nuclear translocation and the upregulation of SRF target genes. Moreover, knocking down P-cadherin, or preventing F-actin polymerization, impairs SRF transcriptional activity. Furthermore, blocking MRTF-A nuclear translocation hampers proliferation, self-renewal and invasion. Thus, in addition to sustaining malignant phenotypes, P-cadherin can also play a major role in the early stages of breast carcinogenesis by promoting a transient boost of MRTF-A-SRF signaling through actin regulation.
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Affiliation(s)
- Lídia Faria
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto (Ipatimup), Rua Júlio Amaral de Carvalho, n 45, 4200-135 Porto, Portugal
- Master Programme in Oncology, School of Medicine and Biomedical Sciences, University of Porto (ICBAS-UP), Rua Jorge Viterbo Ferreira 228, 4050-513 Porto, Portugal
| | - Sara Canato
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto (Ipatimup), Rua Júlio Amaral de Carvalho, n 45, 4200-135 Porto, Portugal
- Physiology and Cancer Program, Champalimaud Foundation, Avenida de Brasília, 1400-038 Lisboa, Portugal
| | - Tito T. Jesus
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto (Ipatimup), Rua Júlio Amaral de Carvalho, n 45, 4200-135 Porto, Portugal
| | - Margarida Gonçalves
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Patrícia S. Guerreiro
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto (Ipatimup), Rua Júlio Amaral de Carvalho, n 45, 4200-135 Porto, Portugal
- Vector B2B - Drug Developing - Associação Para Investigação em Biotecnologia, Av. Prof. Egas Moniz, Edifício Egas Moniz, 1649-028 Lisboa, Portugal
| | - Carla S. Lopes
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Isabel Meireles
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto (Ipatimup), Rua Júlio Amaral de Carvalho, n 45, 4200-135 Porto, Portugal
| | - Eurico Morais-de-Sá
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Joana Paredes
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto (Ipatimup), Rua Júlio Amaral de Carvalho, n 45, 4200-135 Porto, Portugal
- FMUP, Medical Faculty of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Florence Janody
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto (Ipatimup), Rua Júlio Amaral de Carvalho, n 45, 4200-135 Porto, Portugal
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, P-2780-156 Oeiras, Portugal
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Nieminuszczy J, Martin PR, Broderick R, Krwawicz J, Kanellou A, Mocanu C, Bousgouni V, Smith C, Wen KK, Woodward BL, Bakal C, Shackley F, Aguilera A, Stewart GS, Vyas YM, Niedzwiedz W. Actin nucleators safeguard replication forks by limiting nascent strand degradation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.12.523639. [PMID: 36711944 PMCID: PMC9882250 DOI: 10.1101/2023.01.12.523639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Accurate genome replication is essential for all life and a key mechanism of disease prevention, underpinned by the ability of cells to respond to replicative stress (RS) and protect replication forks. These responses rely on the formation of Replication Protein A (RPA)-single stranded (ss) DNA complexes, yet this process remains largely uncharacterized. Here we establish that actin nucleation-promoting factors (NPFs) associate with replication forks, promote efficient DNA replication and facilitate association of RPA with ssDNA at sites of RS. Accordingly, their loss leads to deprotection of ssDNA at perturbed forks, impaired ATR activation, global replication defects and fork collapse. Supplying an excess of RPA restores RPA foci formation and fork protection, suggesting a chaperoning role for actin nucleators (ANs) (i.e., Arp2/3, DIAPH1) and NPFs (i.e, WASp, N-WASp) in regulating RPA availability upon RS. We also discover that β-actin interacts with RPA directly in vitro , and in vivo a hyper-depolymerizing β-actin mutant displays a heightened association with RPA and the same dysfunctional replication phenotypes as loss of ANs/NPFs, which contrasts with the phenotype of a hyper-polymerizing β-actin mutant. Thus, we identify components of actin polymerization pathways that are essential for preventing ectopic nucleolytic degradation of perturbed forks by modulating RPA activity.
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Affiliation(s)
| | - Peter R. Martin
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Ronan Broderick
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Joanna Krwawicz
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | | | - Camelia Mocanu
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Vicky Bousgouni
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Charlotte Smith
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Kuo-Kuang Wen
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, PennState College of Medicine, PennState Health Children’s Hospital, Hershey, Pennsylvania 17033, USA
| | - Beth L. Woodward
- Genome Stability and Human Disease Laboratory, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Chris Bakal
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Fiona Shackley
- Paediatric Immunology, Allergy and Infectious Diseases, Sheffield Children's Hospital NHS Foundation Trust, Sheffield, UK
| | - Andres Aguilera
- Centro Andaluz de Biologia Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Grant S. Stewart
- Genome Stability and Human Disease Laboratory, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Yatin M. Vyas
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, PennState College of Medicine, PennState Health Children’s Hospital, Hershey, Pennsylvania 17033, USA
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14
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Mehta V, Decan N, Ooi S, Gaudreau-Lapierre A, Copeland JW, Trinkle-Mulcahy L. SPECC1L binds the myosin phosphatase complex MYPT1/PP1β and can regulate its distribution between microtubules and filamentous actin. J Biol Chem 2023; 299:102893. [PMID: 36634848 PMCID: PMC9929477 DOI: 10.1016/j.jbc.2023.102893] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 12/19/2022] [Accepted: 12/21/2022] [Indexed: 01/11/2023] Open
Abstract
The subcellular localization, activity , and substrate specificity of the serine/threonine protein phosphatase 1 catalytic subunit (PP1cat) is mediated through its dynamic association with regulatory subunits in holoenzyme complexes. While some functional overlap is observed for the three human PP1cat isoforms, they also show distinct targeting based on relative preferences for specific regulatory subunits. A well-known example is the preferential association of MYPT1 with PP1β in the myosin phosphatase complex. In smooth muscle, MYPT1/PP1β counteracts the muscle contraction induced by phosphorylation of the light chains of myosin by the myosin light chain kinase. This phosphatase complex is also found in nonmuscle cells, where it is targeted to both myosin and nonmyosin substrates and contributes to regulation of the balance of cytoskeletal structure and motility during cell migration and division. Although it remains unclear how MYPT1/PP1β traffics between microtubule- and actin-associated substrates, our identification of the microtubule- and actin-binding protein SPECC1L in both the PP1β and MYPT1 interactomes suggests that it is the missing link. Our validation of their association using coimmunoprecipitation and proximity biotinylation assays, together with the strong overlap that we observed for the SPECC1L and MYPT1 interactomes, confirmed that they exist in a stable complex in the cell. We further showed that SPECC1L binds MYPT1 directly and that it can impact the balance of the distribution of the MYPT1/PP1β complex between the microtubule and filamentous actin networks.
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Affiliation(s)
- Virja Mehta
- Department of Cellular and Molecular Medicine, University of Ottawa, Faculty of Medicine, Ottawa, Canada,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Nathalie Decan
- Department of Cellular and Molecular Medicine, University of Ottawa, Faculty of Medicine, Ottawa, Canada,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Sarah Ooi
- Department of Cellular and Molecular Medicine, University of Ottawa, Faculty of Medicine, Ottawa, Canada,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Antoine Gaudreau-Lapierre
- Department of Cellular and Molecular Medicine, University of Ottawa, Faculty of Medicine, Ottawa, Canada,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - John W. Copeland
- Department of Cellular and Molecular Medicine, University of Ottawa, Faculty of Medicine, Ottawa, Canada
| | - Laura Trinkle-Mulcahy
- Department of Cellular and Molecular Medicine, University of Ottawa, Faculty of Medicine, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada.
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15
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Zagelbaum J, Gautier J. Double-strand break repair and mis-repair in 3D. DNA Repair (Amst) 2023; 121:103430. [PMID: 36436496 PMCID: PMC10799305 DOI: 10.1016/j.dnarep.2022.103430] [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: 10/05/2022] [Revised: 11/13/2022] [Accepted: 11/15/2022] [Indexed: 11/18/2022]
Abstract
DNA double-strand breaks (DSBs) are lesions that arise frequently from exposure to damaging agents as well as from ongoing physiological DNA transactions. Mis-repair of DSBs leads to rearrangements and structural variations in chromosomes, including insertions, deletions, and translocations implicated in disease. The DNA damage response (DDR) limits pathologic mutations and large-scale chromosome rearrangements. DSB repair initiates in 2D at DNA lesions with the stepwise recruitment of repair proteins and local chromatin remodeling which facilitates break accessibility. More complex structures are then formed via protein assembly into nanodomains and via genome folding into chromatin loops. Subsequently, 3D reorganization of DSBs is guided by clustering forces which drive the assembly of repair domains harboring multiple lesions. These domains are further stabilized and insulated into condensates via liquid-liquid phase-separation. Here, we discuss the benefits and risks associated with this 3D reorganization of the broken genome.
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Affiliation(s)
- Jennifer Zagelbaum
- Institute for Cancer Genetics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Jean Gautier
- Institute for Cancer Genetics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Department of Genetics and Development, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA.
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16
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The Impact of Membrane Protein Diffusion on GPCR Signaling. Cells 2022; 11:cells11101660. [PMID: 35626696 PMCID: PMC9139411 DOI: 10.3390/cells11101660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/12/2022] [Accepted: 05/14/2022] [Indexed: 12/10/2022] Open
Abstract
Spatiotemporal signal shaping in G protein-coupled receptor (GPCR) signaling is now a well-established and accepted notion to explain how signaling specificity can be achieved by a superfamily sharing only a handful of downstream second messengers. Dozens of Gs-coupled GPCR signals ultimately converge on the production of cAMP, a ubiquitous second messenger. This idea is almost always framed in terms of local concentrations, the differences in which are maintained by means of spatial separation. However, given the dynamic nature of the reaction-diffusion processes at hand, the dynamics, in particular the local diffusional properties of the receptors and their cognate G proteins, are also important. By combining some first principle considerations, simulated data, and experimental data of the receptors diffusing on the membranes of living cells, we offer a short perspective on the modulatory role of local membrane diffusion in regulating GPCR-mediated cell signaling. Our analysis points to a diffusion-limited regime where the effective production rate of activated G protein scales linearly with the receptor–G protein complex’s relative diffusion rate and to an interesting role played by the membrane geometry in modulating the efficiency of coupling.
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17
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Romani P, Nirchio N, Arboit M, Barbieri V, Tosi A, Michielin F, Shibuya S, Benoist T, Wu D, Hindmarch CCT, Giomo M, Urciuolo A, Giamogante F, Roveri A, Chakravarty P, Montagner M, Calì T, Elvassore N, Archer SL, De Coppi P, Rosato A, Martello G, Dupont S. Mitochondrial fission links ECM mechanotransduction to metabolic redox homeostasis and metastatic chemotherapy resistance. Nat Cell Biol 2022; 24:168-180. [PMID: 35165418 PMCID: PMC7615745 DOI: 10.1038/s41556-022-00843-w] [Citation(s) in RCA: 63] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 01/06/2022] [Indexed: 01/07/2023]
Abstract
Metastatic breast cancer cells disseminate to organs with a soft microenvironment. Whether and how the mechanical properties of the local tissue influence their response to treatment remains unclear. Here we found that a soft extracellular matrix empowers redox homeostasis. Cells cultured on a soft extracellular matrix display increased peri-mitochondrial F-actin, promoted by Spire1C and Arp2/3 nucleation factors, and increased DRP1- and MIEF1/2-dependent mitochondrial fission. Changes in mitochondrial dynamics lead to increased production of mitochondrial reactive oxygen species and activate the NRF2 antioxidant transcriptional response, including increased cystine uptake and glutathione metabolism. This retrograde response endows cells with resistance to oxidative stress and reactive oxygen species-dependent chemotherapy drugs. This is relevant in a mouse model of metastatic breast cancer cells dormant in the lung soft tissue, where inhibition of DRP1 and NRF2 restored cisplatin sensitivity and prevented disseminated cancer-cell awakening. We propose that targeting this mitochondrial dynamics- and redox-based mechanotransduction pathway could open avenues to prevent metastatic relapse.
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Affiliation(s)
- Patrizia Romani
- Department of Molecular Medicine (DMM), University of Padua, Padua, Italy
| | - Nunzia Nirchio
- Department of Molecular Medicine (DMM), University of Padua, Padua, Italy
| | - Mattia Arboit
- Department of Biology (DiBio), University of Padua, Padua, Italy
| | - Vito Barbieri
- Department of Surgery, Oncology and Gastroenterology (DiSCOG), University of Padua, Padua, Italy
- Veneto Institute of Oncology IOV-IRCCS, Padua, Italy
| | - Anna Tosi
- Veneto Institute of Oncology IOV-IRCCS, Padua, Italy
| | - Federica Michielin
- Institute of Child Health, NIHR Biomedical Research Centre, Great Ormond Street Institute of Child Health, UCL, London, UK
| | - Soichi Shibuya
- Institute of Child Health, NIHR Biomedical Research Centre, Great Ormond Street Institute of Child Health, UCL, London, UK
| | - Thomas Benoist
- Institute of Child Health, NIHR Biomedical Research Centre, Great Ormond Street Institute of Child Health, UCL, London, UK
| | - Danchen Wu
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | | | - Monica Giomo
- Department of Industrial Engineering (DII), University of Padua, Padua, Italy
- Venetian Institute of Molecular Medicine (VIMM), Padua, Italy
| | - Anna Urciuolo
- Department of Molecular Medicine (DMM), University of Padua, Padua, Italy
- Fondazione Istituto di Ricerca Pediatrica (IRP), Città della Speranza, Padua, Italy
| | - Flavia Giamogante
- Department of Biomedical Sciences (DSB), University of Padua, Padua, Italy
| | - Antonella Roveri
- Department of Molecular Medicine (DMM), University of Padua, Padua, Italy
| | | | - Marco Montagner
- Department of Molecular Medicine (DMM), University of Padua, Padua, Italy
| | - Tito Calì
- Department of Biomedical Sciences (DSB), University of Padua, Padua, Italy
| | - Nicola Elvassore
- Institute of Child Health, NIHR Biomedical Research Centre, Great Ormond Street Institute of Child Health, UCL, London, UK
- Department of Industrial Engineering (DII), University of Padua, Padua, Italy
- Venetian Institute of Molecular Medicine (VIMM), Padua, Italy
| | - Stephen L Archer
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Paolo De Coppi
- Institute of Child Health, NIHR Biomedical Research Centre, Great Ormond Street Institute of Child Health, UCL, London, UK
| | - Antonio Rosato
- Department of Surgery, Oncology and Gastroenterology (DiSCOG), University of Padua, Padua, Italy
- Veneto Institute of Oncology IOV-IRCCS, Padua, Italy
| | | | - Sirio Dupont
- Department of Molecular Medicine (DMM), University of Padua, Padua, Italy.
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18
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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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19
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Petzold J, Gentleman E. Intrinsic Mechanical Cues and Their Impact on Stem Cells and Embryogenesis. Front Cell Dev Biol 2021; 9:761871. [PMID: 34820380 PMCID: PMC8606660 DOI: 10.3389/fcell.2021.761871] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/14/2021] [Indexed: 12/25/2022] Open
Abstract
Although understanding how soluble cues direct cellular processes revolutionised the study of cell biology in the second half of the 20th century, over the last two decades, new insights into how mechanical cues similarly impact cell fate decisions has gained momentum. During development, extrinsic cues such as fluid flow, shear stress and compressive forces are essential for normal embryogenesis to proceed. Indeed, both adult and embryonic stem cells can respond to applied forces, but they can also detect intrinsic mechanical cues from their surrounding environment, such as the stiffness of the extracellular matrix, which impacts differentiation and morphogenesis. Cells can detect changes in their mechanical environment using cell surface receptors such as integrins and focal adhesions. Moreover, dynamic rearrangements of the cytoskeleton have been identified as a key means by which forces are transmitted from the extracellular matrix to the cell and vice versa. Although we have some understanding of the downstream mechanisms whereby mechanical cues are translated into changes in cell behaviour, many of the signalling pathways remain to be defined. This review discusses the importance of intrinsic mechanical cues on adult cell fate decisions, the emerging roles of cell surface mechano-sensors and the cytoskeleton in enabling cells to sense its microenvironment, and the role of intracellular signalling in translating mechanical cues into transcriptional outputs. In addition, the contribution of mechanical cues to fundamental processes during embryogenesis such as apical constriction and convergent extension is discussed. The continued development of tools to measure the biomechanical properties of soft tissues in vivo is likely to uncover currently underestimated contributions of these cues to adult stem cell fate decisions and embryogenesis, and may inform on regenerative strategies for tissue repair.
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Affiliation(s)
- Jonna Petzold
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Eileen Gentleman
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
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20
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Marco S, Neilson M, Moore M, Perez-Garcia A, Hall H, Mitchell L, Lilla S, Blanco GR, Hedley A, Zanivan S, Norman JC. Nuclear-capture of endosomes depletes nuclear G-actin to promote SRF/MRTF activation and cancer cell invasion. Nat Commun 2021; 12:6829. [PMID: 34819513 PMCID: PMC8613289 DOI: 10.1038/s41467-021-26839-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/21/2021] [Indexed: 11/09/2022] Open
Abstract
Signals are relayed from receptor tyrosine kinases (RTKs) at the cell surface to effector systems in the cytoplasm and nucleus, and coordination of this process is important for the execution of migratory phenotypes, such as cell scattering and invasion. The endosomal system influences how RTK signalling is coded, but the ways in which it transmits these signals to the nucleus to influence gene expression are not yet clear. Here we show that hepatocyte growth factor, an activator of MET (an RTK), promotes Rab17- and clathrin-dependent endocytosis of EphA2, another RTK, followed by centripetal transport of EphA2-positive endosomes. EphA2 then mediates physical capture of endosomes on the outer surface of the nucleus; a process involving interaction between the nuclear import machinery and a nuclear localisation sequence in EphA2's cytodomain. Nuclear capture of EphA2 promotes RhoG-dependent phosphorylation of the actin-binding protein, cofilin to oppose nuclear import of G-actin. The resulting depletion of nuclear G-actin drives transcription of Myocardin-related transcription factor (MRTF)/serum-response factor (SRF)-target genes to implement cell scattering and the invasive behaviour of cancer cells.
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Affiliation(s)
- Sergi Marco
- CRUK Beatson Institute, Glasgow, G61 1BD, Scotland, UK
| | | | | | - Arantxa Perez-Garcia
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, Scotland, UK
| | - Holly Hall
- CRUK Beatson Institute, Glasgow, G61 1BD, Scotland, UK
| | | | - Sergio Lilla
- CRUK Beatson Institute, Glasgow, G61 1BD, Scotland, UK
| | | | - Ann Hedley
- CRUK Beatson Institute, Glasgow, G61 1BD, Scotland, UK
| | - Sara Zanivan
- CRUK Beatson Institute, Glasgow, G61 1BD, Scotland, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, Scotland, UK
| | - Jim C Norman
- CRUK Beatson Institute, Glasgow, G61 1BD, Scotland, UK.
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, Scotland, UK.
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21
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Bamburg JR, Minamide LS, Wiggan O, Tahtamouni LH, Kuhn TB. Cofilin and Actin Dynamics: Multiple Modes of Regulation and Their Impacts in Neuronal Development and Degeneration. Cells 2021; 10:cells10102726. [PMID: 34685706 PMCID: PMC8534876 DOI: 10.3390/cells10102726] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 02/06/2023] Open
Abstract
Proteins of the actin depolymerizing factor (ADF)/cofilin family are ubiquitous among eukaryotes and are essential regulators of actin dynamics and function. Mammalian neurons express cofilin-1 as the major isoform, but ADF and cofilin-2 are also expressed. All isoforms bind preferentially and cooperatively along ADP-subunits in F-actin, affecting the filament helical rotation, and when either alone or when enhanced by other proteins, promotes filament severing and subunit turnover. Although self-regulating cofilin-mediated actin dynamics can drive motility without post-translational regulation, cells utilize many mechanisms to locally control cofilin, including cooperation/competition with other proteins. Newly identified post-translational modifications function with or are independent from the well-established phosphorylation of serine 3 and provide unexplored avenues for isoform specific regulation. Cofilin modulates actin transport and function in the nucleus as well as actin organization associated with mitochondrial fission and mitophagy. Under neuronal stress conditions, cofilin-saturated F-actin fragments can undergo oxidative cross-linking and bundle together to form cofilin-actin rods. Rods form in abundance within neurons around brain ischemic lesions and can be rapidly induced in neurites of most hippocampal and cortical neurons through energy depletion or glutamate-induced excitotoxicity. In ~20% of rodent hippocampal neurons, rods form more slowly in a receptor-mediated process triggered by factors intimately connected to disease-related dementias, e.g., amyloid-β in Alzheimer’s disease. This rod-inducing pathway requires a cellular prion protein, NADPH oxidase, and G-protein coupled receptors, e.g., CXCR4 and CCR5. Here, we will review many aspects of cofilin regulation and its contribution to synaptic loss and pathology of neurodegenerative diseases.
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Affiliation(s)
- James R. Bamburg
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
- Correspondence: ; Tel.: +1-970-988-9120; Fax: +1-970-491-0494
| | - Laurie S. Minamide
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
| | - O’Neil Wiggan
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
| | - Lubna H. Tahtamouni
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
- Department of Biology and Biotechnology, The Hashemite University, Zarqa 13115, Jordan
| | - Thomas B. Kuhn
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
- Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, AK 99775, USA
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22
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Miranda MZ, Lichner Z, Szászi K, Kapus A. MRTF: Basic Biology and Role in Kidney Disease. Int J Mol Sci 2021; 22:ijms22116040. [PMID: 34204945 PMCID: PMC8199744 DOI: 10.3390/ijms22116040] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/21/2021] [Accepted: 05/30/2021] [Indexed: 12/23/2022] Open
Abstract
A lesser known but crucially important downstream effect of Rho family GTPases is the regulation of gene expression. This major role is mediated via the cytoskeleton, the organization of which dictates the nucleocytoplasmic shuttling of a set of transcription factors. Central among these is myocardin-related transcription factor (MRTF), which upon actin polymerization translocates to the nucleus and binds to its cognate partner, serum response factor (SRF). The MRTF/SRF complex then drives a large cohort of genes involved in cytoskeleton remodeling, contractility, extracellular matrix organization and many other processes. Accordingly, MRTF, activated by a variety of mechanical and chemical stimuli, affects a plethora of functions with physiological and pathological relevance. These include cell motility, development, metabolism and thus metastasis formation, inflammatory responses and—predominantly-organ fibrosis. The aim of this review is twofold: to provide an up-to-date summary about the basic biology and regulation of this versatile transcriptional coactivator; and to highlight its principal involvement in the pathobiology of kidney disease. Acting through both direct transcriptional and epigenetic mechanisms, MRTF plays a key (yet not fully appreciated) role in the induction of a profibrotic epithelial phenotype (PEP) as well as in fibroblast-myofibroblast transition, prime pathomechanisms in chronic kidney disease and renal fibrosis.
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Affiliation(s)
- Maria Zena Miranda
- Keenan Research Centre for Biomedical Science of the St. Michael’s Hospital, Toronto, ON M5B 1W8, Canada; (M.Z.M.); (Z.L.); (K.S.)
| | - Zsuzsanna Lichner
- Keenan Research Centre for Biomedical Science of the St. Michael’s Hospital, Toronto, ON M5B 1W8, Canada; (M.Z.M.); (Z.L.); (K.S.)
| | - Katalin Szászi
- Keenan Research Centre for Biomedical Science of the St. Michael’s Hospital, Toronto, ON M5B 1W8, Canada; (M.Z.M.); (Z.L.); (K.S.)
- Department of Surgery, University of Toronto, Toronto, ON M5T 1P5, Canada
| | - András Kapus
- Keenan Research Centre for Biomedical Science of the St. Michael’s Hospital, Toronto, ON M5B 1W8, Canada; (M.Z.M.); (Z.L.); (K.S.)
- Department of Surgery, University of Toronto, Toronto, ON M5T 1P5, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
- Correspondence:
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23
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Sarcomeres regulate murine cardiomyocyte maturation through MRTF-SRF signaling. Proc Natl Acad Sci U S A 2021; 118:2008861118. [PMID: 33361330 DOI: 10.1073/pnas.2008861118] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The paucity of knowledge about cardiomyocyte maturation is a major bottleneck in cardiac regenerative medicine. In development, cardiomyocyte maturation is characterized by orchestrated structural, transcriptional, and functional specializations that occur mainly at the perinatal stage. Sarcomeres are the key cytoskeletal structures that regulate the ultrastructural maturation of other organelles, but whether sarcomeres modulate the signal transduction pathways that are essential for cardiomyocyte maturation remains unclear. To address this question, here we generated mice with cardiomyocyte-specific, mosaic, and hypomorphic mutations of α-actinin-2 (Actn2) to study the cell-autonomous roles of sarcomeres in postnatal cardiomyocyte maturation. Actn2 mutation resulted in defective structural maturation of transverse-tubules and mitochondria. In addition, Actn2 mutation triggered transcriptional dysregulation, including abnormal expression of key sarcomeric and mitochondrial genes, and profound impairment of the normal progression of maturational gene expression. Mechanistically, the transcriptional changes in Actn2 mutant cardiomyocytes strongly correlated with those in cardiomyocytes deleted of serum response factor (SRF), a critical transcription factor that regulates cardiomyocyte maturation. Actn2 mutation increased the monomeric form of cardiac α-actin, which interacted with the SRF cofactor MRTFA and perturbed its nuclear localization. Overexpression of a dominant-negative MRTFA mutant was sufficient to recapitulate the morphological and transcriptional defects in Actn2 and Srf mutant cardiomyocytes. Together, these data indicate that Actn2-based sarcomere organization regulates structural and transcriptional maturation of cardiomyocytes through MRTF-SRF signaling.
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24
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Okuno T, Li WY, Hatano Y, Takasu A, Sakamoto Y, Yamamoto M, Ikeda Z, Shindo T, Plessner M, Morita K, Matsumoto K, Yamagata K, Grosse R, Miyamoto K. Zygotic Nuclear F-Actin Safeguards Embryonic Development. Cell Rep 2021; 31:107824. [PMID: 32610125 DOI: 10.1016/j.celrep.2020.107824] [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: 09/09/2019] [Revised: 02/27/2020] [Accepted: 06/04/2020] [Indexed: 12/20/2022] Open
Abstract
After fertilization, sperm and oocyte nuclei are rapidly remodeled to form swollen pronuclei (PN) in mammalian zygotes, and the proper formation and function of PN are key to producing totipotent zygotes. However, how mature PN are formed has been unclear. We find that filamentous actin (F-actin) assembles in the PN of mouse zygotes and is required for fully functional PN. The perturbation of nuclear actin dynamics in zygotes results in the misregulation of genes related to genome integrity and abnormal development of mouse embryos. We show that nuclear F-actin ensures DNA damage repair, thus preventing the activation of a zygotic checkpoint. Furthermore, optogenetic control of cofilin nuclear localization reveals the dynamically regulated F-actin nucleoskeleton in zygotes, and its timely disassembly is needed for developmental progression. Nuclear F-actin is a hallmark of totipotent zygotic PN, and the temporal regulation of its polymerized state is necessary for normal embryonic development.
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Affiliation(s)
- Tomomi Okuno
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Wayne Yang Li
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Yu Hatano
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Atsushi Takasu
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Yuko Sakamoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Mari Yamamoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Zenki Ikeda
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Taiki Shindo
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Matthias Plessner
- Institute of Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs-University Freiburg, Albertstrasse 25, 79104 Freiburg, Germany
| | - Kohtaro Morita
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Kazuya Matsumoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Kazuo Yamagata
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Robert Grosse
- Institute of Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs-University Freiburg, Albertstrasse 25, 79104 Freiburg, Germany; CIBSS-Centre for Integrative Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestr. 18, 79104 Freiburg, Germany
| | - Kei Miyamoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan.
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25
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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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26
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Lane BS, Heller B, Hollenberg MD, Wells CD. The RGS-RhoGEFs control the amplitude of YAP1 activation by serum. Sci Rep 2021; 11:2348. [PMID: 33504879 PMCID: PMC7841162 DOI: 10.1038/s41598-021-82027-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 01/14/2021] [Indexed: 12/16/2022] Open
Abstract
Actin-dependent mechanisms drive the nuclear translocation of Yap1 to enable its co-activation of transcription factors that induce pro-growth and survival programs. While Rho GTPases are necessary for the nuclear import of YAP1, the relevant Guanine Exchange Factors (GEFs) and GTPase Activating Proteins (GAPs) that connect this process to upstream signaling are not well defined. To this end, we measured the impact of expressing sixty-seven RhoGEFs and RhoGAPs on the YAP1 dependent activity of a TEAD element transcriptional reporter. Robust effects by all three members of the regulator of G-protein signaling (RGS) domain containing RhoGEFs (ArhGEF1, ArhGEF11 and ArhGEF12) prompted studies relating their known roles in serum signaling onto the regulation of Yap1. Under all conditions examined, ArhGEF12 preferentially mediated the activation of YAP1/TEAD by serum versus ArhGEF1 or ArhGEF11. Conversely, ArhGEF1 in multiple contexts inhibited both basal and serum elevated YAP1 activity through its GAP activity for Gα13. The sensitivity of such inhibition to cellular density and to low states of serum signaling supports that ArhGEF1 is a context dependent regulator of YAP1. Taken together, the relative activities of the RGS-RhoGEFs were found to dictate the degree to which serum signaling promotes YAP1 activity.
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Affiliation(s)
- Brandon S Lane
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Brigitte Heller
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Morley D Hollenberg
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Clark D Wells
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA. .,Indiana University School of Medicine, John D. Van Nuys Medical Science Building. 635 Barnhill Dr., Rm. 4079A, Indianapolis, IN, USA.
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27
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Molecular Mechanisms to Target Cellular Senescence in Hepatocellular Carcinoma. Cells 2020; 9:cells9122540. [PMID: 33255630 PMCID: PMC7761055 DOI: 10.3390/cells9122540] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 11/17/2020] [Accepted: 11/20/2020] [Indexed: 12/24/2022] Open
Abstract
Hepatocellular carcinoma (HCC) has emerged as a major cause of cancer-related death and is the most common type of liver cancer. Due to the current paucity of drugs for HCC therapy there is a pressing need to develop new therapeutic concepts. In recent years, the role of Serum Response Factor (SRF) and its coactivators, Myocardin-Related Transcription Factors A and B (MRTF-A and -B), in HCC formation and progression has received considerable attention. Targeting MRTFs results in HCC growth arrest provoked by oncogene-induced senescence. The induction of senescence acts as a tumor-suppressive mechanism and therefore gains consideration for pharmacological interventions in cancer therapy. In this article, we describe the key features and the functional role of senescence in light of the development of novel drug targets for HCC therapy with a focus on MRTFs.
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28
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Mechanosensing dysregulation in the fibroblast: A hallmark of the aging heart. Ageing Res Rev 2020; 63:101150. [PMID: 32846223 DOI: 10.1016/j.arr.2020.101150] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/03/2020] [Accepted: 08/14/2020] [Indexed: 12/16/2022]
Abstract
The myofibroblast is a specialized fibroblast that expresses α-smooth muscle actin (α-SMA) and participates in wound contraction and fibrosis. The fibroblast to myofibroblast transition depends on chemical and mechanical signals. A fibroblast senses the changes in the environment (extracellular matrix (ECM)) and transduces these changes to the cytoskeleton and the nucleus, resulting in activation or inhibition of α-SMA transcription in a process called mechanosensing. A stiff matrix greatly facilitates the transition from fibroblast to myofibroblast, and although the aging heart is much stiffer than the young one, the aging fibroblast has difficulties in transitioning into the contractile phenotype. This suggests that the events occurring downstream of the matrix, such as activation or changes in expression levels of various proteins participating in mechanotransduction can negatively alter the ability of the aging fibroblast to become a myofibroblast. In this review, we will discuss in detail the changes in ECM, receptors (integrin or non-integrin), focal adhesions, cytoskeleton, and transcription factors involved in mechanosensing that occur with aging.
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29
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Holstein I, Singh AK, Pohl F, Misiak D, Braun J, Leitner L, Hüttelmaier S, Posern G. Post-transcriptional regulation of MRTF-A by miRNAs during myogenic differentiation of myoblasts. Nucleic Acids Res 2020; 48:8927-8942. [PMID: 32692361 PMCID: PMC7498330 DOI: 10.1093/nar/gkaa596] [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: 09/06/2019] [Revised: 07/01/2020] [Accepted: 07/09/2020] [Indexed: 12/02/2022] Open
Abstract
The differentiation and regeneration of skeletal muscle from myoblasts to myotubes involves myogenic transcription factors, such as myocardin-related transcription factor A (MRTF-A) and serum response factor (SRF). In addition, post-transcriptional regulation by miRNAs is required during myogenesis. Here, we provide evidence for novel mechanisms regulating MRTF-A during myogenic differentiation. Endogenous MRTF-A protein abundance and activity decreased during C2C12 differentiation, which was attributable to miRNA-directed inhibition. Conversely, overexpression of MRTF-A impaired differentiation and myosin expression. Applying miRNA trapping by RNA affinity purification (miTRAP), we identified miRNAs which directly regulate MRTF-A via its 3′UTR, including miR-1a-3p, miR-206-3p, miR-24-3p and miR-486-5p. These miRNAs were upregulated during differentiation and specifically recruited to the 3′UTR of MRTF-A. Concomitantly, Ago2 recruitment to the MRTF-A 3′UTR was considerably increased, whereas Dicer1 depletion or 3′UTR deletion elevated MRTF-A and inhibited differentiation. MRTF-A protein expression was inhibited by ectopic miRNA expression in murine C2C12 and primary human myoblasts. 3′UTR reporter activity diminished upon differentiation or miRNA expression, whereas deletion of the predicted binding sites reversed these effects. Furthermore, TGF-β abolished MRTF-A reduction and decreased miR-486-5p expression. Our findings implicate miR-24-3p and miR-486-5p in the repression of MRTF-A and suggest a complex network of transcriptional and post-transcriptional mechanisms regulating myogenesis.
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Affiliation(s)
- Ingo Holstein
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Hollystrasse 1, 06114 Halle (Saale), Germany
| | - Anurag Kumar Singh
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Hollystrasse 1, 06114 Halle (Saale), Germany
| | - Falk Pohl
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Hollystrasse 1, 06114 Halle (Saale), Germany
| | - Danny Misiak
- Institute of Molecular Medicine, Medical Faculty, Martin Luther University Halle-Wittenberg, Charles Tanford Protein Center, Kurt-Mothes-Straße 3a, 06120 Halle (Saale), Germany
| | - Juliane Braun
- Institute of Molecular Medicine, Medical Faculty, Martin Luther University Halle-Wittenberg, Charles Tanford Protein Center, Kurt-Mothes-Straße 3a, 06120 Halle (Saale), Germany
| | - Laura Leitner
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Hollystrasse 1, 06114 Halle (Saale), Germany
| | - Stefan Hüttelmaier
- Institute of Molecular Medicine, Medical Faculty, Martin Luther University Halle-Wittenberg, Charles Tanford Protein Center, Kurt-Mothes-Straße 3a, 06120 Halle (Saale), Germany
| | - Guido Posern
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Hollystrasse 1, 06114 Halle (Saale), Germany
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30
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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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31
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Taskinen ME, Närvä E, Conway JR, Hinojosa LS, Lilla S, Mai A, De Franceschi N, Elo LL, Grosse R, Zanivan S, Norman JC, Ivaska J. MASTL promotes cell contractility and motility through kinase-independent signaling. J Cell Biol 2020; 219:e201906204. [PMID: 32311005 PMCID: PMC7265322 DOI: 10.1083/jcb.201906204] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 02/03/2020] [Accepted: 03/11/2020] [Indexed: 02/07/2023] Open
Abstract
Microtubule-associated serine/threonine-protein kinase-like (MASTL) is a mitosis-accelerating kinase with emerging roles in cancer progression. However, possible cell cycle-independent mechanisms behind its oncogenicity remain ambiguous. Here, we identify MASTL as an activator of cell contractility and MRTF-A/SRF (myocardin-related transcription factor A/serum response factor) signaling. Depletion of MASTL increased cell spreading while reducing contractile actin stress fibers in normal and breast cancer cells and strongly impairing breast cancer cell motility and invasion. Transcriptome and proteome profiling revealed MASTL-regulated genes implicated in cell movement and actomyosin contraction, including Rho guanine nucleotide exchange factor 2 (GEF-H1, ARHGEF2) and MRTF-A target genes tropomyosin 4.2 (TPM4), vinculin (VCL), and nonmuscle myosin IIB (NM-2B, MYH10). Mechanistically, MASTL associated with MRTF-A and increased its nuclear retention and transcriptional activity. Importantly, MASTL kinase activity was not required for regulation of cell spreading or MRTF-A/SRF transcriptional activity. Taken together, we present a previously unknown kinase-independent role for MASTL as a regulator of cell adhesion, contractility, and MRTF-A/SRF activity.
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Affiliation(s)
- Maria Emilia Taskinen
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Elisa Närvä
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - James R.W. Conway
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Laura Soto Hinojosa
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, and Center for Integrative Biological Signalling Studies, Freiburg, Germany
| | - Sergio Lilla
- Cancer Research UK Beatson Institute, Glasgow, UK
| | - Anja Mai
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Nicola De Franceschi
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Laura L. Elo
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Robert Grosse
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, and Center for Integrative Biological Signalling Studies, Freiburg, Germany
| | - Sara Zanivan
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Jim C. Norman
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Johanna Ivaska
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
- Department of Biochemistry, University of Turku, Turku, Finland
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32
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STIP1/HOP Regulates the Actin Cytoskeleton through Interactions with Actin and Changes in Actin-Binding Proteins Cofilin and Profilin. Int J Mol Sci 2020; 21:ijms21093152. [PMID: 32365744 PMCID: PMC7246624 DOI: 10.3390/ijms21093152] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/26/2020] [Accepted: 04/27/2020] [Indexed: 12/13/2022] Open
Abstract
Cell migration plays a vital role in both health and disease. It is driven by reorganization of the actin cytoskeleton, which is regulated by actin-binding proteins cofilin and profilin. Stress-inducible phosphoprotein 1 (STIP1) is a well-described co-chaperone of the Hsp90 chaperone system, and our findings identify a potential regulatory role of STIP1 in actin dynamics. We show that STIP1 can be isolated in complex with actin and Hsp90 from HEK293T cells and directly interacts with actin in vitro via the C-terminal TPR2AB-DP2 domain of STIP1, potentially due to a region spanning two putative actin-binding motifs. We found that STIP1 could stimulate the in vitro ATPase activity of actin, suggesting a potential role in the modulation of F-actin formation. Interestingly, while STIP1 depletion in HEK293T cells had no major effect on total actin levels, it led to increased nuclear accumulation of actin, disorganization of F-actin structures, and an increase and decrease in cofilin and profilin levels, respectively. This study suggests that STIP1 regulates the cytoskeleton by interacting with actin, or via regulating the ratio of proteins known to affect actin dynamics.
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33
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Wei M, Fan X, Ding M, Li R, Shao S, Hou Y, Meng S, Tang F, Li C, Sun Y. Nuclear actin regulates inducible transcription by enhancing RNA polymerase II clustering. SCIENCE ADVANCES 2020; 6:eaay6515. [PMID: 32494599 PMCID: PMC7159918 DOI: 10.1126/sciadv.aay6515] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 01/22/2020] [Indexed: 05/22/2023]
Abstract
Gene expression in response to stimuli underlies many fundamental processes. However, how transcription is regulated under these scenarios is largely unknown. Here, we find a previously unknown role of nuclear actin in transcriptional regulation. The RNA-seq data reveal that nuclear actin is required for the serum-induced transcriptional program. Using super-resolution imaging, we found a remarkable enhancement of RNA polymerase II (Pol II) clustering upon serum stimulation, and this enhancement requires nuclear actin. Pol II clusters colocalized with the serum-response genes and nuclear actin filaments upon serum stimulation. Furthermore, N-WASP is required for serum-enhanced Pol II clustering. N-WASP phase-separated with Pol II and nuclear actin. In addition to serum stimulation, nuclear actin also enhanced Pol II clustering upon interferon-γ treatment. Together, our work unveils that nuclear actin promotes the formation of transcription factory on inducible genes, acting as a general mechanism underlying the rapid response to environmental cues.
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Affiliation(s)
- Mian Wei
- State Key Laboratory of Membrane Biology, Biomedical Pioneer Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
| | - Xiaoying Fan
- State Key Laboratory of Membrane Biology, Biomedical Pioneer Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
| | - Miao Ding
- State Key Laboratory of Membrane Biology, Biomedical Pioneer Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
| | - Ruifeng Li
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing 100871, China
| | - Shipeng Shao
- State Key Laboratory of Membrane Biology, Biomedical Pioneer Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
| | - Yingping Hou
- State Key Laboratory of Membrane Biology, Biomedical Pioneer Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
| | - Shaoshuai Meng
- State Key Laboratory of Membrane Biology, Biomedical Pioneer Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
| | - Fuchou Tang
- State Key Laboratory of Membrane Biology, Biomedical Pioneer Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing 100871, China
| | - Cheng Li
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing 100871, China
- Center for Statistical Science, Center for Bioinformatics, Peking University, Beijing 100871, China
| | - Yujie Sun
- State Key Laboratory of Membrane Biology, Biomedical Pioneer Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
- Corresponding author.
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34
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Lysosomal Hydrolase Cathepsin D Non-proteolytically Modulates Dendritic Morphology in Drosophila. Neurosci Bull 2020; 36:1147-1157. [PMID: 32170568 PMCID: PMC7532236 DOI: 10.1007/s12264-020-00479-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 12/19/2019] [Indexed: 01/09/2023] Open
Abstract
The main lysosomal protease cathepsin D (cathD) is essential for maintaining tissue homeostasis via its degradative function, and its loss leads to ceroid accumulation in the mammalian nervous system, which results in progressive neurodegeneration. Increasing evidence implies non-proteolytic roles of cathD in regulating various biological processes such as apoptosis, cell proliferation, and migration. Along these lines, we here showed that cathD is required for modulating dendritic architecture in the nervous system independent of its traditional degradative function. Upon cathD depletion, class I and class III arborization (da) neurons in Drosophila larvae exhibited aberrant dendritic morphology, including over-branching, aberrant turning, and elongation defects. Re-introduction of wild-type cathD or its proteolytically-inactive mutant dramatically abolished these morphological defects. Moreover, cathD knockdown also led to dendritic defects in the adult mushroom bodies, suggesting that cathD-mediated processes are required in both the peripheral and central nervous systems. Taken together, our results demonstrate a critical role of cathD in shaping dendritic architecture independent of its proteolytic function.
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35
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Wang A, Kolhe JA, Gioacchini N, Baade I, Brieher WM, Peterson CL, Freeman BC. Mechanism of Long-Range Chromosome Motion Triggered by Gene Activation. Dev Cell 2020; 52:309-320.e5. [PMID: 31902656 DOI: 10.1016/j.devcel.2019.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 11/18/2019] [Accepted: 12/12/2019] [Indexed: 12/18/2022]
Abstract
Movement of chromosome sites within interphase cells is critical for numerous pathways including RNA transcription and genome organization. Yet, a mechanism for reorganizing chromatin in response to these events had not been reported. Here, we delineate a molecular chaperone-dependent pathway for relocating activated gene loci in yeast. Our presented data support a model in which a two-authentication system mobilizes a gene promoter through a dynamic network of polymeric nuclear actin. Transcription factor-dependent nucleation of a myosin motor propels the gene locus through the actin matrix, and fidelity of the actin association was ensured by ARP-containing chromatin remodelers. Motor activity of nuclear myosin was dependent on the Hsp90 chaperone. Hsp90 further contributed by biasing the remodeler-actin interaction toward nucleosomes with the non-canonical histone H2A.Z, thereby focusing the pathway on select sites such as transcriptionally active genes. Together, the system provides a rapid and effective means to broadly yet selectively mobilize chromatin sites.
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Affiliation(s)
- Anqi Wang
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Janhavi A Kolhe
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Nate Gioacchini
- Program of Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Imke Baade
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - William M Brieher
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Craig L Peterson
- Program of Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Brian C Freeman
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
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36
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Sato Y, Kamijo K, Tsutsumi M, Murakami Y, Takahashi M. Nonmuscle myosin IIA and IIB differently suppress microtubule growth to stabilize cell morphology. J Biochem 2019; 167:25-39. [DOI: 10.1093/jb/mvz082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 09/22/2019] [Indexed: 12/21/2022] Open
Abstract
Abstract
Precise regulation of cytoskeletal dynamics is important in many fundamental cellular processes such as cell shape determination. Actin and microtubule (MT) cytoskeletons mutually regulate their stability and dynamics. Nonmuscle myosin II (NMII) is a candidate protein that mediates the actin–MT crosstalk. NMII regulates the stability and dynamics of actin filaments to control cell morphology. Additionally, previous reports suggest that NMII-dependent cellular contractility regulates MT dynamics, and MTs also control cell morphology; however, the detailed mechanism whereby NMII regulates MT dynamics and the relationship among actin dynamics, MT dynamics and cell morphology remain unclear. The present study explores the roles of two well-characterized NMII isoforms, NMIIA and NMIIB, on the regulation of MT growth dynamics and cell morphology. We performed RNAi and drug experiments and demonstrated the NMII isoform-specific mechanisms—NMIIA-dependent cellular contractility upregulates the expression of some mammalian diaphanous-related formin (mDia) proteins that suppress MT dynamics; NMIIB-dependent inhibition of actin depolymerization suppresses MT growth independently of cellular contractility. The depletion of either NMIIA or NMIIB resulted in the increase in cellular morphological dynamicity, which was alleviated by the perturbation of MT dynamics. Thus, the NMII-dependent control of cell morphology significantly relies on MT dynamics.
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Affiliation(s)
- Yuta Sato
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
| | - Keiju Kamijo
- Division of Anatomy and Cell Biology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1 Fukumuro, Miyagino-ku, Sendai Miyagi, Japan
| | - Motosuke Tsutsumi
- Research Institute for Electronic Science, Hokkaido University, Kita 20, Nishi 10, Kita-ku, Sapporo Hokkaido, Japan
| | - Yota Murakami
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
| | - Masayuki Takahashi
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
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37
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Rangrez AY, Kilian L, Stiebeling K, Dittmann S, Schulze-Bahr E, Frey N, Frank D. A cardiac α-actin (ACTC1) p. Gly247Asp mutation inhibits SRF-signaling in vitro in neonatal rat cardiomyocytes. Biochem Biophys Res Commun 2019; 518:500-505. [PMID: 31434612 DOI: 10.1016/j.bbrc.2019.08.081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 08/14/2019] [Indexed: 12/23/2022]
Abstract
We recently identified a novel, heterozygous, and non-synonymous ACTC1 mutation (p.Gly247Asp or G247D) in a large, multi-generational family, causing atrial-septal defect followed by late-onset dilated cardiomyopathy (DCM). Molecular dynamics studies revealed possible actin polymerization defects as G247D mutation resides at the juncture of side-chain interaction, which was indeed confirmed by in vitro actin polymerization assays. Since polymerization/de-polymerization is important for the activation of Rho-GTPase-mediated serum response factor (SRF)-signaling, we studied the effect of G247D mutation using luciferase assay. Overexpression of native human ACTC1 in neonatal rat cardiomyocytes (NRVCMs) strongly activated SRF-signaling both in C2C12 cells and NRVCMs, whereas, G247D mutation abolished this activation. Mechanistically, we found reduced GTP-bound Rho-GTPase and increased nuclear localization of globular actin in NRVCMs overexpressing mutant ACTC1 possibly causing inhibition of SRF-signaling activation. In conclusion, our data suggests that human G247D ACTC1 mutation negatively regulates SRF-signaling likely contributing to the late-onset DCM observed in mutation carrier patients.
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Affiliation(s)
- Ashraf Yusuf Rangrez
- Department of Internal Medicine III, Cardiology and Angiology, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany.
| | - Lucia Kilian
- Department of Internal Medicine III, Cardiology and Angiology, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Katharina Stiebeling
- Department of Internal Medicine III, Cardiology and Angiology, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Sven Dittmann
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Norbert Frey
- Department of Internal Medicine III, Cardiology and Angiology, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Derk Frank
- Department of Internal Medicine III, Cardiology and Angiology, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany.
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38
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Chatzifrangkeskou M, Pefani D, Eyres M, Vendrell I, Fischer R, Pankova D, O'Neill E. RASSF1A is required for the maintenance of nuclear actin levels. EMBO J 2019; 38:e101168. [PMID: 31414556 PMCID: PMC6694222 DOI: 10.15252/embj.2018101168] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 04/23/2019] [Accepted: 05/14/2019] [Indexed: 01/19/2023] Open
Abstract
Nuclear actin participates in many essential cellular processes including gene transcription, chromatin remodelling and mRNA processing. Actin shuttles into and out the nucleus through the action of dedicated transport receptors importin-9 and exportin-6, but how this transport is regulated remains unclear. Here, we show that RASSF1A is a novel regulator of actin nucleocytoplasmic trafficking and is required for the active maintenance of nuclear actin levels through supporting binding of exportin-6 (XPO6) to RAN GTPase. RASSF1A (Ras association domain family 1 isoform A) is a tumour suppressor gene frequently silenced by promoter hypermethylation in all major solid cancers. Specifically, we demonstrate that endogenous RASSF1A localises to the nuclear envelope (NE) and is required for nucleocytoplasmic actin transport and the concomitant regulation of myocardin-related transcription factor A (MRTF-A), a co-activator of the transcription factor serum response factor (SRF). The RASSF1A/RAN/XPO6/nuclear actin pathway is aberrant in cancer cells where RASSF1A expression is lost and correlates with reduced MRTF-A/SRF activity leading to cell adhesion defects. Taken together, we have identified a previously unknown mechanism by which the nuclear actin pool is regulated and uncovered a previously unknown link of RASSF1A and MRTF-A/SRF in tumour suppression.
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Affiliation(s)
| | - Dafni‐Eleftheria Pefani
- Department of OncologyUniversity of OxfordOxfordUK
- Laboratory of BiologyMedical SchoolNational and Kapodistrian University of AthensAthensGreece
- Biomedical Research Foundation of the Academy of AthensAthensGreece
| | | | - Iolanda Vendrell
- Department of OncologyUniversity of OxfordOxfordUK
- Nuffield Department of MedicineTarget Discovery InstituteUniversity of OxfordOxfordUK
| | - Roman Fischer
- Nuffield Department of MedicineTarget Discovery InstituteUniversity of OxfordOxfordUK
| | | | - Eric O'Neill
- Department of OncologyUniversity of OxfordOxfordUK
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39
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Loss of serum response factor in mature neurons in the dentate gyrus alters the morphology of dendritic spines and hippocampus-dependent behavioral tasks. Brain Struct Funct 2019; 224:2691-2701. [PMID: 31375980 PMCID: PMC6778544 DOI: 10.1007/s00429-019-01925-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 07/19/2019] [Indexed: 12/12/2022]
Abstract
Serum response factor (SRF) is a major transcription factor that regulates the expression of several plasticity-associated genes in the brain. Although the developmental expression of SRF in excitatory neurons is crucial for establishing proper hippocampal circuitry, no substantial evidence of its role in unstimulated mature neurons has been provided. The present study used time-controlled, conditional SRF knockout mice and found that the lack of SRF in adult neurons led to decreased actin levels and inactivation of the actin-severing protein cofilin 1 through its increase in phosphorylation at Ser3. The augmentation of cofilin 1 phosphorylation correlated with an alteration of dendritic spine morphology in the dentate gyrus, which was reflected by an increase in the number of spines that clustered into the long-spine category. The changes in spine morphology coincided with a lower amplitude and frequency of miniature excitatory postsynaptic currents. Moreover, SRF knockout animals were hyperactive and exhibited impairments in hippocampus-dependent behaviors, such as digging, marble burying, and nesting. Altogether, our data indicate that the adult deletion of neuronal SRF leads to alterations of spine morphology and function and hippocampus-dependent behaviors. Thus, SRF deletion in adult neurons recapitulates some aspects of morphological, electrophysiological, and behavioral changes that are observed in such psychiatric disorders as schizophrenia and autism spectrum disorders.
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40
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Diring J, Mouilleron S, McDonald NQ, Treisman R. RPEL-family rhoGAPs link Rac/Cdc42 GTP loading to G-actin availability. Nat Cell Biol 2019; 21:845-855. [PMID: 31209295 PMCID: PMC6960015 DOI: 10.1038/s41556-019-0337-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 04/29/2019] [Indexed: 12/29/2022]
Abstract
RPEL proteins, which contain the G-actin-binding RPEL motif, coordinate cytoskeletal processes with actin dynamics. We show that the ArhGAP12- and ArhGAP32-family GTPase-activating proteins (GAPs) are RPEL proteins. We determine the structure of the ArhGAP12/G-actin complex, and show that G-actin contacts the RPEL motif and GAP domain sequences. G-actin inhibits ArhGAP12 GAP activity, and this requires the G-actin contacts identified in the structure. In B16 melanoma cells, ArhGAP12 suppresses basal Rac and Cdc42 activity, F-actin assembly, invadopodia formation and experimental metastasis. In this setting, ArhGAP12 mutants defective for G-actin binding exhibit more effective downregulation of Rac GTP loading following HGF stimulation and enhanced inhibition of Rac-dependent processes, including invadopodia formation. Potentiation or disruption of the G-actin/ArhGAP12 interaction, by treatment with the actin-binding drugs latrunculin B or cytochalasin D, has corresponding effects on Rac GTP loading. The interaction of G-actin with RPEL-family rhoGAPs thus provides a negative feedback loop that couples Rac activity to actin dynamics.
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Affiliation(s)
- Jessica Diring
- Signalling and Transcription Group, The Francis Crick Institute, London, UK
| | - Stephane Mouilleron
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | - Neil Q McDonald
- Signalling and Structural Biology Group, The Francis Crick Institute, London, UK
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, London, UK
| | - Richard Treisman
- Signalling and Transcription Group, The Francis Crick Institute, London, UK.
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41
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Djemai H, Hassani M, Daou N, Li Z, Sotiropoulos A, Noirez P, Coletti D. Srf KO and wild-type mice similarly adapt to endurance exercise. Eur J Transl Myol 2019; 29:8205. [PMID: 31354926 PMCID: PMC6615070 DOI: 10.4081/ejtm.2019.8205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 05/03/2019] [Indexed: 12/18/2022] Open
Abstract
Physical exercise has important effects as secondary prevention or intervention against several diseases. Endurance exercise induces local and global effects, resulting in skeletal muscle adaptations to aerobic activity and contributes to an amelioration of muscle performance. Furthermore, it prevents muscle loss. Serum response factor (Srf) is a transcription factor of pivotal importance for muscle tissues and animal models of Srf genetic deletion/over-expression are widely used to study Srf role in muscle homeostasis, physiology and pathology. A global characterisation of exercise adaptation in the absence of Srf has not been reported. We measured body composition, muscle force, running speed, energy expenditure and metabolism in WT and inducible skeletal muscle-specific Srf KO mice, following three weeks of voluntary exercise by wheel running. We found a major improvement in the aerobic capacity and muscle function in WT mice following exercise, as expected, and no major differences were observed in Srf KO mice as compared to WT mice, following exercise. Taken together, these observations suggest that Srf is not required for an early (within 3 weeks) adaptation to spontaneous exercise and that Srf KO mice behave similarly to the WT in terms of spontaneous physical activity and the resulting adaptive responses. Therefore, Srf KO mice can be used in functional muscle studies, without the results being affected by the lack of Srf. Since lack of Srf induces premature sarcopenia, our observations suggest that the modifications due to the absence of Srf take time to occur and that young, Srf KO mice behave similarly to WT in aerobic physical activities.
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Affiliation(s)
- Haidar Djemai
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,IRMES, INSEP, Paris, France.,= equal contribution
| | - Medhi Hassani
- Sorbonne University, Paris, France.,Sapienza University of Rome, Rome, Italy.,Interuniversity Institute of Myology, Rome, Italy.,= equal contribution
| | | | | | - Athanassia Sotiropoulos
- Institut National de la Santé et de la Recherche Médicale U1016, Institut Cochin, Paris, France
| | - Philippe Noirez
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,IRMES, INSEP, Paris, France.,Department of Exercise Science, UQAM, Montréal, Canada
| | - Dario Coletti
- Sorbonne University, Paris, France.,Sapienza University of Rome, Rome, Italy.,Interuniversity Institute of Myology, Rome, Italy
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42
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Viita T, Kyheröinen S, Prajapati B, Virtanen J, Frilander MJ, Varjosalo M, Vartiainen MK. Nuclear actin interactome analysis links actin to KAT14 histone acetyl transferase and mRNA splicing. J Cell Sci 2019; 132:jcs226852. [PMID: 30890647 PMCID: PMC6503952 DOI: 10.1242/jcs.226852] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 03/05/2019] [Indexed: 12/25/2022] Open
Abstract
In addition to its essential functions within the cytoskeleton, actin also localizes to the cell nucleus, where it is linked to many important nuclear processes from gene expression to maintenance of genomic integrity. However, the molecular mechanisms by which actin operates in the nucleus remain poorly understood. Here, we have used two complementary mass spectrometry (MS) techniques, AP-MS and BioID, to identify binding partners for nuclear actin. Common high-confidence interactions highlight the role of actin in chromatin-remodeling complexes and identify the histone-modifying complex human Ada-Two-A-containing (hATAC) as a novel actin-containing nuclear complex. Actin binds directly to the hATAC subunit KAT14, and modulates its histone acetyl transferase activity in vitro and in cells. Transient interactions detected through BioID link actin to several steps of transcription as well as to RNA processing. Alterations in nuclear actin levels disturb alternative splicing in minigene assays, likely by affecting the transcription elongation rate. This interactome analysis thus identifies both novel direct binding partners and functional roles for nuclear actin, as well as forms a platform for further mechanistic studies on how actin operates during essential nuclear processes.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Tiina Viita
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
- Helsinki Institute of Life Science, University of Helsinki, Helsinki 00014, Finland
| | - Salla Kyheröinen
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
- Helsinki Institute of Life Science, University of Helsinki, Helsinki 00014, Finland
| | - Bina Prajapati
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
- Helsinki Institute of Life Science, University of Helsinki, Helsinki 00014, Finland
| | - Jori Virtanen
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
- Helsinki Institute of Life Science, University of Helsinki, Helsinki 00014, Finland
| | - Mikko J Frilander
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
- Helsinki Institute of Life Science, University of Helsinki, Helsinki 00014, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
- Helsinki Institute of Life Science, University of Helsinki, Helsinki 00014, Finland
- Proteomics Unit, University of Helsinki, Helsinki 00014, Finland
| | - Maria K Vartiainen
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
- Helsinki Institute of Life Science, University of Helsinki, Helsinki 00014, Finland
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43
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Kim J, Han KY, Khanna N, Ha T, Belmont AS. Nuclear speckle fusion via long-range directional motion regulates speckle morphology after transcriptional inhibition. J Cell Sci 2019; 132:jcs.226563. [PMID: 30858197 DOI: 10.1242/jcs.226563] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 03/03/2019] [Indexed: 01/17/2023] Open
Abstract
Although the formation of RNA-protein bodies has been studied intensively, their mobility and how their number and size are regulated are still poorly understood. Here, we show significantly increased mobility of nuclear speckles after transcriptional inhibition, including long-range directed motion of one speckle towards another speckle, terminated by speckle fusion, over distances up to 4 µm and with velocities between 0.2 µm/min and 1.5 µm/min. Frequently, three or even four speckles follow very similar paths, with new speckles appearing along the path followed by a preceding speckle. Speckle movements and fusion events contribute to fewer, but larger, speckles after transcriptional inhibition. These speckle movements are not actin dependent, but occur within chromatin-depleted channels enriched with small granules containing the speckle marker protein SON. Similar long-range speckle movements and fusion events were observed after heat shock or heavy metal stress, and during late G2 and early prophase. Our observations suggest a mechanism for long-range, directional nuclear speckle movements, contributing to overall regulation of nuclear speckle number and size as well as overall nuclear organization. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Jiah Kim
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Kyu Young Han
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Howard Hughes Medical Institute, Baltimore, MD 21205, USA.,CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, FL 32816, USA
| | - Nimish Khanna
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Taekjip Ha
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Howard Hughes Medical Institute, Baltimore, MD 21205, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Biophysics and Biophysical Chemistry and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Andrew S Belmont
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA .,Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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44
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Hurst V, Shimada K, Gasser SM. Nuclear Actin and Actin-Binding Proteins in DNA Repair. Trends Cell Biol 2019; 29:462-476. [PMID: 30954333 DOI: 10.1016/j.tcb.2019.02.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 12/27/2022]
Abstract
Nuclear actin has been implicated in a variety of DNA-related processes including chromatin remodeling, transcription, replication, and DNA repair. However, the mechanistic understanding of actin in these processes has been limited, largely due to a lack of research tools that address the roles of nuclear actin specifically, that is, distinct from its cytoplasmic functions. Recent findings support a model for homology-directed DNA double-strand break (DSB) repair in which a complex of ARP2 and ARP3 (actin-binding proteins 2 and 3) binds at the break and works with actin to promote DSB clustering and homology-directed repair. Further, it has been reported that relocalization of heterochromatic DSBs to the nuclear periphery in Drosophila is ARP2/3 dependent and actin-myosin driven. Here we provide an overview of the role of nuclear actin and actin-binding proteins in DNA repair, critically evaluating the experimental tools used and potential indirect effects.
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Affiliation(s)
- Verena Hurst
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland; University of Basel, Faculty of Natural Sciences, CH-4056 Basel, Switzerland
| | - Kenji Shimada
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland; University of Basel, Faculty of Natural Sciences, CH-4056 Basel, Switzerland.
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Single-molecule imaging of the transcription factor SRF reveals prolonged chromatin-binding kinetics upon cell stimulation. Proc Natl Acad Sci U S A 2018; 116:880-889. [PMID: 30598445 PMCID: PMC6338867 DOI: 10.1073/pnas.1812734116] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
How transcription factors (TFs) activate transcription is a long-standing but still unsolved question. We analyzed serum response factor (SRF), a stimulus-responsive TF mediating immediate early gene (IEG) and cytoskeletal gene expression at single-molecule resolution. Cell stimulation enhanced SRF activity by increasing the number of long chromatin-associated SRF molecules in an oscillating pattern. Further, stimulation enhanced the SRF chromatin residence time, and SRF binding events segregated into three distinct residence time regimes (short, intermediate, and long bound). In summary, our single-molecule imaging study reveals highly dynamic and diverse SRF interactions with DNA. Thus, cell stimulation regulates TF activity by several interconnected mechanisms including nucleus−cytoplasm shuttling, TF phosphorylation, cofactor recruitment, and extension of chromatin residence time and enhancing chromatin-bound TF numbers. Serum response factor (SRF) mediates immediate early gene (IEG) and cytoskeletal gene expression programs in almost any cell type. So far, SRF transcriptional dynamics have not been investigated at single-molecule resolution. We provide a study of single Halo-tagged SRF molecules in fibroblasts and primary neurons. In both cell types, individual binding events of SRF molecules segregated into three chromatin residence time regimes, short, intermediate, and long binding, indicating a cell type-independent SRF property. The chromatin residence time of the long bound fraction was up to 1 min in quiescent cells and significantly increased upon stimulation. Stimulation also enhanced the long bound SRF fraction at specific timepoints (20 and 60 min) in both cell types. These peaks correlated with activation of the SRF cofactors MRTF-A and MRTF-B (myocardin-related transcription factors). Interference with signaling pathways and cofactors demonstrated modulation of SRF chromatin occupancy by actin signaling, MAP kinases, and MRTFs.
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46
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Kluge F, Weissbach J, Weber A, Stradal T, Posern G. Regulation of MRTF-A by JMY via a nucleation-independent mechanism. Cell Commun Signal 2018; 16:86. [PMID: 30463620 PMCID: PMC6249979 DOI: 10.1186/s12964-018-0299-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 11/13/2018] [Indexed: 11/23/2022] Open
Abstract
Background MRTF-A (myocardin-related transcription factor A) is a coactivator for SRF-mediated gene expression. The activity of MRTF-A is critically dependent on the dissociation of G-actin from N-terminal RPEL motifs. MRTF-SRF induction often correlates with enhanced polymerization of F-actin. Here we investigate MRTF regulation by the multifunctional JMY protein, which contains three WASP/verprolin homology 2 (WH2/V) domains and facilitates Arp2/3-dependent and -independent actin nucleation. Methods Co-immunoprecipitation experiments, immunofluorescence and luciferase reporter assays were combined with selective inhibitors to investigate the effect of JMY and its domains on MRTF-A in NIH 3 T3 mouse fibroblasts. Results JMY induced MRTF-A transcriptional activity and enhanced its nuclear translocation. Unexpectedly, MRTF-A was hyperactivated when the Arp2/3-recruiting CA region of JMY was deleted or mutated, suggesting an autoinhibitory mechanism for full-length JMY. Moreover, isolated WH2/V domains which are unable to nucleate actin were sufficient for nuclear accumulation and SRF activation. Recombinant WH2/V regions of JMY biochemically competed with MRTF-A for actin binding. Activation of MRTF-A by JMY was unaffected by Arp3 knockdown, by an Arp2/3 inhibitor, and by latrunculin which disassembles cellular F-actin. Restriction of JMY to the nucleus abrogated its MRTF-A activation. Finally, JMY RNAi reduced basal and stimulated transcriptional activation via MRTF-A. Conclusions Our results suggest that JMY activates MRTF-SRF independently of F-actin via WH2/V-mediated competition with the RPEL region for G-actin binding in the cytoplasm. Furthermore, the C-terminal region facilitates an autoinhibitory effect on full-length JMY, possibly by intramolecular folding.
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Affiliation(s)
- Franziska Kluge
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, 06114, Halle (Saale), Germany
| | - Julia Weissbach
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, 06114, Halle (Saale), Germany
| | - Anja Weber
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, 06114, Halle (Saale), Germany
| | - Theresia Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
| | - Guido Posern
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, 06114, Halle (Saale), Germany.
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Nuclear Actin Polymerized by mDia2 Confines Centromere Movement during CENP-A Loading. iScience 2018; 9:314-327. [PMID: 30448731 PMCID: PMC6240728 DOI: 10.1016/j.isci.2018.10.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 10/04/2018] [Accepted: 10/29/2018] [Indexed: 12/31/2022] Open
Abstract
Centromeres are specialized chromosomal regions epigenetically defined by the histone H3 variant centromere protein A (CENP-A). CENP-A needs to be replenished in every cell cycle, but how new CENP-A is stably incorporated into centromeric chromatin remains unclear. We have discovered that a cytoskeletal protein, diaphanous formin mDia2, is essential for the stable incorporation of new CENP-A proteins into centromeric nucleosomes. Here we report that mDia2-mediated formation of dynamic and short nuclear actin filaments in G1 nucleus is required to maintain CENP-A levels at the centromere. Importantly, mDia2 and nuclear actin are required for constrained centromere movement during CENP-A loading, and depleting nuclear actin or MgcRacGAP, which lies upstream of mDia2, extends centromeric association of the CENP-A loading chaperone Holliday junction recognition protein (HJURP). Our findings thus suggest that nuclear actin polymerized by mDia2 contributes to the physical confinement of G1 centromeres so that HJURP-mediated CENP-A loading reactions can be productive, and centromere's epigenetic identity can be stably maintained. Formin mDia2 is required for nuclear actin polymerization at G1 centromeres Nuclear actin polymerization is required to maintain centromeric CENP-A levels mDia2 and nuclear actin restrict centromere movement during CENP-A loading Nuclear actin and MgcRacGAP are required for timely turnover of centromeric HJURP
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48
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Pei H, Hu W, Guo Z, Chen H, Ma J, Mao W, Li B, Wang A, Wan J, Zhang J, Nie J, Zhou G, Hei TK. Long Noncoding RNA CRYBG3 Blocks Cytokinesis by Directly Binding G-Actin. Cancer Res 2018; 78:4563-4572. [PMID: 29934435 PMCID: PMC6095725 DOI: 10.1158/0008-5472.can-18-0988] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 05/23/2018] [Accepted: 06/15/2018] [Indexed: 01/05/2023]
Abstract
The dynamic interchange between monomeric globular actin (G-actin) and polymeric filamentous actin filaments (F-actin) is fundamental and essential to many cellular processes, including cytokinesis and maintenance of genomic stability. Here, we report that the long noncoding RNA LNC CRYBG3 directly binds G-actin to inhibit its polymerization and formation of contractile rings, resulting in M-phase cell arrest. Knockdown of LNC CRYBG3 in tumor cells enhanced their malignant phenotypes. Nucleotide sequence 228-237 of the full-length LNC CRYBG3 and the ser14 domain of β-actin is essential for their interaction, and mutation of either of these sites abrogated binding of LNC CRYBG3 to G-actin. Binding of LNC CRYBG3 to G-actin blocked nuclear localization of MAL, which consequently kept serum response factor (SRF) away from the promoter region of several immediate early genes, including JUNB and Arp3, which are necessary for cellular proliferation, tumor growth, adhesion, movement, and metastasis. These findings reveal a novel lncRNA-actin-MAL-SRF pathway and highlight LNC CRYBG3 as a means to block cytokinesis and to treat cancer by targeting the actin cytoskeleton.Significance: Identification of the long noncoding RNA LNC CRYBG3 as a mediator of microfilament disorganization marks it as a novel therapeutic antitumor strategy. Cancer Res; 78(16); 4563-72. ©2018 AACR.
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Affiliation(s)
- Hailong Pei
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Wentao Hu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Ziyang Guo
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Huaiyuan Chen
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Ji Ma
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Weidong Mao
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China
- The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Bingyan Li
- Medical College of Soochow University, Suzhou, China
| | - Aiqing Wang
- Medical College of Soochow University, Suzhou, China
| | - Jianmei Wan
- Medical College of Soochow University, Suzhou, China
| | - Jian Zhang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Jing Nie
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Guangming Zhou
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China.
- Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Tom K Hei
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, China.
- Center for Radiological Research, College of Physician and Surgeons, Columbia University, New York, New York
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Gegenfurtner FA, Jahn B, Wagner H, Ziegenhain C, Enard W, Geistlinger L, Rädler JO, Vollmar AM, Zahler S. Micropatterning as a tool to identify regulatory triggers and kinetics of actin-mediated endothelial mechanosensing. J Cell Sci 2018; 131:jcs.212886. [PMID: 29724912 DOI: 10.1242/jcs.212886] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 04/25/2018] [Indexed: 12/11/2022] Open
Abstract
Developmental processes, such as angiogenesis, are associated with a constant remodeling of the actin cytoskeleton in response to different mechanical stimuli. The mechanosensitive transcription factors MRTF-A (MKL1) and YAP (also known as YAP1) are important mediators of this challenging adaptation process. However, it is as yet unknown whether both pathways respond in an identical or in a divergent manner to a given microenvironmental guidance cue. Here, we use a micropatterning approach to dissect single aspects of cellular behavior in a spatiotemporally controllable setting. Using the exemplary process of angiogenesis, we show that cell-cell contacts and adhesive surface area are shared regulatory parameters of MRTF and YAP on rigid 2D surfaces. By analyzing MRTF and YAP under laminar flow conditions and during cell migration on dumbbell-shaped microstructures, we demonstrate that they exhibit different translocation kinetics. In conclusion, our work promotes the application of micropatterning techniques as a cell biological tool to study mechanosensitive signaling in the context of angiogenesis.
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Affiliation(s)
- Florian A Gegenfurtner
- Ludwig-Maximilians-University Munich, Department of Pharmacy, Center for Drug Research, 81377 Munich, Germany
| | - Berenice Jahn
- Ludwig-Maximilians-University Munich, Department of Pharmacy, Center for Drug Research, 81377 Munich, Germany
| | - Helga Wagner
- ibidi GmbH, Am Klopferspitz 19, 82152 Martinsried, Germany
| | - Christoph Ziegenhain
- Ludwig-Maximilians-University Munich, Department of Biology II, Anthropology and Human Genomics, 82152 Martinsried, Germany
| | - Wolfgang Enard
- Ludwig-Maximilians-University Munich, Department of Biology II, Anthropology and Human Genomics, 82152 Martinsried, Germany
| | - Ludwig Geistlinger
- Ludwig-Maximilians-University Munich, Institute for Informatics, Teaching and Research Unit Bioinformatics, 80333 Munich, Germany
| | - Joachim O Rädler
- Ludwig-Maximilians-University Munich, Faculty of Physics, Soft Condensed Matter Group, 80539 Munich, Germany
| | - Angelika M Vollmar
- Ludwig-Maximilians-University Munich, Department of Pharmacy, Center for Drug Research, 81377 Munich, Germany
| | - Stefan Zahler
- Ludwig-Maximilians-University Munich, Department of Pharmacy, Center for Drug Research, 81377 Munich, Germany
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50
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Bar-Yosef H, Gildor T, Ramírez-Zavala B, Schmauch C, Weissman Z, Pinsky M, Naddaf R, Morschhäuser J, Arkowitz RA, Kornitzer D. A Global Analysis of Kinase Function in Candida albicans Hyphal Morphogenesis Reveals a Role for the Endocytosis Regulator Akl1. Front Cell Infect Microbiol 2018; 8:17. [PMID: 29473018 PMCID: PMC5809406 DOI: 10.3389/fcimb.2018.00017] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/12/2018] [Indexed: 11/22/2022] Open
Abstract
The human pathogenic fungus Candida albicans can switch between yeast and hyphal morphologies as a function of environmental conditions and cellular physiology. The yeast-to-hyphae morphogenetic switch is activated by well-established, kinase-based signal transduction pathways that are induced by extracellular stimuli. In order to identify possible inhibitory pathways of the yeast-to-hyphae transition, we interrogated a collection of C. albicans protein kinases and phosphatases ectopically expressed under the regulation of the TETon promoter. Proportionately more phosphatases than kinases were identified that inhibited hyphal morphogenesis, consistent with the known role of protein phosphorylation in hyphal induction. Among the kinases, we identified AKL1 as a gene that significantly suppressed hyphal morphogenesis in serum. Akl1 specifically affected hyphal elongation rather than initiation: overexpression of AKL1 repressed hyphal growth, and deletion of AKL1 resulted in acceleration of the rate of hyphal elongation. Akl1 suppressed fluid-phase endocytosis, probably via Pan1, a putative clathrin-mediated endocytosis scaffolding protein. In the absence of Akl1, the Pan1 patches were delocalized from the sub-apical region, and fluid-phase endocytosis was intensified. These results underscore the requirement of an active endocytic pathway for hyphal morphogenesis. Furthermore, these results suggest that under standard conditions, endocytosis is rate-limiting for hyphal elongation.
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Affiliation(s)
- Hagit Bar-Yosef
- B. Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
| | - Tsvia Gildor
- B. Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
| | | | - Christian Schmauch
- Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institute Biology Valrose, Université Côte d'Azur, Nice, France
| | - Ziva Weissman
- B. Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
| | - Mariel Pinsky
- B. Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
| | - Rawi Naddaf
- B. Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
| | - Joachim Morschhäuser
- Institut für Molekulare Infektionsbiologie, Universität Würzburg, Würzburg, Germany
| | - Robert A Arkowitz
- Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institute Biology Valrose, Université Côte d'Azur, Nice, France
| | - Daniel Kornitzer
- B. Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
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