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Ferrer P, Upadhyay S, Cai JJ, Clement TM. Novel Nuclear Roles for Testis-Specific ACTL7A and ACTL7B Supported by In Vivo Characterizations and AI Facilitated In Silico Mechanistic Modeling with Implications for Epigenetic Regulation in Spermiogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.29.582797. [PMID: 38464253 PMCID: PMC10925299 DOI: 10.1101/2024.02.29.582797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
A mechanistic role for nuclear function of testis-specific actin related proteins (ARPs) is proposed here through contributions of ARP subunit swapping in canonical chromatin regulatory complexes. This is significant to our understanding of both mechanisms controlling regulation of spermiogenesis, and the expanding functional roles of the ARPs in cell biology. Among these roles, actins and ARPs are pivotal not only in cytoskeletal regulation, but also in intranuclear chromatin organization, influencing gene regulation and nucleosome remodeling. This study focuses on two testis-specific ARPs, ACTL7A and ACTL7B, exploring their intranuclear activities and broader implications utilizing combined in vivo, in vitro, and in silico approaches. ACTL7A and ACTL7B, previously associated with structural roles, are hypothesized here to serve in chromatin regulation during germline development. This study confirms the intranuclear presence of ACTL7B in spermatocytes and round spermatids, revealing a potential role in intranuclear processes, and identifies a putative nuclear localization sequence conserved across mammalian ACTL7B, indicating a potentially unique mode of nuclear transport which differs from conventional actin. Ablation of ACTL7B leads to varied transcriptional changes reported here. Additionally, in the absence of ACTL7A or ACTL7B there is a loss of intranuclear localization of HDAC1 and HDAC3, which are known regulators of epigenetic associated acetylation changes that in turn regulate gene expression. Thus, these HDACs are implicated as contributors to the aberrant gene expression observed in the KO mouse testis transcriptomic analysis. Furthermore, this study employed and confirmed the accuracy of in silico models to predict ARP interactions with Helicase-SANT-associated (HSA) domains, uncovering putative roles for testis-specific ARPs in nucleosome remodeling complexes. In these models, ACTL7A and ACTL7B were found capable of binding to INO80 and SWI/SNF nucleosome remodeler family members in a manner akin to nuclear actin and ACTL6A. These models thus implicate germline-specific ARP subunit swapping within chromatin regulatory complexes as a potential regulatory mechanism for chromatin and associated molecular machinery adaptations in nuclear reorganizations required during spermiogenesis. These results hold implications for male fertility and epigenetic programing in the male-germline that warrant significant future investigation. In summary, this study reveals that ACTL7A and ACTL7B play intranuclear gene regulation roles in male gametogenesis, adding to the multifaceted roles identified also spanning structural, acrosomal, and flagellar stability. ACTL7A and ACTL7B unique nuclear transport, impact on HDAC nuclear associations, impact on transcriptional processes, and proposed mechanism for involvement in nucleosome remodeling complexes supported by AI facilitated in silico modeling contribute to a more comprehensive understanding of the indispensable functions of ARPs broadly in cell biology, and specifically in male fertility.
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Affiliation(s)
- Pierre Ferrer
- Interdisciplinary Faculty of Toxicology Program, Texas A&M University, College Station, TX 77843
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
| | - Srijana Upadhyay
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
| | - James J Cai
- Department of Veterinary Integrative Biosciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
| | - Tracy M Clement
- Interdisciplinary Faculty of Toxicology Program, Texas A&M University, College Station, TX 77843
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
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2
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Li Z, Su M, Xie X, Wang P, Bi H, Li E, Ren K, Dong L, Lv Z, Ma X, Liu Y, Zhao B, Peng Y, Liu J, Liu L, Yang J, Ji P, Mei Y. mDia formins form hetero-oligomers and cooperatively maintain murine hematopoiesis. PLoS Genet 2023; 19:e1011084. [PMID: 38157491 PMCID: PMC10756686 DOI: 10.1371/journal.pgen.1011084] [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: 05/12/2023] [Accepted: 11/22/2023] [Indexed: 01/03/2024] Open
Abstract
mDia formin proteins regulate the dynamics and organization of the cytoskeleton through their linear actin nucleation and polymerization activities. We previously showed that mDia1 deficiency leads to aberrant innate immune activation and induces myelodysplasia in a mouse model, and mDia2 regulates enucleation and cytokinesis of erythroblasts and the engraftment of hematopoietic stem and progenitor cells (HSPCs). However, whether and how mDia formins interplay and regulate hematopoiesis under physiological and stress conditions remains unknown. Here, we found that both mDia1 and mDia2 are required for HSPC regeneration under stress, such as serial plating, aging, and reconstitution after myeloid ablation. We showed that mDia1 and mDia2 form hetero-oligomers through the interactions between mDia1 GBD-DID and mDia2 DAD domains. Double knockout of mDia1 and mDia2 in hematopoietic cells synergistically impaired the filamentous actin network and serum response factor-involved transcriptional signaling, which led to declined HSPCs, severe anemia, and significant mortality in neonates and newborn mice. Our data demonstrate the potential roles of mDia hetero-oligomerization and their non-rodent functions in the regulation of HSPCs activity and orchestration of hematopoiesis.
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Affiliation(s)
- Zhaofeng Li
- Hunan Provincial Key Laboratory of Animal Model and Molecular Medicine, Hunan University, Changsha, China
- School of Biomedical Sciences, Hunan University, Changsha, China
| | - Meng Su
- Hunan Provincial Key Laboratory of Animal Model and Molecular Medicine, Hunan University, Changsha, China
- School of Biomedical Sciences, Hunan University, Changsha, China
| | - Xinshu Xie
- Hunan Provincial Key Laboratory of Animal Model and Molecular Medicine, Hunan University, Changsha, China
- School of Biomedical Sciences, Hunan University, Changsha, China
| | - Pan Wang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Honghao Bi
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Ermin Li
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Kehan Ren
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Lili Dong
- Hunan Provincial Key Laboratory of Animal Model and Molecular Medicine, Hunan University, Changsha, China
- School of Biomedical Sciences, Hunan University, Changsha, China
| | - Zhiyi Lv
- Hunan Provincial Key Laboratory of Animal Model and Molecular Medicine, Hunan University, Changsha, China
- School of Biomedical Sciences, Hunan University, Changsha, China
| | - Xuezhen Ma
- Hunan Provincial Key Laboratory of Animal Model and Molecular Medicine, Hunan University, Changsha, China
- School of Biomedical Sciences, Hunan University, Changsha, China
| | - Yijie Liu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Baobing Zhao
- Department of Pharmacology, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Yuanliang Peng
- Department of Hematology, the Second Xiangya Hospital; Molecular Biology Research Center, School of Life Sciences; Hunan Province Key Laboratory of Basic and Applied Hematology, Central South University; Changsha, China
| | - Jing Liu
- Department of Hematology, the Second Xiangya Hospital; Molecular Biology Research Center, School of Life Sciences; Hunan Province Key Laboratory of Basic and Applied Hematology, Central South University; Changsha, China
| | - Lu Liu
- Hunan Provincial Key Laboratory of Animal Model and Molecular Medicine, Hunan University, Changsha, China
- School of Biomedical Sciences, Hunan University, Changsha, China
| | - Jing Yang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Peng Ji
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Yang Mei
- Hunan Provincial Key Laboratory of Animal Model and Molecular Medicine, Hunan University, Changsha, China
- School of Biomedical Sciences, Hunan University, Changsha, China
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3
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Schneider SE, Scott AK, Seelbinder B, Elzen CVD, Wilson RL, Miller EY, Beato QI, Ghosh S, Barthold JE, Bilyeu J, Emery NC, Pierce DM, Neu CP. Dynamic biophysical responses of neuronal cell nuclei and cytoskeletal structure following high impulse loading. Acta Biomater 2023; 163:339-350. [PMID: 35811070 PMCID: PMC10019187 DOI: 10.1016/j.actbio.2022.07.002] [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: 12/15/2021] [Revised: 06/11/2022] [Accepted: 07/01/2022] [Indexed: 12/28/2022]
Abstract
Cells are continuously exposed to dynamic environmental cues that influence their behavior. Mechanical cues can influence cellular and genomic architecture, gene expression, and intranuclear mechanics, providing evidence of mechanosensing by the nucleus, and a mechanoreciprocity between the nucleus and environment. Force disruption at the tissue level through aging, disease, or trauma, propagates to the nucleus and can have lasting consequences on proper functioning of the cell and nucleus. While the influence of mechanical cues leading to axonal damage has been well studied in neuronal cells, the mechanics of the nucleus following high impulse loading is still largely unexplored. Using an in vitro model of traumatic neural injury, we show a dynamic nuclear behavioral response to impulse stretch (up to 170% strain per second) through quantitative measures of nuclear movement, including tracking of rotation and internal motion. Differences in nuclear movement were observed between low and high strain magnitudes. Increased exposure to impulse stretch exaggerated the decrease in internal motion, assessed by particle tracking microrheology, and intranuclear displacements, assessed through high-resolution deformable image registration. An increase in F-actin puncta surrounding nuclei exposed to impulse stretch additionally demonstrated a corresponding disruption of the cytoskeletal network. Our results show direct biophysical nuclear responsiveness in neuronal cells through force propagation from the substrate to the nucleus. Understanding how mechanical forces perturb the morphological and behavioral response can lead to a greater understanding of how mechanical strain drives changes within the cell and nucleus, and may inform fundamental nuclear behavior after traumatic axonal injury. STATEMENT OF SIGNIFICANCE: The nucleus of the cell has been implicated as a mechano-sensitive organelle, courting molecular sensors and transmitting physical cues in order to maintain cellular and tissue homeostasis. Disruption of this network due to disease or high velocity forces (e.g., trauma) can not only result in orchestrated biochemical cascades, but also biophysical perturbations. Using an in vitro model of traumatic neural injury, we aimed to provide insight into the neuronal nuclear mechanics and biophysical responses at a continuum of strain magnitudes and after repetitive loads. Our image-based methods demonstrate mechanically-induced changes in cellular and nuclear behavior after high intensity loading and have the potential to further define mechanical thresholds of neuronal cell injury.
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Affiliation(s)
- Stephanie E Schneider
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Adrienne K Scott
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Benjamin Seelbinder
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Courtney Van Den Elzen
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Robert L Wilson
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Emily Y Miller
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, CO, USA
| | - Quinn I Beato
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Soham Ghosh
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA; School of Biomedical Engineering, Colorado State University, Fort Collins, CO, USA
| | - Jeanne E Barthold
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Jason Bilyeu
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Nancy C Emery
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, USA
| | - David M Pierce
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT, USA; Department of Biomedical Engineering, University of Connecticut, Storrs, CT, USA
| | - Corey P Neu
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA; Biomedical Engineering Program, University of Colorado Boulder, Boulder, CO, USA; BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA.
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4
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Sadhu L, Tsopoulidis N, Hasanuzzaman M, Laketa V, Way M, Fackler OT. ARPC5 isoforms and their regulation by calcium-calmodulin-N-WASP drive distinct Arp2/3-dependent actin remodeling events in CD4 T cells. eLife 2023; 12:e82450. [PMID: 37162507 PMCID: PMC10171864 DOI: 10.7554/elife.82450] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 04/06/2023] [Indexed: 05/11/2023] Open
Abstract
CD4 T cell activation induces nuclear and cytoplasmic actin polymerization via the Arp2/3 complex to activate cytokine expression and strengthen T cell receptor (TCR) signaling. Actin polymerization dynamics and filament morphology differ between nucleus and cytoplasm. However, it is unclear how the Arp2/3 complex mediates distinct nuclear and cytoplasmic actin polymerization in response to a common stimulus. In humans, the ARP3, ARPC1, and ARPC5 subunits of the Arp2/3 complex exist as two different isoforms, resulting in complexes with different properties. Here, we show that the Arp2/3 subunit isoforms ARPC5 and ARPC5L play a central role in coordinating distinct actin polymerization events in CD4 T cells. While ARPC5L is heterogeneously expressed in individual CD4 T cells, it specifically drives nuclear actin polymerization upon T cell activation. In contrast, ARPC5 is evenly expressed in CD4 T cell populations and is required for cytoplasmic actin dynamics. Interestingly, nuclear actin polymerization triggered by a different stimulus, DNA replication stress, specifically requires ARPC5 but not ARPC5L. TCR signaling but not DNA replication stress induces nuclear actin polymerization via nuclear calcium-calmodulin signaling and N-WASP. Diversity in the molecular properties and individual expression patterns of ARPC5 subunit isoforms thus tailors Arp2/3-mediated actin polymerization to different physiological stimuli.
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Affiliation(s)
- Lopamudra Sadhu
- Department of Infectious Diseases, Integrative Virology, University Hospital HeidelbergHeidelbergGermany
| | - Nikolaos Tsopoulidis
- Department of Infectious Diseases, Integrative Virology, University Hospital HeidelbergHeidelbergGermany
| | - Md Hasanuzzaman
- Department of Infectious Diseases, Integrative Virology, University Hospital HeidelbergHeidelbergGermany
| | - Vibor Laketa
- Department of Infectious Diseases, Virology, University Hospital HeidelbergHeidelbergGermany
| | - Michael Way
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick InstituteLondonUnited Kingdom
- Department of Infectious Disease, Imperial CollegeLondonUnited Kingdom
| | - Oliver T Fackler
- Department of Infectious Diseases, Integrative Virology, University Hospital HeidelbergHeidelbergGermany
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5
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Leonov S, Inyang O, Achkasov K, Bogdan E, Kontareva E, Chen Y, Fu Y, Osipov AN, Pustovalova M, Merkher Y. Proteomic Markers for Mechanobiological Properties of Metastatic Cancer Cells. Int J Mol Sci 2023; 24:ijms24054773. [PMID: 36902201 PMCID: PMC10003476 DOI: 10.3390/ijms24054773] [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: 12/12/2022] [Revised: 01/26/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023] Open
Abstract
The major cause (more than 90%) of all cancer-related deaths is metastasis, thus its prediction can critically affect the survival rate. Metastases are currently predicted by lymph-node status, tumor size, histopathology and genetic testing; however, all these are not infallible, and obtaining results may require weeks. The identification of new potential prognostic factors will be an important source of risk information for the practicing oncologist, potentially leading to enhanced patient care through the proactive optimization of treatment strategies. Recently, the new mechanobiology-related techniques, independent of genetics, based on the mechanical invasiveness of cancer cells (microfluidic, gel indentation assays, migration assays etc.), demonstrated a high success rate for the detection of tumor cell metastasis propensity. However, they are still far away from clinical implementation due to complexity. Hence, the exploration of novel markers related to the mechanobiological properties of tumor cells may have a direct impact on the prognosis of metastasis. Our concise review deepens our knowledge of the factors that regulate cancer cell mechanotype and invasion, and incites further studies to develop therapeutics that target multiple mechanisms of invasion for improved clinical benefit. It may open a new clinical dimension that will improve cancer prognosis and increase the effectiveness of tumor therapies.
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Affiliation(s)
- Sergey Leonov
- School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, Russia
- Institute of Cell Biophysics, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| | - Olumide Inyang
- School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, Russia
| | - Konstantin Achkasov
- School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, Russia
| | - Elizaveta Bogdan
- School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, Russia
| | - Elizaveta Kontareva
- School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, Russia
| | - Yongheng Chen
- Department of Oncology, NHC Key Laboratory of Cancer Proteomics & State Local Joint Engineering Laboratory for Anticancer Drugs, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Ying Fu
- Department of Oncology, NHC Key Laboratory of Cancer Proteomics & State Local Joint Engineering Laboratory for Anticancer Drugs, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Andreyan N. Osipov
- State Research Center—Burnasyan Federal Medical Biophysical Center of Federal Medical-Biological Agency, 123098 Moscow, Russia
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia
- Correspondence:
| | - Margarita Pustovalova
- School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, Russia
- State Research Center—Burnasyan Federal Medical Biophysical Center of Federal Medical-Biological Agency, 123098 Moscow, Russia
| | - Yulia Merkher
- School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, Russia
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Kramer DA, Piper HK, Chen B. WASP family proteins: Molecular mechanisms and implications in human disease. Eur J Cell Biol 2022; 101:151244. [PMID: 35667337 PMCID: PMC9357188 DOI: 10.1016/j.ejcb.2022.151244] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 02/08/2023] Open
Abstract
Proteins of the Wiskott-Aldrich syndrome protein (WASP) family play a central role in regulating actin cytoskeletal dynamics in a wide range of cellular processes. Genetic mutations or misregulation of these proteins are tightly associated with many diseases. The WASP-family proteins act by transmitting various upstream signals to their conserved WH2-Central-Acidic (WCA) peptide sequence at the C-terminus, which in turn binds to the Arp2/3 complex to stimulate the formation of branched actin networks at membranes. Despite this common feature, the regulatory mechanisms and cellular functions of distinct WASP-family proteins are very different. Here, we summarize and clarify our current understanding of WASP-family proteins and how disruption of their functions is related to human disease.
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Affiliation(s)
- Daniel A Kramer
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA
| | - Hannah K Piper
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA
| | - Baoyu Chen
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA.
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Echarri A. A Multisensory Network Drives Nuclear Mechanoadaptation. Biomolecules 2022; 12:biom12030404. [PMID: 35327596 PMCID: PMC8945967 DOI: 10.3390/biom12030404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 12/03/2022] Open
Abstract
Cells have adapted to mechanical forces early in evolution and have developed multiple mechanisms ensuring sensing of, and adaptation to, the diversity of forces operating outside and within organisms. The nucleus must necessarily adapt to all types of mechanical signals, as its functions are essential for virtually all cell processes, many of which are tuned by mechanical cues. To sense forces, the nucleus is physically connected with the cytoskeleton, which senses and transmits forces generated outside and inside the cell. The nuclear LINC complex bridges the cytoskeleton and the nuclear lamina to transmit mechanical information up to the chromatin. This system creates a force-sensing macromolecular complex that, however, is not sufficient to regulate all nuclear mechanoadaptation processes. Within the nucleus, additional mechanosensitive structures, including the nuclear envelope and the nuclear pore complex, function to regulate nuclear mechanoadaptation. Similarly, extra nuclear mechanosensitive systems based on plasma membrane dynamics, mechanotransduce information to the nucleus. Thus, the nucleus has the intrinsic structural components needed to receive and interpret mechanical inputs, but also rely on extra nuclear mechano-sensors that activate nuclear regulators in response to force. Thus, a network of mechanosensitive cell structures ensures that the nucleus has a tunable response to mechanical cues.
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Affiliation(s)
- Asier Echarri
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Mechanoadaptation and Caveolae Biology Laboratory, Areas of Cell & Developmental Biology, Calle Melchor Fernández Almagro, 3, 28029 Madrid, Spain
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8
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Post-Translational Modification and Subcellular Compartmentalization: Emerging Concepts on the Regulation and Physiopathological Relevance of RhoGTPases. Cells 2021; 10:cells10081990. [PMID: 34440759 PMCID: PMC8393718 DOI: 10.3390/cells10081990] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/31/2021] [Accepted: 08/02/2021] [Indexed: 12/26/2022] Open
Abstract
Cells and tissues are continuously exposed to both chemical and physical stimuli and dynamically adapt and respond to this variety of external cues to ensure cellular homeostasis, regulated development and tissue-specific differentiation. Alterations of these pathways promote disease progression-a prominent example being cancer. Rho GTPases are key regulators of the remodeling of cytoskeleton and cell membranes and their coordination and integration with different biological processes, including cell polarization and motility, as well as other signaling networks such as growth signaling and proliferation. Apart from the control of GTP-GDP cycling, Rho GTPase activity is spatially and temporally regulated by post-translation modifications (PTMs) and their assembly onto specific protein complexes, which determine their controlled activity at distinct cellular compartments. Although Rho GTPases were traditionally conceived as targeted from the cytosol to the plasma membrane to exert their activity, recent research demonstrates that active pools of different Rho GTPases also localize to endomembranes and the nucleus. In this review, we discuss how PTM-driven modulation of Rho GTPases provides a versatile mechanism for their compartmentalization and functional regulation. Understanding how the subcellular sorting of active small GTPase pools occurs and what its functional significance is could reveal novel therapeutic opportunities.
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9
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Kim HR, Park JS, Karabulut H, Yasmin F, Jun CD. Transgelin-2: A Double-Edged Sword in Immunity and Cancer Metastasis. Front Cell Dev Biol 2021; 9:606149. [PMID: 33898417 PMCID: PMC8060441 DOI: 10.3389/fcell.2021.606149] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 03/17/2021] [Indexed: 12/12/2022] Open
Abstract
Transgelin-2, a small actin-binding protein, is the only transgelin family member expressed in immune cells. In T and B lymphocytes, transgelin-2 is constitutively expressed, but in antigen-presenting cells, it is significantly upregulated upon lipopolysaccharide stimulation. Transgelin-2 acts as a molecular staple to stabilize the actin cytoskeleton, and it competes with cofilin to bind filamentous (F)-actin. This action may enable immune synapse stabilization during T-cell interaction with cognate antigen-presenting cells. Furthermore, transgelin-2 blocks Arp2/3 complex-nucleated actin branching, which is presumably related to small filopodia formation, enhanced phagocytic function, and antigen presentation. Overall, transgelin-2 is an essential part of the molecular armament required for host defense against neoplasms and infectious diseases. However, transgelin-2 acts as a double-edged sword, as its expression is also essential for a wide range of tumor development, including drug resistance and metastasis. Thus, targeting transgelin-2 can also have a therapeutic advantage for cancer treatment; selectively suppressing transgelin-2 expression may prevent multidrug resistance in cancer chemotherapy. Here, we review newly discovered molecular characteristics of transgelin-2 and discuss clinical applications for cancer and immunotherapy.
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Affiliation(s)
- Hye-Ran Kim
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Immune Synapse and Cell Therapy Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea
| | - Jeong-Su Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Immune Synapse and Cell Therapy Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea
| | - Hatice Karabulut
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Immune Synapse and Cell Therapy Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea
| | - Fatima Yasmin
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Immune Synapse and Cell Therapy Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea
| | - Chang-Duk Jun
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Immune Synapse and Cell Therapy Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea
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10
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Schrank B, Gautier J. Assembling nuclear domains: Lessons from DNA repair. J Cell Biol 2019; 218:2444-2455. [PMID: 31324649 PMCID: PMC6683749 DOI: 10.1083/jcb.201904202] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/24/2019] [Accepted: 06/27/2019] [Indexed: 12/14/2022] Open
Abstract
Schrank and Gautier discuss the generation and function of nuclear domains during DNA repair with a special focus on nuclear actin polymerization. Eukaryotic nuclei are organized into nuclear domains that unite loci sharing a common function. These domains are essential for diverse processes including (1) the formation of topologically associated domains (TADs) that coordinate replication and transcription, (2) the formation of specialized transcription and splicing factories, and (3) the clustering of DNA double-strand breaks (DSBs), which concentrates damaged DNA for repair. The generation of nuclear domains requires forces that are beginning to be identified. In the case of DNA DSBs, DNA movement and clustering are driven by actin filament nucleators. Furthermore, RNAs and low-complexity protein domains such as RNA-binding proteins also accumulate around sites of transcription and repair. The link between liquid–liquid phase separation and actin nucleation in the formation of nuclear domains is still unknown. This review discusses DSB repair domain formation as a model for functional nuclear domains in other genomic contexts.
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Affiliation(s)
- Benjamin Schrank
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY
| | - Jean Gautier
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY
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11
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Yang X, Lin Y. Functions of nuclear actin-binding proteins in human cancer. Oncol Lett 2017; 15:2743-2748. [PMID: 29434999 DOI: 10.3892/ol.2017.7658] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 11/10/2017] [Indexed: 12/19/2022] Open
Abstract
Nuclear actin-binding proteins (ABPs) perform distinguishable functions compared with their cytoplasmic counterparts in extensive activities of living cells. In addition to the ability to regulate actin cytoskeleton dynamics, nuclear ABPs are associated with multiple nuclear biological processes, including chromatin remodeling, gene transcriptional regulation, DNA damage response, nucleocytoplasmic trafficking and nuclear structure maintenance. The nuclear translocation of ABPs is affected by numerous intracellular or extracellular stimuli, which may lead to developmental malformation, tumor initiation, tumor progression and metastasis. Abnormal expression of certain ABPs have been reported in different types of cancer. This review focuses on the newly identified roles of nuclear ABPs in the pathological processes associated with cancer.
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Affiliation(s)
- Xinyi Yang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510120, P.R. China.,Department of Gastroenterology and Hepatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510120, P.R. China
| | - Ying Lin
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510120, P.R. China.,Department of Gastroenterology and Hepatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510120, P.R. China
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12
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Manjón E, Edreira T, Muñoz S, Sánchez Y. Rgf1p (Rho1p GEF) is required for double-strand break repair in fission yeast. Nucleic Acids Res 2017; 45:5269-5284. [PMID: 28334931 PMCID: PMC5435928 DOI: 10.1093/nar/gkx176] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 03/07/2017] [Indexed: 12/04/2022] Open
Abstract
Rho GTPases are conserved molecules that control cytoskeletal dynamics. These functions are expedited by Rho GEFs that stimulate the release of GDP to enable GTP binding, thereby allowing Rho proteins to initiate intracellular signaling. How Rho GEFs and Rho GTPases protect cells from DNA damage is unknown. Here, we explore the extreme sensitivity of a deletion mutation in the Rho1p exchange factor Rgf1p to the DNA break/inducing antibiotic phleomycin (Phl). The Rgf1p mutant cells are defective in reentry into the cell cycle following the induction of severe DNA damage. This phenotype correlates with the inability of rgf1Δ cells to efficiently repair fragmented chromosomes after Phl treatment. Consistent with this observation Rad11p (ssDNA binding protein, RPA), Rad52p, Rad54p and Rad51p, which facilitate strand invasion in the process of homology-directed repair (HDR), are permanently stacked in Phl-induced foci in rgf1Δ cells. These phenotypes are phenocopied by genetic inhibition of Rho1p. Our data provide evidence that Rgf1p/Rho1p activity positively controls a repair function that confers resistance against the anti-cancer drug Phl.
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Affiliation(s)
- Elvira Manjón
- Instituto de Biología Funcional y Genómica, CSIC. Departamento de Microbiología y Genética, Universidad de Salamanca. C/Zacarías González, s/n. Salamanca, Spain
| | - Tomás Edreira
- Instituto de Biología Funcional y Genómica, CSIC. Departamento de Microbiología y Genética, Universidad de Salamanca. C/Zacarías González, s/n. Salamanca, Spain
| | - Sofía Muñoz
- Instituto de Biología Funcional y Genómica, CSIC. Departamento de Microbiología y Genética, Universidad de Salamanca. C/Zacarías González, s/n. Salamanca, Spain
| | - Yolanda Sánchez
- Instituto de Biología Funcional y Genómica, CSIC. Departamento de Microbiología y Genética, Universidad de Salamanca. C/Zacarías González, s/n. Salamanca, Spain
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Functional Actin Networks under Construction: The Cooperative Action of Actin Nucleation and Elongation Factors. Trends Biochem Sci 2017; 42:414-430. [DOI: 10.1016/j.tibs.2017.03.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 03/04/2017] [Accepted: 03/07/2017] [Indexed: 12/31/2022]
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14
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Myogenic differentiation depends on the interplay of Grb2 and N-WASP. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:487-497. [PMID: 27965114 DOI: 10.1016/j.bbamcr.2016.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 12/02/2016] [Accepted: 12/09/2016] [Indexed: 12/19/2022]
Abstract
Myogenesis requires a well-coordinated withdrawal from cell cycle, morphological changes and cell fusion mediated by actin cytoskeleton. Grb2 is an adaptor protein whose central SH2 domain binds to phosphorylated tyrosine residues of activated receptors and activates intracellular signaling pathway, while its N-terminal and C-terminal SH3 domains bind to proline rich proteins such as N-WASP (Neural-Wiskott Aldrich Syndrome Protein). We found that the expression of Grb2 was increased at the beginning of differentiation and remained constant during differentiation in C2C12 myoblasts. Knocking down endogenous Grb2 expression caused a significant increase in the fusion index and expression of MyHC, a terminal differentiation marker when compared with the control. Over expression of Grb2 in C2C12 (C2C12Grb2-Myc) reduced myotube formation and expression of MyHC. Similarly over expression of Grb2P49L-Myc (N-terminal SH3 domain mutant) or Grb2R86K-Myc (SH2 domain mutant) inhibited myogenic differentiation of C2C12 cells. However, the expression of Grb2P206L-Myc (C-terminal SH3 domain mutant) did not inhibit myotube formation and expression of MyHC. This suggests that the C-terminal SH3 domain of Grb2 is critical for the inhibition of myogenic differentiation. The C2C12Grb2-Myc cells have reduced phalloidin staining at late stages of differentiation. Expression of N-WASP in C2C12Grb2-Myc cells rescued the myogenic defect and increased phalloidin staining (increased F-actin) in these cells. Thus our results suggest that Grb2 is a negative regulator of myogenesis and reduces myogenic differentiation by inhibiting actin polymerization/remodeling through its C-terminal SH3 domain.
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Liu L, Luo Q, Sun J, Song G. Nucleus and nucleus-cytoskeleton connections in 3D cell migration. Exp Cell Res 2016; 348:56-65. [DOI: 10.1016/j.yexcr.2016.09.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 09/02/2016] [Accepted: 09/03/2016] [Indexed: 12/21/2022]
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16
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Coutts AS, La Thangue NB. Regulation of actin nucleation and autophagosome formation. Cell Mol Life Sci 2016; 73:3249-63. [PMID: 27147468 PMCID: PMC4967107 DOI: 10.1007/s00018-016-2224-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/21/2016] [Accepted: 04/08/2016] [Indexed: 01/08/2023]
Abstract
Autophagy is a process of self-eating, whereby cytosolic constituents are enclosed by a double-membrane vesicle before delivery to the lysosome for degradation. This is an important process which allows for recycling of nutrients and cellular components and thus plays a critical role in normal cellular homeostasis as well as cell survival during stresses such as starvation or hypoxia. A large number of proteins regulate various stages of autophagy in a complex and still incompletely understood series of events. In this review, we will discuss recent studies which provide a growing body of evidence that actin dynamics and proteins that influence actin nucleation play an important role in the regulation of autophagosome formation and maturation.
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Affiliation(s)
- Amanda S Coutts
- Laboratory of Cancer Biology, Medical Sciences Division, Department of Oncology, University of Oxford, Old Road Campus Research Building, Old Road Campus, Off Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Nicholas B La Thangue
- Laboratory of Cancer Biology, Medical Sciences Division, Department of Oncology, University of Oxford, Old Road Campus Research Building, Old Road Campus, Off Roosevelt Drive, Oxford, OX3 7DQ, UK.
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Activation of the cAMP Pathway Induces RACK1-Dependent Binding of β-Actin to BDNF Promoter. PLoS One 2016; 11:e0160948. [PMID: 27505161 PMCID: PMC4978483 DOI: 10.1371/journal.pone.0160948] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 07/27/2016] [Indexed: 11/28/2022] Open
Abstract
RACK1 is a scaffolding protein that contributes to the specificity and propagation of several signaling cascades including the cAMP pathway. As such, RACK1 participates in numerous cellular functions ranging from cell migration and morphology to gene transcription. To obtain further insights on the mechanisms whereby RACK1 regulates cAMP-dependent processes, we set out to identify new binding partners of RACK1 during activation of the cAMP signaling using a proteomics strategy. We identified β-actin as a direct RACK1 binding partner and found that the association between β-actin and RACK1 is increased in response to the activation of the cAMP pathway. Furthermore, we show that cAMP-dependent increase in BDNF expression requires filamentous actin. We further report that β-actin associates with the BDNF promoter IV upon the activation of the cAMP pathway and present data to suggest that the association of β-actin with BDNF promoter IV is RACK1-dependent. Taken together, our data suggest that β-actin is a new RACK1 binding partner and that the RACK1 and β-actin association participate in the cAMP-dependent regulation of BDNF transcription.
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Pochukalina GN, Ilicheva NV, Podgornaya OI, Voronin AP. Nucleolus-like body of mouse oocytes contains lamin A and B and TRF2 but not actin and topo II. Mol Cytogenet 2016; 9:50. [PMID: 27347007 PMCID: PMC4921027 DOI: 10.1186/s13039-016-0259-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 06/18/2016] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND During the final stages of oocyte development, all chromosomes join in a limited nuclear volume for the final formation of a single complex chromatin structure - the karyosphere. In the majority of mammalian species, the chromosomes surround a round protein/fibrillar body known as the central body, or nucleolus-like body (NLB). Nothing seems to unite the inner portion of the karyosphere with the nucleolus except position at its remnants. Nevertheless, in this study we will use term NLB as the conventional one for karyosphere with the central body. At the morphological level, NLBs consist of tightly-packed fibres of 6-10 nm. The biochemical structure of this dense, compact NLB fibre centre remains uncertain. RESULTS The aim of this study was to determine which proteins represent the NLB components at final stages of karyosphere formation in mouse oogenesis. To determine this, three antibodies (ABs) have been examined against different actin epitopes. Examination of both ABs against the actin N-end provided similar results: spots inside the nucleus. Double staining with AB against SC35 and actin revealed the colocalization of these proteins in IGCs (interchromatin granule clusters/nuclear speckles/SC35 domains). In contrast, examination of polyclonal AB against peptide at the C-end reveals a different result: actin is localized exclusively in connection with the chromatin. Surprisingly, no forms of actin or topoisomerase II are present as components of the NLB. It was discovered that: (1) lamin B is an NLB component from the beginning of NLB formation, and a major portion of it resides in the NLB at the end of oocyte development; (2) lamin A undergoes rapid movement into the NLB, and a majority of it remains in the NLB; (3) the telomere-binding protein TRF2 resides in the IGCs/nuclear speckles until the end of oocyte development, when significant part of it transfers to the NLB. CONCLUSIONS NLBs do not contain actin or topo II. Lamin B is involved from the beginning of NLB formation. Both Lamin A and TRF2 exhibit rapid movement to the NLB at the end of oogenesis. This dynamic distribution of proteins may reflect the NLB's role in future chromatin organization post-fertilisation.
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Affiliation(s)
| | - Nadya V. Ilicheva
- />Institute of Cytology, Russian Academy of Sciences, St Petersburg, 194064 Russia
| | - Olga I. Podgornaya
- />Institute of Cytology, Russian Academy of Sciences, St Petersburg, 194064 Russia
- />Saint Petersburg State University, St Petersburg, 199034 Russia
- />Far Eastern Federal University, Vladivostok, 690950 Russia
| | - Alexey P. Voronin
- />Institute of Cytology, Russian Academy of Sciences, St Petersburg, 194064 Russia
- />Saint Petersburg State University, St Petersburg, 199034 Russia
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Actin, actin-binding proteins, and actin-related proteins in the nucleus. Histochem Cell Biol 2016; 145:373-88. [PMID: 26847179 DOI: 10.1007/s00418-015-1400-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2015] [Indexed: 10/25/2022]
Abstract
Extensive research in the past decade has significantly broadened our view about the role actin plays in the life of the cell and added novel aspects to actin research. One of these new aspects is the discovery of the existence of nuclear actin which became evident only recently. Nuclear activities including transcriptional activation in the case of all three RNA polymerases, editing and nuclear export of mRNAs, and chromatin remodeling all depend on actin. It also became clear that there is a fine-tuned equilibrium between cytoplasmic and nuclear actin pools and that this balance is ensured by an export-import system dedicated to actin. After over half a century of research on conventional actin and its organizing partners in the cytoplasm, it was also an unexpected finding that the nucleus contains more than 30 actin-binding proteins and new classes of actin-related proteins which are not able to form filaments but had evolved nuclear-specific functions. The actin-binding and actin-related proteins in the nucleus have been linked to RNA transcription and processing, nuclear transport, and chromatin remodeling. In this paper, we attempt to provide an overview of the wide range of information that is now available about actin, actin-binding, and actin-related proteins in the nucleus.
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Gayle S, Pan Y, Landrette S, Xu T. piggyBac insertional mutagenesis screen identifies a role for nuclear RHOA in human ES cell differentiation. Stem Cell Reports 2015; 4:926-38. [PMID: 25866159 PMCID: PMC4437468 DOI: 10.1016/j.stemcr.2015.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 01/22/2023] Open
Abstract
The mechanisms regulating human embryonic stem (ES) cell self-renewal and differentiation are not well defined in part due to the lack of tools for forward genetic analysis. We present a piggyBac transposon gain of function screen in human ES cells that identifies DENND2C, which genetically cooperates with NANOG to maintain self-renewal in the presence of retinoic acid. We show that DENND2C negatively regulates RHOA activity, which cooperates with NANOG to block differentiation. It has been recently shown that RHOA exists in the nucleus and is activated by DNA damage; however, its nuclear function remains unknown. We discovered that RHOA associates with DNA and that DENND2C affects nuclear RHOA localization, activity, and DNA association. Our study illustrates the power of piggyBac as a cost-effective, efficient, and easy to use tool for forward genetic screens in human ES cells and provides insight into the role of RHOA in the nucleus. NANOG-sensitized piggyBac screen for regulators of stem cell differentiation DENND2C is a negative regulator of RHOA Genetic cooperation exists between RHOA and NANOG Nuclear RHOA associates with DNA
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Affiliation(s)
- Sophia Gayle
- Howard Hughes Medical Institute and Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Yukun Pan
- Howard Hughes Medical Institute and Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Sean Landrette
- Howard Hughes Medical Institute and Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Tian Xu
- Howard Hughes Medical Institute and Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
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21
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Plessner M, Melak M, Chinchilla P, Baarlink C, Grosse R. Nuclear F-actin formation and reorganization upon cell spreading. J Biol Chem 2015; 290:11209-16. [PMID: 25759381 DOI: 10.1074/jbc.m114.627166] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Indexed: 12/30/2022] Open
Abstract
We recently discovered signal-regulated nuclear actin network assembly. However, in contrast to cytoplasmic actin regulation, polymeric nuclear actin structures and functions remain only poorly understood. Here we describe a novel molecular tool to visualize real-time nuclear actin dynamics by targeting the Actin-Chromobody-TagGFP to the nucleus, thus establishing a nuclear Actin-Chromobody. Interestingly, we observe nuclear actin polymerization into dynamic filaments upon cell spreading and fibronectin stimulation, both of which appear to be triggered by integrin signaling. Furthermore, we show that nucleoskeletal proteins such as the LINC (linker of nucleoskeleton and cytoskeleton) complex and components of the nuclear lamina couple cell spreading or integrin activation by fibronectin to nuclear actin polymerization. Spreading-induced nuclear actin polymerization results in serum response factor (SRF)-mediated transcription through nuclear retention of myocardin-related transcription factor A (MRTF-A). Our results reveal a signaling pathway, which links integrin activation by extracellular matrix interaction to nuclear actin polymerization through the LINC complex, and therefore suggest a role for nuclear actin polymerization in the context of cellular adhesion and mechanosensing.
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Affiliation(s)
- Matthias Plessner
- From the Institute of Pharmacology, Biochemical-Pharmacological Center (BPC), University of Marburg, Karl-von-Frisch-Strasse 1, 35043 Marburg, Germany
| | - Michael Melak
- From the Institute of Pharmacology, Biochemical-Pharmacological Center (BPC), University of Marburg, Karl-von-Frisch-Strasse 1, 35043 Marburg, Germany
| | - Pilar Chinchilla
- From the Institute of Pharmacology, Biochemical-Pharmacological Center (BPC), University of Marburg, Karl-von-Frisch-Strasse 1, 35043 Marburg, Germany
| | - Christian Baarlink
- From the Institute of Pharmacology, Biochemical-Pharmacological Center (BPC), University of Marburg, Karl-von-Frisch-Strasse 1, 35043 Marburg, Germany
| | - Robert Grosse
- From the Institute of Pharmacology, Biochemical-Pharmacological Center (BPC), University of Marburg, Karl-von-Frisch-Strasse 1, 35043 Marburg, Germany
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22
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Chang CY, Leu JD, Lee YJ. The actin depolymerizing factor (ADF)/cofilin signaling pathway and DNA damage responses in cancer. Int J Mol Sci 2015; 16:4095-120. [PMID: 25689427 PMCID: PMC4346946 DOI: 10.3390/ijms16024095] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 01/26/2015] [Accepted: 02/09/2015] [Indexed: 01/06/2023] Open
Abstract
The actin depolymerizing factor (ADF)/cofilin protein family is essential for actin dynamics, cell division, chemotaxis and tumor metastasis. Cofilin-1 (CFL-1) is a primary non-muscle isoform of the ADF/cofilin protein family accelerating the actin filamental turnover in vitro and in vivo. In response to environmental stimulation, CFL-1 enters the nucleus to regulate the actin dynamics. Although the purpose of this cytoplasm-nucleus transition remains unclear, it is speculated that the interaction between CFL-1 and DNA may influence various biological responses, including DNA damage repair. In this review, we will discuss the possible involvement of CFL-1 in DNA damage responses (DDR) induced by ionizing radiation (IR), and the implications for cancer radiotherapy.
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Affiliation(s)
- Chun-Yuan Chang
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan.
| | - Jyh-Der Leu
- Division of Radiation Oncology, Taipei City Hospital RenAi Branch, Taipei 106, Taiwan.
| | - Yi-Jang Lee
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan.
- Biophotonics & Molecular Imaging Research Center (BMIRC), National Yang-Ming University, Taipei 112, Taiwan.
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23
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Hendzel MJ. The F-act's of nuclear actin. Curr Opin Cell Biol 2014; 28:84-9. [DOI: 10.1016/j.ceb.2014.04.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 03/24/2014] [Accepted: 04/11/2014] [Indexed: 10/25/2022]
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Myogenesis defect due to Toca-1 knockdown can be suppressed by expression of N-WASP. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:1930-41. [PMID: 24861867 DOI: 10.1016/j.bbamcr.2014.05.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 05/15/2014] [Accepted: 05/16/2014] [Indexed: 01/09/2023]
Abstract
Skeletal muscle formation is a multistep process involving proliferation, differentiation, alignment and fusion of myoblasts to form myotubes which fuse with additional myoblast to form myofibers. Toca-1 (Transducer of Cdc42-dependent actin assembly), is an adaptor protein which activates N-WASP in conjunction with Cdc42 to facilitate membrane invagination, endocytosis and actin cytoskeleton remodeling. Expression of Toca-1 in mouse primary myoblasts and C2C12 myoblasts was up-regulated on day 1 of differentiation and subsequently down-regulated during differentiation. Knocking down Toca-1 expression in C2C12 cells (Toca-1(KD) cells) resulted in a significant decrease in myotube formation and expression of shRNA-resistant Toca-1 in Toca-1(KD) cells rescued the myogenic defect, suggesting that the knockdown was specific and Toca-1 is essential for myotube formation. Toca-1(KD) cells exhibited elongated spindle-like morphology, expressed myogenic markers (MyoD and MyHC) and localized N-Cadherin at cell periphery similar to control cells suggesting that Toca-1 is not essential for morphological changes or expression of proteins critical for differentiation. Toca-1(KD) cells displayed prominent actin fibers suggesting a defect in actin cytoskeleton turnover necessary for cell-cell fusion. Toca-1(KD) cells migrated faster than control cells and had a reduced number of vinculin patches similar to N-WASP(KO) MEF cells. Transfection of N-WASP-expressing plasmid into Toca-1(KD) cells restored myotube formation of Toca-1(KD) cells. Thus, our results suggest that Toca-1(KD) cells have defects in formation of myotubes probably due to reduced activity of actin cytoskeleton regulators such as N-WASP. This is the first study to identify and characterize the role of Toca-1 in myogenesis.
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25
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Rubenstein PA, Wen KK. Insights into the effects of disease-causing mutations in human actins. Cytoskeleton (Hoboken) 2014; 71:211-29. [PMID: 24574087 DOI: 10.1002/cm.21169] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 02/13/2013] [Accepted: 02/19/2014] [Indexed: 01/04/2023]
Abstract
Mutations in all six actins in humans have now been shown to cause diseases. However, a number of factors have made it difficult to gain insight into how the changes in actin functions brought about by these pathogenic mutations result in the disease phenotype. These include the presence of multiple actins in the same cell, limited accessibility to pure mutant material, and complexities associated with the structures and their component cells that manifest the diseases. To try to circumvent these difficulties, investigators have turned to the use of model systems. This review describes these various approaches, the initial results obtained using them, and the insight they have provided into allosteric mechanisms that govern actin function. Although results so far have not explained a particular disease phenotype at the molecular level, they have provided valuable insight into actin function at the mechanistic level which can be utilized in the future to delineate the molecular bases of these different actinopathies.
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Affiliation(s)
- Peter A Rubenstein
- Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, Iowa
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26
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To be or not to be assembled: progressing into nuclear actin filaments. Nat Rev Mol Cell Biol 2013; 14:693-7. [PMID: 24088744 DOI: 10.1038/nrm3681] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The paradigm states that cytoplasmic actin operates as filaments and nuclear actin is mainly monomeric, acting as a scaffold in transcription complexes. However, why should a powerful function of actin, namely polymerization, not be used in the nucleus? Recent progress in the field forces us to rethink this issue, as many actin filament assembly proteins have been linked to nuclear functions and new experimental approaches have provided the first direct visualizations of polymerized nuclear actin.
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27
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Guardians of the actin monomer. Eur J Cell Biol 2013; 92:316-32. [DOI: 10.1016/j.ejcb.2013.10.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 10/03/2013] [Accepted: 10/23/2013] [Indexed: 11/22/2022] Open
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Abstract
Intracellular pathogens have developed elaborate mechanisms to exploit the different cellular systems of their unwilling hosts to facilitate their entry, replication, and survival. In particular, a diverse range of bacteria and viruses have evolved unique strategies to harness the power of Arp2/3-mediated actin polymerization to enhance their cell-to-cell spread. In this review, we discuss how studying these pathogens has revolutionized our molecular understanding of Arp2/3-dependent actin assembly and revealed key signaling pathways regulating actin assembly in cells. Future analyses of microbe-host interactions are likely to continue uncovering new mechanisms regulating actin assembly and dynamics, as well as unexpected cellular functions for actin. Further, studies with known and newly emerging pathogens will also undoubtedly continue to enhance our understanding of the role of the actin cytoskeleton during pathogenesis and potentially highlight future therapeutic approaches.
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Affiliation(s)
- Matthew D Welch
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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29
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Miyamoto K, Gurdon JB. Transcriptional regulation and nuclear reprogramming: roles of nuclear actin and actin-binding proteins. Cell Mol Life Sci 2013; 70:3289-302. [PMID: 23275942 PMCID: PMC3753470 DOI: 10.1007/s00018-012-1235-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 12/03/2012] [Accepted: 12/04/2012] [Indexed: 12/18/2022]
Abstract
Proper regulation of transcription is essential for cells to acquire and maintain cell identity. Transcriptional activation plays a central role in gene regulation and can be modulated by introducing transcriptional activators such as transcription factors. Activators act on their specific target genes to induce transcription. Reprogramming experiments have revealed that as cells become differentiated, some genes are highly silenced and even introduction of activators that target these silenced genes does not induce transcription. This can be explained by chromatin-based repression that restricts access of transcriptional activators to silenced genes. Transcriptional activation from these genes can be accomplished by opening chromatin, in addition to providing activators. Once a de novo transcription network is established, cells are differentiated or reprogrammed to a new cell type. Emerging evidence suggests that actin in the nucleus (nuclear actin) and nuclear actin-binding proteins are implicated in these transcriptional regulatory processes. This review summarizes roles of nuclear actin and actin-binding proteins in transcriptional regulation. We also discuss possible functions of nuclear actin during reprogramming in the context of transcription and chromatin remodeling.
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Affiliation(s)
- Kei Miyamoto
- The Wellcome Trust/Cancer Research UK Gurdon Institute, The Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.
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30
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Treisman R. Shedding light on nuclear actin dynamics and function. Trends Biochem Sci 2013; 38:376-7. [PMID: 23810602 DOI: 10.1016/j.tibs.2013.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 06/04/2013] [Indexed: 01/08/2023]
Abstract
The functions of nuclear actin have been a mystery for many years. Recent papers demonstrate that the nuclear and cytoplasmic actin pools are in dynamic communication, but that not all nuclear actin freely exchanges. Extracellular signals can induce changes in nuclear actin dynamics, affecting activity of the myocardin-related transcription factor (MRTF) transcriptional coactivators, which reversibly bind G-actin. By contrast, actin is stably associated with the Ino80 chromatin remodelling complex, where it plays a role in the recognition of nucleosome linker DNA.
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Affiliation(s)
- Richard Treisman
- CR-UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK.
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31
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Zhang C, Mallery EL, Szymanski DB. ARP2/3 localization in Arabidopsis leaf pavement cells: a diversity of intracellular pools and cytoskeletal interactions. FRONTIERS IN PLANT SCIENCE 2013; 4:238. [PMID: 23874346 PMCID: PMC3709099 DOI: 10.3389/fpls.2013.00238] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 06/16/2013] [Indexed: 05/03/2023]
Abstract
In plant cells the actin cytoskeleton adopts many configurations, but is best understood as an unstable, interconnected track that rearranges to define the patterns of long distance transport of organelles during growth. Actin filaments do not form spontaneously; instead filament nucleators, such as the evolutionarily conserved actin-related protein (ARP) 2/3 complex, can efficiently generate new actin filament networks when in a fully activated state. A growing number of genetic experiments have shown that ARP2/3 is necessary for morphogenesis in processes that range from tip growth during root nodule formation to the diffuse polarized growth of leaf trichomes and pavement cells. Although progress has been rapid in the identification of proteins that function in series to positively regulate ARP2/3, less has been learned about the actual function of ARP2/3 in cells. In this paper, we analyze the localization of ARP2/3 in Arabidopsis leaf pavement cells. We detect a pool of ARP2/3 in the nucleus, and also find that ARP2/3 is efficiently and specifically clustered on multiple organelle surfaces and associates with both the actin filament and microtubule cytoskeletons. Our mutant analyses and ARP2/3 and actin double labeling experiments indicate that the clustering of ARP2/3 on organelle surfaces and an association with actin bundles does not necessarily reflect an active pool of ARP2/3, and instead most of the complex appears to exist as a latent organelle-associated pool.
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Affiliation(s)
- Chunhua Zhang
- Department of Agronomy, Purdue UniversityWest Lafayette, IN, USA
| | | | - Daniel B. Szymanski
- Department of Agronomy, Purdue UniversityWest Lafayette, IN, USA
- Department of Biology, Purdue UniversityWest Lafayette, IN, USA
- *Correspondence: Daniel B. Szymanski, Department of Agronomy, Purdue University, Lily Hall of Life Sciences, 915 West State Street, West Lafayette, IN 47907-2054, USA e-mail:
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