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Pimm ML, Haarer BK, Nobles AD, Haney LM, Marcin AG, Alcaide Eligio M, Henty-Ridilla JL. Coordination of actin plus-end dynamics by IQGAP1, formin, and capping protein. J Cell Biol 2024; 223:e202305065. [PMID: 38787349 PMCID: PMC11117073 DOI: 10.1083/jcb.202305065] [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: 05/16/2023] [Revised: 04/01/2024] [Accepted: 05/13/2024] [Indexed: 05/25/2024] Open
Abstract
Cell processes require precise regulation of actin polymerization that is mediated by plus-end regulatory proteins. Detailed mechanisms that explain plus-end dynamics involve regulators with opposing roles, including factors that enhance assembly, e.g., the formin mDia1, and others that stop growth (capping protein, CP). We explore IQGAP1's roles in regulating actin filament plus-ends and the consequences of perturbing its activity in cells. We confirm that IQGAP1 pauses elongation and interacts with plus ends through two residues (C756 and C781). We directly visualize the dynamic interplay between IQGAP1 and mDia1, revealing that IQGAP1 displaces the formin to influence actin assembly. Using four-color TIRF, we show that IQGAP1's displacement activity extends to formin-CP "decision complexes," promoting end-binding protein turnover at plus-ends. Loss of IQGAP1 or its plus-end activities disrupts morphology and migration, emphasizing its essential role. These results reveal a new role for IQGAP1 in promoting protein turnover on filament ends and provide new insights into how plus-end actin assembly is regulated in cells.
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Affiliation(s)
- Morgan L. Pimm
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Brian K. Haarer
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Alexander D. Nobles
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Laura M. Haney
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Alexandra G. Marcin
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Marcela Alcaide Eligio
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Jessica L. Henty-Ridilla
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, USA
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2
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Conboy JP, IstĆŗriz Petitjean I, van der Net A, Koenderink GH. How cytoskeletal crosstalk makes cells move: Bridging cell-free and cell studies. BIOPHYSICS REVIEWS 2024; 5:021307. [PMID: 38840976 PMCID: PMC11151447 DOI: 10.1063/5.0198119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 05/13/2024] [Indexed: 06/07/2024]
Abstract
Cell migration is a fundamental process for life and is highly dependent on the dynamical and mechanical properties of the cytoskeleton. Intensive physical and biochemical crosstalk among actin, microtubules, and intermediate filaments ensures their coordination to facilitate and enable migration. In this review, we discuss the different mechanical aspects that govern cell migration and provide, for each mechanical aspect, a novel perspective by juxtaposing two complementary approaches to the biophysical study of cytoskeletal crosstalk: live-cell studies (often referred to as top-down studies) and cell-free studies (often referred to as bottom-up studies). We summarize the main findings from both experimental approaches, and we provide our perspective on bridging the two perspectives to address the open questions of how cytoskeletal crosstalk governs cell migration and makes cells move.
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Affiliation(s)
- James P. Conboy
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Irene IstĆŗriz Petitjean
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Anouk van der Net
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Gijsje H. Koenderink
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
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3
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Pimm ML, Haarer BK, Nobles AD, Haney LM, Marcin AG, Marcela Alcaide Eligio, Henty-Ridilla JL. Coordination of actin plus-end dynamics by IQGAP1, formin, and capping protein. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.04.539490. [PMID: 37205555 PMCID: PMC10187324 DOI: 10.1101/2023.05.04.539490] [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: 05/21/2023]
Abstract
Cell processes require precise regulation of actin polymerization that is mediated by plus-end regulatory proteins. Detailed mechanisms that explain plus-end dynamics involve regulators with opposing roles, including factors that enhance assembly, e.g., the formin mDia1, and others that stop growth (Capping Protein, CPz). We explore IQGAP1's roles regulating actin filament plus-ends and the consequences of perturbing its activity in cells. We confirm that IQGAP1 pauses elongation and interacts with plus ends through two residues (C756 and C781). We directly visualize the dynamic interplay between IQGAP1 and mDia1, revealing that IQGAP1 displaces the formin to influence actin assembly. Using four-color TIRF we show that IQGAP1's displacement activity extends to formin-CPz 'decision complexes', promoting end-binding protein turnover at plus-ends. Loss of IQGAP1 or its plus-end activities disrupts morphology and migration, emphasizing its essential role. These results reveal a new role for IQGAP1 in promoting protein turnover on filament ends and provide new insights into how plus-end actin assembly is regulated in cells.
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Affiliation(s)
- Morgan L Pimm
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Brian K Haarer
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Alexander D Nobles
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Laura M Haney
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Alexandra G Marcin
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Marcela Alcaide Eligio
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Jessica L Henty-Ridilla
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
- Department of Neuroscience & Physiology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
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4
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Frank D, Bergamasco M, Mlodzianoski MJ, Kueh A, Tsui E, Hall C, Kastrappis G, Voss AK, McLean C, Faux M, Rogers KL, Tran B, Vincan E, Komander D, Dewson G, Tran H. Trabid patient mutations impede the axonal trafficking of adenomatous polyposis coli to disrupt neurite growth. eLife 2023; 12:RP90796. [PMID: 38099646 PMCID: PMC10723793 DOI: 10.7554/elife.90796] [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: 12/17/2023] Open
Abstract
ZRANB1 (human Trabid) missense mutations have been identified in children diagnosed with a range of congenital disorders including reduced brain size, but how Trabid regulates neurodevelopment is not understood. We have characterized these patient mutations in cells and mice to identify a key role for Trabid in the regulation of neurite growth. One of the patient mutations flanked the catalytic cysteine of Trabid and its deubiquitylating (DUB) activity was abrogated. The second variant retained DUB activity, but failed to bind STRIPAK, a large multiprotein assembly implicated in cytoskeleton organization and neural development. Zranb1 knock-in mice harboring either of these patient mutations exhibited reduced neuronal and glial cell densities in the brain and a motor deficit consistent with fewer dopaminergic neurons and projections. Mechanistically, both DUB-impaired and STRIPAK-binding-deficient Trabid variants impeded the trafficking of adenomatous polyposis coli (APC) to microtubule plus-ends. Consequently, the formation of neuronal growth cones and the trajectory of neurite outgrowth from mutant midbrain progenitors were severely compromised. We propose that STRIPAK recruits Trabid to deubiquitylate APC, and that in cells with mutant Trabid, APC becomes hyperubiquitylated and mislocalized causing impaired organization of the cytoskeleton that underlie the neuronal and developmental phenotypes.
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Affiliation(s)
- Daniel Frank
- Ubiquitin Signalling Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Maria Bergamasco
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
- Epigenetics and Development Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Michael J Mlodzianoski
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
- Centre for Dynamic Imaging, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Andrew Kueh
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
- Melbourne Advanced Genome Editing Centre, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Olivia Newton-John Cancer Research Institute, Heidelberg, Australia
- School of Cancer Medicine, La Trobe University, Heidelberg, Australia
| | - Ellen Tsui
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
- Histology Facility, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Cathrine Hall
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
- Inflammation Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Georgios Kastrappis
- Department of Infectious Diseases, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Anne Kathrin Voss
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
- Epigenetics and Development Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Catriona McLean
- Department of Anatomical Pathology, The Alfred Hospital, Melbourne, Australia
| | - Maree Faux
- Neuro-Oncology Group, Murdoch Children's Research Institute, Parkville, Australia
| | - Kelly L Rogers
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
- Centre for Dynamic Imaging, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Bang Tran
- Department of Infectious Diseases, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Elizabeth Vincan
- Department of Infectious Diseases, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- The Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - David Komander
- Ubiquitin Signalling Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Grant Dewson
- Ubiquitin Signalling Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Hoanh Tran
- Ubiquitin Signalling Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
- Department of Infectious Diseases, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
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5
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Alfadil E, Bradke F. Moving through the crowd. Where are we at understanding physiological axon growth? Semin Cell Dev Biol 2023; 140:63-71. [PMID: 35817655 DOI: 10.1016/j.semcdb.2022.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 01/28/2023]
Abstract
Axon growth enables the rapid wiring of the central nervous system. Understanding this process is a prerequisite to retriggering it under pathological conditions, such as a spinal cord injury, to elicit axon regeneration. The last decades saw progress in understanding the mechanisms underlying axon growth. Most of these studies employed cultured neurons grown on flat surfaces. Only recently studies on axon growth were performed in 3D. In these studies, physiological environments exposed more complex and dynamic aspects of axon development. Here, we describe current views on axon growth and highlight gaps in our knowledge. We discuss how axons interact with the extracellular matrix during development and the role of the growth cone and its cytoskeleton within. Finally, we propose that the time is ripe to study axon growth in a more physiological setting. This will help us uncover the physiologically relevant mechanisms underlying axon growth, and how they can be reactivated to induce axon regeneration.
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Affiliation(s)
- Eissa Alfadil
- Laboratory of Axon Growth and Regeneration, Deutsches Zentrum fĆ¼r Neurodegenerative Erkrankungen (DZNE), Venusberg-Campus 1, Building 99, 53127, Bonn, Germany.
| | - Frank Bradke
- Laboratory of Axon Growth and Regeneration, Deutsches Zentrum fĆ¼r Neurodegenerative Erkrankungen (DZNE), Venusberg-Campus 1, Building 99, 53127, Bonn, Germany
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6
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Bressler SG, Mitrany A, Wenger A, NƤthke I, Friedler A. The Oligomerization Domains of the APC Protein Mediate Liquid-Liquid Phase Separation That Is Phosphorylation Controlled. Int J Mol Sci 2023; 24:ijms24076478. [PMID: 37047451 PMCID: PMC10095272 DOI: 10.3390/ijms24076478] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023] Open
Abstract
One of the most important properties of intrinsically disordered proteins is their ability to undergo liquid-liquid phase separation and form droplets. The Adenomatous Polyposis Coli (APC) protein is an IDP that plays a key role in Wnt signaling and mutations in Apc initiate cancer. APC forms droplets via its 20R domains and self-association domain (ASAD) and in the context of Axin. However, the mechanism involved is unknown. Here, we used peptides to study the molecular mechanism and regulation of APC droplet formation. We found that a peptide derived from the ASAD of APC-formed droplets. Peptide array screening showed that the ASAD bound other APC peptides corresponding to the 20R3 and 20R5 domains. We discovered that the 20R3/5 peptides also formed droplets by themselves and mapped specific residues within 20R3/5 that are necessary for droplet formation. When incubated together, the ASAD and 20R3/5 did not form droplets. Thus, the interaction of the ASAD with 20R3 and 20R5 may regulate the droplet formation as a means of regulating different cellular functions. Phosphorylation of 20R3 or 20R5 at specific residues prevented droplet formation of 20R3/5. Our results reveal that phosphorylation and the ability to undergo liquid-liquid phase separation, which are both important properties of intrinsically disordered proteins, are related to each other in APC. Phosphorylation inhibited the liquid-liquid phase separation of APC, acting as an āon-offā switch for droplet formation. Phosphorylation may thus be a common mechanism regulating LLPS in intrinsically disordered proteins.
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Affiliation(s)
- Shachar G. Bressler
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Amit Mitrany
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Alon Wenger
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Inke NƤthke
- Division of Molecular Cell and Developmental Biology, University of Dundee, Dundee DD1 5AA, Scotland, UK
- Correspondence: (I.N.); (A.F.)
| | - Assaf Friedler
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
- Correspondence: (I.N.); (A.F.)
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7
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Perrin L, Matic Vignjevic D. The emerging roles of the cytoskeleton in intestinal epithelium homeostasis. Semin Cell Dev Biol 2023:S1084-9521(23)00071-X. [PMID: 36948998 DOI: 10.1016/j.semcdb.2023.03.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/06/2023] [Accepted: 03/14/2023] [Indexed: 03/24/2023]
Abstract
The intestinal epithelium must absorb many nutrients and water while forming a barrier that is impermeable to pathogens present in the external environment. Concurrently to fulfill this dual role, the intestinal epithelium is challenged by a rapid renewal of cells and forces resulting from digestion. Hence, intestinal homeostasis requires precise control of tissue integrity, tissue renewal, cell polarity, and force generation/transmission. In this review, we highlight the contribution of the cell cytoskeleton- actin, microtubules, and intermediate filaments- to intestinal epithelium homeostasis. With a focus on enterocytes, we first discuss the role of these networks in the formation and maintenance of cell-cell and cell-matrix junctions. Then, we cover their role in intracellular trafficking related to the apicobasal polarity of enterocytes. Finally, we report on the cytoskeletal changes that occur during tissue renewal. In conclusion, the importance of the cytoskeleton in maintaining intestinal homeostasis is emerging, and we think this field will keep evolving.
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Affiliation(s)
- Louisiane Perrin
- Institut Curie, PSL Research University, CNRS UMR 144, F-75005 Paris, France.
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8
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Rodgers NC, Lawrence EJ, Sawant AV, Efimova N, Gonzalez-Vasquez G, Hickman TT, Kaverina I, Zanic M. CLASP2 facilitates dynamic actin filament organization along the microtubule lattice. Mol Biol Cell 2023; 34:br3. [PMID: 36598814 PMCID: PMC10011731 DOI: 10.1091/mbc.e22-05-0149] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 12/14/2022] [Accepted: 12/21/2022] [Indexed: 01/05/2023] Open
Abstract
Coordination between the microtubule and actin networks is essential for cell motility, neuronal growth cone guidance, and wound healing. Members of the CLASP (cytoplasmic linker-associated protein) family of proteins have been implicated in the cytoskeletal cross-talk between microtubules and actin networks; however, the molecular mechanisms underlying the role of CLASP in cytoskeletal coordination are unclear. Here, we investigate CLASP2Ī±'s cross-linking function with microtubules and F-actin. Our results demonstrate that CLASP2Ī± cross-links F-actin to the microtubule lattice in vitro. We find that the cross-linking ability is retained by L-TOG2-S, a minimal construct containing the TOG2 domain and serine-arginine-rich region of CLASP2Ī±. Furthermore, CLASP2Ī± promotes the accumulation of multiple actin filaments along the microtubule, supporting up to 11 F-actin landing events on a single microtubule lattice region. CLASP2Ī± also facilitates the dynamic organization of polymerizing actin filaments templated by the microtubule network, with F-actin forming bridges between individual microtubules. Finally, we find that depletion of CLASPs in vascular smooth muscle cells results in disorganized actin fibers and reduced coalignment of actin fibers with microtubules, suggesting that CLASP and microtubules contribute to higher-order actin structures. Taken together, our results indicate that CLASP2Ī± can directly cross-link F-actin to microtubules and that this microtubule-CLASP-actin interaction may influence overall cytoskeletal organization in cells.
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Affiliation(s)
- N. C. Rodgers
- Chemical and Physical Biology Graduate Program, Vanderbilt University, Nashville, TN 37232
| | - E. J. Lawrence
- Department of Cell and Development Biology, Vanderbilt University, Nashville, TN 37232
| | - A. V. Sawant
- Department of Cell and Development Biology, Vanderbilt University, Nashville, TN 37232
| | - N. Efimova
- Department of Cell and Development Biology, Vanderbilt University, Nashville, TN 37232
| | - G. Gonzalez-Vasquez
- Interdisciplinary Graduate Program, Vanderbilt University, Nashville, TN 37232
| | - T. T. Hickman
- Quantitative and Chemical Biology Graduate Program, Vanderbilt University, Nashville, TN 37232
| | - I. Kaverina
- Department of Cell and Development Biology, Vanderbilt University, Nashville, TN 37232
| | - M. Zanic
- Department of Cell and Development Biology, Vanderbilt University, Nashville, TN 37232
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37232
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232
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9
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Septins mediate a microtubule-actin crosstalk that enables actin growth on microtubules. Proc Natl Acad Sci U S A 2022; 119:e2202803119. [PMID: 36475946 PMCID: PMC9897426 DOI: 10.1073/pnas.2202803119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cellular morphogenesis and processes such as cell division and migration require the coordination of the microtubule and actin cytoskeletons. Microtubule-actin crosstalk is poorly understood and largely regarded as the capture and regulation of microtubules by actin. Septins are filamentous guanosine-5'-triphosphate (GTP) binding proteins, which comprise the fourth component of the cytoskeleton along microtubules, actin, and intermediate filaments. Here, we report that septins mediate microtubule-actin crosstalk by coupling actin polymerization to microtubule lattices. Superresolution and platinum replica electron microscopy (PREM) show that septins localize to overlapping microtubules and actin filaments in the growth cones of neurons and non-neuronal cells. We demonstrate that recombinant septin complexes directly crosslink microtubules and actin filaments into hybrid bundles. In vitro reconstitution assays reveal that microtubule-bound septins capture and align stable actin filaments with microtubules. Strikingly, septins enable the capture and polymerization of growing actin filaments on microtubule lattices. In neuronal growth cones, septins are required for the maintenance of the peripheral actin network that fans out from microtubules. These findings show that septins directly mediate microtubule interactions with actin filaments, and reveal a mechanism of microtubule-templated actin growth with broader significance for the self-organization of the cytoskeleton and cellular morphogenesis.
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10
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Yang C, Colosi P, Hugelier S, Zabezhinsky D, Lakadamyali M, Svitkina T. Actin polymerization promotes invagination of flat clathrin-coated lattices in mammalian cells by pushing at lattice edges. Nat Commun 2022; 13:6127. [PMID: 36253374 PMCID: PMC9576739 DOI: 10.1038/s41467-022-33852-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/05/2022] [Indexed: 12/24/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) requires energy input from actin polymerization in mechanically challenging conditions. The roles of actin in CME are poorly understood due to inadequate knowledge of actin organization at clathrin-coated structures (CCSs). Using platinum replica electron microscopy of mammalian cells, we show that Arp2/3 complex-dependent branched actin networks, which often emerge from microtubule tips, assemble along the CCS perimeter, lack interaction with the apical clathrin lattice, and have barbed ends oriented toward the CCS. This structure is hardly compatible with the widely held "apical pulling" model describing actin functions in CME. Arp2/3 complex inhibition or epsin knockout produce large flat non-dynamic CCSs, which split into invaginating subdomains upon recovery from Arp2/3 inhibition. Moreover, epsin localization to CCSs depends on Arp2/3 activity. We propose an "edge pushing" model for CME, wherein branched actin polymerization promotes severing and invagination of flat CCSs in an epsin-dependent manner by pushing at the CCS boundary, thus releasing forces opposing the intrinsic curvature of clathrin lattices.
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Affiliation(s)
- Changsong Yang
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
| | - Patricia Colosi
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Siewert Hugelier
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Daniel Zabezhinsky
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
| | - Melike Lakadamyali
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Tatyana Svitkina
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
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11
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Higgs VE, Das RM. Establishing neuronal polarity: microtubule regulation during neurite initiation. OXFORD OPEN NEUROSCIENCE 2022; 1:kvac007. [PMID: 38596701 PMCID: PMC10913830 DOI: 10.1093/oons/kvac007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/25/2022] [Accepted: 05/02/2022] [Indexed: 04/11/2024]
Abstract
The initiation of nascent projections, or neurites, from the neuronal cell body is the first stage in the formation of axons and dendrites, and thus a critical step in the establishment of neuronal architecture and nervous system development. Neurite formation relies on the polarized remodelling of microtubules, which dynamically direct and reinforce cell shape, and provide tracks for cargo transport and force generation. Within neurons, microtubule behaviour and structure are tightly controlled by an array of regulatory factors. Although microtubule regulation in the later stages of axon development is relatively well understood, how microtubules are regulated during neurite initiation is rarely examined. Here, we discuss how factors that direct microtubule growth, remodelling, stability and positioning influence neurite formation. In addition, we consider microtubule organization by the centrosome and modulation by the actin and intermediate filament networks to provide an up-to-date picture of this vital stage in neuronal development.
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Affiliation(s)
- Victoria E Higgs
- Division of Molecular and Cellular Function, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Raman M Das
- Division of Molecular and Cellular Function, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK
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12
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Molecular Dissection of DAAM Function during Axon Growth in Drosophila Embryonic Neurons. Cells 2022; 11:cells11091487. [PMID: 35563792 PMCID: PMC9102401 DOI: 10.3390/cells11091487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/21/2022] [Accepted: 04/25/2022] [Indexed: 02/04/2023] Open
Abstract
Axonal growth is mediated by coordinated changes of the actin and microtubule (MT) cytoskeleton. Ample evidence suggests that members of the formin protein family are involved in the coordination of these cytoskeletal rearrangements, but the molecular mechanisms of the formin-dependent actināmicrotubule crosstalk remains largely elusive. Of the six Drosophila formins, DAAM was shown to play a pivotal role during axonal growth in all stages of nervous system development, while FRL was implicated in axonal development in the adult brain. Here, we aimed to investigate the potentially redundant function of these two formins, and we attempted to clarify which molecular activities are important for axonal growth. We used a combination of genetic analyses, cellular assays and biochemical approaches to demonstrate that the actin-processing activity of DAAM is indispensable for axonal growth in every developmental condition. In addition, we identified a novel MT-binding motif within the FH2 domain of DAAM, which is required for proper growth and guidance of the mushroom body axons, while being dispensable during embryonic axon development. Together, these data suggest that DAAM is the predominant formin during axonal growth in Drosophila, and highlight the contribution of multiple formin-mediated mechanisms in cytoskeleton coordination during axonal growth.
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13
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Fang X, Svitkina TM. Adenomatous polyposis coli (APC) in cell migration. Eur J Cell Biol 2022; 101:151228. [DOI: 10.1016/j.ejcb.2022.151228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/15/2022] [Accepted: 04/20/2022] [Indexed: 12/22/2022] Open
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14
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Cross-linkers at growing microtubule ends generate forces that drive actin transport. Proc Natl Acad Sci U S A 2022; 119:e2112799119. [PMID: 35271394 PMCID: PMC8931237 DOI: 10.1073/pnas.2112799119] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Complex cellular processes such as cell migration require coordinated remodeling of both the actin and the microtubule cytoskeleton. The two networks for instance exert forces on each other via active motor proteins. Here we show that, surprisingly, coupling via passive cross-linkers can also result in force generation. We specifically study the transport of actin filaments by growing microtubule ends. We show by cell-free reconstitution experiments, computer simulations, and theoretical modeling that this transport is driven by the affinity of the cross-linker for the chemically distinct microtubule tip region. Our work predicts that growing microtubules could potentially rapidly relocate newly nucleated actin filaments to the leading edge of the cell and thus boost migration. The actin and microtubule cytoskeletons form active networks in the cell that can contract and remodel, resulting in vital cellular processes such as cell division and motility. Motor proteins play an important role in generating the forces required for these processes, but more recently the concept of passive cross-linkers being able to generate forces has emerged. So far, these passive cross-linkers have been studied in the context of separate actin and microtubule systems. Here, we show that cross-linkers also allow actin and microtubules to exert forces on each other. More specifically, we study single actin filaments that are cross-linked to growing microtubule ends, using in vitro reconstitution, computer simulations, and a minimal theoretical model. We show that microtubules can transport actin filaments over large (micrometer-range) distances and find that this transport results from two antagonistic forces arising from the binding of cross-linkers to the overlap between the actin and microtubule filaments. The cross-linkers attempt to maximize the overlap between the actin and the tip of the growing microtubules, creating an affinity-driven forward condensation force, and simultaneously create a competing friction force along the microtubule lattice. We predict and verify experimentally how the average transport time depends on the actin filament length and the microtubule growth velocity, confirming the competition between a forward condensation force and a backward friction force. In addition, we theoretically predict and experimentally verify that the condensation force is of the order of 0.1 pN. Thus, our results reveal an active mechanism for local actin remodeling by growing microtubules that relies on passive cross-linkers.
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15
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Abstract
The cytoskeleton is a complex of detergent-insoluble components of the cytoplasm playing critical roles in cell motility, shape generation, and mechanical properties of a cell. Fibrillar polymers-actin filaments, microtubules, and intermediate filaments-are major constituents of the cytoskeleton, which constantly change their organization during cellular activities. The actin cytoskeleton is especially polymorphic, as actin filaments can form multiple higher-order assemblies performing different functions. Structural information about cytoskeleton organization is critical for understanding its functions and mechanisms underlying various forms of cellular activity. Because of the nanometer-scale thickness of cytoskeletal fibers, electron microscopy (EM) is a key tool to determine the structure of the cytoskeleton.This article describes application of rotary shadowing (or platinum replica ) EM (PREM) for visualization of the cytoskeleton . The procedure is applicable to thin cultured cells growing on glass coverslips and consists of detergent extraction (or mechanical "unroofing") of cells to expose their cytoskeleton , chemical fixation to provide stability, ethanol dehydration and critical point drying to preserve three-dimensionality, rotary shadowing with platinum to create contrast, and carbon coating to stabilize replicas. This technique provides easily interpretable three-dimensional images, in which individual cytoskeletal fibers are clearly resolved and individual proteins can be identified by immunogold labeling. More importantly, PREM is easily compatible with live cell imaging, so that one can correlate the dynamics of a cell or its components, e.g., expressed fluorescent proteins, with high-resolution structural organization of the cytoskeleton in the same cell.
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Affiliation(s)
- Tatyana Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
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16
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SƔnchez-Huertas C, Herrera E. With the Permission of Microtubules: An Updated Overview on Microtubule Function During Axon Pathfinding. Front Mol Neurosci 2021; 14:759404. [PMID: 34924953 PMCID: PMC8675249 DOI: 10.3389/fnmol.2021.759404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/01/2021] [Indexed: 01/27/2023] Open
Abstract
During the establishment of neural circuitry axons often need to cover long distances to reach remote targets. The stereotyped navigation of these axons defines the connectivity between brain regions and cellular subtypes. This chemotrophic guidance process mostly relies on the spatio-temporal expression patterns of extracellular proteins and the selective expression of their receptors in projection neurons. Axon guidance is stimulated by guidance proteins and implemented by neuronal traction forces at the growth cones, which engage local cytoskeleton regulators and cell adhesion proteins. Different layers of guidance signaling regulation, such as the cleavage and processing of receptors, the expression of co-receptors and a wide variety of intracellular cascades downstream of receptors activation, have been progressively unveiled. Also, in the last decades, the regulation of microtubule (MT) assembly, stability and interactions with the submembranous actin network in the growth cone have emerged as crucial effector mechanisms in axon pathfinding. In this review, we will delve into the intracellular signaling cascades downstream of guidance receptors that converge on the MT cytoskeleton of the growing axon. In particular, we will focus on the microtubule-associated proteins (MAPs) network responsible of MT dynamics in the axon and growth cone. Complementarily, we will discuss new evidences that connect defects in MT scaffold proteins, MAPs or MT-based motors and axon misrouting during brain development.
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Affiliation(s)
- Carlos SƔnchez-Huertas
- Instituto de Neurociencias, Consejo Superior de Investigaciones CientĆficas-Universidad Miguel HernĆ”ndez (CSIC-UMH), Alicante, Spain
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17
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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: 50] [Impact Index Per Article: 16.7] [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-Ī² in Alzheimerās 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.)
| | - OāNeil 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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18
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Abstract
Actin filaments and microtubules are cytoskeletal polymers that participate in many vital cell functions including division, morphogenesis, phagocytosis, and motility. Despite the persistent dogma that actin filament and microtubule networks are distinct in localization, structure, and function, a growing body of evidence shows that these elements are choreographed through intricate mechanisms sensitive to either polymer. Many proteins and cellular signals that mediate actināmicrotubule interactions have already been identified. However, the impact of these regulators is typically assessed with actin filament or microtubule polymers alone, independent of the other system. Further, unconventional modes and regulators coordinating actināmicrotubule interactions are still being discovered.Ā Here we examine several methods of actināmicrotubule crosstalk with an emphasis on the molecular links between both polymer systems and their higher-order interactions.
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Affiliation(s)
- Morgan L Pimm
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210
| | - Jessica L Henty-Ridilla
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210.,Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210
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19
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Pinto-Costa R, Sousa MM. Microtubules, actin and cytolinkers: how to connect cytoskeletons in the neuronal growth cone. Neurosci Lett 2021; 747:135693. [PMID: 33529653 DOI: 10.1016/j.neulet.2021.135693] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/12/2021] [Accepted: 01/16/2021] [Indexed: 01/20/2023]
Abstract
Cytolinkers ensure the integration of the different cytoskeleton components in the neuronal growth cone during development and in the course of axon regeneration. In neurons, an integrated skeleton guarantees appropriate function, and connectivity of high order circuits. Over the past years, several cytoskeleton regulatory proteins with actin-microtubule crosslinking activity have been identified. In neurons, the importance of spectrins, formins and other cytolinkers capable of coupling actin and microtubules has been extensively highlighted during axon outgrowth and guidance. In this Review, we discuss the current knowledge on cytolinkers specifically expressed in the neuronal growth cone of developing and regenerating axons.
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Affiliation(s)
- Rita Pinto-Costa
- Nerve Regeneration Group, i3S-Instituto de InvestigaĆ§Ć£o e InovaĆ§Ć£o em SaĆŗde and IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135, Porto, Portugal
| | - Monica Mendes Sousa
- Nerve Regeneration Group, i3S-Instituto de InvestigaĆ§Ć£o e InovaĆ§Ć£o em SaĆŗde and IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135, Porto, Portugal.
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20
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Juanes MA. Cytoskeletal Control and Wnt Signaling-APC's Dual Contributions in Stem Cell Division and Colorectal Cancer. Cancers (Basel) 2020; 12:E3811. [PMID: 33348689 PMCID: PMC7766042 DOI: 10.3390/cancers12123811] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/12/2020] [Accepted: 12/15/2020] [Indexed: 12/12/2022] Open
Abstract
Intestinal epithelium architecture is sustained by stem cell division. In principle, stem cells can divide symmetrically to generate two identical copies of themselves or asymmetrically to sustain tissue renewal in a balanced manner. The choice between the two helps preserve stem cell and progeny pools and is crucial for tissue homeostasis. Control of spindle orientation is a prime contributor to the specification of symmetric versus asymmetric cell division. Competition for space within the niche may be another factor limiting the stem cell pool. An integrative view of the multiple links between intracellular and extracellular signals and molecular determinants at play remains a challenge. One outstanding question is the precise molecular roles of the tumour suppressor Adenomatous polyposis coli (APC) for sustaining gut homeostasis through its respective functions as a cytoskeletal hub and a down regulator in Wnt signalling. Here, we review our current understanding of APC inherent activities and partners in order to explore novel avenues by which APC may act as a gatekeeper in colorectal cancer and as a therapeutic target.
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Affiliation(s)
- M. Angeles Juanes
- School of Health and Life Science, Teesside University, Middlesbrough TS1 3BX, UK;
- National Horizons Centre, Teesside University, 38 John Dixon Lane, Darlington DL1 1HG, UK
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21
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Stefanski CD, Prosperi JR. Wnt-Independent and Wnt-Dependent Effects of APC Loss on the Chemotherapeutic Response. Int J Mol Sci 2020; 21:E7844. [PMID: 33105836 PMCID: PMC7660076 DOI: 10.3390/ijms21217844] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 12/12/2022] Open
Abstract
Resistance to chemotherapy occurs through mechanisms within the epithelial tumor cells or through interactions with components of the tumor microenvironment (TME). Chemoresistance and the development of recurrent tumors are two of the leading factors of cancer-related deaths. The Adenomatous Polyposis Coli (APC) tumor suppressor is lost in many different cancers, including colorectal, breast, and prostate cancer, and its loss correlates with a decreased overall survival in cancer patients. While APC is commonly known for its role as a negative regulator of the WNT pathway, APC has numerous binding partners and functional roles. Through APC's interactions with DNA repair proteins, DNA replication proteins, tubulin, and other components, recent evidence has shown that APC regulates the chemotherapy response in cancer cells. In this review article, we provide an overview of some of the cellular processes in which APC participates and how they impact chemoresistance through both epithelial- and TME-derived mechanisms.
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Affiliation(s)
- Casey D. Stefanski
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46617, USA;
- Mike and Josie Harper Cancer Research Institute, South Bend, IN 46617, USA
| | - Jenifer R. Prosperi
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46617, USA;
- Mike and Josie Harper Cancer Research Institute, South Bend, IN 46617, USA
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine-South Bend, South Bend, IN 46617, USA
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