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Chang H, Huang C, Cheng S, Li J, Wang X. Fbxo28 is essential for spindle migration and morphology during mouse oocyte meiosis I. Int J Biol Macromol 2024; 275:133232. [PMID: 38960234 DOI: 10.1016/j.ijbiomac.2024.133232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/28/2024] [Accepted: 06/15/2024] [Indexed: 07/05/2024]
Abstract
Spindle migration and assembly regulates asymmetric oocyte division, which is essential for fertility. Fbxo28, as a member of SCF (Skp1-Cul1-F-box) ubiquitin E3 ligases complex, is specifically expressed in oocytes. However, little is known about the functions of Fbxo28 in spindle assembly and migration during oocyte meiosis I. In present study, microinjection with morpholino oligonucleotides and exogenous mRNA for knockdown and rescue experiments, and immunofluorescence staining, western blot, timelapse confocal microscopy and chromosome spreading were utilized to explore the roles of Fbxo28 in asymmetric division during meiotic maturation. Our data suggested that Fbxo28 mainly localized at chromosomes and acentriolar microtubule-organizing centers (aMTOCs). Depletion of Fbxo28 did not affect polar body extrusion but caused defects in spindle morphology and migration, indicative of the failure of asymmetric division. Moreover, absence of Fbxo28 disrupted both cortical and cytoplasmic actin assembly and decreased the expression of ARPC2 and ARP3. These defects could be rescued by exogenous Fbxo28-myc mRNA supplement. Collectively, this study demonstrated that Fbxo28 affects spindle morphology and actin-based spindle migration during mouse oocyte meiotic maturation.
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Affiliation(s)
- Haoya Chang
- Department of Obstetrics and Gynecology, Tangdu Hospital, Air Force Medical University, Xi'an 710038, China; Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Chenyang Huang
- Department of Human Cell Biology and Genetics, School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Siyu Cheng
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Jian Li
- Department of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, China.
| | - Xiaohong Wang
- Department of Obstetrics and Gynecology, Tangdu Hospital, Air Force Medical University, Xi'an 710038, China.
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2
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Gallo G. The Axonal Actin Filament Cytoskeleton: Structure, Function, and Relevance to Injury and Degeneration. Mol Neurobiol 2024; 61:5646-5664. [PMID: 38216856 DOI: 10.1007/s12035-023-03879-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 12/13/2023] [Indexed: 01/14/2024]
Abstract
Early investigations of the neuronal actin filament cytoskeleton gave rise to the notion that, although growth cones exhibit high levels of actin filaments, the axon shaft exhibits low levels of actin filaments. With the development of new tools and imaging techniques, the axonal actin filament cytoskeleton has undergone a renaissance and is now an active field of research. This article reviews the current state of knowledge about the actin cytoskeleton of the axon shaft. The best understood forms of actin filament organization along axons are axonal actin patches and a submembranous system of rings that endow the axon with protrusive competency and structural integrity, respectively. Additional forms of actin filament organization along the axon have also been described and their roles are being elucidated. Extracellular signals regulate the axonal actin filament cytoskeleton and our understanding of the signaling mechanisms involved is being elaborated. Finally, recent years have seen advances in our perspective on how the axonal actin cytoskeleton is impacted by, and contributes to, axon injury and degeneration. The work to date has opened new venues and future research will undoubtedly continue to provide a richer understanding of the axonal actin filament cytoskeleton.
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Affiliation(s)
- Gianluca Gallo
- Department of Neural Sciences, Shriners Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 North Broad St, Philadelphia, PA, 19140, USA.
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3
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Kitel R, Surmiak E, Borggräfe J, Kalinowska-Tluscik J, Golik P, Czub M, Uzar W, Musielak B, Madej M, Popowicz GM, Dubin G, Holak TA. Discovery of Inhibitory Fragments That Selectively Target Spire2-FMN2 Interaction. J Med Chem 2023; 66:15715-15727. [PMID: 38039505 PMCID: PMC10726347 DOI: 10.1021/acs.jmedchem.3c00877] [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: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 12/03/2023]
Abstract
Here, we report the fragment-based drug discovery of potent and selective fragments that disrupt the Spire2-FMN2 but not the Spire1-FMN2 interaction. Hit fragments were identified in a differential scanning fluorimetry-based screen of an in-house library of 755 compounds and subsequently validated in multiple orthogonal biophysical assays, including fluorescence polarization, microscale thermophoresis, and 1H-15N HSQC nuclear magnetic resonance. Extensive structure-activity relationships combined with molecular docking followed by chemical optimization led to the discovery of compound 13, which exhibits micromolar potency and high ligand efficiency (LE = 0.38). Therefore, this fragment represents a validated starting point for the future development of selective chemical probes targeting the Spire2-FMN2 interaction.
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Affiliation(s)
- Radoslaw Kitel
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kracow, Poland
| | - Ewa Surmiak
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kracow, Poland
| | - Jan Borggräfe
- Institute
of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz Zentrum München, Neuherberg, 85764 München, Germany
- Bavarian
NMR Center, School of Natural Sciences, Technical University of Munich Garching, 85748 München, Germany
| | | | - Przemyslaw Golik
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kracow, Poland
| | - Miroslawa Czub
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kracow, Poland
| | - Wiktor Uzar
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kracow, Poland
- Doctoral
School of Exact and Natural Sciences, Jagiellonian
University, Prof. S.
Lojasiewicza 11, 30-348 Krakow, Poland
| | - Bogdan Musielak
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kracow, Poland
| | - Mariusz Madej
- Faculty
of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Cracow, Poland
| | - Grzegorz M. Popowicz
- Institute
of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz Zentrum München, Neuherberg, 85764 München, Germany
- Bavarian
NMR Center, School of Natural Sciences, Technical University of Munich Garching, 85748 München, Germany
| | - Grzegorz Dubin
- Malopolska
Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Krakow, Poland
| | - Tad A. Holak
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kracow, Poland
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Antagonistic Activities of Fmn2 and ADF Regulate Axonal F-Actin Patch Dynamics and the Initiation of Collateral Branching. J Neurosci 2022; 42:7355-7369. [PMID: 36481742 PMCID: PMC9525169 DOI: 10.1523/jneurosci.3107-20.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 08/17/2022] [Accepted: 08/22/2022] [Indexed: 12/15/2022] Open
Abstract
Interstitial collateral branching of axons is a critical component in the development of functional neural circuits. Axon collateral branches are established through a series of cellular processes initiated by the development of a specialized, focal F-actin network in axons. The formation, maintenance and remodeling of this F-actin patch is critical for the initiation of axonal protrusions that are subsequently consolidated to form a collateral branch. However, the mechanisms regulating F-actin patch dynamics are poorly understood. Fmn2 is a formin family member implicated in multiple neurodevelopmental disorders. We find that Fmn2 regulates the initiation of axon collateral protrusions in chick spinal neurons and in zebrafish motor neurons. Fmn2 localizes to the protrusion-initiating axonal F-actin patches and regulates the lifetime and size of these F-actin networks. The F-actin nucleation activity of Fmn2 is necessary for F-actin patch stability but not for initiating patch formation. We show that Fmn2 insulates the F-actin patches from disassembly by the actin-depolymerizing factor, ADF, and promotes long-lived, larger patches that are competent to initiate axonal protrusions. The regulation of axonal branching can contribute to the neurodevelopmental pathologies associated with Fmn2 and the dynamic antagonism between Fmn2 and ADF may represent a general mechanism of formin-dependent protection of Arp2/3-initiated F-actin networks from disassembly.SIGNIFICANCE STATEMENT Axonal branching is a key process in the development of functional circuits and neural plasticity. Axon collateral branching is initiated by the elaboration of F-actin filaments from discrete axonal F-actin networks. We show that the neurodevelopmental disorder-associated formin, Fmn2, is a critical regulator of axon collateral branching. Fmn2 localizes to the collateral branch-inducing F-actin patches in axons and regulates the stability of these actin networks. The F-actin nucleation activity of Fmn2 protects the patches from ADF-mediated disassembly. Opposing activities of Fmn2 and ADF exert a dynamic regulatory control on axon collateral branch initiation and may underly the neurodevelopmental defects associated with Fmn2.
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Actin Cross-Linking Toxin Is a Universal Inhibitor of Tandem-Organized and Oligomeric G-Actin Binding Proteins. Curr Biol 2018; 28:1536-1547.e9. [PMID: 29731300 DOI: 10.1016/j.cub.2018.03.065] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/06/2018] [Accepted: 03/28/2018] [Indexed: 11/20/2022]
Abstract
Delivery of bacterial toxins to host cells is hindered by host protective barriers. This obstruction dictates a remarkable efficiency of toxins, a single copy of which may kill a host cell. Efficiency of actin-targeting toxins is further hampered by an overwhelming abundance of their target. The actin cross-linking domain (ACD) toxins of Vibrio species and related bacterial genera catalyze the formation of covalently cross-linked actin oligomers. Recently, we reported that the ACD toxicity can be amplified via a multivalent inhibitory association of actin oligomers with actin assembly factors formins, suggesting that the oligomers may act as secondary toxins. Importantly, many proteins involved in nucleation, elongation, severing, branching, and bundling of actin filaments contain G-actin-binding Wiskott-Aldrich syndrome protein (WASP)-homology motifs 2 (WH2) organized in tandem and therefore may act as a multivalent platform for high-affinity interaction with the ACD-cross-linked actin oligomers. Using live-cell single-molecule speckle (SiMS) microscopy, total internal reflection fluorescence (TIRF) microscopy, and actin polymerization assays, we show that, in addition to formins, the oligomers bind with high affinity and potently inhibit several families of actin assembly factors: Ena/vasodilator-stimulated phosphorprotein (VASP); Spire; and the Arp2/3 complex, both in vitro and in live cells. As a result, ACD blocks the actin retrograde flow and membrane dynamics and disrupts association of Ena/VASP with adhesion complexes. This study defines ACD as a universal inhibitor of tandem-organized G-actin binding proteins that overcomes the abundance of actin by redirecting the toxicity cascade toward less abundant targets and thus leading to profound disorganization of the actin cytoskeleton and disruption of actin-dependent cellular functions.
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Agís-Balboa RC, Pinheiro PS, Rebola N, Kerimoglu C, Benito E, Gertig M, Bahari-Javan S, Jain G, Burkhardt S, Delalle I, Jatzko A, Dettenhofer M, Zunszain PA, Schmitt A, Falkai P, Pape JC, Binder EB, Mulle C, Fischer A, Sananbenesi F. Formin 2 links neuropsychiatric phenotypes at young age to an increased risk for dementia. EMBO J 2017; 36:2815-2828. [PMID: 28768717 PMCID: PMC5623844 DOI: 10.15252/embj.201796821] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 06/23/2017] [Accepted: 06/27/2017] [Indexed: 12/12/2022] Open
Abstract
Age-associated memory decline is due to variable combinations of genetic and environmental risk factors. How these risk factors interact to drive disease onset is currently unknown. Here we begin to elucidate the mechanisms by which post-traumatic stress disorder (PTSD) at a young age contributes to an increased risk to develop dementia at old age. We show that the actin nucleator Formin 2 (Fmn2) is deregulated in PTSD and in Alzheimer's disease (AD) patients. Young mice lacking the Fmn2 gene exhibit PTSD-like phenotypes and corresponding impairments of synaptic plasticity, while the consolidation of new memories is unaffected. However, Fmn2 mutant mice develop accelerated age-associated memory decline that is further increased in the presence of additional risk factors and is mechanistically linked to a loss of transcriptional homeostasis. In conclusion, our data present a new approach to explore the connection between AD risk factors across life span and provide mechanistic insight to the processes by which neuropsychiatric diseases at a young age affect the risk for developing dementia.
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Affiliation(s)
- Roberto Carlos Agís-Balboa
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Paulo S Pinheiro
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
- CNRS UMR 5297, Bordeaux, France
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Nelson Rebola
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
- CNRS UMR 5297, Bordeaux, France
| | - Cemil Kerimoglu
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Eva Benito
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Michael Gertig
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Sanaz Bahari-Javan
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Gaurav Jain
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Susanne Burkhardt
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Ivana Delalle
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Alexander Jatzko
- Department of Psychosomatics, Westpfalzklinikum-Kaiserslautern, Teaching Hospital, University of Mainz, Mainz, Germany
| | - Markus Dettenhofer
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Patricia A Zunszain
- Stress, Psychiatry and Immunology Laboratory, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Andrea Schmitt
- Department of Psychiatry and Psychotherapy, LMU Munich, Munich, Germany
- Laboratory of Neuroscience (LIM27), Institute of Psychiatry, University of Sao Paulo, São Paulo, Brazil
| | - Peter Falkai
- Department of Psychiatry and Psychotherapy, LMU Munich, Munich, Germany
| | - Julius C Pape
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
| | - Elisabeth B Binder
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
| | - Christophe Mulle
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
- CNRS UMR 5297, Bordeaux, France
| | - Andre Fischer
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Farahnaz Sananbenesi
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
- Research Group for Genome Dynamics in Brain Diseases, Göttingen, Germany
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7
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New nuclear and perinuclear functions of formins. Biochem Soc Trans 2017; 44:1701-1708. [PMID: 27913680 DOI: 10.1042/bst20160187] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/29/2016] [Accepted: 09/02/2016] [Indexed: 12/12/2022]
Abstract
Formin family proteins (formins) represent an evolutionary conserved protein family encoded in the genome of a wide range of eukaryotes. Formins are hallmarked by a formin homology 1 (FH1) domain juxtaposed to an FH2 domain whereby they control actin and microtubule dynamics. Not surprisingly, formins are best known as key regulators of the cytoskeleton in a variety of morphogenetic processes. However, mounting evidence implicates several formins in the assembly and organization of actin within and around the nucleus. In addition, actin-independent roles for formins have recently been discovered. In this mini-review, we summarize these findings and highlight the novel nuclear and perinulcear functions of formins. In light of the emerging new biology of formins, we also discuss the fundamental principles governing the versatile activity and multimodal regulation of these proteins.
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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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9
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Shekhar S, Pernier J, Carlier MF. Regulators of actin filament barbed ends at a glance. J Cell Sci 2016; 129:1085-91. [PMID: 26940918 DOI: 10.1242/jcs.179994] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Cells respond to external stimuli by rapidly remodeling their actin cytoskeleton. At the heart of this function lies the intricately controlled regulation of individual filaments. The barbed end of an actin filament is the hotspot for the majority of the biochemical reactions that control filament assembly. Assays performed in bulk solution and with single filaments have enabled characterization of a plethora of barbed-end-regulating proteins. Interestingly, many of these regulators work in tandem with other proteins, which increase or decrease their affinity for the barbed end in a spatially and temporally controlled manner, often through simultaneous binding of two regulators at the barbed ends, in addition to standard mutually exclusive binding schemes. In this Cell Science at a Glance and the accompanying poster, we discuss key barbed-end-interacting proteins and the kinetic mechanisms by which they regulate actin filament assembly. We take F-actin capping protein, gelsolin, profilin and barbed-end-tracking polymerases, including formins and WH2-domain-containing proteins, as examples, and illustrate how their activity and competition for the barbed end regulate filament dynamics.
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Affiliation(s)
- Shashank Shekhar
- Cytoskeleton Dynamics and Cell Motility, I2BC, CNRS, Gif-sur-Yvette 91198, France
| | - Julien Pernier
- Cytoskeleton Dynamics and Cell Motility, I2BC, CNRS, Gif-sur-Yvette 91198, France
| | - Marie-France Carlier
- Cytoskeleton Dynamics and Cell Motility, I2BC, CNRS, Gif-sur-Yvette 91198, France
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