1
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Robinson BP, Bass NR, Bhakt P, Spiliotis ET. Septin-coated microtubules promote maturation of multivesicular bodies by inhibiting their motility. J Cell Biol 2024; 223:e202308049. [PMID: 38668767 PMCID: PMC11046855 DOI: 10.1083/jcb.202308049] [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: 08/09/2023] [Revised: 02/06/2024] [Accepted: 04/10/2024] [Indexed: 04/29/2024] Open
Abstract
The microtubule cytoskeleton consists of microtubule subsets with distinct compositions of microtubule-associated proteins, which instruct the position and traffic of subcellular organelles. In the endocytic pathway, these microtubule-associated cues are poorly understood. Here, we report that in MDCK cells, endosomes with multivesicular body (MVB) and late endosome (LE) markers localize preferentially to microtubules coated with septin GTPases. Compared with early endosomes, CD63-containing MVBs/LEs are largely immotile on septin-coated microtubules. In vitro reconstitution assays revealed that the motility of isolated GFP-CD63 endosomes is directly inhibited by microtubule-associated septins. Quantification of CD63-positive endosomes containing the early endosome antigen (EEA1), the Rab7 effector and dynein adaptor RILP or Rab27a, showed that intermediary EEA1- and RILP-positive GFP-CD63 preferentially associate with septin-coated microtubules. Septin knockdown enhanced GFP-CD63 motility and decreased the percentage of CD63-positive MVBs/LEs with lysobiphosphatidic acid without impacting the fraction of EEA1-positive CD63. These results suggest that MVB maturation involves immobilization on septin-coated microtubules, which may facilitate multivesiculation and/or organelle-organelle contacts.
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Affiliation(s)
| | - Naomi R. Bass
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Priyanka Bhakt
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Elias T. Spiliotis
- Department of Biology, Drexel University, Philadelphia, PA, USA
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
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2
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Prislusky MI, Lam JGT, Contreras VR, Ng M, Chamberlain M, Pathak-Sharma S, Fields M, Zhang X, Amer AO, Seveau S. The septin cytoskeleton is required for plasma membrane repair. EMBO Rep 2024:10.1038/s44319-024-00195-6. [PMID: 38969946 DOI: 10.1038/s44319-024-00195-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/30/2024] [Accepted: 06/07/2024] [Indexed: 07/07/2024] Open
Abstract
Plasma membrane repair is a fundamental homeostatic process of eukaryotic cells. Here, we report a new function for the conserved cytoskeletal proteins known as septins in the repair of cells perforated by pore-forming toxins or mechanical disruption. Using a silencing RNA screen, we identified known repair factors (e.g. annexin A2, ANXA2) and novel factors such as septin 7 (SEPT7) that is essential for septin assembly. Upon plasma membrane injury, the septin cytoskeleton is extensively redistributed to form submembranous domains arranged as knob and loop structures containing F-actin, myosin IIA, S100A11, and ANXA2. Formation of these domains is Ca2+-dependent and correlates with plasma membrane repair efficiency. Super-resolution microscopy revealed that septins and F-actin form intertwined filaments associated with ANXA2. Depletion of SEPT7 prevented ANXA2 recruitment and formation of submembranous actomyosin domains. However, ANXA2 depletion had no effect on domain formation. Collectively, our data support a novel septin-based mechanism for resealing damaged cells, in which the septin cytoskeleton plays a key structural role in remodeling the plasma membrane by promoting the formation of SEPT/F-actin/myosin IIA/ANXA2/S100A11 repair domains.
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Affiliation(s)
- M Isabella Prislusky
- Department of Microbial Infection & Immunity, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Jonathan G T Lam
- Department of Microbial Infection & Immunity, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Viviana Ruiz Contreras
- Department of Microbial Infection & Immunity, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
- Grupo Investigaciones Biomédicas, Universidad de Sucre, Sincelejo, Sucre, Colombia
| | - Marilynn Ng
- Department of Microbial Infection & Immunity, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Madeline Chamberlain
- Department of Microbial Infection & Immunity, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Sarika Pathak-Sharma
- Department of Microbial Infection & Immunity, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Madalyn Fields
- Department of Microbial Infection & Immunity, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Xiaoli Zhang
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
| | - Amal O Amer
- Department of Microbial Infection & Immunity, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Stephanie Seveau
- Department of Microbial Infection & Immunity, Wexner Medical Center, The Ohio State University, Columbus, OH, USA.
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3
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Mendonça DC, Morais STB, Ciol H, Pinto APA, Leonardo DA, Pereira HD, Valadares NF, Portugal RV, Klaholz BP, Garratt RC, Araujo APU. Structural Insights into Ciona intestinalis Septins: Complexes Suggest a Mechanism for Nucleotide-dependent Interfacial Cross-talk. J Mol Biol 2024; 436:168693. [PMID: 38960133 DOI: 10.1016/j.jmb.2024.168693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Revised: 06/19/2024] [Accepted: 06/27/2024] [Indexed: 07/05/2024]
Abstract
Septins are filamentous nucleotide-binding proteins which can associate with membranes in a curvature-dependent manner leading to structural remodelling and barrier formation. Ciona intestinalis, a model for exploring the development and evolution of the chordate lineage, has only four septin-coding genes within its genome. These represent orthologues of the four classical mammalian subgroups, making it a minimalist non-redundant model for studying the modular assembly of septins into linear oligomers and thereby filamentous polymers. Here, we show that C. intestinalis septins present a similar biochemistry to their human orthologues and also provide the cryo-EM structures of an octamer, a hexamer and a tetrameric sub-complex. The octamer, which has the canonical arrangement (2-6-7-9-9-7-6-2) clearly shows an exposed NC-interface at its termini enabling copolymerization with hexamers into mixed filaments. Indeed, only combinations of septins which had CiSEPT2 occupying the terminal position were able to assemble into filaments via NC-interface association. The CiSEPT7-CiSEPT9 tetramer is the smallest septin particle to be solved by Cryo-EM to date and its good resolution (2.7 Å) provides a well-defined view of the central NC-interface. On the other hand, the CiSEPT7-CiSEPT9 G-interface shows signs of fragility permitting toggling between hexamers and octamers, similar to that seen in human septins but not in yeast. The new structures provide insights concerning the molecular mechanism for cross-talk between adjacent interfaces. This indicates that C. intestinalis may represent a valuable tool for future studies, fulfilling the requirements of a complete but simpler system to understand the mechanisms behind the assembly and dynamics of septin filaments.
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Affiliation(s)
| | | | - Heloísa Ciol
- São Carlos Institute of Physics, USP, São Carlos, SP, Brazil
| | | | | | | | | | - Rodrigo V Portugal
- Brazilian Nanotechnology National Laboratory, CNPEM, Campinas, SP, Brazil; Biotechnosciency Program, Federal University of ABC, Santo André, SP, Brazil
| | - Bruno P Klaholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 67404 Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U964, 67404 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France
| | | | - Ana P U Araujo
- São Carlos Institute of Physics, USP, São Carlos, SP, Brazil.
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4
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Prever L, Squillero G, Hirsch E, Gulluni F. Linking phosphoinositide function to mitosis. Cell Rep 2024; 43:114273. [PMID: 38843397 DOI: 10.1016/j.celrep.2024.114273] [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: 03/18/2024] [Revised: 04/12/2024] [Accepted: 05/09/2024] [Indexed: 07/02/2024] Open
Abstract
Phosphoinositides (PtdIns) are a family of differentially phosphorylated lipid second messengers localized to the cytoplasmic leaflet of both plasma and intracellular membranes. Kinases and phosphatases can selectively modify the PtdIns composition of different cellular compartments, leading to the recruitment of specific binding proteins, which control cellular homeostasis and proliferation. Thus, while PtdIns affect cell growth and survival during interphase, they are also emerging as key drivers in multiple temporally defined membrane remodeling events of mitosis, like cell rounding, spindle orientation, cytokinesis, and abscission. In this review, we summarize and discuss what is known about PtdIns function during mitosis and how alterations in the production and removal of PtdIns can interfere with proper cell division.
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Affiliation(s)
- Lorenzo Prever
- University of Turin, Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center "Guido Tarone", Via Nizza 52, 10126 Turin, Italy
| | - Gabriele Squillero
- University of Turin, Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center "Guido Tarone", Via Nizza 52, 10126 Turin, Italy
| | - Emilio Hirsch
- University of Turin, Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center "Guido Tarone", Via Nizza 52, 10126 Turin, Italy.
| | - Federico Gulluni
- University of Turin, Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center "Guido Tarone", Via Nizza 52, 10126 Turin, Italy.
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5
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Stjepić V, Nakamura M, Hui J, Parkhurst SM. Two Septin complexes mediate actin dynamics during cell wound repair. Cell Rep 2024; 43:114215. [PMID: 38728140 PMCID: PMC11203717 DOI: 10.1016/j.celrep.2024.114215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 03/18/2024] [Accepted: 04/24/2024] [Indexed: 05/12/2024] Open
Abstract
Cells have robust wound repair systems to prevent further damage or infection and to quickly restore cell cortex integrity when exposed to mechanical and chemical stress. Actomyosin ring formation and contraction at the wound edge are major events during closure of the plasma membrane and underlying cytoskeleton during cell wound repair. Here, we show that all five Drosophila Septins are required for efficient cell wound repair. Based on their different recruitment patterns and knockdown/mutant phenotypes, two distinct Septin complexes, Sep1/Sep2/Pnut and Sep4/Sep5/Pnut, are assembled to regulate actin ring assembly, contraction, and remodeling during the repair process. Intriguingly, we find that these two Septin complexes have different F-actin bending activities. In addition, we find that Anillin regulates the recruitment of only one of two Septin complexes upon wounding. Our results demonstrate that two functionally distinct Septin complexes work side by side to discretely regulate actomyosin ring dynamics during cell wound repair.
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Affiliation(s)
- Viktor Stjepić
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Mitsutoshi Nakamura
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Justin Hui
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Susan M Parkhurst
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA.
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6
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Brock K, Alpha KM, Brennan G, De Jong EP, Luke E, Turner CE. A comparative analysis of paxillin and Hic-5 proximity interactomes. Cytoskeleton (Hoboken) 2024. [PMID: 38801098 DOI: 10.1002/cm.21878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 04/18/2024] [Accepted: 05/06/2024] [Indexed: 05/29/2024]
Abstract
Focal adhesions serve as structural and signaling hubs, facilitating bidirectional communication at the cell-extracellular matrix interface. Paxillin and the related Hic-5 (TGFβ1i1) are adaptor/scaffold proteins that recruit numerous structural and regulatory proteins to focal adhesions, where they perform both overlapping and discrete functions. In this study, paxillin and Hic-5 were expressed in U2OS osteosarcoma cells as biotin ligase (BioID2) fusion proteins and used as bait proteins for proximity-dependent biotinylation in order to directly compare their respective interactomes. The fusion proteins localized to both focal adhesions and the centrosome, resulting in biotinylation of components of each of these structures. Biotinylated proteins were purified and analyzed by mass spectrometry. The list of proximity interactors for paxillin and Hic-5 comprised numerous shared core focal adhesion proteins that likely contribute to their similar functions in cell adhesion and migration, as well as proteins unique to paxillin and Hic-5 that have been previously localized to focal adhesions, the centrosome, or the nucleus. Western blotting confirmed biotinylation and enrichment of FAK and vinculin, known interactors of Hic-5 and paxillin, as well as several potentially unique proximity interactors of Hic-5 and paxillin, including septin 7 and ponsin, respectively. Further investigation into the functional relationship between the unique interactors and Hic-5 or paxillin may yield novel insights into their distinct roles in cell migration.
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Affiliation(s)
- Katia Brock
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Kyle M Alpha
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Grant Brennan
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Ebbing P De Jong
- Proteomics Core Facility, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Elizabeth Luke
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Christopher E Turner
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
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7
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Xian W, Fu J, Zhang Q, Li C, Zhao YB, Tang Z, Yuan Y, Wang Y, Zhou Y, Brzoic PS, Zheng N, Ouyang S, Luo ZQ, Liu X. The Shigella kinase effector OspG modulates host ubiquitin signaling to escape septin-cage entrapment. Nat Commun 2024; 15:3890. [PMID: 38719850 PMCID: PMC11078946 DOI: 10.1038/s41467-024-48205-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 04/19/2024] [Indexed: 05/12/2024] Open
Abstract
Shigella flexneri is a Gram-negative bacterium causing severe bloody dysentery. Its pathogenesis is largely dictated by a plasmid-encoded type III secretion system (T3SS) and its associated effectors. Among these, the effector OspG has been shown to bind to the ubiquitin conjugation machinery (E2~Ub) to activate its kinase activity. However, the cellular targets of OspG remain elusive despite years of extensive efforts. Here we show by unbiased phosphoproteomics that a major target of OspG is CAND1, a regulatory protein controlling the assembly of cullin-RING ubiquitin ligases (CRLs). CAND1 phosphorylation weakens its interaction with cullins, which is expected to impact a large panel of CRL E3s. Indeed, global ubiquitome profiling reveals marked changes in the ubiquitination landscape when OspG is introduced. Notably, OspG promotes ubiquitination of a class of cytoskeletal proteins called septins, thereby inhibiting formation of cage-like structures encircling cytosolic bacteria. Overall, we demonstrate that pathogens have evolved an elaborate strategy to modulate host ubiquitin signaling to evade septin-cage entrapment.
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Affiliation(s)
- Wei Xian
- Department of Microbiology and Infectious Disease Center, NHC Key Laboratory of Medical Immunology, School of Basic Medical Sciences, Peking University Health Science Center, 100191, Beijing, China
| | - Jiaqi Fu
- Department of Respiratory Medicine, Center for Infectious Diseases and Pathogen Biology, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, The First Hospital of Jilin University, 130021, Changchun, China
| | - Qinxin Zhang
- Department of Microbiology and Infectious Disease Center, NHC Key Laboratory of Medical Immunology, School of Basic Medical Sciences, Peking University Health Science Center, 100191, Beijing, China
| | - Chuang Li
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Yan-Bo Zhao
- Key Laboratory of Microbial Pathogenesis and Interventions of Fujian Province University, the Key Laboratory of Innate Immune Biology of Fujian Province, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Zhiheng Tang
- Department of Microbiology and Infectious Disease Center, NHC Key Laboratory of Medical Immunology, School of Basic Medical Sciences, Peking University Health Science Center, 100191, Beijing, China
| | - Yi Yuan
- Department of Microbiology and Infectious Disease Center, NHC Key Laboratory of Medical Immunology, School of Basic Medical Sciences, Peking University Health Science Center, 100191, Beijing, China
| | - Ying Wang
- Department of Microbiology and Infectious Disease Center, NHC Key Laboratory of Medical Immunology, School of Basic Medical Sciences, Peking University Health Science Center, 100191, Beijing, China
| | - Yan Zhou
- Institute of Microbiology, College of Life Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Peter S Brzoic
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - Songying Ouyang
- Key Laboratory of Microbial Pathogenesis and Interventions of Fujian Province University, the Key Laboratory of Innate Immune Biology of Fujian Province, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Zhao-Qing Luo
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA.
| | - Xiaoyun Liu
- Department of Microbiology and Infectious Disease Center, NHC Key Laboratory of Medical Immunology, School of Basic Medical Sciences, Peking University Health Science Center, 100191, Beijing, China.
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8
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Weiler SME, Bissinger M, Rose F, von Bubnoff F, Lutz T, Ori A, Schirmacher P, Breuhahn K. SEPTIN10-mediated crosstalk between cytoskeletal networks controls mechanotransduction and oncogenic YAP/TAZ signaling. Cancer Lett 2024; 584:216637. [PMID: 38242197 DOI: 10.1016/j.canlet.2024.216637] [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: 09/12/2023] [Revised: 12/19/2023] [Accepted: 01/09/2024] [Indexed: 01/21/2024]
Abstract
The transcriptional co-activators of the Hippo pathway, YAP and TAZ, are regulated by mechanotransduction, which depends on dynamic actin cytoskeleton remodeling. Here, we identified SEPTIN10 as a novel cytoskeletal protein, which is transcriptionally regulated by YAP/TAZ and whose overexpression correlates with poor survival and vascular invasion in hepatocellular carcinoma (HCC) patients. Functional characterization demonstrated that SEPTIN10 promotes YAP/TAZ-dependent cell viability, migration and invasion of liver cancer cells. Mechanistically, SEPTIN10 interacts with actin and microtubule filaments supporting actin stress fiber formation and intracellular tension through binding to CAPZA2 while concurrently inhibiting microtubule polymerization through the blockage of MAP4 function. This functional antagonism is important for cytoskeleton-dependent feedback activation of YAP/TAZ, as microtubule depolymerization induces actin stress fiber formation and subsequently YAP/TAZ activity. Importantly, the crosstalk between microfilaments and microtubules is mediated by SEPTIN10 as its loss abrogates actin stress fiber formation after microtubule disruption. Together, the YAP/TAZ target gene SEPTIN10 controls the dynamic interplay between actin and microtubule filaments, which feeds back on Hippo pathway activity in HCC cells and thus acts as molecular switch with impact on oncogenic signaling and cancer cell biology.
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Affiliation(s)
- Sofia M E Weiler
- Institute of Pathology, University Hospital Heidelberg, 69120, Heidelberg, Germany.
| | - Michaela Bissinger
- Institute of Pathology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Fabian Rose
- Institute of Pathology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Fabian von Bubnoff
- Institute of Pathology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Teresa Lutz
- Institute of Pathology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Alessandro Ori
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), 07745, Jena, Germany
| | - Peter Schirmacher
- Institute of Pathology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Kai Breuhahn
- Institute of Pathology, University Hospital Heidelberg, 69120, Heidelberg, Germany.
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9
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Becker IC, Wilkie AR, Unger BA, Sciaudone AR, Fatima F, Tsai IT, Xu K, Machlus KR, Italiano JE. Dynamic actin/septin network in megakaryocytes coordinates proplatelet elaboration. Haematologica 2024; 109:915-928. [PMID: 37675512 PMCID: PMC10905084 DOI: 10.3324/haematol.2023.283369] [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: 04/19/2023] [Accepted: 08/18/2023] [Indexed: 09/08/2023] Open
Abstract
Megakaryocytes (MK) undergo extensive cytoskeletal rearrangements as they give rise to platelets. While cortical microtubule sliding has been implicated in proplatelet formation, the role of the actin cytoskeleton in proplatelet elongation is less understood. It is assumed that actin filament reorganization is important for platelet generation given that mouse models with mutations in actin-associated proteins exhibit thrombocytopenia. However, due to the essential role of the actin network during MK development, a differential understanding of the contribution of the actin cytoskeleton on proplatelet release is lacking. Here, we reveal that inhibition of actin polymerization impairs the formation of elaborate proplatelets by hampering proplatelet extension and bead formation along the proplatelet shaft, which was mostly independent of changes in cortical microtubule sliding. We identify Cdc42 and its downstream effectors, septins, as critical regulators of intracellular actin dynamics in MK, inhibition of which, similarly to inhibition of actin polymerization, impairs proplatelet movement and beading. Super-resolution microscopy revealed a differential association of distinctive septins with the actin and microtubule cytoskeleton, respectively, which was disrupted upon septin inhibition and diminished intracellular filamentous actin dynamics. In vivo, septins, similarly to F-actin, were subject to changes in expression upon enforcing proplatelet formation through prior platelet depletion. In summary, we demonstrate that a Cdc42/septin axis is not only important for MK maturation and polarization, but is further required for intracellular actin dynamics during proplatelet formation.
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Affiliation(s)
- Isabelle C Becker
- Vascular Biology Program, Boston Children's Hospital, 1 Blackfan Circle, Boston, MA, 02115; Department of Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115
| | - Adrian R Wilkie
- Vascular Biology Program, Boston Children's Hospital, 1 Blackfan Circle, Boston, MA, 02115; Department of Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115
| | - Bret A Unger
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720
| | | | - Farheen Fatima
- Vascular Biology Program, Boston Children's Hospital, 1 Blackfan Circle, Boston, MA, 02115; Department of Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115
| | - I-Ting Tsai
- Vascular Biology Program, Boston Children's Hospital, 1 Blackfan Circle, Boston, MA, 02115; Department of Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115
| | - Ke Xu
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720
| | - Kellie R Machlus
- Vascular Biology Program, Boston Children's Hospital, 1 Blackfan Circle, Boston, MA, 02115; Department of Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115
| | - Joseph E Italiano
- Vascular Biology Program, Boston Children's Hospital, 1 Blackfan Circle, Boston, MA, 02115; Department of Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115.
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10
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Blua F, Monge C, Gastaldi S, Clemente N, Pizzimenti S, Lazzarato L, Senetta R, Vittorio S, Gigliotti CL, Boggio E, Dianzani U, Vistoli G, Altomare AA, Aldini G, Dianzani C, Marini E, Bertinaria M. Discovery of a septin-4 covalent binder with antimetastatic activity in a mouse model of melanoma. Bioorg Chem 2024; 144:107164. [PMID: 38306824 DOI: 10.1016/j.bioorg.2024.107164] [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: 12/06/2023] [Revised: 01/23/2024] [Accepted: 01/28/2024] [Indexed: 02/04/2024]
Abstract
Cancer spreading through metastatic processes is one of the major causes of tumour-related mortality. Metastasis is a complex phenomenon which involves multiple pathways ranging from cell metabolic alterations to changes in the biophysical phenotype of cells and tissues. In the search for new effective anti-metastatic agents, we modulated the chemical structure of the lead compound AA6, in order to find the structural determinants of activity, and to identify the cellular target responsible of the downstream anti-metastatic effects observed. New compounds synthesized were able to inhibit in vitro B16-F10 melanoma cell invasiveness, and one selected compound, CM365, showed in vivo anti-metastatic effects in a lung metastasis mouse model of melanoma. Septin-4 was identified as the most likely molecular target responsible for these effects. This study showed that CM365 is a promising molecule for metastasis prevention, remarkably effective alone or co-administered with drugs normally used in cancer therapy, such as paclitaxel.
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Affiliation(s)
- Federica Blua
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - Chiara Monge
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - Simone Gastaldi
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - Nausicaa Clemente
- Settore Centri di Ricerca e Infrastrutture di Ateneo e Laboratori - Polo di NO, University of Piemonte Orientale, Novara, Italy
| | - Stefania Pizzimenti
- Department of Clinical and Biological Science, University of Turin, Torino, Italy
| | - Loretta Lazzarato
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - Rebecca Senetta
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Serena Vittorio
- Department of Pharmaceutical Sciences, University of Milan, Milan, Italy
| | | | - Elena Boggio
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Umberto Dianzani
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Giulio Vistoli
- Department of Pharmaceutical Sciences, University of Milan, Milan, Italy
| | | | - Giancarlo Aldini
- Department of Pharmaceutical Sciences, University of Milan, Milan, Italy
| | - Chiara Dianzani
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - Elisabetta Marini
- Department of Drug Science and Technology, University of Turin, Turin, Italy.
| | - Massimo Bertinaria
- Department of Drug Science and Technology, University of Turin, Turin, Italy
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11
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Ge K, Du X, Liu H, Meng R, Wu C, Zhang Z, Liang X, Yang J, Zhang H. The cytotoxicity of microcystin-LR: ultrastructural and functional damage of cells. Arch Toxicol 2024; 98:663-687. [PMID: 38252150 DOI: 10.1007/s00204-023-03676-0] [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: 10/23/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024]
Abstract
Microcystin-LR (MC-LR) is a toxin produced by cyanobacteria, which is widely distributed in eutrophic water bodies and has multi-organ toxicity. Previous cytotoxicity studies have mostly elucidated the effects of MC-LR on intracellular-related factors, proteins, and DNA at the molecular level. However, there have been few studies on the adverse effects of MC-LR on cell ultrastructure and function. Therefore, research on the cytotoxicity of MC-LR in recent years was collected and summarized. It was found that MC-LR can induce a series of cytotoxic effects, including decreased cell viability, induced autophagy, apoptosis and necrosis, altered cell cycle, altered cell morphology, abnormal cell migration and invasion as well as leading to genetic damage. The above cytotoxic effects were related to the damage of various ultrastructure and functions such as cell membranes and mitochondria. Furthermore, MC-LR can disrupt cell ultrastructure and function by inducing oxidative stress and inhibiting protein phosphatase activity. In addition, the combined toxic effects of MC-LR and other environmental pollutants were investigated. This review explored the toxic targets of MC-LR at the subcellular level, which will provide new ideas for the prevention and treatment of multi-organ toxicity caused by MC-LR.
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Affiliation(s)
- Kangfeng Ge
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Xingde Du
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Haohao Liu
- Department of Public Health, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450001, China
| | - Ruiyang Meng
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Chunrui Wu
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Zongxin Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Xiao Liang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Jun Yang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China.
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12
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Xu Y, Ding K, Peng T. Chemical Proteomics Reveals N ε-Fatty-Acylation of Septins by Rho Inactivation Domain (RID) of the Vibrio MARTX Toxin to Alter Septin Localization and Organization. Mol Cell Proteomics 2024; 23:100730. [PMID: 38311109 PMCID: PMC10924143 DOI: 10.1016/j.mcpro.2024.100730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/16/2024] [Accepted: 01/31/2024] [Indexed: 02/06/2024] Open
Abstract
Vibrio species, the Gram-negative bacterial pathogens causing cholera and sepsis, produce multiple secreted virulence factors for infection and pathogenesis. Among these is the multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin that releases several critical effector domains with distinct functions inside eukaryotic host cells. One such effector domain, the Rho inactivation domain (RID), has been discovered to catalyze long-chain Nε-fatty-acylation on lysine residues of Rho GTPases, causing inactivation of Rho GTPases and disruption of the host actin cytoskeleton. However, whether RID modifies other host proteins to exert additional functions remains to be determined. Herein, we describe the integration of bioorthogonal chemical labeling and quantitative proteomics to globally profile the target proteins modified by RID in living cells. More than 246 proteins are identified as new RID substrates, including many involved in GTPase regulation, cytoskeletal organization, and cell division. We demonstrate that RID extensively Nε-fatty-acylates septin proteins, the fourth cytoskeletal component of mammalian cells with important roles in diverse cellular processes. While affinity purification and mass spectrometry analysis show that RID-mediated Nε-fatty-acylation does not affect septin-septin interactions, this modification increases the membrane association of septins and confers localization to detergent-resistant membrane rafts. As a result, the filamentous assembly and organization of septins are disrupted by RID-mediated Nε-fatty-acylation, further contributing to cytoskeletal and mitotic defects that phenocopy the effects of septin depletion. Overall, our work greatly expands the substrate scope and function of RID and demonstrates the role of RID-mediated Nε-fatty-acylation in manipulating septin localization and organization.
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Affiliation(s)
- Yaxin Xu
- State Key Laboratory of Chemical Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Ke Ding
- State Key Laboratory of Chemical Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Tao Peng
- State Key Laboratory of Chemical Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China; Shenzhen Bay Laboratory, Institute of Chemical Biology, Shenzhen, China.
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13
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Devitt CC, Weng S, Bejar-Padilla VD, Alvarado J, Wallingford JB. PCP and Septins govern the polarized organization of the actin cytoskeleton during convergent extension. Curr Biol 2024; 34:615-622.e4. [PMID: 38199065 PMCID: PMC10887425 DOI: 10.1016/j.cub.2023.12.025] [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: 06/07/2022] [Revised: 09/25/2023] [Accepted: 12/08/2023] [Indexed: 01/12/2024]
Abstract
Convergent extension (CE) requires the coordinated action of the planar cell polarity (PCP) proteins1,2 and the actin cytoskeleton,3,4,5,6 but this relationship remains incompletely understood. For example, PCP signaling orients actomyosin contractions, yet actomyosin is also required for the polarized localization of PCP proteins.7,8 Moreover, the actin-regulating Septins play key roles in actin organization9 and are implicated in PCP and CE in frogs, mice, and fish5,6,10,11,12 but execute only a subset of PCP-dependent cell behaviors. Septin loss recapitulates the severe tissue-level CE defects seen after core PCP disruption yet leaves overt cell polarity intact.5 Together, these results highlight the general fact that cell movement requires coordinated action by distinct but integrated actin populations, such as lamella and lamellipodia in migrating cells13 or medial and junctional actin populations in cells engaged in apical constriction.14,15 In the context of Xenopus mesoderm CE, three such actin populations are important, a superficial meshwork known as the "node-and-cable" system,4,16,17,18 a contractile network at deep cell-cell junctions,6,19 and mediolaterally oriented actin-rich protrusions, which are present both superficially and deeply.4,19,20,21 Here, we exploited the amenability of the uniquely "two-dimensional" node and cable system to probe the relationship between PCP proteins, Septins, and the polarization of this actin network. We find that the PCP proteins Vangl2 and Prickle2 and Septins co-localize at nodes, and that the node and cable system displays a cryptic, PCP- and Septin-dependent anteroposterior (AP) polarity in its organization and dynamics.
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Affiliation(s)
- Caitlin C Devitt
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Shinuo Weng
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | | | - José Alvarado
- Department of Physics, University of Texas, Austin, TX 78712, USA
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA.
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14
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Prislusky MI, Lam JG, Contreras VR, Ng M, Chamberlain M, Pathak-Sharma S, Fields M, Zhang X, Amer AO, Seveau S. The Septin Cytoskeleton is Required for Plasma Membrane Repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.12.548547. [PMID: 37503091 PMCID: PMC10369955 DOI: 10.1101/2023.07.12.548547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Mammalian cells are frequently exposed to mechanical and biochemical stressors resulting in plasma membrane injuries. Repair mechanisms reseal the plasma membrane to restore homeostasis and prevent cell death. In the present work, a silencing RNA screen was performed to uncover plasma membrane repair mechanisms of cells exposed to a pore-forming toxin (listeriolysin O). This screen identified molecules previously known to repair the injured plasma membrane such as annexin A2 (ANXA2) as well as novel plasma membrane repair candidate proteins. Of the novel candidates, we focused on septin 7 (SEPT7) because the septins are an important family of conserved eukaryotic cytoskeletal proteins. Using diverse experimental approaches, we established for the first time that SEPT7 plays a general role in plasma membrane repair of cells perforated by pore-forming toxins and mechanical wounding. Remarkably, upon cell injury, the septin cytoskeleton is extensively redistributed in a Ca 2+ -dependent fashion, a hallmark of plasma membrane repair machineries. The septins reorganize into subplasmalemmal domains arranged as knob and loop (or ring) structures containing F-actin, myosin II, and annexin A2 (ANXA2) and protrude from the cell surface. Importantly, the formation of these domains correlates with the plasma membrane repair efficiency. Super-resolution microscopy shows that septins and actin are arranged in intertwined filaments associated with ANXA2. Silencing SEPT7 expression prevented the formation of the F-actin/myosin II/ANXA2 domains, however, silencing expression of ANXA2 had no observable effect on their formation. These results highlight the key structural role of the septins in remodeling the plasma membrane and in the recruitment of the repair molecule ANXA2. Collectively, our data support a novel model in which the septin cytoskeleton acts as a scaffold to promote the formation of plasma membrane repair domains containing contractile F-actin and annexin A2.
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15
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Zhovmer AS, Manning A, Smith C, Nguyen A, Prince O, Sáez PJ, Ma X, Tsygankov D, Cartagena-Rivera AX, Singh NA, Singh RK, Tabdanov ED. Septins provide microenvironment sensing and cortical actomyosin partitioning in motile amoeboid T lymphocytes. SCIENCE ADVANCES 2024; 10:eadi1788. [PMID: 38170778 DOI: 10.1126/sciadv.adi1788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 12/01/2023] [Indexed: 01/05/2024]
Abstract
The all-terrain motility of lymphocytes in tissues and tissue-like gels is best described as amoeboid motility. For amoeboid motility, lymphocytes do not require specific biochemical or structural modifications to the surrounding extracellular matrix. Instead, they rely on changing shape and steric interactions with the microenvironment. However, the exact mechanism of amoeboid motility remains elusive. Here, we report that septins participate in amoeboid motility of T cells, enabling the formation of F-actin and α-actinin-rich cortical rings at the sites of cell cortex-indenting collisions with the extracellular matrix. Cortical rings compartmentalize cells into chains of spherical segments that are spatially conformed to the available lumens, forming transient "hourglass"-shaped steric locks onto the surrounding collagen fibers. The steric lock facilitates pressure-driven peristaltic propulsion of cytosolic content by individually contracting cell segments. Our results suggest that septins provide microenvironment-guided partitioning of actomyosin contractility and steric pivots required for amoeboid motility of T cells in tissue-like microenvironments.
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Affiliation(s)
- Alexander S Zhovmer
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Alexis Manning
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Chynna Smith
- Section on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Ashley Nguyen
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Olivia Prince
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Pablo J Sáez
- Cell Communication and Migration Laboratory, Institute of Biochemistry and Molecular Cell Biology, and Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Xuefei Ma
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Denis Tsygankov
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Alexander X Cartagena-Rivera
- Section on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Niloy A Singh
- Department of Hematology Oncology, University of Rochester Medical Center, Rochester, NY, USA
| | - Rakesh K Singh
- Department of Obstetrics and Gynecology, University of Rochester Medical Center, Rochester, NY, USA
| | - Erdem D Tabdanov
- Department of Pharmacology, Penn State College of Medicine, The Pennsylvania State University, Hershey-Hummelstown, PA, USA
- Penn State Cancer Institute, Penn State College of Medicine, The Pennsylvania State University, Hershey, PA, USA
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16
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Robertin S, Brokatzky D, Lobato-Márquez D, Mostowy S. Regulation of integrin α5β1-mediated Staphylococcus aureus cellular invasion by the septin cytoskeleton. Eur J Cell Biol 2023; 102:151359. [PMID: 37683588 DOI: 10.1016/j.ejcb.2023.151359] [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: 04/05/2023] [Revised: 08/10/2023] [Accepted: 09/01/2023] [Indexed: 09/10/2023] Open
Abstract
Staphylococcus aureus, a Gram-positive bacterial pathogen, is an urgent health threat causing a wide range of clinical infections. Originally viewed as a strict extracellular pathogen, accumulating evidence has revealed S. aureus to be a facultative intracellular pathogen subverting host cell signalling to support invasion. The majority of clinical isolates produce fibronectin-binding proteins A and B (FnBPA and FnBPB) to interact with host integrin α5β1, a key component of focal adhesions. S. aureus binding of integrin α5β1 promotes its clustering on the host cell surface, triggering activation of focal adhesion kinase (FAK) and cytoskeleton rearrangements to promote bacterial invasion into non-phagocytic cells. Here, we discover that septins, a component of the cytoskeleton that assembles on membranes, are recruited as collar-like structures with actin to S. aureus invasion sites engaging integrin α5β1. To investigate septin recruitment to the plasma membrane in a bacteria-free system, we used FnBPA-coated latex beads and showed that septins are recruited upon activation of integrin α5β1. SEPT2 depletion reduced S. aureus invasion, but increased surface expression of integrin α5 and adhesion of S. aureus to host cells. Consistent with this, SEPT2 depletion increased cellular protein levels of integrin α5 and β1 subunits, as well as FAK. Collectively, these results provide insights into regulation of integrin α5β1 and invasion of S. aureus by the septin cytoskeleton.
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Affiliation(s)
- Stevens Robertin
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Dominik Brokatzky
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Damián Lobato-Márquez
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom.
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17
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Perry JA, Werner ME, Heck BW, Maddox PS, Maddox AS. Septins throughout phylogeny are predicted to have a transmembrane domain, which in Caenorhabditis elegans is functionally important. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.20.567915. [PMID: 38045322 PMCID: PMC10690161 DOI: 10.1101/2023.11.20.567915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Septins, a conserved family of filament-forming proteins, contribute to eukaryotic cell division, polarity, and membrane trafficking. Septins are thought to act in these processes by scaffolding other proteins to the plasma membrane. The mechanisms by which septins associate with the plasma membrane are not well understood but can involve two polybasic domains and/or an amphipathic helix. We discovered that the genomes of organisms throughout phylogeny, but not most commonly used model organisms, encode one or more septins predicted to have transmembrane domains. The nematode Caenorhabditis elegans, which was thought to express only two septin proteins, UNC-59 and UNC-61, translates multiple isoforms of UNC-61, and one isoform, UNC-61a, is predicted to contain a transmembrane domain. UNC-61a localizes specifically to the apical membrane of the C. elegans vulva and is important for maintaining vulval morphology. UNC-61a partially compensates for the loss of the other two UNC-61 isoforms, UNC-61b and UNC-61c. The UNC-61a transmembrane domain is sufficient to localize a fluorophore to membranes in mammalian cells, and its deletion from UNC-61a recapitulates the phenotypes of unc-61a null animals. The localization and loss-of-function phenotypes of UNC-61a and its transmembrane domain suggest roles in cell polarity and secretion and help explain the cellular and tissue biological underpinnings of C. elegans septin null alleles' enigmatically hypomorphic phenotypes. Together, our findings reveal a novel mechanism of septin-membrane association with profound implications for the dynamics and regulation of this association.
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Affiliation(s)
- Jenna A Perry
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Michael E Werner
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Bryan W Heck
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Paul S Maddox
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Amy Shaub Maddox
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
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18
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Stjepić V, Nakamura M, Hui J, Parkhurst SM. Two Septin Complexes Mediate Actin Dynamics During Cell Wound Repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.567084. [PMID: 38014090 PMCID: PMC10680708 DOI: 10.1101/2023.11.14.567084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Cells have robust wound repair systems to prevent further damage or infection and to quickly restore cell cortex integrity when exposed to mechanical and chemical stress. Actomyosin ring formation and contraction at the wound edge are major events during closure of the plasma membrane and underlying cytoskeleton during cell wound repair. Here, we show that all five Drosophila Septins are required for efficient cell wound repair. Based on their different recruitment patterns and knockdown/mutant phenotypes, two distinct Septin complexes, Sep1-Sep2-Pnut and Sep4-Sep5-Pnut, are assembled to regulate actin ring assembly, contraction, and remodeling during the repair process. Intriguingly, we find that these two Septin complexes have different F-actin bending activities. In addition, we find that Anillin regulates the recruitment of only one of two Septin complexes upon wounding. Our results demonstrate that two functionally distinct Septin complexes work side-by-side to discretely regulate actomyosin ring dynamics during cell wound repair.
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Affiliation(s)
- Viktor Stjepić
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Mitsutoshi Nakamura
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Justin Hui
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Susan M. Parkhurst
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
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19
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Nakazawa K, Chauvin B, Mangenot S, Bertin A. Reconstituted in vitro systems to reveal the roles and functions of septins. J Cell Sci 2023; 136:jcs259448. [PMID: 37815088 DOI: 10.1242/jcs.259448] [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] [Indexed: 10/11/2023] Open
Abstract
Septins are essential cytoskeletal proteins involved in key cellular processes and have also been implicated in diseases from cancers to neurodegenerative pathologies. However, they have not been as thoroughly studied as other cytoskeletal proteins. In vivo, septins interact with other cytoskeletal proteins and with the inner plasma membrane. Hence, bottom-up in vitro cell-free assays are well suited to dissect the roles and behavior of septins in a controlled environment. Specifically, in vitro studies have been invaluable in describing the self-assembly of septins into a large diversity of ultrastructures. Given that septins interact specifically with membrane, the details of these septin-membrane interactions have been analyzed using reconstituted lipid systems. In particular, at a membrane, septins are often localized at curvatures of micrometer scale. In that context, in vitro assays have been performed with substrates of varying curvatures (spheres, cylinders or undulated substrates) to probe the sensitivity of septins to membrane curvature. This Review will first present the structural properties of septins in solution and describe the interplay of septins with cytoskeletal partners. We will then discuss how septins interact with biomimetic membranes and induce their reshaping. Finally, we will highlight the curvature sensitivity of septins and how they alter the mechanical properties of membranes.
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Affiliation(s)
- Koyomi Nakazawa
- Physico Chimie Curie , Institut Curie, CNRS UMR 168, Sorbonne Université, 11 Rue Pierre et Paris Curie, 75005 Paris, France
| | - Brieuc Chauvin
- Physico Chimie Curie , Institut Curie, CNRS UMR 168, Sorbonne Université, 11 Rue Pierre et Paris Curie, 75005 Paris, France
| | - Stéphanie Mangenot
- Laboratoire Matière et Systèmes Complexes , Université de Paris Cité, CNRS UMR 7057, 45 Rue des Saint Pères, 75006 Paris, France
| | - Aurélie Bertin
- Physico Chimie Curie , Institut Curie, CNRS UMR 168, Sorbonne Université, 11 Rue Pierre et Paris Curie, 75005 Paris, France
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20
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Suber Y, Alam MNA, Nakos K, Bhakt P, Spiliotis ET. Microtubule-associated septin complexes modulate kinesin and dynein motility with differential specificities. J Biol Chem 2023; 299:105084. [PMID: 37495111 PMCID: PMC10463263 DOI: 10.1016/j.jbc.2023.105084] [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: 03/19/2023] [Revised: 06/27/2023] [Accepted: 07/14/2023] [Indexed: 07/28/2023] Open
Abstract
Long-range membrane traffic is guided by microtubule-associated proteins and posttranslational modifications, which collectively comprise a traffic code. The regulatory principles of this code and how it orchestrates the motility of kinesin and dynein motors are largely unknown. Septins are a large family of GTP-binding proteins, which assemble into complexes that associate with microtubules. Using single-molecule in vitro motility assays, we tested how the microtubule-associated SEPT2/6/7, SEPT2/6/7/9, and SEPT5/7/11 complexes affect the motilities of the constitutively active kinesins KIF5C and KIF1A and the dynein-dynactin-bicaudal D (DDB) motor complex. We found that microtubule-associated SEPT2/6/7 is a potent inhibitor of DDB and KIF5C, preventing mainly their association with microtubules. SEPT2/6/7 also inhibits KIF1A by obstructing stepping along microtubules. On SEPT2/6/7/9-coated microtubules, KIF1A inhibition is dampened by SEPT9, which alone enhances KIF1A, showing that individual septin subunits determine the regulatory properties of septin complexes. Strikingly, SEPT5/7/11 differs from SEPT2/6/7, in permitting the motility of KIF1A and immobilizing DDB to the microtubule lattice. In hippocampal neurons, filamentous SEPT5 colocalizes with somatodendritic microtubules that underlie Golgi membranes and lack SEPT6. Depletion of SEPT5 disrupts Golgi morphology and polarization of Golgi ribbons into the shaft of somato-proximal dendrites, which is consistent with the tethering of DDB to microtubules by SEPT5/7/11. Collectively, these results suggest that microtubule-associated complexes have differential specificities in the regulation of the motility and positioning of microtubule motors. We posit that septins are an integral part of the microtubule-based code that spatially controls membrane traffic.
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Affiliation(s)
- Yani Suber
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Md Noor A Alam
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Konstantinos Nakos
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Priyanka Bhakt
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA.
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21
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Szabó L, Telek A, Fodor J, Dobrosi N, Dócs K, Hegyi Z, Gönczi M, Csernoch L, Dienes B. Reduced Expression of Septin7 Hinders Skeletal Muscle Regeneration. Int J Mol Sci 2023; 24:13536. [PMID: 37686339 PMCID: PMC10487768 DOI: 10.3390/ijms241713536] [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: 06/05/2023] [Revised: 07/28/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
Septins are considered the fourth component of the cytoskeleton with the septin7 isoform playing a critical role in the formation of diffusion barriers in phospholipid bilayers and intra- and extracellular scaffolds. While its importance has already been confirmed in different intracellular processes, very little is known about its role in skeletal muscle. Muscle regeneration was studied in a Sept7 conditional knock-down mouse model to prove the possible role of septin7 in this process. Sterile inflammation in skeletal muscle was induced which was followed by regeneration resulting in the upregulation of septin7 expression. Partial knock-down of Sept7 resulted in an increased number of inflammatory cells and myofibers containing central nuclei. Taken together, our data suggest that partial knock-down of Sept7 hinders the kinetics of muscle regeneration, indicating its crucial role in skeletal muscle functions.
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Affiliation(s)
- László Szabó
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
| | - Andrea Telek
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - János Fodor
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Nóra Dobrosi
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
| | - Klaudia Dócs
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Zoltán Hegyi
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
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22
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Okletey J, Angelis D, Jones TM, Montagna C, Spiliotis ET. An oncogenic isoform of septin 9 promotes the formation of juxtanuclear invadopodia by reducing nuclear deformability. Cell Rep 2023; 42:112893. [PMID: 37516960 PMCID: PMC10530659 DOI: 10.1016/j.celrep.2023.112893] [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: 03/11/2023] [Revised: 06/17/2023] [Accepted: 07/13/2023] [Indexed: 08/01/2023] Open
Abstract
Invadopodia are extracellular matrix (ECM) degrading structures, which promote cancer cell invasion. The nucleus is increasingly viewed as a mechanosensory organelle that determines migratory strategies. However, how the nucleus crosstalks with invadopodia is little known. Here, we report that the oncogenic septin 9 isoform 1 (SEPT9_i1) is a component of breast cancer invadopodia. SEPT9_i1 depletion diminishes invadopodium formation and the clustering of the invadopodium precursor components TKS5 and cortactin. This phenotype is characterized by deformed nuclei and nuclear envelopes with folds and grooves. We show that SEPT9_i1 localizes to the nuclear envelope and juxtanuclear invadopodia. Moreover, exogenous lamin A rescues nuclear morphology and juxtanuclear TKS5 clusters. Importantly, SEPT9_i1 is required for the amplification of juxtanuclear invadopodia, which is induced by the epidermal growth factor. We posit that nuclei of low deformability favor the formation of juxtanuclear invadopodia in a SEPT9_i1-dependent manner, which functions as a tunable mechanism for overcoming ECM impenetrability.
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Affiliation(s)
- Joshua Okletey
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA
| | - Dimitrios Angelis
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA
| | - Tia M Jones
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA
| | - Cristina Montagna
- Department of Radiology and Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08901, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA.
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23
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Wills RC, Doyle CP, Zewe JP, Pacheco J, Hansen SD, Hammond GRV. A novel homeostatic mechanism tunes PI(4,5)P2-dependent signaling at the plasma membrane. J Cell Sci 2023; 136:jcs261494. [PMID: 37534432 PMCID: PMC10482388 DOI: 10.1242/jcs.261494] [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: 07/19/2023] [Accepted: 07/19/2023] [Indexed: 08/04/2023] Open
Abstract
The lipid molecule phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] controls all aspects of plasma membrane (PM) function in animal cells, from its selective permeability to the attachment of the cytoskeleton. Although disruption of PI(4,5)P2 is associated with a wide range of diseases, it remains unclear how cells sense and maintain PI(4,5)P2 levels to support various cell functions. Here, we show that the PIP4K family of enzymes, which synthesize PI(4,5)P2 via a minor pathway, also function as sensors of tonic PI(4,5)P2 levels. PIP4Ks are recruited to the PM by elevated PI(4,5)P2 levels, where they inhibit the major PI(4,5)P2-synthesizing PIP5Ks. Perturbation of this simple homeostatic mechanism reveals differential sensitivity of PI(4,5)P2-dependent signaling to elevated PI(4,5)P2 levels. These findings reveal that a subset of PI(4,5)P2-driven functions might drive disease associated with disrupted PI(4,5)P2 homeostasis.
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Affiliation(s)
- Rachel C. Wills
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Colleen P. Doyle
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - James P. Zewe
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Jonathan Pacheco
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Scott D. Hansen
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA
| | - Gerald R. V. Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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24
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Ráduly Z, Szabó L, Dienes B, Szentesi P, Bana ÁV, Hajdú T, Kókai E, Hegedűs C, Csernoch L, Gönczi M. Migration of Myogenic Cells Is Highly Influenced by Cytoskeletal Septin7. Cells 2023; 12:1825. [PMID: 37508490 PMCID: PMC10378681 DOI: 10.3390/cells12141825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/19/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023] Open
Abstract
Septin7 as a unique member of the GTP binding protein family, is widely expressed in the eukaryotic cells and considered to be essential in the formation of hetero-oligomeric septin complexes. As a cytoskeletal component, Septin7 is involved in many important cellular processes. However, its contribution in striated muscle physiology is poorly described. In skeletal muscle, a highly orchestrated process of migration is crucial in the development of functional fibers and in regeneration. Here, we describe the pronounced appearance of Septin7 filaments and a continuous change of Septin7 protein architecture during the migration of myogenic cells. In Septin7 knockdown C2C12 cultures, the basic parameters of migration are significantly different, and the intracellular calcium concentration change in migrating cells are lower compared to that of scrambled cultures. Using a plant cytokinin, forchlorfenuron, to dampen septin dynamics, the altered behavior of the migrating cells is described, where Septin7-depleted cells are more resistant to the treatment. These results indicate the functional relevance of Septin7 in the migration of myoblasts, implying its contribution to muscle myogenesis and regeneration.
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Affiliation(s)
- Zsolt Ráduly
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - László Szabó
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Péter Szentesi
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Ágnes Viktória Bana
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Tibor Hajdú
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Endre Kókai
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Csaba Hegedűs
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
| | - Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
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25
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Kim J, Mooren OL, Onken MD, Cooper JA. Septin and actin contributions to endothelial cell-cell junctions and monolayer integrity. Cytoskeleton (Hoboken) 2023; 80:228-241. [PMID: 36205643 PMCID: PMC10079785 DOI: 10.1002/cm.21732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/02/2022] [Accepted: 10/04/2022] [Indexed: 11/10/2022]
Abstract
Septins in endothelial cells (ECs) have important roles supporting the integrity of the endothelial monolayer. Cell-cell junctions in EC monolayers are highly dynamic, with continuous retractions and protrusions. Depletion of septins in ECs leads to disruption of cell-cell junctions, which are composed of VE-cadherin and other junctional proteins. In EC monolayers, septins are concentrated at the plasma membrane at sites of cell-cell contact, in curved- and scallop-shaped patterns. These membrane-associated septin accumulations are located in regions of positive membrane curvature, and those regions are often associated with and immediately adjacent to actin-rich protrusions with negative membrane curvature. EC septins associate directly with plasma membrane lipids, based on findings with site-specific mutations of septins in ECs, which is consistent with biochemical and cell biological studies in other systems. Loss of septins leads to disruption of the EC monolayer, and gaps form between cells. The number and breadth of cell-cell contacts and junctions decreases, and the number and frequency of retractions, ruffles, and protrusions at cell edges also decreases. In addition, loss of septins leads to decreased amounts of F-actin at the cortical membrane, along with increased amounts of F-actin in stress fibers of the cytoplasm. Endothelial monolayer disruption from loss of septins is also associated with decreased transendothelial electric resistance (TEER) and increased levels of transendothelial migration (TEM) by immune and cancer cells, owing to the gaps in the monolayer. A current working model is that assembly of septin filaments at regions of positive membrane curvature contributes to a mechanical footing or base for actin-based protrusive forces generated at adjoining regions of the membrane. Specific molecular interactions between the septin and actin components of the cytoskeleton may also be important contributors. Regulators of actin assembly may promote and support the assembly of septin filaments at the membrane, as part of a molecular feedback loop between the assembly of septin and actin filaments.
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Affiliation(s)
- Joanna Kim
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Olivia L Mooren
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Michael D Onken
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
| | - John A Cooper
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
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26
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Tomasso MR, Padrick SB. BORG family proteins in physiology and human disease. Cytoskeleton (Hoboken) 2023; 80:182-198. [PMID: 37403807 DOI: 10.1002/cm.21768] [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: 12/11/2022] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/06/2023]
Abstract
The binder of rho GTPases (BORG)/Cdc42 effector proteins (Cdc42EP) family is composed of five Rho GTPase binding proteins whose functions and mechanism of actions are of emerging interest. Here, we review recent findings pertaining to the family as a whole and consider how these change our understanding of cellular organization. Recent studies have implicated BORGs in both fundamental physiology and in human diseases, mainly cancers. An emerging pattern suggests that BORG family members cancer-promoting properties are related to their ability to regulate the cytoskeleton, with many impacting the organization of acto-myosin stress fibers. This is consistent with the broader literature indicating that BORG family members are regulators of both the septin and actin cytoskeleton networks. The exact mechanism through which BORGs modify the cytoskeleton is not clear, but we consider here a few data-supported and speculative possibilities. Finally, we delve into how the Rho GTPase Cdc42 modifies BORG function in cells. This remains open-ended as Cdc42's effects on BORGs appear cell type- and cell state-dependent. Collectively, these data point to the importance of the BORG family and suggest broader themes in their function and regulation.
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Affiliation(s)
- Meagan R Tomasso
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Shae B Padrick
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA
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27
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Torraca V, Bielecka MK, Gomes MC, Brokatzky D, Busch‐Nentwich EM, Mostowy S. Zebrafish null mutants of Sept6 and Sept15 are viable but more susceptible to Shigella infection. Cytoskeleton (Hoboken) 2023; 80:266-274. [PMID: 36855298 PMCID: PMC10952258 DOI: 10.1002/cm.21750] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/21/2023] [Accepted: 02/24/2023] [Indexed: 03/02/2023]
Abstract
Septins are evolutionarily conserved GTP-binding proteins known for their roles in cell division and host defence against Shigella infection. Although septin group members are viewed to function as hetero-oligomeric complexes, the role of individual septins within these complexes or in isolation is poorly understood. Decades of work using mouse models has shown that some septins (including SEPT7) are essential for animal development, while others (including SEPT6) are dispensable, suggesting that some septins may compensate for the absence of others. The zebrafish genome encodes 19 septin genes, representing the full complement of septin groups described in mice and humans. In this report, we characterise null mutants for zebrafish Sept6 (a member of the SEPT6 group) and Sept15 (a member of the SEPT7 group) and test their role in zebrafish development and host defence against Shigella infection. We show that null mutants for Sept6 and Sept15 are both viable, and that expression of other zebrafish septins are not significantly affected by their mutation. Consistent with previous reports using knockdown of Sept2, Sept7b, and Sept15, we show that Sept6 and Sept15 are required for host defence against Shigella infection. These results highlight Shigella infection of zebrafish as a powerful system to study the role of individual septins in vivo.
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Affiliation(s)
- Vincenzo Torraca
- Department of Infection BiologyLondon School of Hygiene & Tropical MedicineLondonUK
- School of Life SciencesUniversity of WestminsterLondonUK
| | | | - Margarida C. Gomes
- Department of Infection BiologyLondon School of Hygiene & Tropical MedicineLondonUK
| | - Dominik Brokatzky
- Department of Infection BiologyLondon School of Hygiene & Tropical MedicineLondonUK
| | - Elisabeth M. Busch‐Nentwich
- Department of Medicine, Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID)University of CambridgeCambridgeUK
- School of Biological and Behavioural Sciences, Faculty of Science and EngineeringQueen Mary University of LondonLondonUK
| | - Serge Mostowy
- Department of Infection BiologyLondon School of Hygiene & Tropical MedicineLondonUK
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28
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Van Ngo H, Robertin S, Brokatzky D, Bielecka MK, Lobato‐Márquez D, Torraca V, Mostowy S. Septins promote caspase activity and coordinate mitochondrial apoptosis. Cytoskeleton (Hoboken) 2023; 80:254-265. [PMID: 35460543 PMCID: PMC10952901 DOI: 10.1002/cm.21696] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/08/2022] [Accepted: 04/05/2022] [Indexed: 11/06/2022]
Abstract
Apoptosis is a form of regulated cell death essential for tissue homeostasis and embryonic development. Apoptosis also plays a key role during bacterial infection, yet some intracellular bacterial pathogens (such as Shigella flexneri, whose lipopolysaccharide can block apoptosis) can manipulate cell death programs as an important survival strategy. Septins are a component of the cytoskeleton essential for mitochondrial dynamics and host defense, however, the role of septins in regulated cell death is mostly unknown. Here, we discover that septins promote mitochondrial (i.e., intrinsic) apoptosis in response to treatment with staurosporine (a pan-kinase inhibitor) or etoposide (a DNA topoisomerase inhibitor). Consistent with a role for septins in mitochondrial dynamics, septins promote the release of mitochondrial protein cytochrome c in apoptotic cells and are required for the proteolytic activation of caspase-3, caspase-7, and caspase-9 (core components of the apoptotic machinery). Apoptosis of HeLa cells induced in response to infection by S. flexneri ΔgalU (a lipopolysaccharide mutant unable to block apoptosis) is also septin-dependent. In vivo, zebrafish larvae are significantly more susceptible to infection with S. flexneri ΔgalU (as compared to infection with wildtype S. flexneri), yet septin deficient larvae are equally susceptible to infection with S. flexneri ΔgalU and wildtype S. flexneri. These data provide a new molecular framework to understand the complexity of mitochondrial apoptosis and its ability to combat bacterial infection.
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Affiliation(s)
- Hoan Van Ngo
- Department of Infection BiologyLondon School of Hygiene and Tropical MedicineLondonUK
| | - Stevens Robertin
- Department of Infection BiologyLondon School of Hygiene and Tropical MedicineLondonUK
| | - Dominik Brokatzky
- Department of Infection BiologyLondon School of Hygiene and Tropical MedicineLondonUK
| | - Magdalena K. Bielecka
- Department of Infection BiologyLondon School of Hygiene and Tropical MedicineLondonUK
| | - Damián Lobato‐Márquez
- Department of Infection BiologyLondon School of Hygiene and Tropical MedicineLondonUK
| | - Vincenzo Torraca
- Department of Infection BiologyLondon School of Hygiene and Tropical MedicineLondonUK
- School of Life SciencesUniversity of WestminsterLondonUK
| | - Serge Mostowy
- Department of Infection BiologyLondon School of Hygiene and Tropical MedicineLondonUK
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29
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Okletey J, Angelis D, Jones TM, Montagna C, Spiliotis ET. An oncogenic isoform of septin 9 promotes the formation of juxtanuclear invadopodia by reducing nuclear deformability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.18.545473. [PMID: 37398172 PMCID: PMC10312791 DOI: 10.1101/2023.06.18.545473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Invadopodia are extracellular matrix (ECM) degrading structures, which promote cancer cell invasion. The nucleus is increasingly viewed as a mechanosensory organelle that determines migratory strategies. However, how the nucleus crosstalks with invadopodia is little known. Here, we report that the oncogenic septin 9 isoform 1 (SEPT9_i1) is a component of breast cancer invadopodia. SEPT9_i1 depletion diminishes invadopodia formation and the clustering of invadopodia precursor components TKS5 and cortactin. This phenotype is characterized by deformed nuclei, and nuclear envelopes with folds and grooves. We show that SEPT9_i1 localizes to the nuclear envelope and juxtanuclear invadopodia. Moreover, exogenous lamin A rescues nuclear morphology and juxtanuclear TKS5 clusters. Importantly, SEPT9_i1 is required for the amplification of juxtanuclear invadopodia, which is induced by the epidermal growth factor. We posit that nuclei of low deformability favor the formation of juxtanuclear invadopodia in a SEPT9_i1-dependent manner, which functions as a tunable mechanism for overcoming ECM impenetrability. Highlights The oncogenic SEPT9_i1 is enriched in breast cancer invadopodia in 2D and 3D ECMSEPT9_i1 promotes invadopodia precursor clustering and invadopodia elongationSEPT9_i1 localizes to the nuclear envelope and reduces nuclear deformabilitySEPT9_i1 is required for EGF-induced amplification of juxtanuclear invadopodia. eTOC Blurb Invadopodia promote the invasion of metastatic cancers. The nucleus is a mechanosensory organelle that determines migratory strategies, but how it crosstalks with invadopodia is unknown. Okletey et al show that the oncogenic isoform SEPT9_i1 promotes nuclear envelope stability and the formation of invadopodia at juxtanuclear areas of the plasma membrane.
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30
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Scharnagl K, Tagirdzhanova G, Talbot NJ. The coming golden age for lichen biology. Curr Biol 2023; 33:R512-R518. [PMID: 37279685 DOI: 10.1016/j.cub.2023.03.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Lichens are a diverse group of organisms. They are both commonly observed but also mysterious. It has long been known that lichens are composite symbiotic associations of at least one fungus and an algal or cyanobacterial partner, but recent evidence suggests that they may be much more complex. We now know that there can be many constituent microorganisms in a lichen, organized into reproducible patterns that suggest a sophisticated communication and interplay between symbionts. We feel the time is right for a more concerted effort to understand lichen biology. Rapid advances in comparative genomics and metatranscriptomic approaches, coupled with recent breakthroughs in gene functional studies, suggest that lichens may now be more tractable to detailed analysis. Here we set out some of the big questions in lichen biology, and we speculate about the types of gene functions that may be critical to their development, as well as the molecular events that may lead to initial lichen formation. We define both the challenges and opportunities in lichen biology and offer a call to arms to study this remarkable group of organisms.
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Affiliation(s)
- Klara Scharnagl
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK; University & Jepson Herbaria, University of California Berkeley, Valley Life Sciences Building, Berkeley, CA 94720, USA
| | - Gulnara Tagirdzhanova
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
| | - Nicholas J Talbot
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK.
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31
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K S V Castro D, V D Rosa H, Mendonça DC, Cavini IA, P U Araujo A, Garratt RC. Dissecting the binding interface of the septin polymerization enhancer Borg BD3. J Mol Biol 2023; 435:168132. [PMID: 37121395 DOI: 10.1016/j.jmb.2023.168132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/02/2023]
Abstract
The molecular basis for septin filament assembly has begun to emerge over recent years. These filaments are essential for many septin functions which depend on their association with biological membranes or components of the cytoskeleton. Much less is known about how septins specifically interact with their binding partners. Here we describe the essential role played by the C-terminal domains in both septin polymerization and their association with the BD3 motif of the Borg family of Cdc42 effector proteins. We provide a detailed description, at the molecular level, of a previously reported interaction between BD3 and the NC-interface between SEPT6 and SEPT7. Upon ternary complex formation, the heterodimeric coiled coil formed by the C-terminal domains of the septins becomes stabilized and filament formation is promoted under conditions of ionic strength/protein concentration which are not normally permissible, likely by favouring hexamers over smaller oligomeric states. This demonstrates that binding partners, such as Borg's, have the potential to control filament assembly/disassembly in vivo in a way which can be emulated in vitro by altering the ionic strength. Experimentally validated models indicate that the BD3 peptide lies antiparallel to the coiled coil and is stabilized by a mixture of polar and apolar contacts. At its center, an LGPS motif, common to all human Borg sequences, interacts with charged residues from both helices of the coiled coil (K368 from SEPT7 and the conserved E354 from SEPT6) suggesting a universal mechanism which governs Borg-septin interactions.
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Affiliation(s)
- Danielle K S V Castro
- São Carlos Institute of Chemistry, University of São Paulo, São Carlos, Brazil; São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Higor V D Rosa
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Deborah C Mendonça
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Italo A Cavini
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Ana P U Araujo
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Richard C Garratt
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil.
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32
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Güler GÖ, Mostowy S. The septin cytoskeleton: Heteromer composition defines filament function. J Cell Biol 2023; 222:e202302010. [PMID: 36821087 PMCID: PMC9998967 DOI: 10.1083/jcb.202302010] [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] [Indexed: 02/24/2023] Open
Abstract
Septins are an evolutionarily conserved protein family whose members form hetero-oligomeric complexes that assemble into filaments and higher-order structures. In this issue, Martins et al. (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202203016) and Cannon et al. (2023. J. Cell Biol.https://doi.org/10.1083/jcb.202204063) report that heteromer composition impacts the physiological role of septin filaments in yeast and human cells.
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Affiliation(s)
- Gizem Özbaykal Güler
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
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33
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Kho M, Hladyshau S, Tsygankov D, Nie S. Coordinated regulation of Cdc42ep1, actin, and septin filaments during neural crest cell migration. Front Cell Dev Biol 2023; 11:1106595. [PMID: 36923257 PMCID: PMC10009165 DOI: 10.3389/fcell.2023.1106595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 02/15/2023] [Indexed: 03/02/2023] Open
Abstract
The septin cytoskeleton has been demonstrated to interact with other cytoskeletal components to regulate various cellular processes, including cell migration. However, the mechanisms of how septin regulates cell migration are not fully understood. In this study, we use the highly migratory neural crest cells of frog embryos to examine the role of septin filaments in cell migration. We found that septin filaments are required for the proper migration of neural crest cells by controlling both the speed and the direction of cell migration. We further determined that septin filaments regulate these features of cell migration by interacting with actin stress fibers. In neural crest cells, septin filaments co-align with actin stress fibers, and the loss of septin filaments leads to impaired stability and contractility of actin stress fibers. In addition, we showed that a partial loss of septin filaments leads to drastic changes in the orientations of newly formed actin stress fibers, suggesting that septin filaments help maintain the persistent orientation of actin stress fibers during directed cell migration. Lastly, our study revealed that these activities of septin filaments depend on Cdc42ep1, which colocalizes with septin filaments in the center of neural crest cells. Cdc42ep1 interacts with septin filaments in a reciprocal manner, with septin filaments recruiting Cdc42ep1 to the cell center and Cdc42ep1 supporting the formation of septin filaments.
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Affiliation(s)
- Mary Kho
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Siarhei Hladyshau
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Denis Tsygankov
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, United States
| | - Shuyi Nie
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, United States
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34
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El-Mansi S, Robinson CL, Kostelnik KB, McCormack JJ, Mitchell TP, Lobato-Márquez D, Rajeeve V, Cutillas P, Cutler DF, Mostowy S, Nightingale TD. Proximity proteomics identifies septins and PAK2 as decisive regulators of actomyosin-mediated expulsion of von Willebrand factor. Blood 2023; 141:930-944. [PMID: 36564030 PMCID: PMC10023740 DOI: 10.1182/blood.2022017419] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/07/2022] [Accepted: 11/27/2022] [Indexed: 12/25/2022] Open
Abstract
In response to tissue injury, within seconds the ultra-large glycoprotein von Willebrand factor (VWF) is released from endothelial storage organelles (Weibel-Palade bodies) into the lumen of the blood vasculature, where it leads to the recruitment of platelets. The marked size of VWF multimers represents an unprecedented burden on the secretory machinery of endothelial cells (ECs). ECs have evolved mechanisms to overcome this, most notably an actomyosin ring that forms, contracts, and squeezes out its unwieldy cargo. Inhibiting the formation or function of these structures represents a novel therapeutic target for thrombotic pathologies, although characterizing proteins associated with such a dynamic process has been challenging. We have combined APEX2 proximity labeling with an innovative dual loss-of-function screen to identify proteins associated with actomyosin ring function. We show that p21 activated kinase 2 (PAK2) recruits septin hetero-oligomers, a molecular interaction that forms a ring around exocytic sites. This cascade of events controls actomyosin ring function, aiding efficient exocytic release. Genetic or pharmacological inhibition of PAK2 or septins led to inefficient release of VWF and a failure to form platelet-catching strings. This new molecular mechanism offers additional therapeutic targets for the control of thrombotic disease and is highly relevant to other secretory systems that employ exocytic actomyosin machinery.
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Affiliation(s)
- Sammy El-Mansi
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Christopher L. Robinson
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Katja B. Kostelnik
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Jessica J. McCormack
- MRC Laboratory of Molecular Cell Biology, University College London, London, United Kingdom
| | - Tom P. Mitchell
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Damián Lobato-Márquez
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Vinothini Rajeeve
- Cell Signalling & Proteomics Group, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Pedro Cutillas
- Cell Signalling & Proteomics Group, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Daniel F. Cutler
- MRC Laboratory of Molecular Cell Biology, University College London, London, United Kingdom
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Thomas D. Nightingale
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
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Curvature sensing as an emergent property of multiscale assembly of septins. Proc Natl Acad Sci U S A 2023; 120:e2208253120. [PMID: 36716363 PMCID: PMC9963131 DOI: 10.1073/pnas.2208253120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The ability of cells to sense and communicate their shape is central to many of their functions. Much is known about how cells generate complex shapes, yet how they sense and respond to geometric cues remains poorly understood. Septins are GTP-binding proteins that localize to sites of micrometer-scale membrane curvature. Assembly of septins is a multistep and multiscale process, but it is unknown how these discrete steps lead to curvature sensing. Here, we experimentally examine the time-dependent binding of septins at different curvatures and septin bulk concentrations. These experiments unexpectedly indicated that septins' curvature preference is not absolute but rather is sensitive to the combinations of membrane curvatures present in a reaction, suggesting that there is competition between different curvatures for septin binding. To understand the physical underpinning of this result, we developed a kinetic model that connects septins' self-assembly and curvature-sensing properties. Our experimental and modeling results are consistent with curvature-sensitive assembly being driven by cooperative associations of septin oligomers in solution with the bound septins. When combined, the work indicates that septin curvature sensing is an emergent property of the multistep, multiscale assembly of membrane-bound septins. As a result, curvature preference is not absolute and can be modulated by changing the physicochemical and geometric parameters involved in septin assembly, including bulk concentration, and the available membrane curvatures. While much geometry-sensitive assembly in biology is thought to be guided by intrinsic material properties of molecules, this is an important example of how curvature sensing can arise from multiscale assembly of polymers.
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Pacheco J, Cassidy AC, Zewe JP, Wills RC, Hammond GR. PI(4,5)P2 diffuses freely in the plasma membrane even within high-density effector protein complexes. J Cell Biol 2023; 222:e202204099. [PMID: 36416724 PMCID: PMC9698391 DOI: 10.1083/jcb.202204099] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/11/2022] [Accepted: 11/04/2022] [Indexed: 11/24/2022] Open
Abstract
The lipid phosphatidyl-D-myo-inositol-4,5-bisphosphate [PI(4,5)P2] is a master regulator of plasma membrane (PM) function. Its effector proteins regulate transport, signaling, and cytoskeletal processes that define PM structure and function. How a single type of lipid regulates so many parallel processes is unclear. We tested the hypothesis that spatially separate PI(4,5)P2 pools associate with different PM complexes. The mobility of PI(4,5)P2 was measured using biosensors by single-particle tracking. We found that PM lipids including PI(4,5)P2 diffuse rapidly (∼0.3 µm2/s) with Brownian motion, although they spend one third of their time diffusing more slowly. Surprisingly, areas of the PM occupied by PI(4,5)P2-dependent complexes did not slow PI(4,5)P2 lateral mobility. Only the spectrin and septin cytoskeletons showed reduced PI(4,5)P2 diffusion. We conclude that even structures with high densities of PI(4,5)P2 effector proteins, such as clathrin-coated pits and focal adhesions, do not corral unbound PI(4,5)P2, questioning a role for spatially segregated PI(4,5)P2 pools in organizing and regulating PM functions.
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Affiliation(s)
- Jonathan Pacheco
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Anna C. Cassidy
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - James P. Zewe
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Rachel C. Wills
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Gerald R.V. Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA
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Ho CT, Gupton SL. Cytoskeleton: Septin wreaths regulate actin in neuritogenesis. Curr Biol 2023; 33:R98-R100. [PMID: 36750031 DOI: 10.1016/j.cub.2022.12.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The shape of a neuron changes dramatically during development. New work reports a novel septin cytoskeleton network that is important in establishing proper neuronal morphology.
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Affiliation(s)
- Chris T Ho
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, 111 Mason Farm Road, Medical Biomolecular Research Building 4332, Campus Box 7090, Chapel Hill, NC 27599-7545, USA
| | - Stephanie L Gupton
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, 111 Mason Farm Road, Medical Biomolecular Research Building 4332, Campus Box 7090, Chapel Hill, NC 27599-7545, USA; UNC Neuroscience Center, University of North Carolina at Chapel Hill, 116 Manning Drive, Chapel Hill, NC 27599, USA.
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Radler MR, Liu X, Peng M, Doyle B, Toyo-Oka K, Spiliotis ET. Pyramidal neuron morphogenesis requires a septin network that stabilizes filopodia and suppresses lamellipodia during neurite initiation. Curr Biol 2023; 33:434-448.e8. [PMID: 36538929 PMCID: PMC9905282 DOI: 10.1016/j.cub.2022.11.043] [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: 06/20/2022] [Revised: 10/31/2022] [Accepted: 11/18/2022] [Indexed: 12/23/2022]
Abstract
Pyramidal neurons are a major cell type of the forebrain, consisting of a pyramidally shaped soma with axonal and apicobasal dendritic processes. It is poorly understood how the neuronal soma develops its pyramidal morphology, while generating neurites of the proper shape and orientation. Here, we discovered that the spherical somata of immature neurite-less neurons possess a circumferential wreath-like network of septin filaments, which promotes neuritogenesis by balancing the protrusive activity of lamellipodia and filopodia. In embryonic rat hippocampal and mouse cortical neurons, the septin wreath network consists of curvilinear filaments that contain septins 5, 7, and 11 (Sept5/7/11). The Sept5/7/11 wreath network demarcates a zone of myosin II enrichment and Arp2/3 diminution at the base of filopodial actin bundles. In Sept7-depleted neurons, cell bodies are enlarged with hyperextended lamellae and abnormally shaped neurites that originate from lamellipodia. This phenotype is accompanied by diminished myosin II and filopodia lifetimes and increased Arp2/3 and lamellipodial activity. Inhibition of Arp2/3 rescues soma and neurite phenotypes, indicating that the septin wreath network suppresses the extension of lamellipodia, facilitating the formation of neurites from the filopodia of a consolidated soma. We show that this septin function is critical for developing a pyramidally shaped soma with properly distributed and oriented dendrites in cultured rat hippocampal neurons and in vivo in mouse perinatal cortical neurons. Therefore, the somatic septin cytoskeleton provides a key morphogenetic mechanism for neuritogenesis and the development of pyramidal neurons.
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Affiliation(s)
- Megan R Radler
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA
| | - Xiaonan Liu
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Megan Peng
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA
| | - Brenna Doyle
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA
| | - Kazuhito Toyo-Oka
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA.
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Yang Z, Zhou L, Si T, Chen S, Liu C, Ng KK, Wang Z, Chen Z, Qiu C, Liu G, Wang Q, Zhou X, Zhang L, Yao Z, He S, Yang M, Zhou Z. Lysyl hydroxylase LH1 promotes confined migration and metastasis of cancer cells by stabilizing Septin2 to enhance actin network. Mol Cancer 2023; 22:21. [PMID: 36721170 PMCID: PMC9887875 DOI: 10.1186/s12943-023-01727-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 01/22/2023] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Excessive extracellular matrix deposition and increased stiffness are typical features of solid tumors such as hepatocellular carcinoma (HCC) and pancreatic ductal adenocarcinoma (PDAC). These conditions create confined spaces for tumor cell migration and metastasis. The regulatory mechanism of confined migration remains unclear. METHODS LC-MS was applied to determine the differentially expressed proteins between HCC tissues and corresponding adjacent tissue. Collective migration and single cell migration microfluidic devices with 6 μm-high confined channels were designed and fabricated to mimic the in vivo confined space. 3D invasion assay was created by Matrigel and Collagen I mixture treat to adherent cells. 3D spheroid formation under various stiffness environment was developed by different substitution percentage GelMA. Immunoprecipitation was performed to pull down the LH1-binding proteins, which were identified by LC-MS. Immunofluorescent staining, FRET, RT-PCR, Western blotting, FRAP, CCK-8, transwell cell migration, wound healing, orthotopic liver injection mouse model and in vivo imaging were used to evaluate the target expression and cellular phenotype. RESULTS Lysyl hydroxylase 1 (LH1) promoted the confined migration of cancer cells at both collective and single cell levels. In addition, LH1 enhanced cell invasion in a 3D biomimetic model and spheroid formation in stiffer environments. High LH1 expression correlated with poor prognosis of both HCC and PDAC patients, while it also promoted in vivo metastasis. Mechanistically, LH1 bound and stabilized Septin2 (SEPT2) to enhance actin polymerization, depending on the hydroxylase domain. Finally, the subpopulation with high expression of both LH1 and SEPT2 had the poorest prognosis. CONCLUSIONS LH1 promotes the confined migration and metastasis of cancer cells by stabilizing SEPT2 and thus facilitating actin polymerization.
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Affiliation(s)
- Zihan Yang
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.35030.350000 0004 1792 6846Department of Precision Diagnostic and Therapeutic Technology, City University of Hong Kong Futian Research Institute, Shenzhen, Guangdong China
| | - Li Zhou
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.412461.40000 0004 9334 6536Department of Gastroenterology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Tongxu Si
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.35030.350000 0004 1792 6846Department of Precision Diagnostic and Therapeutic Technology, City University of Hong Kong Futian Research Institute, Shenzhen, Guangdong China
| | - Siyuan Chen
- grid.412461.40000 0004 9334 6536Department of Gastroenterology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Chengxi Liu
- grid.16890.360000 0004 1764 6123State Key Laboratory of Chemical Biology and Drug Discovery, Research Institute for Future Food and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China
| | - Kelvin Kaki Ng
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.35030.350000 0004 1792 6846Department of Precision Diagnostic and Therapeutic Technology, City University of Hong Kong Futian Research Institute, Shenzhen, Guangdong China
| | - Zesheng Wang
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.35030.350000 0004 1792 6846Department of Precision Diagnostic and Therapeutic Technology, City University of Hong Kong Futian Research Institute, Shenzhen, Guangdong China
| | - Zhiji Chen
- grid.412461.40000 0004 9334 6536Department of Gastroenterology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Chan Qiu
- grid.412461.40000 0004 9334 6536Department of Gastroenterology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Guopan Liu
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.35030.350000 0004 1792 6846Department of Precision Diagnostic and Therapeutic Technology, City University of Hong Kong Futian Research Institute, Shenzhen, Guangdong China
| | - Qingliang Wang
- grid.412461.40000 0004 9334 6536Department of Pathology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xiaoyu Zhou
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.35030.350000 0004 1792 6846Department of Precision Diagnostic and Therapeutic Technology, City University of Hong Kong Futian Research Institute, Shenzhen, Guangdong China
| | - Liang Zhang
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.35030.350000 0004 1792 6846Department of Precision Diagnostic and Therapeutic Technology, City University of Hong Kong Futian Research Institute, Shenzhen, Guangdong China
| | - Zhongping Yao
- grid.16890.360000 0004 1764 6123State Key Laboratory of Chemical Biology and Drug Discovery, Research Institute for Future Food and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China
| | - Song He
- grid.412461.40000 0004 9334 6536Department of Gastroenterology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Mengsu Yang
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.35030.350000 0004 1792 6846Department of Precision Diagnostic and Therapeutic Technology, City University of Hong Kong Futian Research Institute, Shenzhen, Guangdong China
| | - Zhihang Zhou
- grid.35030.350000 0004 1792 6846Department of Biomedical Sciences, and Tung Biomedical Sciences Center, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People’s Republic of China ,grid.412461.40000 0004 9334 6536Department of Gastroenterology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Benoit B, Poüs C, Baillet A. Septins as membrane influencers: direct play or in association with other cytoskeleton partners. Front Cell Dev Biol 2023; 11:1112319. [PMID: 36875762 PMCID: PMC9982393 DOI: 10.3389/fcell.2023.1112319] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/23/2023] [Indexed: 02/19/2023] Open
Abstract
The cytoskeleton comprises three polymerizing structures that have been studied for a long time, actin microfilaments, microtubules and intermediate filaments, plus more recently investigated dynamic assemblies like septins or the endocytic-sorting complex required for transport (ESCRT) complex. These filament-forming proteins control several cell functions through crosstalks with each other and with membranes. In this review, we report recent works that address how septins bind to membranes, and influence their shaping, organization, properties and functions, either by binding to them directly or indirectly through other cytoskeleton elements.
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Affiliation(s)
- Béatrice Benoit
- INSERM UMR-S 1193, UFR de Pharmacie, University Paris-Saclay, Orsay, France
| | - Christian Poüs
- INSERM UMR-S 1193, UFR de Pharmacie, University Paris-Saclay, Orsay, France.,Laboratoire de Biochimie-Hormonologie, Hôpital Antoine Béclère, AP-HP, Hôpitaux Universitaires Paris-Saclay, Clamart, France
| | - Anita Baillet
- INSERM UMR-S 1193, UFR de Pharmacie, University Paris-Saclay, Orsay, France
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41
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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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Ibanes S, El-Alaoui F, Lai-Kee-Him J, Cazevieille C, Hoh F, Lyonnais S, Bron P, Cipelletti L, Picas L, Piatti S. The Syp1/FCHo2 protein induces septin filament bundling through its intrinsically disordered domain. Cell Rep 2022; 41:111765. [PMID: 36476870 DOI: 10.1016/j.celrep.2022.111765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 09/30/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022] Open
Abstract
The septin collar of budding yeast is an ordered array of septin filaments that serves a scaffolding function for the cytokinetic machinery at the bud neck and compartmentalizes the membrane between mother and daughter cell. How septin architecture is aided by septin-binding proteins is largely unknown. Syp1 is an endocytic protein that was implicated in the timely recruitment of septins to the newly forming collar through an unknown mechanism. Using advanced microscopy and in vitro reconstitution assays, we show that Syp1 is able to align laterally and tightly pack septin filaments, thereby forming flat bundles or sheets. This property is shared by the Syp1 mammalian counterpart FCHo2, thus emphasizing conserved protein functions. Interestingly, the septin-bundling activity of Syp1 resides mainly in its intrinsically disordered region. Our data uncover the mechanism through which Syp1 promotes septin collar assembly and offer another example of functional diversity of unstructured protein domains.
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Affiliation(s)
- Sandy Ibanes
- CRBM (Centre de Recherche en Biologie cellulaire de Montpellier), University of Montpellier, CNRS UMR 5237, 1919 Route de Mende, 34293 Montpellier, France
| | - Fatima El-Alaoui
- IRIM (Institut de Recherche en Infectiologie de Montpellier), University of Montpellier, CNRS UMR 9004, 1919 Route de Mende, 34293 Montpellier, France
| | - Joséphine Lai-Kee-Him
- CBS (Centre de Biologie Structurale), University of Montpellier, CNRS UMR 5048, INSERM U 1054, 29 Rue de Navacelles, 34090 Montpellier, France
| | - Chantal Cazevieille
- COMET Electron Microscopy Platform, INM (Institute for Neurosciences of Montpellier), University of Montpellier, INSERM U 1298, 80 Rue Augustin Fliche, 34091 Montpellier, France
| | - François Hoh
- CBS (Centre de Biologie Structurale), University of Montpellier, CNRS UMR 5048, INSERM U 1054, 29 Rue de Navacelles, 34090 Montpellier, France
| | - Sébastien Lyonnais
- CEMIPAI (Centre d'Etudes des Maladies Infectieuses et Pharmacologie Anti-Infectieuse), University of Montpellier, UAR 3725 CNRS, Montpellier, France
| | - Patrick Bron
- CBS (Centre de Biologie Structurale), University of Montpellier, CNRS UMR 5048, INSERM U 1054, 29 Rue de Navacelles, 34090 Montpellier, France
| | - Luca Cipelletti
- L2C (Laboratoire Charles Coulomb), University of Montpellier, CNRS, Place E. Bataillon, 34095 Montpellier, France; IUF (Institut Universitaire de France), Paris, France
| | - Laura Picas
- IRIM (Institut de Recherche en Infectiologie de Montpellier), University of Montpellier, CNRS UMR 9004, 1919 Route de Mende, 34293 Montpellier, France
| | - Simonetta Piatti
- CRBM (Centre de Recherche en Biologie cellulaire de Montpellier), University of Montpellier, CNRS UMR 5237, 1919 Route de Mende, 34293 Montpellier, France.
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Hinson SR, Honorat JA, Grund EM, Clarkson BD, Miske R, Scharf M, Zivelonghi C, Al-Lozi MT, Bucelli RC, Budhram A, Cho T, Choi E, Grell J, Lopez-Chiriboga AS, Levin M, Merati M, Montalvo M, Pittock SJ, Wilson MR, Howe CL, McKeon A. Septin-5 and -7-IgGs: Neurologic, Serologic, and Pathophysiologic Characteristics. Ann Neurol 2022; 92:1090-1101. [PMID: 36053822 PMCID: PMC9672904 DOI: 10.1002/ana.26482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 08/03/2022] [Accepted: 08/09/2022] [Indexed: 11/08/2022]
Abstract
BACKGROUND AND OBJECTIVES We sought to determine clinical significance of neuronal septin autoimmunity and evaluate for potential IgG effects. METHODS Septin-IgGs were detected by indirect immunofluorescence assays (IFAs; mouse tissue and cell based) or Western blot. IgG binding to (and internalization of) extracellular septin epitopes were evaluated for by live rat hippocampal neuron assay. The impact of purified patient IgGs on murine cortical neuron function was determined by recording extracellular field potentials in a multielectrode array platform. RESULTS Septin-IgGs were identified in 23 patients. All 8 patients with septin-5-IgG detected had cerebellar ataxia, and 7 had prominent eye movement disorders. One of 2 patients with co-existing septin-7-IgG had additional psychiatric phenotype (apathy, emotional blunting, and poor insight). Fifteen patients had septin-7 autoimmunity, without septin-5-IgG detected. Disorders included encephalopathy (11; 2 patients with accompanying myelopathy, and 2 were relapsing), myelopathy (3), and episodic ataxia (1). Psychiatric symptoms (≥1 of agitation, apathy, catatonia, disorganized thinking, and paranoia) were prominent in 6 of 11 patients with encephalopathic symptoms. Eight of 10 patients with data available (from 23 total) improved after immunotherapy, and a further 2 patients improved spontaneously. Staining of plasma membranes of live hippocampal neurons produced by patient IgGs (subclasses 1 and 2) colocalized with pre- and post-synaptic markers. Decreased spiking and bursting behavior in mixed cultures of murine glutamatergic and GABAergic cortical neurons produced by patient IgGs were attributable to neither antigenic crosslinking and internalization nor complement activation. INTERPRETATION Septin-IgGs are predictive of distinct treatment-responsive autoimmune central nervous system (CNS) disorders. Live neuron binding and induced electrophysiologic effects by patient IgGs may support septin-specific pathophysiology. ANN NEUROL 2022;92:1090-1101.
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Affiliation(s)
- Shannon R. Hinson
- Department of Laboratory Medicine and Pathology, Mayo
Clinic, Rochester, MN, USA
| | - Josephe A. Honorat
- Department of Laboratory Medicine and Pathology, Mayo
Clinic, Rochester, MN, USA
| | - Ethan M. Grund
- Department of Neurology, Mayo Clinic, Rochester, MN,
USA
| | | | - Ramona Miske
- Institute for Experimental Immunology, affiliated to
EUROIMMUN Medizinische Labordiagnostika, Lubeck, Germany
| | - Madeleine Scharf
- Institute for Experimental Immunology, affiliated to
EUROIMMUN Medizinische Labordiagnostika, Lubeck, Germany
| | - Cecilia Zivelonghi
- Department of Laboratory Medicine and Pathology, Mayo
Clinic, Rochester, MN, USA
| | | | | | - Adrian Budhram
- Department of Neurology, Mayo Clinic, Rochester, MN,
USA
| | - Tracey Cho
- Department of Neurology, University of Iowa, Iowa,
USA
| | - Ellie Choi
- Overlake Hospital, Bellevue, Washington, USA
| | - Jacquelyn Grell
- Department of Laboratory Medicine and Pathology, Mayo
Clinic, Rochester, MN, USA
| | | | - Marc Levin
- Department of Ophthalmology, Palo Alto Medical Foundation,
Palo Alto, CA, USA
| | - Melody Merati
- Department of Neurology, Michigan State University,
Lansing, MI, USA
| | - Mayra Montalvo
- Department of Neurology, Mayo Clinic, Rochester, MN,
USA
| | - Sean J. Pittock
- Department of Laboratory Medicine and Pathology, Mayo
Clinic, Rochester, MN, USA
- Department of Neurology, Mayo Clinic, Rochester, MN,
USA
| | - Michael R. Wilson
- Weill Institute for Neurosciences, Department of
Neurology, University of California, San Francisco, USA
| | | | - Andrew McKeon
- Department of Laboratory Medicine and Pathology, Mayo
Clinic, Rochester, MN, USA
- Department of Neurology, Mayo Clinic, Rochester, MN,
USA
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44
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Cowan JM, Duggan JJ, Hewitt BR, Petrie RJ. Non-muscle myosin II and the plasticity of 3D cell migration. Front Cell Dev Biol 2022; 10:1047256. [DOI: 10.3389/fcell.2022.1047256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 10/31/2022] [Indexed: 11/11/2022] Open
Abstract
Confined cells migrating through 3D environments are also constrained by the laws of physics, meaning for every action there must be an equal and opposite reaction for cells to achieve motion. Fascinatingly, there are several distinct molecular mechanisms that cells can use to move, and this is reflected in the diverse ways non-muscle myosin II (NMII) can generate the mechanical forces necessary to sustain 3D cell migration. This review summarizes the unique modes of 3D migration, as well as how NMII activity is regulated and localized within each of these different modes. In addition, we highlight tropomyosins and septins as two protein families that likely have more secrets to reveal about how NMII activity is governed during 3D cell migration. Together, this information suggests that investigating the mechanisms controlling NMII activity will be helpful in understanding how a single cell transitions between distinct modes of 3D migration in response to the physical environment.
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45
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Embryonic Development and Histological Analysis of Skeletal Muscles of Tenuidactylus caspius (Eichwald, 1831) Lizards (Reptilia: Squamata). J ZOOL SYST EVOL RES 2022. [DOI: 10.1155/2022/3618288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
During embryonic development of the Caspian thin-toed gecko migration, formation of myoblast and myosatellite cells occurs in the cranial-distal direction. Somite formation begins in the body part close to the skull and ends in the tail. The time of separation of somites from the proximal mesoderm depends on the temperature of the air and the substrate. Myoblast cells reach their targets and are connected, and the membranes in the area of their contact are destroyed. Myoblast’s fusion creates myosymplasts. The intermediate stage is observed after the formation of small myosymplasts. After that, the chain shape of myosymplasts are transformed into an intermediate plaque form. At this intermediate stage, the number of a nucleus is small, the shape of the nucleus differs from each other, and the location of the nucleus varies. Afterward, the connection of the intermediate forms with each other and with myoblasts forms a rounded shape, where the initial development of myotubules takes place. A fully formed myotubular and myosatellite cells are surrounded by a basal membrane and shape a muscle fiber. The skeletal muscles of the adult Caspian thin-toed gecko are mainly composed of white fibers. Thus, it allows the gecko to move very fast in a short time. Due to the small number of mitochondria in the myotubes, oxygen gas demand is decreased and the body is prevented from overheating.
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46
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Tanzhu G, Chen L, Xiao G, Shi W, Peng H, Chen D, Zhou R. The schemes, mechanisms and molecular pathway changes of Tumor Treating Fields (TTFields) alone or in combination with radiotherapy and chemotherapy. Cell Death Dis 2022; 8:416. [PMID: 36220835 PMCID: PMC9553876 DOI: 10.1038/s41420-022-01206-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 09/22/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022]
Abstract
Tumor Treating Fields (TTFields) is a physical therapy that uses moderate frequency (100–300 kHz) and low-intensity (1–3 V/cm) alternating electric fields to inhibit tumors. Currently, the Food and Drug Administration approves TTFields for treating recurrent or newly diagnosed glioblastoma (GBM) and malignant pleural mesothelioma (MPM). The classical mechanism of TTFields is mitotic inhibition by hindering the formation of tubulin and spindle. In addition, TTFields inhibits cell proliferation, invasion, migration and induces cell death, such as apoptosis, autophagy, pyroptosis, and cell cycle arrest. Meanwhile, it regulates immune function and changes the permeability of the nuclear membrane, cell membrane, and blood-brain barrier. Based on the current researches on TTFields in various tumors, this review comprehensively summarizes the in-vitro effects, changes in pathways and molecules corresponding to relevant parameters of TTFields (frequency, intensity, and duration). In addition, radiotherapy and chemotherapy are common tumor treatments. Thus, we also pay attention to the sequence and dose when TTFields combined with radiotherapy or chemotherapy. TTFields has inhibitory effects in a variety of tumors. The study of TTFields mechanism is conducive to subsequent research. How to combine common tumor therapy such as radiotherapy and chemotherapy to obtain the maximum benefit is also a problem that’s worthy of our attention.
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Affiliation(s)
- Guilong Tanzhu
- Department of Oncology, Xiangya Hospital, Central South University, 410008, Changsha, China
| | - Liu Chen
- Department of Oncology, Xiangya Hospital, Central South University, 410008, Changsha, China
| | - Gang Xiao
- Department of Oncology, Xiangya Hospital, Central South University, 410008, Changsha, China
| | - Wen Shi
- Department of Oncology, Xiangya Hospital, Central South University, 410008, Changsha, China
| | - Haiqin Peng
- Department of Oncology, Xiangya Hospital, Central South University, 410008, Changsha, China
| | - Dikang Chen
- Hunan An Tai Kang Cheng Biotechnology Co., Ltd, Changsha, China
| | - Rongrong Zhou
- Department of Oncology, Xiangya Hospital, Central South University, 410008, Changsha, China. .,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan Province, P.R. China. .,Xiangya Lung Cancer Center, Xiangya Hospital, Central South University, 410008, Changsha, China.
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47
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Gönczi M, Ráduly Z, Szabó L, Fodor J, Telek A, Dobrosi N, Balogh N, Szentesi P, Kis G, Antal M, Trencsenyi G, Dienes B, Csernoch L. Septin7 is indispensable for proper skeletal muscle architecture and function. eLife 2022; 11:e75863. [PMID: 35929607 PMCID: PMC9355566 DOI: 10.7554/elife.75863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 07/03/2022] [Indexed: 11/13/2022] Open
Abstract
Today septins are considered as the fourth component of the cytoskeleton, with the Septin7 isoform playing a critical role in the formation of higher-order structures. While its importance has already been confirmed in several intracellular processes of different organs, very little is known about its role in skeletal muscle. Here, using Septin7 conditional knockdown (KD) mouse model, the C2C12 cell line, and enzymatically isolated adult muscle fibers, the organization and localization of septin filaments are revealed, and an ontogenesis-dependent expression of Septin7 is demonstrated. KD mice displayed a characteristic hunchback phenotype with skeletal deformities, reduction in in vivo and in vitro force generation, and disorganized mitochondrial networks. Furthermore, knockout of Septin7 in C2C12 cells resulted in complete loss of cell division while KD cells provided evidence that Septin7 is essential for proper myotube differentiation. These and the transient increase in Septin7 expression following muscle injury suggest that it may be involved in muscle regeneration and development.
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Affiliation(s)
- Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Zsolt Ráduly
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
- Doctoral School of Molecular Medicine, University of DebrecenDebrecenHungary
| | - László Szabó
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
- Doctoral School of Molecular Medicine, University of DebrecenDebrecenHungary
| | - János Fodor
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Andrea Telek
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Nóra Dobrosi
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Norbert Balogh
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
- Doctoral School of Molecular Medicine, University of DebrecenDebrecenHungary
| | - Péter Szentesi
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Gréta Kis
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Miklós Antal
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - György Trencsenyi
- Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of DebrecenDebrecenHungary
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48
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Bian C, Su J, Zheng Z, Wei J, Wang H, Meng L, Xin Y, Jiang X. ARTS, an unusual septin, regulates tumorigenesis by promoting apoptosis. Biomed Pharmacother 2022; 152:113281. [PMID: 35714512 DOI: 10.1016/j.biopha.2022.113281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/04/2022] [Accepted: 06/08/2022] [Indexed: 11/02/2022] Open
Abstract
Apoptosis plays particularly important roles in tumorigenesis through various mechanisms. Apoptosis can be initiated by both extrinsic and intrinsic signals centered in and coming from the mitochondria. Antiapoptotic proteins promote tumor progression, and the occurrence and progression of tumors are closely related to antiapoptotic protein expression. As the only member of the septin gene family with proapoptotic function, apoptosis-related proteins in the TGF-β signaling pathway (ARTS) has received extensive attention for its unique structure. In contrast, unlike other known inhibitors of apoptosis protein (IAP) antagonists, ARTS exhibits a stronger tumor suppressor potential. Recent research has shown that ARTS can bind and inhibit XIAP and Bcl-2 directly or assist p53 in the degradation of Bcl-XL. Here, we review recent advances in the molecular mechanisms by which the proapoptotic protein ARTS, with its unique structure, inhibits tumorigenesis. We also discuss the possibility of mimicking ARTS to develop small-molecule drugs.
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Affiliation(s)
- Chenbin Bian
- Jilin Provincial Key Laboratory of Radiation Oncology & Therapy, The First Hospital of Jilin University, Changchun 130021, China; Department of Radiation Oncology, The First Hospital of Jilin University, Changchun 130021, China; NHC Key Laboratory of Radiobiology, School of Public Health, Jilin University, Changchun 130021, China.
| | - Jing Su
- Jilin Provincial Key Laboratory of Radiation Oncology & Therapy, The First Hospital of Jilin University, Changchun 130021, China; Department of Radiation Oncology, The First Hospital of Jilin University, Changchun 130021, China; NHC Key Laboratory of Radiobiology, School of Public Health, Jilin University, Changchun 130021, China.
| | - Zhuangzhuang Zheng
- Jilin Provincial Key Laboratory of Radiation Oncology & Therapy, The First Hospital of Jilin University, Changchun 130021, China; Department of Radiation Oncology, The First Hospital of Jilin University, Changchun 130021, China; NHC Key Laboratory of Radiobiology, School of Public Health, Jilin University, Changchun 130021, China.
| | - Jinlong Wei
- Jilin Provincial Key Laboratory of Radiation Oncology & Therapy, The First Hospital of Jilin University, Changchun 130021, China; Department of Radiation Oncology, The First Hospital of Jilin University, Changchun 130021, China; NHC Key Laboratory of Radiobiology, School of Public Health, Jilin University, Changchun 130021, China.
| | - Huanhuan Wang
- Jilin Provincial Key Laboratory of Radiation Oncology & Therapy, The First Hospital of Jilin University, Changchun 130021, China; Department of Radiation Oncology, The First Hospital of Jilin University, Changchun 130021, China; NHC Key Laboratory of Radiobiology, School of Public Health, Jilin University, Changchun 130021, China.
| | - Lingbin Meng
- Department of Hematology and Medical Oncology, Moffitt Cancer Center, Tampa, FL 33612, USA.
| | - Ying Xin
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun 130021, China.
| | - Xin Jiang
- Jilin Provincial Key Laboratory of Radiation Oncology & Therapy, The First Hospital of Jilin University, Changchun 130021, China; Department of Radiation Oncology, The First Hospital of Jilin University, Changchun 130021, China; NHC Key Laboratory of Radiobiology, School of Public Health, Jilin University, Changchun 130021, China.
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49
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Radler MR, Spiliotis ET. Right place, right time - Spatial guidance of neuronal morphogenesis by septin GTPases. Curr Opin Neurobiol 2022; 75:102557. [PMID: 35609489 PMCID: PMC9968515 DOI: 10.1016/j.conb.2022.102557] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/07/2022] [Accepted: 04/20/2022] [Indexed: 12/21/2022]
Abstract
Neuronal morphogenesis is guided by outside-in signals and inside-out mechanisms, which require spatiotemporal precision. How the intracellular mechanisms of neuronal morphogenesis are spatiotemporally controlled is not well understood. Septins comprise a unique GTPase module, which consists of complexes with differential localizations and functions. Septins demarcate distinct membrane domains in neural precursor cells, orienting the axis of cell division and the sites of neurite formation. By controlling the localization of membrane and cytoskeletal proteins, septins promote axon-dendrite formation and polarity. Furthermore, septins modulate vesicle exocytosis at pre-synaptic terminals, and stabilize dendritic spines and post-synaptic densities in a phospho-regulatable manner. We posit that neuronal septins are topologically and functionally specialized for the spatiotemporal regulation of neuronal morphogenesis and plasticity.
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Affiliation(s)
- Megan R. Radler
- Department of Biology, Drexel University, Papadakis Integrated Sciences Building 423, 3245 Chestnut St, Philadelphia, PA 19104, USA
| | - Elias T. Spiliotis
- Department of Biology, Drexel University, Papadakis Integrated Sciences Building 423, 3245 Chestnut St, Philadelphia, PA 19104, USA
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50
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Vadnjal N, Nourreddine S, Lavoie G, Serres M, Roux PP, Paluch EK. Proteomic analysis of the actin cortex in interphase and mitosis. J Cell Sci 2022; 135:276117. [PMID: 35892282 PMCID: PMC9481927 DOI: 10.1242/jcs.259993] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 07/07/2022] [Indexed: 11/20/2022] Open
Abstract
Many animal cell shape changes are driven by gradients in the contractile tension of the actomyosin cortex, a thin cytoskeletal network supporting the plasma membrane. Elucidating cortical tension control is thus essential for understanding cell morphogenesis. Increasing evidence shows that alongside myosin activity, actin network organisation and composition are key to cortex tension regulation. However, owing to a poor understanding of how cortex composition changes when tension changes, which cortical components are important remains unclear. In this article, we compared cortices from cells with low and high cortex tensions. We purified cortex-enriched fractions from cells in interphase and mitosis, as mitosis is characterised by high cortical tension. Mass spectrometry analysis identified 922 proteins consistently represented in both interphase and mitotic cortices. Focusing on actin-related proteins narrowed down the list to 238 candidate regulators of the mitotic cortical tension increase. Among these candidates, we found that there is a role for septins in mitotic cell rounding control. Overall, our study provides a comprehensive dataset of candidate cortex regulators, paving the way for systematic investigations of the regulation of cell surface mechanics. This article has an associated First Person interview with the first author of the paper. Summary: Contractile tension at the actomyosin cortex is a key determinant of cell shape. Cortices from cells with high and low tension were analysed using mass spectrometry, generating a dataset of candidate cortex mechanics regulators.
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Affiliation(s)
- Neza Vadnjal
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK.,Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Sami Nourreddine
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal QC, H3T 1J4, Canada
| | - Geneviève Lavoie
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal QC, H3T 1J4, Canada
| | - Murielle Serres
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Philippe P Roux
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal QC, H3T 1J4, Canada.,Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montreal, QC, H3T 1J4, Canada
| | - Ewa K Paluch
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK.,Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
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