1
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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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2
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Fu B, Xiong Y, Sha Z, Xue W, Xu B, Tan S, Guo D, Lin F, Wang L, Ji J, Luo Y, Lin X, Wu H. SEPTIN2 suppresses an IFN-γ-independent, proinflammatory macrophage activation pathway. Nat Commun 2023; 14:7441. [PMID: 37978190 PMCID: PMC10656488 DOI: 10.1038/s41467-023-43283-2] [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: 02/13/2023] [Accepted: 11/06/2023] [Indexed: 11/19/2023] Open
Abstract
Interferon-gamma (IFN-γ) signaling is necessary for the proinflammatory activation of macrophages but IFN-γ-independent pathways, for which the initiating stimuli and downstream mechanisms are lesser known, also contribute. Here we identify, by high-content screening, SEPTIN2 (SEPT2) as a negative regulation of IFN-γ-independent macrophage autoactivation. Mechanistically, endoplasmic reticulum (ER) stress induces the expression of SEPT2, which balances the competition between acetylation and ubiquitination of heat shock protein 5 at position Lysine 327, thereby alleviating ER stress and constraining M1-like polarization and proinflammatory cytokine release. Disruption of this negative feedback regulation leads to the accumulation of unfolded proteins, resulting in accelerated M1-like polarization, excessive inflammation and tissue damage. Our study thus uncovers an IFN-γ-independent macrophage proinflammatory autoactivation pathway and suggests that SEPT2 may play a role in the prevention or resolution of inflammation during infection.
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Affiliation(s)
- Beibei Fu
- School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Yan Xiong
- School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Zhou Sha
- School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Weiwei Xue
- School of Pharmaceutical Sciences, Chongqing University, 401331, Chongqing, China
| | - Binbin Xu
- School of Pharmaceutical Sciences, Chongqing University, 401331, Chongqing, China
| | - Shun Tan
- Chongqing Public Health Medical Center, 400036, Chongqing, China
| | - Dong Guo
- School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Feng Lin
- School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Lulu Wang
- School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Jianjian Ji
- Jiangsu Key Laboratory of Pediatric Respiratory Disease, Institute of Pediatrics, Nanjing University of Chinese Medicine, 210023, Nanjing, China
| | - Yang Luo
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing University, 400044, Chongqing, China.
| | - Xiaoyuan Lin
- Institut für Virologie, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany.
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), 400038, Chongqing, China.
| | - Haibo Wu
- School of Life Sciences, Chongqing University, 401331, Chongqing, China.
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing University, 400044, Chongqing, China.
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3
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Cavini IA, Winter AJ, D’Muniz Pereira H, Woolfson DN, Crump MP, Garratt RC. X-ray structure of the metastable SEPT14-SEPT7 coiled coil reveals a hendecad region crucial for heterodimerization. Acta Crystallogr D Struct Biol 2023; 79:881-894. [PMID: 37712436 PMCID: PMC10565730 DOI: 10.1107/s2059798323006514] [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: 05/11/2023] [Accepted: 07/27/2023] [Indexed: 09/16/2023] Open
Abstract
Septins are membrane-associated, GTP-binding proteins that are present in most eukaryotes. They polymerize to play important roles as scaffolds and/or diffusion barriers as part of the cytoskeleton. α-Helical coiled-coil domains are believed to contribute to septin assembly, and those observed in both human SEPT6 and SEPT8 form antiparallel homodimers. These are not compatible with their parallel heterodimeric organization expected from the current model for protofilament assembly, but they could explain the interfilament cross-bridges observed by microscopy. Here, the first structure of a heterodimeric septin coiled coil is presented, that between SEPT14 and SEPT7; the former is a SEPT6/SEPT8 homolog. This new structure is parallel, with two long helices that are axially shifted by a full helical turn with reference to their sequence alignment. The structure also has unusual knobs-into-holes packing of side chains. Both standard seven-residue (heptad) and the less common 11-residue (hendecad) repeats are present, creating two distinct regions with opposite supercoiling, which gives rise to an overall straight coiled coil. Part of the hendecad region is required for heterodimerization and therefore may be crucial for selective septin recognition. These unconventional sequences and structural features produce a metastable heterocomplex that nonetheless has enough specificity to promote correct protofilament assembly. For instance, the lack of supercoiling may facilitate unzipping and transitioning to the antiparallel homodimeric state.
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Affiliation(s)
- Italo A. Cavini
- São Carlos Institute of Physics, University of São Paulo, Avenida João Dagnone 1100, São Carlos, SP 13563-120, Brazil
| | - Ashley J. Winter
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Humberto D’Muniz Pereira
- São Carlos Institute of Physics, University of São Paulo, Avenida João Dagnone 1100, São Carlos, SP 13563-120, Brazil
| | - Derek N. Woolfson
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
- School of Biochemistry, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
- BrisSynBio, University of Bristol, School of Chemistry, Bristol BS8 1TS, United Kingdom
| | - Matthew P. Crump
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
- BrisSynBio, University of Bristol, School of Chemistry, Bristol BS8 1TS, United Kingdom
| | - Richard C. Garratt
- São Carlos Institute of Physics, University of São Paulo, Avenida João Dagnone 1100, São Carlos, SP 13563-120, Brazil
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4
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Zhovmer AS, Manning A, Smith C, Wang J, Ma X, Tsygankov D, Dokholyan NV, Cartagena-Rivera AX, Singh RK, Tabdanov ED. Septins Enable T Cell Contact Guidance via Amoeboid-Mesenchymal Switch. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.26.559597. [PMID: 37808814 PMCID: PMC10557721 DOI: 10.1101/2023.09.26.559597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Lymphocytes exit circulation and enter in-tissue guided migration toward sites of tissue pathologies, damage, infection, or inflammation. By continuously sensing and adapting to the guiding chemo-mechano-structural properties of the tissues, lymphocytes dynamically alternate and combine their amoeboid (non-adhesive) and mesenchymal (adhesive) migration modes. However, which mechanisms guide and balance different migration modes are largely unclear. Here we report that suppression of septins GTPase activity induces an abrupt amoeboid-to-mesenchymal transition of T cell migration mode, characterized by a distinct, highly deformable integrin-dependent immune cell contact guidance. Surprisingly, the T cell actomyosin cortex contractility becomes diminished, dispensable and antagonistic to mesenchymal-like migration mode. Instead, mesenchymal-like T cells rely on microtubule stabilization and their non-canonical dynein motor activity for high fidelity contact guidance. Our results establish septin's GTPase activity as an important on/off switch for integrin-dependent migration of T lymphocytes, enabling their dynein-driven fluid-like mesenchymal propulsion along the complex adhesion cues.
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Affiliation(s)
- Alexander S Zhovmer
- Center for Biologics Evaluation & Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Alexis Manning
- Center for Biologics Evaluation & 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
| | - Jian Wang
- Departments of Pharmacology, Penn State College of Medicine, The Pennsylvania State University, Hershey, PA, USA
| | - Xuefei Ma
- Center for Biologics Evaluation & 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
| | - Nikolay V Dokholyan
- Departments of Pharmacology, Penn State College of Medicine, The Pennsylvania State University, Hershey, PA, USA
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, The Pennsylvania State University Hershey-Hummelstown, PA, USA
| | - Alexander X Cartagena-Rivera
- Section on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Rakesh K Singh
- Department of Obstetrics & Gynecology, University of Rochester Medical Center, Rochester, NY, USA
| | - Erdem D Tabdanov
- Departments of Pharmacology, Penn State College of Medicine, The Pennsylvania State University, Hershey, PA, USA
- Penn State Cancer Institute, Penn State College of Medicine, The Pennsylvania State University, Hershey, PA, USA
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5
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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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6
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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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7
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Cai T, Peng J, Omrane M, Benzoubir N, Samuel D, Gassama-Diagne A. Septin 9 Orients the Apico-Basal Polarity Axis and Controls Plasticity Signals. Cells 2023; 12:1815. [PMID: 37508480 PMCID: PMC10377970 DOI: 10.3390/cells12141815] [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: 06/11/2023] [Revised: 07/02/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
The cytoskeleton is a master organizer of the cellular cortex and membrane trafficking and therefore plays a crucial role in apico-basal polarity. Septins form a family of GTPases that assemble into non-polar filaments, which bind to membranes and recruit cytoskeletal elements such as microtubules and actin using their polybasic (PB) domains, to perform their broad biological functions. Nevertheless, the role of septins and the significance of their membrane-binding ability in apico-basal polarity remains under-investigated. Here, using 3D cultures, we demonstrated that septin 9 localizes to the basolateral membrane (BM). Its depletion induces an inverted polarity phenotype, decreasing β-catenin at BM and increasing transforming growth factor (TGFβ) and Epithelial-Mesenchymal Transition (EMT) markers. Similar effects were observed after deleting its two PB domains. The mutant became cytoplasmic and apical. The cysts with an inverted polarity phenotype displayed an invasive phenotype, with src and cortactin accumulating at the peripheral membrane. The inhibition of TGFβ-receptor and RhoA rescued the polarized phenotype, although the cysts from overexpressed septin 9 overgrew and presented a filled lumen. Both phenotypes corresponded to tumor features. This suggests that septin 9 expression, along with its assembly through the two PB domains, is essential for establishing and maintaining apico-basal polarity against tumor development.
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Affiliation(s)
- Tingting Cai
- Unité 1193 INSERM, F-94800 Villejuif, France
- Université Paris-Saclay, UMR-S 1193, F-94800 Villejuif, France
| | - Juan Peng
- Unité 1193 INSERM, F-94800 Villejuif, France
- Université Paris-Saclay, UMR-S 1193, F-94800 Villejuif, France
| | - Mohyeddine Omrane
- Unité 1193 INSERM, F-94800 Villejuif, France
- Université Paris-Saclay, UMR-S 1193, F-94800 Villejuif, France
| | - Nassima Benzoubir
- Unité 1193 INSERM, F-94800 Villejuif, France
- Université Paris-Saclay, UMR-S 1193, F-94800 Villejuif, France
| | - Didier Samuel
- Unité 1193 INSERM, F-94800 Villejuif, France
- Université Paris-Saclay, UMR-S 1193, F-94800 Villejuif, France
- AP-HP Hôpital Paul Brousse, Centre Hepato-Biliaire, F-94800 Villejuif, France
| | - Ama Gassama-Diagne
- Unité 1193 INSERM, F-94800 Villejuif, France
- Université Paris-Saclay, UMR-S 1193, F-94800 Villejuif, France
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8
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Sharma K, Menon MB. Decoding post-translational modifications of mammalian septins. Cytoskeleton (Hoboken) 2023; 80:169-181. [PMID: 36797225 DOI: 10.1002/cm.21747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 01/21/2023] [Accepted: 02/10/2023] [Indexed: 02/18/2023]
Abstract
Septins are cytoskeletal GTPases that form nonpolar filaments and higher-ordered structures and they take part in a wide range of cellular processes. Septins are conserved from yeast to mammals but absent from higher plants. The number of septin genes vary between organisms and they usually form complex heteropolymeric networks. Most septins are known to be capable of GTP hydrolysis which may regulate septin dynamics. Knowledge on regulation of septin function by post-translational modifications is still in its infancy. In this review article, we highlight the post-translational modifications reported for the 13 human septins and discuss their implications on septin functions. In addition to the functionally investigated modifications, we also try to make sense of the complex septin post-translational modification code revealed from large-scale phospho-proteomic datasets. Future studies may determine how these isoform-specific and homology group specific modifications affect septin structure and function.
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Affiliation(s)
- Khushboo Sharma
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Manoj B Menon
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
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9
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Martens AK, Erwig M, Patzig J, Fledrich R, Füchtbauer EM, Werner HB. Targeted inactivation of the Septin2 and Septin9 genes in myelinating Schwann cells of mice. Cytoskeleton (Hoboken) 2023; 80:290-302. [PMID: 36378242 DOI: 10.1002/cm.21736] [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: 09/08/2022] [Revised: 11/03/2022] [Accepted: 11/11/2022] [Indexed: 11/16/2022]
Abstract
The formation of axon-enwrapping myelin sheaths by oligodendrocytes in the central nervous system involves the assembly of a scaffolding septin filament comprised of the subunits SEPTIN2, SEPTIN4, SEPTIN7 and SEPTIN8. Conversely, in the peripheral nervous system (PNS), myelin is synthesized by a different cell type termed Schwann cells, and it remained unknown if septins also assemble as a multimer in PNS myelin. According to prior proteome analysis, PNS myelin comprises the subunits SEPTIN2, SEPTIN7, SEPTIN8, SEPTIN9, and SEPTIN11, which localize to the paranodal and abaxonal myelin subcompartments. Here, we use the Cre/loxP-system to delete the Septin9-gene specifically in Schwann cells, causing a markedly reduced abundance of SEPTIN9 in sciatic nerves, implying that Schwann cells are the main cell type expressing SEPTIN9 in the nerve. However, Septin9-deficiency in Schwann cells did not affect the abundance or localization of other septin subunits. In contrast, when deleting the Septin2-gene in Schwann cells the abundance of all relevant septin subunits was markedly reduced, including SEPTIN9. Notably, we did not find evidence that deleting Septin2 or Septin9 in Schwann cells impairs myelin biogenesis, nerve conduction velocity or motor/sensory capabilities, at least at the assessed timepoints. Our data thus show that SEPTIN2 but not SEPTIN9 is required for the formation or stabilization of a septin multimer in PNS myelin in vivo; however, its functional relevance remains to be established.
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Affiliation(s)
- Ann-Kristin Martens
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Michelle Erwig
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Julia Patzig
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Robert Fledrich
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | | | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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10
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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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11
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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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12
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Lobato-Márquez D, Conesa JJ, López-Jiménez AT, Divine ME, Pruneda JN, Mostowy S. Septins and K63 ubiquitin chains are present in separate bacterial microdomains during autophagy of entrapped Shigella. J Cell Sci 2023; 136:jcs261139. [PMID: 36939083 PMCID: PMC10264824 DOI: 10.1242/jcs.261139] [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: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/21/2023] Open
Abstract
During host cell invasion, Shigella escapes to the cytosol and polymerizes actin for cell-to-cell spread. To restrict cell-to-cell spread, host cells employ cell-autonomous immune responses including antibacterial autophagy and septin cage entrapment. How septins interact with the autophagy process to target Shigella for destruction is poorly understood. Here, we employed a correlative light and cryo-soft X-ray tomography (cryo-SXT) pipeline to study Shigella septin cage entrapment in its near-native state. Quantitative cryo-SXT showed that Shigella fragments mitochondria and enabled visualization of X-ray-dense structures (∼30 nm resolution) surrounding Shigella entrapped in septin cages. Using Airyscan confocal microscopy, we observed lysine 63 (K63)-linked ubiquitin chains decorating septin-cage-entrapped Shigella. Remarkably, septins and K63 chains are present in separate bacterial microdomains, indicating they are recruited separately during antibacterial autophagy. Cryo-SXT and live-cell imaging revealed an interaction between septins and LC3B-positive membranes during autophagy of Shigella. Together, these findings demonstrate how septin-caged Shigella are targeted for autophagy and provide fundamental insights into autophagy-cytoskeleton interactions.
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Affiliation(s)
- Damián Lobato-Márquez
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - José Javier Conesa
- MISTRAL beamline, ALBA Synchrotron Light Source, Cerdanyola del Vallès, 08290 Barcelona, Spain
| | - Ana Teresa López-Jiménez
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Michael E. Divine
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Jonathan N. Pruneda
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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13
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Martins CS, Taveneau C, Castro-Linares G, Baibakov M, Buzhinsky N, Eroles M, Milanović V, Omi S, Pedelacq JD, Iv F, Bouillard L, Llewellyn A, Gomes M, Belhabib M, Kuzmić M, Verdier-Pinard P, Lee S, Badache A, Kumar S, Chandre C, Brasselet S, Rico F, Rossier O, Koenderink GH, Wenger J, Cabantous S, Mavrakis M. Human septins organize as octamer-based filaments and mediate actin-membrane anchoring in cells. J Cell Biol 2023; 222:213778. [PMID: 36562751 PMCID: PMC9802686 DOI: 10.1083/jcb.202203016] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 10/20/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Septins are cytoskeletal proteins conserved from algae and protists to mammals. A unique feature of septins is their presence as heteromeric complexes that polymerize into filaments in solution and on lipid membranes. Although animal septins associate extensively with actin-based structures in cells, whether septins organize as filaments in cells and if septin organization impacts septin function is not known. Customizing a tripartite split-GFP complementation assay, we show that all septins decorating actin stress fibers are octamer-containing filaments. Depleting octamers or preventing septins from polymerizing leads to a loss of stress fibers and reduced cell stiffness. Super-resolution microscopy revealed septin fibers with widths compatible with their organization as paired septin filaments. Nanometer-resolved distance measurements and single-protein tracking further showed that septin filaments are membrane bound and largely immobilized. Finally, reconstitution assays showed that septin filaments mediate actin-membrane anchoring. We propose that septin organization as octamer-based filaments is essential for septin function in anchoring and stabilizing actin filaments at the plasma membrane.
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Affiliation(s)
- Carla Silva Martins
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France.,Centre de Recherche en Cancérologie de Toulouse (CRCT), INSERM, Université de Toulouse, UPS, CNRS, Toulouse, France
| | - Cyntia Taveneau
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Gerard Castro-Linares
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands
| | - Mikhail Baibakov
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Nicolas Buzhinsky
- CNRS, INSERM, LAI, Turing Centre for Living Systems, Aix-Marseille Univ, Marseille, France>
| | - Mar Eroles
- CNRS, INSERM, LAI, Turing Centre for Living Systems, Aix-Marseille Univ, Marseille, France>
| | - Violeta Milanović
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France
| | - Shizue Omi
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Jean-Denis Pedelacq
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III-Paul Sabatier (UPS), Toulouse, France
| | - Francois Iv
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Léa Bouillard
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Alexander Llewellyn
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Maxime Gomes
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Mayssa Belhabib
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Mira Kuzmić
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, Marseille, France
| | - Pascal Verdier-Pinard
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, Marseille, France
| | - Stacey Lee
- Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Ali Badache
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, Marseille, France
| | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, CA, USA
| | | | - Sophie Brasselet
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Felix Rico
- CNRS, INSERM, LAI, Turing Centre for Living Systems, Aix-Marseille Univ, Marseille, France>
| | - Olivier Rossier
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France
| | - Gijsje H Koenderink
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands
| | - Jerome Wenger
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Stéphanie Cabantous
- Centre de Recherche en Cancérologie de Toulouse (CRCT), INSERM, Université de Toulouse, UPS, CNRS, Toulouse, France
| | - Manos Mavrakis
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
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14
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Wang G, Zhu X, Gao Y, Lv M, Li K, Tang D, Wu H, Xu C, Geng H, Shen Q, Zha X, Duan Z, Zhang J, Hua R, Tao F, Zhou P, Wei Z, Cao Y, Guo R, He X. Biallelic loss-of-function mutations in SEPTIN4 (C17ORF47), encoding a conserved annulus protein, cause thin midpiece spermatozoa and male infertility in humans. Hum Mutat 2022; 43:2079-2090. [PMID: 36135717 DOI: 10.1002/humu.24475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/29/2022] [Accepted: 09/14/2022] [Indexed: 01/25/2023]
Abstract
Asthenoteratozoospermia is the primary cause of infertility in humans. However, the genetic etiology remains largely unknown for those suffering from severe asthenoteratozoospermia caused by thin midpiece defects. In this study, we identified two biallelic loss-of-function variants of SEPTIN4 (previously SEPT4) (Patient 1: c.A721T, p.R241* and Patient 2: c.C205T, p.R69*) in two unrelated individuals from two consanguineous Chinese families. SEPT4 is a conserved annulus protein that is critical for male fertility and the structural integrity of the sperm midpiece in mice. SEPT4 mutations disrupted the formation of SEPT-based annulus and localization of SEPTIN subunits in sperms from patients. The ultrastructural analysis demonstrated striking thin midpiece spermatozoa defects owing to annulus loss and disorganized mitochondrial sheath. Immunofluorescence and immunoblotting analyses of the mitochondrial sheath proteins TOMM20 and HSP60 further indicated that the distribution and abundance of mitochondria were impaired in men harboring biallelic SEPT4 variants. Additionally, we found that the precise localization of SLC26A8, a testis-specific anion transporter that colocalizes with SEPT4 at the sperm annulus, was missing without SEPT4. Moreover, the patient achieved a good pregnancy outcome following intracytoplasmic sperm injection. Overall, our study demonstrated for the first time that SEPT4 variants that induced thin midpiece spermatozoa defects were directly associated with human asthenoteratozoospermia.
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Affiliation(s)
- Guanxiong Wang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Xiaoyu Zhu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Yang Gao
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Mingrong Lv
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Kuokuo Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Dongdong Tang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Huan Wu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Chuan Xu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Hao Geng
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Qunshan Shen
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Anhui Provincial Human Sperm Bank, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Xiaomin Zha
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Zongliu Duan
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Jingjing Zhang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Rong Hua
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Fangbiao Tao
- NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Ping Zhou
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Zhaolian Wei
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China
| | - Yunxia Cao
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Rui Guo
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Xiaojin He
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, Hefei, Anhui, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, Anhui, China.,Anhui Provincial Engineering Research Center of Biopreservation and Artificial Organs, Hefei, Anhui, China.,Anhui Provincial Human Sperm Bank, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
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15
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Panagiotou TC, Chen A, Wilde A. An anillin-CIN85-SEPT9 complex promotes intercellular bridge maturation required for successful cytokinesis. Cell Rep 2022; 40:111274. [PMID: 36044846 DOI: 10.1016/j.celrep.2022.111274] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 07/17/2022] [Accepted: 08/05/2022] [Indexed: 11/20/2022] Open
Abstract
Cleavage of one cell into two is the most dramatic event in the life of a cell. Plasma membrane fission occurs within a narrow intercellular bridge (ICB) between the daughter cells, but the mechanisms underlying ICB formation and maturation are poorly understood. Here we identify CIN85 as an ICB assembly factor and demonstrate its requirement for robust and timely cytokinesis. CIN85 interacts directly with the N-terminal region of anillin and SEPT9 and thereby facilitates SEPT9-containing filament localization to the plasma membrane of the ICB. In contrast, the C-terminal pleckstrin homology (PH) domain of anillin binds to septin units lacking SEPT9 but enriched in SEPT11. Anillin's interactions with distinct septin units are required to promote ICB elongation and maturation that, we propose, generate the physical space into which the abscission machinery is recruited to drive the final membrane scission event releasing two independent daughter cells.
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Affiliation(s)
- Thomas C Panagiotou
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1M1, Canada
| | - Anan Chen
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1M1, Canada
| | - Andrew Wilde
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1M1, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1M1, Canada.
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16
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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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17
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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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18
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Zehtabian A, Müller PM, Goisser M, Obendorf L, Jänisch L, Hümpfer N, Rentsch J, Ewers H. Precise measurement of nanoscopic septin ring structures with deep learning-assisted quantitative superresolution microscopy. Mol Biol Cell 2022; 33:ar76. [PMID: 35594179 PMCID: PMC9635280 DOI: 10.1091/mbc.e22-02-0039] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
The combination of image analysis and superresolution microscopy methods allows for unprecedented insight into the organization of macromolecular assemblies in cells. Advances in deep learning (DL)-based object recognition enable the automated processing of large amounts of data, resulting in high accuracy through averaging. However, while the analysis of highly symmetric structures of constant size allows for a resolution approaching the dimensions of structural biology, DL-based image recognition may introduce bias. This prohibits the development of readouts for processes that involve significant changes in size or shape of amorphous macromolecular complexes. Here we address this problem by using changes of septin ring structures in single molecule localization-based superresolution microscopy data as a paradigm. We identify potential sources of bias resulting from different training approaches by rigorous testing of trained models using real or simulated data covering a wide range of possible results. In a quantitative comparison of our models, we find that a trade-off exists between measurement accuracy and the range of recognized phenotypes. Using our thus verified models, we find that septin ring size can be explained by the number of subunits they are assembled from alone. Furthermore, we provide a new experimental system for the investigation of septin polymerization.
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Affiliation(s)
- Amin Zehtabian
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Paul Markus Müller
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Maximilian Goisser
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Leon Obendorf
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Lea Jänisch
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Nadja Hümpfer
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Jakob Rentsch
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Helge Ewers
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
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19
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Menon MB, Gaestel M. Editorial: Emerging Functions of Septins—Volume II. Front Cell Dev Biol 2022; 10:949824. [PMID: 35784463 PMCID: PMC9246257 DOI: 10.3389/fcell.2022.949824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 05/31/2022] [Indexed: 11/26/2022] Open
Affiliation(s)
- Manoj B. Menon
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
- *Correspondence: Manoj B. Menon, ; Matthias Gaestel,
| | - Matthias Gaestel
- Institute for Cell Biochemistry, Hannover Medical School, Hannover, Germany
- *Correspondence: Manoj B. Menon, ; Matthias Gaestel,
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20
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Septin 9 and phosphoinositides regulate lysosome localization and their association with lipid droplets. iScience 2022; 25:104288. [PMID: 35573204 PMCID: PMC9097704 DOI: 10.1016/j.isci.2022.104288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/21/2021] [Accepted: 04/20/2022] [Indexed: 11/23/2022] Open
Abstract
The accumulation of lipid droplets (LDs) in the liver is a hallmark of steatosis, which is often associated with lysosomal dysfunction. Nevertheless, the underlying mechanisms remain unclear. Here, using Huh7 cells loaded with oleate as a model to study LD metabolism, we show that cellular content and distribution of LDs are correlated with those of the lysosome and regulated by oleate and septin 9. High expression of septin 9 promotes perinuclear clustering of lysosomes which co-localized with Golgi and not with their surrounding LDs. On the other hand, knockdown of septin 9 disperses the two organelles which colocalize at the cell periphery. The Rab7 is present around these peripheral LDs. PtdIns5P which binds septin 9 and MTMR3 which converts PtdIns(3,5)P2 into PtdIns(5) recapitulates the effects of septin 9. By contrast, PtdIns(3,5)P2 promotes LD/lysosome co-localization. Overall, our data reveal a phosphoinositide/septin 9-dependent mechanism that regulates LD behavior through the control of their association with lysosomes. Septin 9 is regulates oleate-induced lysosome perinuclear clustering Septin 9 and MTs regulate oleate-induced lysosome co-localization with Golgi LDs with high septin 9 have less interaction with Rab7 and LAMP1 PIs have specific effects on LD and lysosome
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21
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Cavini IA, Leonardo DA, Rosa HVD, Castro DKSV, D'Muniz Pereira H, Valadares NF, Araujo APU, Garratt RC. The Structural Biology of Septins and Their Filaments: An Update. Front Cell Dev Biol 2021; 9:765085. [PMID: 34869357 PMCID: PMC8640212 DOI: 10.3389/fcell.2021.765085] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 10/27/2021] [Indexed: 01/22/2023] Open
Abstract
In order to fully understand any complex biochemical system from a mechanistic point of view, it is necessary to have access to the three-dimensional structures of the molecular components involved. Septins and their oligomers, filaments and higher-order complexes are no exception. Indeed, the spontaneous recruitment of different septin monomers to specific positions along a filament represents a fascinating example of subtle molecular recognition. Over the last few years, the amount of structural information available about these important cytoskeletal proteins has increased dramatically. This has allowed for a more detailed description of their individual domains and the different interfaces formed between them, which are the basis for stabilizing higher-order structures such as hexamers, octamers and fully formed filaments. The flexibility of these structures and the plasticity of the individual interfaces have also begun to be understood. Furthermore, recently, light has been shed on how filaments may bundle into higher-order structures by the formation of antiparallel coiled coils involving the C-terminal domains. Nevertheless, even with these advances, there is still some way to go before we fully understand how the structure and dynamics of septin assemblies are related to their physiological roles, including their interactions with biological membranes and other cytoskeletal components. In this review, we aim to bring together the various strands of structural evidence currently available into a more coherent picture. Although it would be an exaggeration to say that this is complete, recent progress seems to suggest that headway is being made in that direction.
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Affiliation(s)
- Italo A Cavini
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Diego A Leonardo
- 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
| | - Danielle K S V Castro
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil.,São Carlos Institute of Chemistry, 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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22
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Kandi R, Senger K, Grigoryan A, Soller K, Sakk V, Schuster T, Eiwen K, Menon MB, Gaestel M, Zheng Y, Florian MC, Geiger H. Cdc42-Borg4-Septin7 axis regulates HSC polarity and function. EMBO Rep 2021; 22:e52931. [PMID: 34661963 PMCID: PMC8647144 DOI: 10.15252/embr.202152931] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 09/13/2021] [Accepted: 09/17/2021] [Indexed: 01/03/2023] Open
Abstract
Aging of hematopoietic stem cells (HSCs) is caused by the elevated activity of the small RhoGTPase Cdc42 and an apolar distribution of proteins. Mechanisms by which Cdc42 activity controls polarity of HSCs are not known. Binder of RhoGTPases proteins (Borgs) are known effector proteins of Cdc42 that are able to regulate the cytoskeletal Septin network. Here, we show that Cdc42 interacts with Borg4, which in turn interacts with Septin7 to regulate the polar distribution of Cdc42, Borg4, and Septin7 within HSCs. Genetic deletion of either Borg4 or Septin7 results in a reduced frequency of HSCs polar for Cdc42 or Borg4 or Septin7, a reduced engraftment potential and decreased lymphoid‐primed multipotent progenitor (LMPP) frequency in the bone marrow. Taken together, our data identify a Cdc42‐Borg4‐Septin7 axis essential for the maintenance of polarity within HSCs and for HSC function and provide a rationale for further investigating the role of Borgs and Septins in the regulation of compartmentalization within stem cells.
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Affiliation(s)
- Ravinder Kandi
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | | | - Ani Grigoryan
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | - Karin Soller
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | - Vadim Sakk
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | - Tanja Schuster
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | - Karina Eiwen
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | - Manoj B Menon
- Institute of Cell Biochemistry, Hannover Medical School, Hannover, Germany.,Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Matthias Gaestel
- Institute of Cell Biochemistry, Hannover Medical School, Hannover, Germany
| | - Yi Zheng
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | | | - Hartmut Geiger
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
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23
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Kuzmić M, Linares GC, Fialová JL, Iv F, Salaün D, Llewellyn A, Gomes M, Belhabib M, Liu Y, Asano K, Rodrigues M, Isnardon D, Tachibana T, Koenderink GH, Badache A, Mavrakis M, Verdier-Pinard P. Septin-microtubule association via a motif unique to the isoform 1 of septin 9 tunes stress fibers. J Cell Sci 2021; 135:273936. [PMID: 34854883 DOI: 10.1242/jcs.258850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 11/19/2021] [Indexed: 10/19/2022] Open
Abstract
Septins, a family of GTP-binding proteins assembling into higher order structures, interface with the membrane, actin filaments and microtubules, which positions them as important regulators of cytoarchitecture. Septin 9 (SEPT9), which is frequently overexpressed in tumors and mutated in hereditary neuralgic amyotrophy (HNA), mediates the binding of septins to microtubules, but the molecular determinants of this interaction remained uncertain. We demonstrate that a short MAP-like motif unique to SEPT9 isoform 1 (SEPT9_i1) drives septin octamer-microtubule interaction in cells and in vitro reconstitutions. Septin-microtubule association requires polymerizable septin octamers harboring SEPT9_i1. Although outside of the MAP-like motif, HNA mutations abrogates this association, identifying a putative regulatory domain. Removal of this domain from SEPT9_i1 sequesters septins on microtubules, promotes microtubule stability and alters actomyosin fiber distribution and tension. Thus, we identify key molecular determinants and potential regulatory roles of septin-microtubule interaction, paving the way to deciphering the mechanisms underlying septin-associated pathologies.
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Affiliation(s)
- Mira Kuzmić
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, 13009 Marseille, France
| | - Gerard Castro Linares
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Jindřiška Leischner Fialová
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, 13009 Marseille, France.,Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - François Iv
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Danièle Salaün
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, 13009 Marseille, France
| | - Alex Llewellyn
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Maxime Gomes
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Mayssa Belhabib
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Yuxiang Liu
- Department of Bioengineering, Graduate School of Engineering, Osaka City University, Osaka, Japan
| | - Keisuke Asano
- Department of Bioengineering, Graduate School of Engineering, Osaka City University, Osaka, Japan
| | - Magda Rodrigues
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, 13009 Marseille, France
| | - Daniel Isnardon
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, 13009 Marseille, France
| | - Taro Tachibana
- Department of Bioengineering, Graduate School of Engineering, Osaka City University, Osaka, Japan.,Cell Engineering Corporation, Osaka, Japan
| | - Gijsje H Koenderink
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Ali Badache
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, 13009 Marseille, France
| | - Manos Mavrakis
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Pascal Verdier-Pinard
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, 13009 Marseille, France
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24
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Almeida-Lousada H, Mestre A, Ramalhete S, Price AJ, de Mello RA, Marreiros AD, Neves RPD, Castelo-Branco P. Screening for Colorectal Cancer Leading into a New Decade: The "Roaring '20s" for Epigenetic Biomarkers? Curr Oncol 2021; 28:4874-4893. [PMID: 34898591 PMCID: PMC8628779 DOI: 10.3390/curroncol28060411] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/12/2021] [Accepted: 11/17/2021] [Indexed: 12/16/2022] Open
Abstract
Colorectal cancer (CRC) has an important bearing (top five) on cancer incidence and mortality in the world. The etiology of sporadic CRC is related to the accumulation of genetic and epigenetic alterations that result in the appearance of cancer hallmarks such as abnormal proliferation, evasion of immune destruction, resistance to apoptosis, replicative immortality, and others, contributing to cancer promotion, invasion, and metastasis. It is estimated that, each year, at least four million people are diagnosed with CRC in the world. Depending on CRC staging at diagnosis, many of these patients die, as CRC is in the top four causes of cancer death in the world. New and improved screening tests for CRC are needed to detect the disease at an early stage and adopt patient management strategies to decrease the death toll. The three pillars of CRC screening are endoscopy, radiological imaging, and molecular assays. Endoscopic procedures comprise traditional colonoscopy, and more recently, capsule-based endoscopy. The main imaging modality remains Computed Tomography (CT) of the colon. Molecular approaches continue to grow in the diversity of biomarkers and the sophistication of the technologies deployed to detect them. What started with simple fecal occult blood tests has expanded to an armamentarium, including mutation detection and identification of aberrant epigenetic signatures known to be oncogenic. Biomarker-based screening methods have critical advantages and are likely to eclipse the classical modalities of imaging and endoscopy in the future. For example, imaging methods are costly and require highly specialized medical personnel. In the case of endoscopy, their invasiveness limits compliance from large swaths of the population, especially those with average CRC risk. Beyond mere discomfort and fear, there are legitimate iatrogenic concerns associated with endoscopy. The risks of perforation and infection make endoscopy best suited for a confirmatory role in cases where there are positive results from other diagnostic tests. Biomarker-based screening methods are largely non-invasive and are growing in scope. Epigenetic biomarkers, in particular, can be detected in feces and blood, are less invasive to the average-risk patient, detect early-stage CRC, and have a demonstrably superior patient follow-up. Given the heterogeneity of CRC as it evolves, optimal screening may require a battery of blood and stool tests, where each can leverage different pathways perturbed during carcinogenesis. What follows is a comprehensive, systematic review of the literature pertaining to the screening and diagnostic protocols used in CRC. Relevant articles were retrieved from the PubMed database using keywords including: "Screening", "Diagnosis", and "Biomarkers for CRC". American and European clinical trials in progress were included as well.
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Affiliation(s)
- Hélder Almeida-Lousada
- Faculty of Medicine and Biomedical Sciences (FMCB), Campus de Gambelas, University of Algarve, 8005-139 Faro, Portugal; (H.A.-L.); (A.M.); (S.R.); (R.A.d.M.); (A.D.M.)
- Algarve Biomedical Center Research Institute (ABC-RI), 8005-139 Faro, Portugal
| | - André Mestre
- Faculty of Medicine and Biomedical Sciences (FMCB), Campus de Gambelas, University of Algarve, 8005-139 Faro, Portugal; (H.A.-L.); (A.M.); (S.R.); (R.A.d.M.); (A.D.M.)
- Algarve Biomedical Center Research Institute (ABC-RI), 8005-139 Faro, Portugal
| | - Sara Ramalhete
- Faculty of Medicine and Biomedical Sciences (FMCB), Campus de Gambelas, University of Algarve, 8005-139 Faro, Portugal; (H.A.-L.); (A.M.); (S.R.); (R.A.d.M.); (A.D.M.)
- Algarve Biomedical Center Research Institute (ABC-RI), 8005-139 Faro, Portugal
| | - Aryeh J. Price
- School of Law, University of California, Berkeley, CA 94704, USA;
| | - Ramon Andrade de Mello
- Faculty of Medicine and Biomedical Sciences (FMCB), Campus de Gambelas, University of Algarve, 8005-139 Faro, Portugal; (H.A.-L.); (A.M.); (S.R.); (R.A.d.M.); (A.D.M.)
- Division of Medical Oncology, Escola Paulista de Medicina, Federal University of São Paulo (UNIFESP), São Paulo 04037-004, Brazil
- Precision Oncology & Health Economics Group (ONCOPRECH), Post-Graduation Program in Medicine, Nine of July University (UNINOVE), São Paulo 01525-000, Brazil
| | - Ana D. Marreiros
- Faculty of Medicine and Biomedical Sciences (FMCB), Campus de Gambelas, University of Algarve, 8005-139 Faro, Portugal; (H.A.-L.); (A.M.); (S.R.); (R.A.d.M.); (A.D.M.)
- Algarve Biomedical Center Research Institute (ABC-RI), 8005-139 Faro, Portugal
| | - Ricardo Pires das Neves
- CNC—Center for Neuroscience and Cell Biology, CIBB—Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, 3004-517 Coimbra, Portugal
- IIIUC—Institute of Interdisciplinary Research, University of Coimbra, 3004-517 Coimbra, Portugal
- Correspondence: (R.P.d.N.); (P.C.-B.); Tel.: +351-231-249-170 (R.P.d.N.); +351-289-800-100 (ext. 7813) (P.C.-B.)
| | - Pedro Castelo-Branco
- Faculty of Medicine and Biomedical Sciences (FMCB), Campus de Gambelas, University of Algarve, 8005-139 Faro, Portugal; (H.A.-L.); (A.M.); (S.R.); (R.A.d.M.); (A.D.M.)
- Algarve Biomedical Center Research Institute (ABC-RI), 8005-139 Faro, Portugal
- Champalimaud Research Program, Champalimaud Center for the Unknown, 1400-038 Lisbon, Portugal
- Correspondence: (R.P.d.N.); (P.C.-B.); Tel.: +351-231-249-170 (R.P.d.N.); +351-289-800-100 (ext. 7813) (P.C.-B.)
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25
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Vakhrusheva AV, Kudryavtsev AV, Sokolova OS, Shaitan KV. Procyanidin B3 as a Potential Inhibitor of Human Septin 9. Biophysics (Nagoya-shi) 2021. [DOI: 10.1134/s000635092106018x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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26
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PIAS1 Regulates Hepatitis C Virus-Induced Lipid Droplet Accumulation by Controlling Septin 9 and Microtubule Filament Assembly. Pathogens 2021; 10:pathogens10101327. [PMID: 34684276 PMCID: PMC8537804 DOI: 10.3390/pathogens10101327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/07/2021] [Accepted: 10/13/2021] [Indexed: 01/22/2023] Open
Abstract
Chronic hepatitis C virus (HCV) infection often leads to fibrosis and chronic hepatitis, then cirrhosis and ultimately hepatocellular carcinoma (HCC). The processes of the HVC life cycle involve intimate interactions between viral and host cell proteins and lipid metabolism. However, the molecules and mechanisms involved in this tripartite interaction remain poorly understood. Herein, we show that the infection of HCC-derived Huh7.5 cells with HCV promotes upregulation of the protein inhibitor of activated STAT1 (PIAS1). Reciprocally, PIAS1 regulated the expression of HCV core protein and HCV-induced LD accumulation and impaired HCV replication. Furthermore, PIAS1 controlled HCV-promoted septin 9 filament formation and microtubule polymerization. Subsequently, we found that PIAS1 interacted with septin 9 and controlled its assembly on filaments, which thus affected septin 9-induced lipid droplet accumulation. Taken together, these data reveal that PIAS1 regulates the accumulation of lipid droplets and offer a meaningful insight into how HCV interacts with host proteins.
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27
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Devlin L, Okletey J, Perkins G, Bowen JR, Nakos K, Montagna C, Spiliotis ET. Proteomic profiling of the oncogenic septin 9 reveals isoform-specific interactions in breast cancer cells. Proteomics 2021; 21:e2100155. [PMID: 34409731 DOI: 10.1002/pmic.202100155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/05/2021] [Indexed: 02/06/2023]
Abstract
Septins are a family of multimeric GTP-binding proteins, which are abnormally expressed in cancer. Septin 9 (SEPT9) is an essential and ubiquitously expressed septin with multiple isoforms, which have differential expression patterns and effects in breast cancer cells. It is unknown, however, if SEPT9 isoforms associate with different molecular networks and functions. Here, we performed a proteomic screen in MCF-7 breast cancer cells to identify the interactome of GFP-SEPT9 isoforms 1, 4 and 5, which vary significantly in their N-terminal extensions. While all three isoforms associated with SEPT2 and SEPT7, the truncated SEPT9_i4 and SEPT9_i5 interacted with septins of the SEPT6 group more promiscuously than SEPT9_i1, which bound predominately SEPT8. Spatial mapping and functional clustering of non-septin partners showed isoform-specific differences in interactions with proteins of distinct subcellular organelles (e.g., nuclei, centrosomes, cilia) and functions such as cell signalling and ubiquitination. The interactome of the full length SEPT9_i1 was more enriched in cytoskeletal regulators, while the truncated SEPT9_i4 and SEPT9_i5 exhibited preferential and isoform-specific interactions with nuclear, signalling, and ubiquitinating proteins. These data provide evidence for isoform-specific interactions, which arise from truncations in the N-terminal extensions of SEPT9, and point to novel roles in the pathogenesis of breast cancer.
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Affiliation(s)
- Louis Devlin
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA.,Sanofi Pasteur, Swiftwater, Pennsylvania, USA
| | - Joshua Okletey
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | | | - Jonathan R Bowen
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Konstantinos Nakos
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Cristina Montagna
- Department of Radiology & Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
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28
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Iv F, Martins CS, Castro-Linares G, Taveneau C, Barbier P, Verdier-Pinard P, Camoin L, Audebert S, Tsai FC, Ramond L, Llewellyn A, Belhabib M, Nakazawa K, Di Cicco A, Vincentelli R, Wenger J, Cabantous S, Koenderink GH, Bertin A, Mavrakis M. Insights into animal septins using recombinant human septin octamers with distinct SEPT9 isoforms. J Cell Sci 2021; 134:jcs258484. [PMID: 34350965 DOI: 10.1242/jcs.258484] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 07/02/2021] [Indexed: 01/22/2023] Open
Abstract
Septin GTP-binding proteins contribute essential biological functions that range from the establishment of cell polarity to animal tissue morphogenesis. Human septins in cells form hetero-octameric septin complexes containing the ubiquitously expressed SEPT9 subunit (also known as SEPTIN9). Despite the established role of SEPT9 in mammalian development and human pathophysiology, biochemical and biophysical studies have relied on monomeric SEPT9, thus not recapitulating its native assembly into hetero-octameric complexes. We established a protocol that enabled, for the first time, the isolation of recombinant human septin octamers containing distinct SEPT9 isoforms. A combination of biochemical and biophysical assays confirmed the octameric nature of the isolated complexes in solution. Reconstitution studies showed that octamers with either a long or a short SEPT9 isoform form filament assemblies, and can directly bind and cross-link actin filaments, raising the possibility that septin-decorated actin structures in cells reflect direct actin-septin interactions. Recombinant SEPT9-containing octamers will make it possible to design cell-free assays to dissect the complex interactions of septins with cell membranes and the actin and microtubule cytoskeleton.
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Affiliation(s)
- Francois Iv
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Carla Silva Martins
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Gerard Castro-Linares
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Cyntia Taveneau
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico Chimie Curie, 75005 Paris, France
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Australia; Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, 3800 Clayton, Australia
| | - Pascale Barbier
- Aix-Marseille Univ, CNRS, UMR 7051, Institut de Neurophysiopathologie (INP), 13005 Marseille, France
| | - Pascal Verdier-Pinard
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, 13009 Marseille, France
| | - Luc Camoin
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille Protéomique, Marseille, France
| | - Stéphane Audebert
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille Protéomique, Marseille, France
| | - Feng-Ching Tsai
- Department of Living Matter, AMOLF, 1098 XG Amsterdam, The Netherlands
| | - Laurie Ramond
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Alex Llewellyn
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Mayssa Belhabib
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Koyomi Nakazawa
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico Chimie Curie, 75005 Paris, France
| | - Aurélie Di Cicco
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico Chimie Curie, 75005 Paris, France
| | - Renaud Vincentelli
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS UMR7257, Aix Marseille Univ, 13009 Marseille, France
| | - Jerome Wenger
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Stéphanie Cabantous
- Centre de Recherche en Cancérologie de Toulouse (CRCT), Inserm, Université Paul Sabatier-Toulouse III, CNRS, 31037 Toulouse, France
| | - Gijsje H Koenderink
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
- Department of Living Matter, AMOLF, 1098 XG Amsterdam, The Netherlands
| | - Aurélie Bertin
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico Chimie Curie, 75005 Paris, France
| | - Manos Mavrakis
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
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Salameh J, Cantaloube I, Benoit B, Poüs C, Baillet A. Cdc42 and its BORG2 and BORG3 effectors control the subcellular localization of septins between actin stress fibers and microtubules. Curr Biol 2021; 31:4088-4103.e5. [PMID: 34329591 DOI: 10.1016/j.cub.2021.07.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 05/28/2021] [Accepted: 07/02/2021] [Indexed: 01/22/2023]
Abstract
Cell resistance to taxanes involves several complementary mechanisms, among which septin relocalization from actin stress fibers to microtubules plays an early role. By investigating the molecular mechanism underlying this relocalization, we found that acute paclitaxel treatment triggers the release from stress fibers and subsequent proteasome-mediated degradation of binder of Rho GTPases 2 (BORG2)/Cdc42 effector protein 3 (Cdc42EP3) and to a lesser extent of BORG3/Cdc42EP5, two Cdc42 effectors that link septins to actin in interphase cells. BORG2 or BORG3 silencing not only caused septin detachment from stress fibers but also mimicked the effects of paclitaxel by triggering both septin relocalization to microtubules and significant drug resistance. Conversely, BORG2 or BORG3 overexpression retained septins on actin fibers even after paclitaxel treatment, without affecting paclitaxel sensitivity. We found that drug-induced inhibition of Cdc42 resulted in a drop in BORG2 level and in the relocalization of septins to microtubules. Accordingly, although septins relocalized when overexpressing an inactive mutant of Cdc42, the expression of a constitutively active mutant acted locally at actin stress fibers to prevent septin release, even after paclitaxel treatment. These findings reveal the role of Cdc42 upstream of BORG2 and BORG3 in controlling the interplay between septins, actin fibers, and microtubules in basal condition and in response to taxanes.
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Affiliation(s)
- Joëlle Salameh
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France
| | - Isabelle Cantaloube
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France
| | - Béatrice Benoit
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France
| | - Christian Poüs
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France; Laboratoire de Biochimie-Hormonologie, Hôpital Antoine Béclère, AP-HP, Clamart, France.
| | - Anita Baillet
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France.
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30
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Mendonça DC, Guimarães SL, Pereira HD, Pinto AA, de Farias MA, de Godoy AS, Araujo APU, van Heel M, Portugal RV, Garratt RC. An atomic model for the human septin hexamer by cryo-EM. J Mol Biol 2021; 433:167096. [PMID: 34116125 DOI: 10.1016/j.jmb.2021.167096] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 05/25/2021] [Accepted: 06/02/2021] [Indexed: 01/22/2023]
Abstract
In order to form functional filaments, human septins must assemble into hetero-oligomeric rod-like particles which polymerize end-to-end. The rules governing the assembly of these particles and the subsequent filaments are incompletely understood. Although crystallographic approaches have been successful in studying the separate components of the system, there has been difficulty in obtaining high resolution structures of the full particle. Here we report a first cryo-EM structure for a hexameric rod composed of human septins 2, 6 and 7 with a global resolution of ~3.6 Å and a local resolution of between ~3.0 Å and ~5.0 Å. By fitting the previously determined high-resolution crystal structures of the component subunits into the cryo-EM map, we are able to provide an essentially complete model for the particle. This exposes SEPT2 NC-interfaces at the termini of the hexamer and leaves internal cavities between the SEPT6-SEPT7 pairs. The floor of the cavity is formed by the two α0 helices including their polybasic regions. These are locked into place between the two subunits by interactions made with the α5 and α6 helices of the neighbouring monomer together with its polyacidic region. The cavity may serve to provide space allowing the subunits to move with respect to one another. The elongated particle shows a tendency to bend at its centre where two copies of SEPT7 form a homodimeric G-interface. Such bending is almost certainly related to the ability of septin filaments to recognize and even induce membrane curvature.
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Affiliation(s)
| | | | | | | | | | | | - Ana P U Araujo
- São Carlos Institute of Physics, USP, São Carlos, SP, Brazil
| | - Marin van Heel
- Brazilian Nanotechnology National Laboratory, CNPEM, Campinas, SP, Brazil
| | - Rodrigo V Portugal
- Brazilian Nanotechnology National Laboratory, CNPEM, Campinas, SP, Brazil.
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31
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Abstract
Septins are an integral component of the cytoskeleton, assembling into higher-order oligomers and filamentous polymers that associate with actin filaments, microtubules and membranes. Here, we review septin interactions with actin and microtubules, and septin-mediated regulation of the organization and dynamics of these cytoskeletal networks, which is critical for cellular morphogenesis. We discuss how actomyosin-associated septins function in cytokinesis, cell migration and host defense against pathogens. We highlight newly emerged roles of septins at the interface of microtubules and membranes with molecular motors, which point to a 'septin code' for the regulation of membrane traffic. Additionally, we revisit the functions of microtubule-associated septins in mitosis and meiosis. In sum, septins comprise a unique module of cytoskeletal regulators that are spatially and functionally specialized and have properties of bona fide actin-binding and microtubule-associated proteins. With many questions still outstanding, the study of septins will continue to provide new insights into fundamental problems of cytoskeletal organization and function.
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32
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Chen F, Yan B, Ren J, Lyu R, Wu Y, Guo Y, Li D, Zhang H, Hu J. FIT2 organizes lipid droplet biogenesis with ER tubule-forming proteins and septins. J Cell Biol 2021; 220:211999. [PMID: 33861319 PMCID: PMC8056755 DOI: 10.1083/jcb.201907183] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 12/29/2020] [Accepted: 02/09/2021] [Indexed: 12/20/2022] Open
Abstract
Lipid droplets (LDs) are critical for lipid storage and energy metabolism. LDs form in the endoplasmic reticulum (ER). However, the molecular basis for LD biogenesis remains elusive. Here, we show that fat storage–inducing transmembrane protein 2 (FIT2) interacts with ER tubule-forming proteins Rtn4 and REEP5. The association is mainly transmembrane domain based and stimulated by oleic acid. Depletion of ER tubule-forming proteins decreases the number and size of LDs in cells and Caenorhabditis elegans, mimicking loss of FIT2. Through cytosolic loops, FIT2 binds to cytoskeletal protein septin 7, an interaction that is also required for normal LD biogenesis. Depletion of ER tubule-forming proteins or septins delays nascent LD formation. In addition, FIT2-interacting proteins are up-regulated during adipocyte differentiation, and ER tubule-forming proteins, septin 7, and FIT2 are transiently enriched at LD formation sites. Thus, FIT2-mediated nascent LD biogenesis is facilitated by ER tubule-forming proteins and septins.
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Affiliation(s)
- Fang Chen
- National Laboratory of Biomacromolecules, Chinese Academy of Sciences Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Bing Yan
- National Laboratory of Biomacromolecules, Chinese Academy of Sciences Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jie Ren
- National Laboratory of Biomacromolecules, Chinese Academy of Sciences Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Rui Lyu
- National Laboratory of Biomacromolecules, Chinese Academy of Sciences Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yanfang Wu
- National Laboratory of Biomacromolecules, Chinese Academy of Sciences Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Yuting Guo
- National Laboratory of Biomacromolecules, Chinese Academy of Sciences Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Dong Li
- National Laboratory of Biomacromolecules, Chinese Academy of Sciences Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Hong Zhang
- National Laboratory of Biomacromolecules, Chinese Academy of Sciences Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Junjie Hu
- National Laboratory of Biomacromolecules, Chinese Academy of Sciences Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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33
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Szuba A, Bano F, Castro-Linares G, Iv F, Mavrakis M, Richter RP, Bertin A, Koenderink GH. Membrane binding controls ordered self-assembly of animal septins. eLife 2021; 10:63349. [PMID: 33847563 PMCID: PMC8099429 DOI: 10.7554/elife.63349] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 04/12/2021] [Indexed: 12/23/2022] Open
Abstract
Septins are conserved cytoskeletal proteins that regulate cell cortex mechanics. The mechanisms of their interactions with the plasma membrane remain poorly understood. Here, we show by cell-free reconstitution that binding to flat lipid membranes requires electrostatic interactions of septins with anionic lipids and promotes the ordered self-assembly of fly septins into filamentous meshworks. Transmission electron microscopy reveals that both fly and mammalian septin hexamers form arrays of single and paired filaments. Atomic force microscopy and quartz crystal microbalance demonstrate that the fly filaments form mechanically rigid, 12- to 18-nm thick, double layers of septins. By contrast, C-terminally truncated septin mutants form 4-nm thin monolayers, indicating that stacking requires the C-terminal coiled coils on DSep2 and Pnut subunits. Our work shows that membrane binding is required for fly septins to form ordered arrays of single and paired filaments and provides new insights into the mechanisms by which septins may regulate cell surface mechanics.
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Affiliation(s)
- Agata Szuba
- AMOLF, Department of Living Matter, Biological Soft Matter group, Amsterdam, Netherlands
| | - Fouzia Bano
- School of Biomedical Sciences, Faculty of Biological Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom.,School of Physics and Astronomy, Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, United Kingdom.,Bragg Centre for Materials Research, University of Leeds, Leeds, United Kingdom
| | - Gerard Castro-Linares
- AMOLF, Department of Living Matter, Biological Soft Matter group, Amsterdam, Netherlands.,Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Francois Iv
- Institut Fresnel, CNRS, Aix-Marseille Univ, Centrale Marseille, Marseille, France
| | - Manos Mavrakis
- Institut Fresnel, CNRS, Aix-Marseille Univ, Centrale Marseille, Marseille, France
| | - Ralf P Richter
- School of Biomedical Sciences, Faculty of Biological Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom.,School of Physics and Astronomy, Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, United Kingdom.,Bragg Centre for Materials Research, University of Leeds, Leeds, United Kingdom
| | - Aurélie Bertin
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, Paris, France.,Sorbonne Université, Paris, France
| | - Gijsje H Koenderink
- AMOLF, Department of Living Matter, Biological Soft Matter group, Amsterdam, Netherlands.,Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
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34
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Kesisova IA, Robinson BP, Spiliotis ET. A septin GTPase scaffold of dynein-dynactin motors triggers retrograde lysosome transport. J Cell Biol 2021; 220:211663. [PMID: 33416861 PMCID: PMC7802366 DOI: 10.1083/jcb.202005219] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 11/22/2020] [Accepted: 12/09/2020] [Indexed: 12/12/2022] Open
Abstract
The metabolic and signaling functions of lysosomes depend on their intracellular positioning and trafficking, but the underlying mechanisms are little understood. Here, we have discovered a novel septin GTPase-based mechanism for retrograde lysosome transport. We found that septin 9 (SEPT9) associates with lysosomes, promoting the perinuclear localization of lysosomes in a Rab7-independent manner. SEPT9 targeting to mitochondria and peroxisomes is sufficient to recruit dynein and cause perinuclear clustering. We show that SEPT9 interacts with both dynein and dynactin through its GTPase domain and N-terminal extension, respectively. Strikingly, SEPT9 associates preferentially with the dynein intermediate chain (DIC) in its GDP-bound state, which favors dimerization and assembly into septin multimers. In response to oxidative cell stress induced by arsenite, SEPT9 localization to lysosomes is enhanced, promoting the perinuclear clustering of lysosomes. We posit that septins function as GDP-activated scaffolds for the cooperative assembly of dynein-dynactin, providing an alternative mechanism of retrograde lysosome transport at steady state and during cellular adaptation to stress.
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35
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Soroor F, Kim MS, Palander O, Balachandran Y, Collins RF, Benlekbir S, Rubinstein JL, Trimble WS. Revised subunit order of mammalian septin complexes explains their in vitro polymerization properties. Mol Biol Cell 2020; 32:289-300. [PMID: 33263440 PMCID: PMC8098831 DOI: 10.1091/mbc.e20-06-0398] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Septins are conserved GTP-binding cytoskeletal proteins that polymerize into filaments by end-to-end joining of hetero-oligomeric complexes. In human cells, both hexamers and octamers exist, and crystallography studies predicted the order of the hexamers to be SEPT7-SEPT6-SEPT2-SEPT2-SEPT6-SEPT7, while octamers are thought to have the same core, but with SEPT9 at the ends. However, based on this septin organization, octamers and hexamers would not be expected to copolymerize due to incompatible ends. Here we isolated hexamers and octamers of specific composition from human cells and show that hexamers and octamers polymerize individually and, surprisingly, with each other. Binding of the Borg homology domain 3 (BD3) domain of Borg3 results in distinctive clustering of each filament type. Moreover, we show that the organization of hexameric and octameric complexes is inverted compared with its original prediction. This revised septin organization is congruent with the organization and behavior of yeast septins suggesting that their properties are more conserved than was previously thought.
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Affiliation(s)
- Forooz Soroor
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON M5G 1A8, Canada
| | - Moshe S Kim
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Oliva Palander
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON M5G 1A8, Canada
| | - Yadu Balachandran
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Richard F Collins
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Samir Benlekbir
- Molecular Medicine Program, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - John L Rubinstein
- Molecular Medicine Program, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON M5G 1A8, Canada
| | - William S Trimble
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON M5G 1A8, Canada
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36
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DeRose BT, Kelley RS, Ravi R, Kokona B, Beld J, Spiliotis ET, Padrick SB. Production and analysis of a mammalian septin hetero-octamer complex. Cytoskeleton (Hoboken) 2020; 77:485-499. [PMID: 33185030 DOI: 10.1002/cm.21643] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/26/2020] [Accepted: 11/08/2020] [Indexed: 01/19/2023]
Abstract
The septins are filament-forming proteins found in diverse eukaryotes from fungi to vertebrates, with roles in cytokinesis, shaping of membranes and modifying cytoskeletal organization. These GTPases assemble into rod-shaped soluble hetero-hexamers and hetero-octamers in mammals, which polymerize into filaments and higher order structures. While the cell biology and pathobiology of septins are advancing rapidly, mechanistic study of the mammalian septins is limited by a lack of recombinant hetero-octamer materials. We describe here the production and characterization of a recombinant mammalian septin hetero-octamer of defined stoichiometry, the SEPT2/SEPT6/SEPT7/SEPT3 complex. Using a fluorescent protein fusion to the complex, we observed filaments assembled from this complex. In addition, we used this novel tool to resolve recent questions regarding the organization of the soluble septin complex. Biochemical characterization of a SEPT3 truncation that disrupts SEPT3-SEPT3 interactions is consistent with SEPT3 occupying a central position in the complex while the SEPT2 subunits are at the ends of the rod-shaped octameric complexes. Consistent with SEPT2 being on the complex ends, we find that our purified SEPT2/SEPT6/SEPT7/SEPT3 hetero-octamer copolymerizes into mixed filaments with separately purified SEPT2/SEPT6/SEPT7 hetero-hexamer. We expect this new recombinant production approach to lay essential groundwork for future studies into mammalian septin mechanism and function.
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Affiliation(s)
- Barry T DeRose
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Robert S Kelley
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA.,VCU Health System, Richmond, Virginia, USA
| | - Roshni Ravi
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA.,WuXi Advanced Therapies, Philadelphia, Pennsylvania, USA
| | - Bashkim Kokona
- Department of Chemistry, Haverford College, Haverford, Pennsylvania, USA
| | - Joris Beld
- Department of Microbiology and Immunology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Shae B Padrick
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA
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37
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Farrugia AJ, Rodríguez J, Orgaz JL, Lucas M, Sanz-Moreno V, Calvo F. CDC42EP5/BORG3 modulates SEPT9 to promote actomyosin function, migration, and invasion. J Cell Biol 2020; 219:e201912159. [PMID: 32798219 PMCID: PMC7480113 DOI: 10.1083/jcb.201912159] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 04/30/2020] [Accepted: 05/27/2020] [Indexed: 01/22/2023] Open
Abstract
Fast amoeboid migration is critical for developmental processes and can be hijacked by cancer cells to enhance metastatic dissemination. This migratory behavior is tightly controlled by high levels of actomyosin contractility, but how it is coupled to other cytoskeletal components is poorly understood. Septins are increasingly recognized as novel cytoskeletal components, but details on their regulation and contribution to migration are lacking. Here, we show that the septin regulator Cdc42EP5 is consistently required for amoeboid melanoma cells to invade and migrate into collagen-rich matrices and locally invade and disseminate in vivo. Cdc42EP5 associates with actin structures, leading to increased actomyosin contractility and amoeboid migration. Cdc42EP5 affects these functions through SEPT9-dependent F-actin cross-linking, which enables the generation of F-actin bundles required for the sustained stabilization of highly contractile actomyosin structures. This study provides evidence that Cdc42EP5 is a regulator of cancer cell motility that coordinates actin and septin networks and describes a unique role for SEPT9 in melanoma invasion and metastasis.
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Affiliation(s)
- Aaron J. Farrugia
- Division of Cancer Biology, The Institute of Cancer Research, London, UK
| | - Javier Rodríguez
- Instituto de Biomedicina y Biotecnología de Cantabria (Consejo Superior de Investigaciones Científicas, Universidad de Cantabria), Santander, Spain
| | - Jose L. Orgaz
- Centre for Cancer and Inflammation, Barts Cancer Institute, Queen Mary University of London, London, UK
| | - María Lucas
- Instituto de Biomedicina y Biotecnología de Cantabria (Consejo Superior de Investigaciones Científicas, Universidad de Cantabria), Santander, Spain
| | - Victoria Sanz-Moreno
- Centre for Cancer and Inflammation, Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Fernando Calvo
- Division of Cancer Biology, The Institute of Cancer Research, London, UK
- Instituto de Biomedicina y Biotecnología de Cantabria (Consejo Superior de Investigaciones Científicas, Universidad de Cantabria), Santander, Spain
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38
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Farkašovský M. Septin architecture and function in budding yeast. Biol Chem 2020; 401:903-919. [PMID: 31913844 DOI: 10.1515/hsz-2019-0401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 12/28/2019] [Indexed: 01/22/2023]
Abstract
The septins constitute a conserved family of guanosine phosphate-binding and filament-forming proteins widespread across eukaryotic species. Septins appear to have two principal functions. One is to form a cortical diffusion barrier, like the septin collar at the bud neck of Saccharomyces cerevisiae, which prevents movement of membrane-associated proteins between the mother and daughter cells. The second is to serve as a polymeric scaffold for recruiting the proteins required for critical cellular processes to particular subcellular areas. In the last decade, structural information about the different levels of septin organization has appeared, but crucial structural determinants and factors responsible for septin assembly remain largely unknown. This review highlights recent findings on the architecture and function of septins and their remodeling with an emphasis on mitotically dividing budding yeasts.
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Affiliation(s)
- Marian Farkašovský
- Department of Biochemistry and Protein Structure, Institute of Molecular Biology SAS, Dubravska cesta 21, 84551 Bratislava, Slovak Republic
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39
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Sun J, Zheng MY, Li YW, Zhang SW. Structure and function of Septin 9 and its role in human malignant tumors. World J Gastrointest Oncol 2020; 12:619-631. [PMID: 32699577 PMCID: PMC7340996 DOI: 10.4251/wjgo.v12.i6.619] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/03/2020] [Accepted: 04/25/2020] [Indexed: 02/05/2023] Open
Abstract
The treatment and prognosis of malignant tumors are closely related to the time when the tumors are diagnosed; the earlier the diagnosis of the tumor, the better the prognosis. However, most tumors are not detected in the early stages of screening and diagnosis. It is of great clinical significance to study the correlation between multiple pathogeneses of tumors and explore simple, safe, specific, and sensitive molecular indicators for early screening, diagnosis, and prognosis. The Septin 9 (SEPT9) gene has been found to be associated with a variety of human diseases, and it plays a role in the development of tumors. SEPT9 is a member of the conserved family of cytoskeletal GTPase, which consists of a P-loop-based GTP-binding domain flanked by a variable N-terminal region and a C-terminal region. SEPT9 is involved in many biological processes such as cytokinesis, polarization, vesicle trafficking, membrane reconstruction, deoxyribonucleic acid repair, cell migration, and apoptosis. Several studies have shown that SEPT9 may serve as a marker for early screening, diagnosis, and prognosis of some malignant tumors, and have the potential to become a new target for anti-cancer therapy. This article reviews the progress in research on the SEPT9 gene in early screening, diagnosis, and prognosis of tumors.
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Affiliation(s)
- Jie Sun
- Department of Pathology, Tianjin Union Medical Center, Tianjin 300121, China
| | - Min-Ying Zheng
- Department of Pathology, Tianjin Union Medical Center, Tianjin 300121, China
| | - Yu-Wei Li
- Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin 300121, China
| | - Shi-Wu Zhang
- Department of Pathology, Tianjin Union Medical Center, Tianjin 300121, China
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40
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Castro DKSDV, da Silva SMDO, Pereira HD, Macedo JNA, Leonardo DA, Valadares NF, Kumagai PS, Brandão-Neto J, Araújo APU, Garratt RC. A complete compendium of crystal structures for the human SEPT3 subgroup reveals functional plasticity at a specific septin interface. IUCRJ 2020; 7:462-479. [PMID: 32431830 PMCID: PMC7201284 DOI: 10.1107/s2052252520002973] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/03/2020] [Indexed: 06/11/2023]
Abstract
Human septins 3, 9 and 12 are the only members of a specific subgroup of septins that display several unusual features, including the absence of a C-terminal coiled coil. This particular subgroup (the SEPT3 septins) are present in rod-like octameric protofilaments but are lacking in similar hexameric assemblies, which only contain representatives of the three remaining subgroups. Both hexamers and octamers can self-assemble into mixed filaments by end-to-end association, implying that the SEPT3 septins may facilitate polymerization but not necessarily function. These filaments frequently associate into higher order complexes which associate with biological membranes, triggering a wide range of cellular events. In the present work, a complete compendium of crystal structures for the GTP-binding domains of all of the SEPT3 subgroup members when bound to either GDP or to a GTP analogue is provided. The structures reveal a unique degree of plasticity at one of the filamentous interfaces (dubbed NC). Specifically, structures of the GDP and GTPγS complexes of SEPT9 reveal a squeezing mechanism at the NC interface which would expel a polybasic region from its binding site and render it free to interact with negatively charged membranes. On the other hand, a polyacidic region associated with helix α5', the orientation of which is particular to this subgroup, provides a safe haven for the polybasic region when retracted within the interface. Together, these results suggest a mechanism which couples GTP binding and hydrolysis to membrane association and implies a unique role for the SEPT3 subgroup in this process. These observations can be accounted for by constellations of specific amino-acid residues that are found only in this subgroup and by the absence of the C-terminal coiled coil. Such conclusions can only be reached owing to the completeness of the structural studies presented here.
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Affiliation(s)
- Danielle Karoline Silva do Vale Castro
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Joao Dagnone 1100, São Carlos-SP 13563-723, Brazil
- Instituto de Química de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, São Carlos-SP 13566-590, Brazil
| | - Sabrina Matos de Oliveira da Silva
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Joao Dagnone 1100, São Carlos-SP 13563-723, Brazil
- Instituto de Química de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, São Carlos-SP 13566-590, Brazil
| | - Humberto D’Muniz Pereira
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Joao Dagnone 1100, São Carlos-SP 13563-723, Brazil
| | - Joci Neuby Alves Macedo
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Joao Dagnone 1100, São Carlos-SP 13563-723, Brazil
- Federal Institute of Education, Science and Technology of Rondonia, Rodovia BR-174, Km 3, Vilhena-RO 76980-000, Brazil
| | - Diego Antonio Leonardo
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Joao Dagnone 1100, São Carlos-SP 13563-723, Brazil
| | - Napoleão Fonseca Valadares
- Departamento de Biologia Celular, Universidade de Brasília, Instituto de Ciências Biológicas, Brasília-DF 70910900, Brazil
| | - Patricia Suemy Kumagai
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Joao Dagnone 1100, São Carlos-SP 13563-723, Brazil
| | - José Brandão-Neto
- Diamond Light Source, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - Ana Paula Ulian Araújo
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Joao Dagnone 1100, São Carlos-SP 13563-723, Brazil
| | - Richard Charles Garratt
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Joao Dagnone 1100, São Carlos-SP 13563-723, Brazil
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41
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Vahabi Barzi N, Kakavand K, Sodeifi N, Ghezelayagh Z, Sabbaghian M. Expression and localization of Septin 14 gene and protein in infertile men testis. Reprod Biol 2020; 20:164-168. [PMID: 32249155 DOI: 10.1016/j.repbio.2020.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 03/09/2020] [Accepted: 03/14/2020] [Indexed: 12/15/2022]
Abstract
An increasing body of data implicates the Septin family in the pathology of several diseases, including male fertility. The objective of this study was to evaluate the gene and protein expression pattern of Septin 14 in the testis tissue of azoospermic men. In addition, Septin 14 localization was also assessed in the sperm. Testicular tissues were obtained from biopsies of non-obstrutive azoospermic men who underwent diagnostic testicular biopsy in Royan institute and were divided into two groups: TESE + with positive result in testicular sperm extraction (with hypospermatogenesis pathology) and TESE- with negative result (included patients with Sertoli cell only syndrome and maturation arrest pathologies). Total RNA and protein was extracted using trizol reagent. Septin 14 gene and protein expression level were assessed by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot techniques, respectively. The localization of Septin 14 protein was also studied by Immunocytochemistry. The expression of Septin 14 was significantly lower (p < 0. 05) in TESE- group than TESE + in both mRNA and protein levels. The localization of Septin 14 protein was detected in the head to tail of normal sperms with high localization in front of the acrosome and the neck. This is a novel localization report on Septin 14 in sperm. Regarding the presence of this protein in the sperm acrosome and neck, it can be concluded that decreasing of Septin 14 protein expression may be associated with the pathogenesis of male infertility and therefore Septin 14 expression level maybe critical for human spermatogenesis.
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Affiliation(s)
- Nastaran Vahabi Barzi
- Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Kianoosh Kakavand
- Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Niloofar Sodeifi
- Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Zeinab Ghezelayagh
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Marjan Sabbaghian
- Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
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42
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Collins KB, Kang H, Matsche J, Klomp JE, Rehman J, Malik AB, Karginov AV. Septin2 mediates podosome maturation and endothelial cell invasion associated with angiogenesis. J Cell Biol 2020; 219:e201903023. [PMID: 31865373 PMCID: PMC7041690 DOI: 10.1083/jcb.201903023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 09/14/2019] [Accepted: 11/08/2019] [Indexed: 12/13/2022] Open
Abstract
Podosomes are compartmentalized actin-rich adhesions, defined by their ability to locally secrete proteases and remodel extracellular matrix. Matrix remodeling by endothelial podosomes facilitates invasion and thereby vessel formation. However, the mechanisms underlying endothelial podosome formation and function remain unclear. Here, we demonstrate that Septin2, Septin6, and Septin7 are required for maturation of nascent endothelial podosomes into matrix-degrading organelles. We show that podosome development occurs through initial mobilization of the scaffolding protein Tks5 and F-actin accumulation, followed by later recruitment of Septin2. Septin2 localizes around the perimeter of podosomes in close proximity to the basolateral plasma membrane, and phosphoinositide-binding residues of Septin2 are required for podosome function. Combined, our results suggest that the septin cytoskeleton forms a diffusive barrier around nascent podosomes to promote their maturation. Finally, we show that Septin2-mediated regulation of podosomes is critical for endothelial cell invasion associated with angiogenesis. Therefore, targeting of Septin2-mediated podosome formation is a potentially attractive anti-angiogenesis strategy.
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Affiliation(s)
| | | | | | | | | | | | - Andrei V. Karginov
- Department of Pharmacology, University of Illinois College of Medicine, Chicago, IL
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43
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Johnson CR, Steingesser MG, Weems AD, Khan A, Gladfelter A, Bertin A, McMurray MA. Guanidine hydrochloride reactivates an ancient septin hetero-oligomer assembly pathway in budding yeast. eLife 2020; 9:e54355. [PMID: 31990274 PMCID: PMC7056273 DOI: 10.7554/elife.54355] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 01/25/2020] [Indexed: 01/22/2023] Open
Abstract
Septin proteins evolved from ancestral GTPases and co-assemble into hetero-oligomers and cytoskeletal filaments. In Saccharomyces cerevisiae, five septins comprise two species of hetero-octamers, Cdc11/Shs1-Cdc12-Cdc3-Cdc10-Cdc10-Cdc3-Cdc12-Cdc11/Shs1. Slow GTPase activity by Cdc12 directs the choice of incorporation of Cdc11 vs Shs1, but many septins, including Cdc3, lack GTPase activity. We serendipitously discovered that guanidine hydrochloride rescues septin function in cdc10 mutants by promoting assembly of non-native Cdc11/Shs1-Cdc12-Cdc3-Cdc3-Cdc12-Cdc11/Shs1 hexamers. We provide evidence that in S. cerevisiae Cdc3 guanidinium occupies the site of a 'missing' Arg side chain found in other fungal species where (i) the Cdc3 subunit is an active GTPase and (ii) Cdc10-less hexamers natively co-exist with octamers. We propose that guanidinium reactivates a latent septin assembly pathway that was suppressed during fungal evolution in order to restrict assembly to octamers. Since homodimerization by a GTPase-active human septin also creates hexamers that exclude Cdc10-like central subunits, our new mechanistic insights likely apply throughout phylogeny.
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Affiliation(s)
- Courtney R Johnson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Marc G Steingesser
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Andrew D Weems
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Anum Khan
- Department of Biology, University of North Carolina at Chapel HillChapel HillUnited States
| | - Amy Gladfelter
- Department of Biology, University of North Carolina at Chapel HillChapel HillUnited States
| | - Aurélie Bertin
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR 168ParisFrance
- Sorbonne Université UPMC Univ Paris 06ParisFrance
| | - Michael A McMurray
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
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44
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Gönczi M, Dienes B, Dobrosi N, Fodor J, Balogh N, Oláh T, Csernoch L. Septins, a cytoskeletal protein family, with emerging role in striated muscle. J Muscle Res Cell Motil 2020; 42:251-265. [PMID: 31955380 PMCID: PMC8332580 DOI: 10.1007/s10974-020-09573-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/06/2020] [Indexed: 12/15/2022]
Abstract
Appropriate organization of cytoskeletal components are required for normal distribution and intracellular localization of different ion channels and proteins involved in calcium homeostasis, signal transduction, and contractile function of striated muscle. Proteins of the contractile system are in direct or indirect connection with the extrasarcomeric cytoskeleton. A number of other molecules which have essential role in regulating stretch-, voltage-, and chemical signal transduction from the surface into the cytoplasm or other intracellular compartments are already well characterized. Sarcomere, the basic contractile unit, is comprised of a precisely organized system of thin (actin), and thick (myosin) filaments. Intermediate filaments connect the sarcomeres and other organelles (mitochondria and nucleus), and are responsible for the cellular integrity. Interacting proteins have a very diverse function in coupling of the intracellular assembly components and regulating the normal physiological function. Despite the more and more intense investigations of a new cytoskeletal protein family, the septins, only limited information is available regarding their expression and role in striated, especially in skeletal muscles. In this review we collected basic and specified knowledge regarding this protein group and emphasize the importance of this emerging field in skeletal muscle biology.
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Affiliation(s)
- Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - Nóra Dobrosi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - János Fodor
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - Norbert Balogh
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary.,Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, 4012, Hungary
| | - Tamás Oláh
- Center of Experimental Orthopaedics, Saarland University, 66421, Homburg, Saar, Germany
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, 4012, Hungary.
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45
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Qiu R, Runxiang Q, Geng A, Liu J, Xu CW, Menon MB, Gaestel M, Lu Q. SEPT7 Interacts with KIF20A and Regulates the Proliferative State of Neural Progenitor Cells During Cortical Development. Cereb Cortex 2019; 30:3030-3043. [PMID: 31813992 DOI: 10.1093/cercor/bhz292] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/01/2019] [Accepted: 10/21/2019] [Indexed: 02/06/2023] Open
Abstract
Balanced proliferation and differentiation of neural progenitor cells (NPCs) are critical for brain development, but how the process is regulated and what components of the cell division machinery is involved are not well understood. Here we report that SEPT7, a cell division regulator originally identified in Saccharomyces cerevisiae, interacts with KIF20A in the intercellular bridge of dividing NPCs and plays an essential role in maintaining the proliferative state of NPCs during cortical development. Knockdown of SEPT7 in NPCs results in displacement of KIF20A from the midbody and early neuronal differentiation. NPC-specific inducible knockout of Sept7 causes early cell cycle exit, precocious neuronal differentiation, and ventriculomegaly in the cortex, but surprisingly does not lead to noticeable cytokinesis defect. Our data uncover an interaction of SEPT7 and KIF20A during NPC divisions and demonstrate a crucial role of SEPT7 in cell fate determination. In addition, this study presents a functional approach for identifying additional cell fate regulators of the mammalian brain.
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Affiliation(s)
- Runxiang Qiu
- Department of Developmental and Stem Cell Biology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Qiu Runxiang
- Department of Developmental and Stem Cell Biology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Anqi Geng
- Department of Developmental and Stem Cell Biology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA.,Institute of Medical Research, Northwestern Polytechnical University, Xian, Shaanxi Province, China
| | - Jiancheng Liu
- Department of Developmental and Stem Cell Biology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - C Wilson Xu
- Balto Pharmaceuticals, Inc., South Pasadena, CA 91030, USA
| | - Manoj B Menon
- Institute of Cell Biochemistry, Hannover Medical School, Hannover 30625, Germany.,Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New-Delhi 110016, India
| | - Matthias Gaestel
- Institute of Cell Biochemistry, Hannover Medical School, Hannover 30625, Germany
| | - Qiang Lu
- Department of Developmental and Stem Cell Biology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
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46
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Mendonça DC, Macedo JN, Guimarães SL, Barroso da Silva FL, Cassago A, Garratt RC, Portugal RV, Araujo APU. A revised order of subunits in mammalian septin complexes. Cytoskeleton (Hoboken) 2019; 76:457-466. [PMID: 31608568 DOI: 10.1002/cm.21569] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 12/15/2022]
Abstract
Septins are GTP binding proteins considered to be novel components of the cytoskeleton. They polymerize into filaments based on hexameric or octameric core particles in which two copies of either three or four different septins, respectively, assemble into a specific sequence. Viable combinations of the 13 human septins are believed to obey substitution rules in which the different septins involved must come from distinct subgroups. The hexameric assembly, for example, has been reported to be SEPT7-SEPT6-SEPT2-SEPT2-SEPT6-SEPT7. Here, we have replaced SEPT2 by SEPT5 according to the substitution rules and used transmission electron microscopy to demonstrate that the resulting recombinant complex assembles into hexameric particles which are inverted with respect that predicted previously. MBP-SEPT5 constructs and immunostaining show that SEPT5 occupies the terminal positions of the hexamer. We further show that this is also true for the assembly including SEPT2, in direct contradiction with that reported previously. Consequently, both complexes expose an NC interface, as reported for yeast, which we show to be more susceptible to high salt concentrations. The correct assembly for the canonical combination of septins 2-6-7 is therefore established to be SEPT2-SEPT6-SEPT7-SEPT7-SEPT6-SEPT2, implying the need for revision of the mechanisms involved in filament assembly.
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Affiliation(s)
| | - Joci N Macedo
- São Carlos Institute of Physics, USP, São Carlos, SP, Brazil
- Federal Institute of Education, Science and Technology of Rondonia
| | | | - Fernando L Barroso da Silva
- Faculty of Pharmaceutical Sciences, USP, Ribeirão Preto, SP, Brazil
- UMR_S 1134, Université Paris Diderot, Paris, France
| | - Alexandre Cassago
- Brazilian Nanotechnology National Laboratory, CNPEM, Campinas, SP, Brazil
| | | | - Rodrigo V Portugal
- Brazilian Nanotechnology National Laboratory, CNPEM, Campinas, SP, Brazil
| | - Ana P U Araujo
- São Carlos Institute of Physics, USP, São Carlos, SP, Brazil
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47
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Nakos K, Radler MR, Spiliotis ET. Septin 2/6/7 complexes tune microtubule plus-end growth and EB1 binding in a concentration- and filament-dependent manner. Mol Biol Cell 2019; 30:2913-2928. [PMID: 31577529 PMCID: PMC6822581 DOI: 10.1091/mbc.e19-07-0362] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Septins (SEPTs) are filamentous guanosine-5′-triphosphate (GTP)-binding proteins, which affect microtubule (MT)-dependent functions including membrane trafficking and cell division, but their precise role in MT dynamics is poorly understood. Here, in vitro reconstitution of MT dynamics with SEPT2/6/7, the minimal subunits of septin heteromers, shows that SEPT2/6/7 has a biphasic concentration-dependent effect on MT growth. Lower concentrations of SEPT2/6/7 enhance MT plus-end growth and elongation, while higher and intermediate concentrations inhibit and pause plus-end growth, respectively. We show that SEPT2/6/7 has a modest preference for GTP- over guanosine diphosphate (GDP)-bound MT lattice and competes with end-binding protein 1 (EB1) for binding to guanosine 5′-O-[γ-thio]triphosphate (GTPγS)-stabilized MTs, which mimic the EB1-preferred GDP-Pi state of polymerized tubulin. Strikingly, SEPT2/6/7 triggers EB1 dissociation from plus-end tips in cis by binding to the MT lattice and in trans when MT plus ends collide with SEPT2/6/7 filaments. At these intersections, SEPT2/6/7 filaments were more potent barriers than actin filaments in pausing MT growth and dissociating EB1 in vitro and in live cells. These data demonstrate that SEPT2/6/7 complexes and filaments can directly impact MT plus-end growth and the tracking of plus end–binding proteins and thereby may facilitate the capture of MT plus ends at intracellular sites of septin enrichment.
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Affiliation(s)
| | - Megan R Radler
- Department of Biology, Drexel University, Philadelphia, PA 19104
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48
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McMurray MA, Thorner J. Turning it inside out: The organization of human septin heterooligomers. Cytoskeleton (Hoboken) 2019; 76:449-456. [PMID: 31614074 PMCID: PMC6872917 DOI: 10.1002/cm.21571] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/02/2019] [Accepted: 10/08/2019] [Indexed: 01/09/2023]
Abstract
Septin family proteins are quite similar to each other both within and between eukaryotic species. Typically, multiple discrete septins co-assemble into linear heterooligomers (usually hexameric or octameric rods) with a variety of cellular functions. We know little about how incorporation of different septins confers different properties to such complexes. This issue is especially acute in human cells where 13 separate septin gene products (often produced in multiple forms arising from alternative start codons and differential splicing) are expressed in a tissue-specific manner. Based on sequence alignments and phylogenetic criteria, human septins fall into four distinct groups predictive of their interactions, that is, members of the same group appear to occupy the same position within oligomeric septin protomers, which are "palindromic" (have twofold rotational symmetry about a central homodimeric pair). Many such protomers are capable of end-to-end polymerization, generating filaments. Over a decade ago, a study using X-ray crystallography and single-particle electron microscopy deduced the arrangement within recombinant heterohexamers comprising representatives of three human septin groups-SEPT2, SEPT6, and SEPT7. This model greatly influenced subsequent studies of human and other septin complexes, including how incorporating a septin from a fourth group forms heterooctamers, as first observed in budding yeast. Two recent studies, including one in this issue of Cytoskeleton, provide clear evidence that, in fact, the organization of subunits within human septin heterohexamers and heterooctamers is inverted relative to the original model. These findings are discussed here in a broader context, including possible causes for the initial confusion.
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Affiliation(s)
- Michael A McMurray
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Jeremy Thorner
- Division of Biochemistry, Biophysics & Structural Biology, University of California, Berkeley, California
- Division of Cell & Developmental Biology, University of California, Berkeley, California
- Department of Molecular and Cell Biology, University of California, Berkeley, California
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49
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An Interaction Network of the Human SEPT9 Established by Quantitative Mass Spectrometry. G3-GENES GENOMES GENETICS 2019; 9:1869-1880. [PMID: 30975701 PMCID: PMC6553528 DOI: 10.1534/g3.119.400197] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Septins regulate the organization of the actin cytoskeleton, vesicle transport and fusion, chromosome alignment and segregation, and cytokinesis in mammalian cells. SEPT9 is part of the core septin hetero-octamer in human cells which is composed of SEPT2, SEPT6, SEPT7, and SEPT9. SEPT9 has been linked to a variety of intracellular functions as well as to diseases and diverse types of cancer. A targeted high-throughput approach to systematically identify the interaction partners of SEPT9 has not yet been performed. We applied a quantitative proteomics approach to establish an interactome of SEPT9 in human fibroblast cells. Among the newly identified interaction partners were members of the myosin family and LIM domain containing proteins. Fluorescence microscopy of SEPT9 and its interaction partners provides additional evidence that SEPT9 might participate in vesicle transport from and to the plasma membrane as well as in the attachment of actin stress fibers to cellular adhesions.
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50
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Brognara G, Pereira HDM, Brandão-Neto J, Araujo APU, Garratt RC. Revisiting SEPT7 and the slippage of β-strands in the septin family. J Struct Biol 2019; 207:67-73. [PMID: 31009756 DOI: 10.1016/j.jsb.2019.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 04/17/2019] [Accepted: 04/18/2019] [Indexed: 12/12/2022]
Abstract
Septins are GTP-binding proteins that will often spontaneously assemble into filaments. In some species, particularly budding yeast, it is well known that these are capable of associating with membranes in order to fulfill their cellular role as a component of the cytoskeleton. Different from other human septins, SEPT7 appears to be unique in that it is an essential component of all hetero-oligomeric complexes described to date. As a step towards understanding the molecular basis of filament assembly, here we present two high-resolution structures of the SEPT7 GTPase domain complexed with GDP. One of these reveals a previously unreported coordination for the magnesium ion involving four water molecules and only a tenuous connection to the protein. The higher resolution structures provide unambiguous insight into the interactions at the G-interface where a structural motif based on an antiparallel β-bridge allows for the rationalization of why some septins show nucleotide-dependent β-strand slippage and others do not.
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Affiliation(s)
- Gabriel Brognara
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil
| | | | - José Brandão-Neto
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
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