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Robinson BP, Bass NR, Bhakt P, Spiliotis ET. Septin-coated microtubules promote maturation of multivesicular bodies by inhibiting their motility. J Cell Biol 2024; 223:e202308049. [PMID: 38668767 PMCID: PMC11046855 DOI: 10.1083/jcb.202308049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 02/06/2024] [Accepted: 04/10/2024] [Indexed: 04/29/2024] Open
Abstract
The microtubule cytoskeleton consists of microtubule subsets with distinct compositions of microtubule-associated proteins, which instruct the position and traffic of subcellular organelles. In the endocytic pathway, these microtubule-associated cues are poorly understood. Here, we report that in MDCK cells, endosomes with multivesicular body (MVB) and late endosome (LE) markers localize preferentially to microtubules coated with septin GTPases. Compared with early endosomes, CD63-containing MVBs/LEs are largely immotile on septin-coated microtubules. In vitro reconstitution assays revealed that the motility of isolated GFP-CD63 endosomes is directly inhibited by microtubule-associated septins. Quantification of CD63-positive endosomes containing the early endosome antigen (EEA1), the Rab7 effector and dynein adaptor RILP or Rab27a, showed that intermediary EEA1- and RILP-positive GFP-CD63 preferentially associate with septin-coated microtubules. Septin knockdown enhanced GFP-CD63 motility and decreased the percentage of CD63-positive MVBs/LEs with lysobiphosphatidic acid without impacting the fraction of EEA1-positive CD63. These results suggest that MVB maturation involves immobilization on septin-coated microtubules, which may facilitate multivesiculation and/or organelle-organelle contacts.
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Affiliation(s)
| | - Naomi R. Bass
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Priyanka Bhakt
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Elias T. Spiliotis
- Department of Biology, Drexel University, Philadelphia, PA, USA
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
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2
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Meiling JB, Boon AJ, Niu Z, Howe BM, Hoskote SS, Spinner RJ, Klein CJ. Parsonage-Turner Syndrome and Hereditary Brachial Plexus Neuropathy. Mayo Clin Proc 2024; 99:124-140. [PMID: 38176820 DOI: 10.1016/j.mayocp.2023.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/10/2023] [Accepted: 06/23/2023] [Indexed: 01/06/2024]
Abstract
Parsonage-Turner syndrome and hereditary brachial plexus neuropathy (HBPN) present with indistinguishable attacks of rapid-onset severe shoulder and arm pain, disabling weakness, and early muscle atrophy. Their combined incidence ranges from 3 to 100 in 100,000 persons per year. Dominant mutations of SEPT9 are the only known mutations responsible for HBPN. Parsonage and Turner termed the disorder "brachial neuralgic amyotrophy," highlighting neuropathic pain and muscle atrophy. Modern electrodiagnostic and imaging testing assists the diagnosis in distinction from mimicking disorders. Shoulder and upper limb nerves outside the brachial plexus are commonly affected including the phrenic nerve where diaphragm ultrasound improves diagnosis. Magnetic resonance imaging can show multifocal T2 nerve and muscle hyperintensities with nerve hourglass swellings and constrictions identifiable also by ultrasound. An inflammatory immune component is suggested by nerve biopsies and associated infectious, immunization, trauma, surgery, and childbirth triggers. High-dose pulsed steroids assist initial pain control; however, weakness and subsequent pain are not clearly responsive to steroids and instead benefit from time, physical therapy, and non-narcotic pain medications. Recurrent attacks in HBPN are common and prophylactic steroids or intravenous immunoglobulin may reduce surgical- or childbirth-induced attacks. Rehabilitation focusing on restoring functional scapular mechanics, energy conservation, contracture prevention, and pain management are critical. Lifetime residual pain and weakness are rare with most making dramatic functional recovery. Tendon transfers can be used when recovery does not occur after 18 months. Early neurolysis and nerve grafts are controversial. This review provides an update including new diagnostic tools, new associations, and new interventions crossing multiple medical disciplines.
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Affiliation(s)
- James B Meiling
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN, USA
| | - Andrea J Boon
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN, USA; Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Zhiyv Niu
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | | | - Sumedh S Hoskote
- Department of Pulmonary Medicine, Mayo Clinic, Rochester, MN, USA
| | | | - Christopher J Klein
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
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Nakazawa K, Chauvin B, Mangenot S, Bertin A. Reconstituted in vitro systems to reveal the roles and functions of septins. J Cell Sci 2023; 136:jcs259448. [PMID: 37815088 DOI: 10.1242/jcs.259448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023] Open
Abstract
Septins are essential cytoskeletal proteins involved in key cellular processes and have also been implicated in diseases from cancers to neurodegenerative pathologies. However, they have not been as thoroughly studied as other cytoskeletal proteins. In vivo, septins interact with other cytoskeletal proteins and with the inner plasma membrane. Hence, bottom-up in vitro cell-free assays are well suited to dissect the roles and behavior of septins in a controlled environment. Specifically, in vitro studies have been invaluable in describing the self-assembly of septins into a large diversity of ultrastructures. Given that septins interact specifically with membrane, the details of these septin-membrane interactions have been analyzed using reconstituted lipid systems. In particular, at a membrane, septins are often localized at curvatures of micrometer scale. In that context, in vitro assays have been performed with substrates of varying curvatures (spheres, cylinders or undulated substrates) to probe the sensitivity of septins to membrane curvature. This Review will first present the structural properties of septins in solution and describe the interplay of septins with cytoskeletal partners. We will then discuss how septins interact with biomimetic membranes and induce their reshaping. Finally, we will highlight the curvature sensitivity of septins and how they alter the mechanical properties of membranes.
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Affiliation(s)
- Koyomi Nakazawa
- Physico Chimie Curie , Institut Curie, CNRS UMR 168, Sorbonne Université, 11 Rue Pierre et Paris Curie, 75005 Paris, France
| | - Brieuc Chauvin
- Physico Chimie Curie , Institut Curie, CNRS UMR 168, Sorbonne Université, 11 Rue Pierre et Paris Curie, 75005 Paris, France
| | - Stéphanie Mangenot
- Laboratoire Matière et Systèmes Complexes , Université de Paris Cité, CNRS UMR 7057, 45 Rue des Saint Pères, 75006 Paris, France
| | - Aurélie Bertin
- Physico Chimie Curie , Institut Curie, CNRS UMR 168, Sorbonne Université, 11 Rue Pierre et Paris Curie, 75005 Paris, France
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4
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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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5
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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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6
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Tomasso MR, Padrick SB. BORG family proteins in physiology and human disease. Cytoskeleton (Hoboken) 2023; 80:182-198. [PMID: 37403807 DOI: 10.1002/cm.21768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/06/2023]
Abstract
The binder of rho GTPases (BORG)/Cdc42 effector proteins (Cdc42EP) family is composed of five Rho GTPase binding proteins whose functions and mechanism of actions are of emerging interest. Here, we review recent findings pertaining to the family as a whole and consider how these change our understanding of cellular organization. Recent studies have implicated BORGs in both fundamental physiology and in human diseases, mainly cancers. An emerging pattern suggests that BORG family members cancer-promoting properties are related to their ability to regulate the cytoskeleton, with many impacting the organization of acto-myosin stress fibers. This is consistent with the broader literature indicating that BORG family members are regulators of both the septin and actin cytoskeleton networks. The exact mechanism through which BORGs modify the cytoskeleton is not clear, but we consider here a few data-supported and speculative possibilities. Finally, we delve into how the Rho GTPase Cdc42 modifies BORG function in cells. This remains open-ended as Cdc42's effects on BORGs appear cell type- and cell state-dependent. Collectively, these data point to the importance of the BORG family and suggest broader themes in their function and regulation.
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Affiliation(s)
- Meagan R Tomasso
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Shae B Padrick
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA
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7
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K S V Castro D, V D Rosa H, Mendonça DC, Cavini IA, P U Araujo A, Garratt RC. Dissecting the binding interface of the septin polymerization enhancer Borg BD3. J Mol Biol 2023; 435:168132. [PMID: 37121395 DOI: 10.1016/j.jmb.2023.168132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/02/2023]
Abstract
The molecular basis for septin filament assembly has begun to emerge over recent years. These filaments are essential for many septin functions which depend on their association with biological membranes or components of the cytoskeleton. Much less is known about how septins specifically interact with their binding partners. Here we describe the essential role played by the C-terminal domains in both septin polymerization and their association with the BD3 motif of the Borg family of Cdc42 effector proteins. We provide a detailed description, at the molecular level, of a previously reported interaction between BD3 and the NC-interface between SEPT6 and SEPT7. Upon ternary complex formation, the heterodimeric coiled coil formed by the C-terminal domains of the septins becomes stabilized and filament formation is promoted under conditions of ionic strength/protein concentration which are not normally permissible, likely by favouring hexamers over smaller oligomeric states. This demonstrates that binding partners, such as Borg's, have the potential to control filament assembly/disassembly in vivo in a way which can be emulated in vitro by altering the ionic strength. Experimentally validated models indicate that the BD3 peptide lies antiparallel to the coiled coil and is stabilized by a mixture of polar and apolar contacts. At its center, an LGPS motif, common to all human Borg sequences, interacts with charged residues from both helices of the coiled coil (K368 from SEPT7 and the conserved E354 from SEPT6) suggesting a universal mechanism which governs Borg-septin interactions.
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Affiliation(s)
- Danielle K S V Castro
- São Carlos Institute of Chemistry, University of São Paulo, São Carlos, Brazil; São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Higor V D Rosa
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Deborah C Mendonça
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Italo A Cavini
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Ana P U Araujo
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Richard C Garratt
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil.
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8
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Mola S, Beauchamp C, Boucher G, Lesage S, Karaky M, Goyette P, Foisy S, Rioux JD. Identifying transcript-level differential expression in primary human immune cells. Mol Immunol 2023; 153:181-193. [PMID: 36527757 DOI: 10.1016/j.molimm.2022.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 11/17/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND Multipotential hematopoietic stem cells differentiate into a wide variety of immune cells with a diversity of functions, including the ability to respond to a variety of stimuli. Importantly, numerous studies have demonstrated the importance of gene transcription in defining cell identity and functions. While these studies have primarily been performed at the level of the gene, it is known that key immune genes such as CD44 and CD45 generate multiple different transcripts that are differentially expressed across different immune cells, and that encode proteins with different sequences and functions. Prior genomic surveys have shown that the mechanisms for generating diversity in expressed transcripts (alternate splicing, alternate transcription start sites, etc.) are very active in immune cells, but have been lacking in terms of identifying genes with multiple transcripts, that are differentially expressed, and likely to affect cell functions. METHODS We first identified the set of genes that had at least two transcripts expressed in our RNA sequencing dataset generated from purified populations of neutrophils, monocytes and five lymphocyte populations (B, NK, γδ T, CD4 + T and CD8 + T) from twelve healthy donors. Next, we developed a heuristic approach to identify genes where two or more transcripts have distinct expression patterns across lymphoid and/or myeloid populations. We then focused our annotation and interpretation on differentially expressed transcripts that affect the coding sequence. This process was repeated to identify transcripts that were differentially expressed between monocytes and populations of macrophages and LPS-stimulated macrophages derived from these monocytes in vitro. RESULTS We found that over 55 % of genes had two or more expressed transcripts, with an average ∼3 transcripts per gene, and that 70 % of these had at least two of the transcripts that encoded proteins with different sequences. As expected, we identified a complex pattern of differential expression for multiple transcripts encoding the CD45 transmembrane protein, but we also found similar evidence for ten other genes (CD300A, FYB1, GPI, LITAF, PSMA1, PTMA, RPL32, SEPTIN9, SH3BP2, SH3KBP1) when comparing the expression patterns of transcripts within myeloid and lymphoid cells. We also identified five genes with differentially expressed transcripts associated with the transition from monocytes to macrophages (FNBP1, KLF6, and SEPTIN9) or between macrophages and LPS-stimulated macrophages (CD44, OAZ2, and SEPTIN9). For the most part, we found that the different transcripts of these genes are expected to impact specific biological functions, for example the different transcripts of SEPTIN9 likely regulate the cytoskeleton in immune cells via their interactions with actins filaments and microtubules. CONCLUSIONS This analytic approach successfully identified multi-transcript genes that are differentially expressed across immune cells and could be applied to other transcriptomic data. DATA AVAILABILITY STATEMENT Researchers can request access to the individual-level data from the current study by contacting the Montreal Heart Institute ethics committee at the following institutional email address: cer.icm@icm-mhi.org.
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Affiliation(s)
- Saraï Mola
- Centre de recherche, Institut de cardiologie de Montréal, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada; Département de biochimie et médecine moléculaire, Université de Montréal, Pavillon Roger-Gaudry, C.P. 6128, Succ. Centre-ville, Montréal, Québec H3C 3J7, Canada.
| | - Claudine Beauchamp
- Centre de recherche, Institut de cardiologie de Montréal, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada.
| | - Gabrielle Boucher
- Centre de recherche, Institut de cardiologie de Montréal, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada.
| | - Sylvie Lesage
- Maisonneuve-Rosemont Hospital Research Center, 5415 boul. De l'Assomption, Montréal, Québec H1T 2M4, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, Québec H3C 3J7, Canada.
| | - Mohamad Karaky
- Centre de recherche, Institut de cardiologie de Montréal, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada.
| | - Philippe Goyette
- Centre de recherche, Institut de cardiologie de Montréal, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada.
| | - Sylvain Foisy
- Centre de recherche, Institut de cardiologie de Montréal, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada.
| | - John D Rioux
- Centre de recherche, Institut de cardiologie de Montréal, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada; Département de biochimie et médecine moléculaire, Université de Montréal, Pavillon Roger-Gaudry, C.P. 6128, Succ. Centre-ville, Montréal, Québec H3C 3J7, Canada; Département de médecine, Université de Montréal, Pavillon Roger-Gaudry, C.P. 6128, Succ. Centre-ville, Montréal, Québec H3C 3J7, Canada.
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9
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Benoit B, Poüs C, Baillet A. Septins as membrane influencers: direct play or in association with other cytoskeleton partners. Front Cell Dev Biol 2023; 11:1112319. [PMID: 36875762 PMCID: PMC9982393 DOI: 10.3389/fcell.2023.1112319] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/23/2023] [Indexed: 02/19/2023] Open
Abstract
The cytoskeleton comprises three polymerizing structures that have been studied for a long time, actin microfilaments, microtubules and intermediate filaments, plus more recently investigated dynamic assemblies like septins or the endocytic-sorting complex required for transport (ESCRT) complex. These filament-forming proteins control several cell functions through crosstalks with each other and with membranes. In this review, we report recent works that address how septins bind to membranes, and influence their shaping, organization, properties and functions, either by binding to them directly or indirectly through other cytoskeleton elements.
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Affiliation(s)
- Béatrice Benoit
- INSERM UMR-S 1193, UFR de Pharmacie, University Paris-Saclay, Orsay, France
| | - Christian Poüs
- INSERM UMR-S 1193, UFR de Pharmacie, University Paris-Saclay, Orsay, France.,Laboratoire de Biochimie-Hormonologie, Hôpital Antoine Béclère, AP-HP, Hôpitaux Universitaires Paris-Saclay, Clamart, France
| | - Anita Baillet
- INSERM UMR-S 1193, UFR de Pharmacie, University Paris-Saclay, Orsay, France
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10
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Septins mediate a microtubule-actin crosstalk that enables actin growth on microtubules. Proc Natl Acad Sci U S A 2022; 119:e2202803119. [PMID: 36475946 PMCID: PMC9897426 DOI: 10.1073/pnas.2202803119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cellular morphogenesis and processes such as cell division and migration require the coordination of the microtubule and actin cytoskeletons. Microtubule-actin crosstalk is poorly understood and largely regarded as the capture and regulation of microtubules by actin. Septins are filamentous guanosine-5'-triphosphate (GTP) binding proteins, which comprise the fourth component of the cytoskeleton along microtubules, actin, and intermediate filaments. Here, we report that septins mediate microtubule-actin crosstalk by coupling actin polymerization to microtubule lattices. Superresolution and platinum replica electron microscopy (PREM) show that septins localize to overlapping microtubules and actin filaments in the growth cones of neurons and non-neuronal cells. We demonstrate that recombinant septin complexes directly crosslink microtubules and actin filaments into hybrid bundles. In vitro reconstitution assays reveal that microtubule-bound septins capture and align stable actin filaments with microtubules. Strikingly, septins enable the capture and polymerization of growing actin filaments on microtubule lattices. In neuronal growth cones, septins are required for the maintenance of the peripheral actin network that fans out from microtubules. These findings show that septins directly mediate microtubule interactions with actin filaments, and reveal a mechanism of microtubule-templated actin growth with broader significance for the self-organization of the cytoskeleton and cellular morphogenesis.
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11
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Localization Patterns of RAB3C Are Associated with Murine and Human Sperm Formation. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58101408. [PMID: 36295569 PMCID: PMC9606999 DOI: 10.3390/medicina58101408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 12/01/2022]
Abstract
Background and Objectives: Septins (SEPTs) are highly conserved GTP-binding proteins and the fourth component of the cytoskeleton. Polymerization of SEPTs contributes to several critical cellular processes such as cytokinesis, cytoskeletal remodeling, and vesicle transportation. In our previous study, we found that SEPT14 mutations resulted in teratozoospermia with >87% sperm morphological defects. SEPT14 interactors were also identified through proteomic assays, and one of the peptides was mapped to RAB3B and RAB3C. Most studies on the RAB3 family have focused on RAB3A, which regulates the exocytosis of neurotransmitters and acrosome reactions. However, the general expression and patterns of the RAB3 family members during human spermatogenesis, and the association between RAB3 and teratozoospermia owing to a SEPT14 mutation, are largely unknown. Materials and Methods: Human sperm and murine male germ cells were collected in this study and immunofluorescence analysis was applied on the collected sperm. Results: In this study, we observed that the RAB3C transcripts were more abundant than those of RAB3A, 3B, and 3D in human testicular tissues. During human spermatogenesis, the RAB3C protein is mainly enriched in elongated spermatids, and RAB3B is undetectable. In mature human spermatozoa, RAB3C is concentrated in the postacrosomal region, neck, and midpiece. The RAB3C signals were delocalized within human spermatozoa harboring the SEPT14 mutation, and the decreased signals were accompanied by a defective head and tail, compared with the healthy controls. To determine whether RAB3C is involved in the morphological formation of the head and tail of the sperm, we separated murine testicular tissue and isolated elongated spermatids for further study. We found that RAB3C is particularly expressed in the manchette structure, which assists sperm head shaping at the spermatid head, and is also localized at the sperm tail. Conclusions: Based on these results, we suggest that the localization of RAB3C proteins in murine and human sperm is associated with SEPT14 mutation-induced morphological defects in sperm.
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12
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Radler MR, Spiliotis ET. Right place, right time - Spatial guidance of neuronal morphogenesis by septin GTPases. Curr Opin Neurobiol 2022; 75:102557. [PMID: 35609489 PMCID: PMC9968515 DOI: 10.1016/j.conb.2022.102557] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/07/2022] [Accepted: 04/20/2022] [Indexed: 12/21/2022]
Abstract
Neuronal morphogenesis is guided by outside-in signals and inside-out mechanisms, which require spatiotemporal precision. How the intracellular mechanisms of neuronal morphogenesis are spatiotemporally controlled is not well understood. Septins comprise a unique GTPase module, which consists of complexes with differential localizations and functions. Septins demarcate distinct membrane domains in neural precursor cells, orienting the axis of cell division and the sites of neurite formation. By controlling the localization of membrane and cytoskeletal proteins, septins promote axon-dendrite formation and polarity. Furthermore, septins modulate vesicle exocytosis at pre-synaptic terminals, and stabilize dendritic spines and post-synaptic densities in a phospho-regulatable manner. We posit that neuronal septins are topologically and functionally specialized for the spatiotemporal regulation of neuronal morphogenesis and plasticity.
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Affiliation(s)
- Megan R. Radler
- Department of Biology, Drexel University, Papadakis Integrated Sciences Building 423, 3245 Chestnut St, Philadelphia, PA 19104, USA
| | - Elias T. Spiliotis
- Department of Biology, Drexel University, Papadakis Integrated Sciences Building 423, 3245 Chestnut St, Philadelphia, PA 19104, USA
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13
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van de Velde ME, Uittenboogaard A, Yang W, Bonten E, Cheng C, Pei D, van den Berg MH, van der Sluis IM, van den Bos C, Abbink FCH, van den Heuvel-Eibrink MM, Segers H, Chantrain C, van der Werff ten Bosch J, Willems L, Evans WE, Kaspers GJL. Genetic Polymorphisms Associated with Vincristine Pharmacokinetics and Vincristine-Induced Peripheral Neuropathy in Pediatric Oncology Patients. Cancers (Basel) 2022; 14:cancers14143510. [PMID: 35884569 PMCID: PMC9321338 DOI: 10.3390/cancers14143510] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/11/2022] [Accepted: 07/14/2022] [Indexed: 12/04/2022] Open
Abstract
Simple Summary Vincristine is a type of chemotherapy that is often used in the treatment of children with cancer. The main side effect of vincristine is nerve damage. Patients experience symptoms such as tingling, pain or muscle weakness. Some children are more sensitive to vincristine than others, which may depend on variations in genes and in the breakdown of vincristine by the body. In this study, we investigated the effect of variations in genes on nerve damage due to vincristine and breakdown of vincristine by the body. We found that nine variations in seven genes were associated with nerve damage due to vincristine, whereas three variations in three genes were associated with the breakdown of vincristine by the body. It is important that future studies try to replicate these findings. Our findings help us towards the goal of tailoring vincristine treatment to each child, with optimal therapeutic effect while limiting nerve damage. Abstract Vincristine (VCR) is an important component of curative chemotherapy for many childhood cancers. Its main side effect is VCR-induced peripheral neuropathy (VIPN), a dose limiting toxicity. Some children are more susceptible to VIPN, which is at least partially dependent on genetic factors and pharmacokinetics (PK). In this study, we identify and replicate genetic variants associated with VCR PK and VIPN. Patient samples from a randomized clinical trial studying the effect of administration duration of VCR on VIPN in 90 patients were used. PK sampling was conducted on between one and five occasions at multiple time points. A linear two-compartment model with first-order elimination was used, and targeted next-generation DNA sequencing was performed. Genotype–trait associations were analyzed using mixed-effect models or logistic regression analysis for repeated measures, or Poisson regression analysis in which the highest VIPN score per patient was included. Nine single-nucleotide polymorphisms (SNPs) in seven genes (NDRG1, GARS, FIG4, FGD4, SEPTIN9, CEP72, and ETAA1) were associated with VIPN. Furthermore, three SNPs in three genes (MTNR1B, RAB7A and SNU13) were associated with PK of VCR. In conclusion, PK of VCR and VIPN are influenced by SNPs; upfront identification of those that lead to an altered susceptibility to VIPN or VCR exposure could help individualize VCR treatment.
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Affiliation(s)
- Mirjam E. van de Velde
- Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, 1081 HV Amsterdam, The Netherlands; (A.U.); (M.H.v.d.B.); (G.J.L.K.)
- Department of Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (W.Y.); (E.B.); (W.E.E.)
- Correspondence:
| | - Aniek Uittenboogaard
- Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, 1081 HV Amsterdam, The Netherlands; (A.U.); (M.H.v.d.B.); (G.J.L.K.)
- Princess Máxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands; (I.M.v.d.S.); (C.v.d.B.); (M.M.v.d.H.-E.)
| | - Wenjian Yang
- Department of Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (W.Y.); (E.B.); (W.E.E.)
| | - Erik Bonten
- Department of Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (W.Y.); (E.B.); (W.E.E.)
| | - Cheng Cheng
- Department of Biostatistics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (C.C.); (D.P.)
| | - Deqing Pei
- Department of Biostatistics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (C.C.); (D.P.)
| | - Marleen H. van den Berg
- Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, 1081 HV Amsterdam, The Netherlands; (A.U.); (M.H.v.d.B.); (G.J.L.K.)
| | - Inge M. van der Sluis
- Princess Máxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands; (I.M.v.d.S.); (C.v.d.B.); (M.M.v.d.H.-E.)
| | - Cor van den Bos
- Princess Máxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands; (I.M.v.d.S.); (C.v.d.B.); (M.M.v.d.H.-E.)
- Emma Children’s Hospital, Amsterdam UMC, Amsterdam Medical Center, Pediatric Oncology, 1105 Amsterdam, The Netherlands;
| | - Floor C. H. Abbink
- Emma Children’s Hospital, Amsterdam UMC, Amsterdam Medical Center, Pediatric Oncology, 1105 Amsterdam, The Netherlands;
| | | | - Heidi Segers
- Department of Pediatric Hemato-Oncology, University Hospitals Leuven and Catholic University Leuven, 3000 Leuven, Belgium;
| | | | | | - Leen Willems
- Department of Paediatric Haematology-Oncology and Stem Cell Transplantation, Ghent University Hospital, 9000 Ghent, Belgium;
| | - William E. Evans
- Department of Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (W.Y.); (E.B.); (W.E.E.)
| | - Gertjan J. L. Kaspers
- Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, 1081 HV Amsterdam, The Netherlands; (A.U.); (M.H.v.d.B.); (G.J.L.K.)
- Princess Máxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands; (I.M.v.d.S.); (C.v.d.B.); (M.M.v.d.H.-E.)
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14
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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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15
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Fischer M, Frank D, Rösler R, Johnsson N, Gronemeyer T. Biochemical Characterization of a Human Septin Octamer. Front Cell Dev Biol 2022; 10:771388. [PMID: 35309913 PMCID: PMC8928218 DOI: 10.3389/fcell.2022.771388] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 02/14/2022] [Indexed: 11/25/2022] Open
Abstract
Septins are part of the cytoskeleton and polymerize into non-polar filaments of heteromeric hexamers or octamers. They belong to the class of P-loop GTPases but the roles of GTP binding and hydrolysis on filament formation and dynamics are not well understood. The basic human septin building block is the septin rod, a hetero-octamer composed of SEPT2, SEPT6, SEPT7, and SEPT9 with a stoichiometry of 2:2:2:2 (2-6-7-9-9-7-6-2). Septin rods polymerize by end-to-end and lateral joining into linear filaments and higher ordered structures such as rings, sheets, and gauzes. We purified a recombinant human septin octamer from E. coli for in vitro experimentation that is able to polymerize into filaments. We could show that the C-terminal region of the central SEPT9 subunit contributes to filament formation and that the human septin rod decreases the rate of in vitro actin polymerization. We provide further first kinetic data on the nucleotide uptake- and exchange properties of human hexameric and octameric septin rods. We could show that nucleotide uptake prior to hydrolysis is a dynamic process and that a bound nucleotide is exchangeable. However, the hydrolyzed γ-phosphate is not released from the native protein complex. We consequently propose that GTP hydrolysis in human septins does not follow the typical mechanism known from other small GTPases.
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Affiliation(s)
- Martin Fischer
- Institute of Molecular Genetics and Cell Biology, Ulm University, Ulm, Germany
| | - Dominik Frank
- Institute of Molecular Genetics and Cell Biology, Ulm University, Ulm, Germany
| | - Reinhild Rösler
- Core Unit Mass Spectrometry and Proteomics, Ulm University, Ulm, Germany
| | - Nils Johnsson
- Institute of Molecular Genetics and Cell Biology, Ulm University, Ulm, Germany
| | - Thomas Gronemeyer
- Institute of Molecular Genetics and Cell Biology, Ulm University, Ulm, Germany
- *Correspondence: Thomas Gronemeyer,
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16
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Shuman B, Momany M. Septins From Protists to People. Front Cell Dev Biol 2022; 9:824850. [PMID: 35111763 PMCID: PMC8801916 DOI: 10.3389/fcell.2021.824850] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 12/16/2021] [Indexed: 11/13/2022] Open
Abstract
Septin GTPases form nonpolar heteropolymers that play important roles in cytokinesis and other cellular processes. The ability to form heteropolymers appears to be critical to many septin functions and to have been a major driver of the high conservation of many septin domains. Septins fall into five orthologous groups. Members of Groups 1–4 interact with each other to form heterooligomers and are known as the “core septins.” Representative core septins are present in all fungi and animals so far examined and show positional orthology with monomer location in the heteropolymer conserved within groups. In contrast, members of Group 5 are not part of canonical heteropolymers and appear to interact only transiently, if at all, with core septins. Group 5 septins have a spotty distribution, having been identified in specific fungi, ciliates, chlorophyte algae, and brown algae. In this review we compare the septins from nine well-studied model organisms that span the tree of life (Homo sapiens, Drosophila melanogaster, Schistosoma mansoni, Caenorhabditis elegans, Saccharomyces cerevisiae, Aspergillus nidulans, Magnaporthe oryzae, Tetrahymena thermophila, and Chlamydomonas reinhardtii). We focus on classification, evolutionary relationships, conserved motifs, interfaces between monomers, and positional orthology within heteropolymers. Understanding the relationships of septins across kingdoms can give new insight into their functions.
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17
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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: 34] [Impact Index Per Article: 11.3] [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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18
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Neubauer K, Zieger B. Role of Septins in Endothelial Cells and Platelets. Front Cell Dev Biol 2021; 9:768409. [PMID: 34858990 PMCID: PMC8632023 DOI: 10.3389/fcell.2021.768409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Septins are conserved cytoskeletal GTP-binding proteins identified in almost all eukaryotes except higher plants. Mammalian septins comprise 13 family members with either ubiquitous or organ- and tissue-specific expression patterns. They form filamentous oligomers and complexes with other proteins to serve as diffusions barrier and/or multi-molecular scaffolds to function in a physiologically regulated manner. Diverse septins are highly expressed in endothelial cells and platelets, which play an important role in hemostasis, a process to prevent blood loss after vascular injury. Endothelial septins are involved in cellular processes such as exocytosis and in processes concerning organismal level, like angiogenesis. Septins are additionally found in endothelial cell-cell junctions where their presence is required to maintain the integrity of the barrier function of vascular endothelial monolayers. In platelets, septins are important for activation, degranulation, adhesion, and aggregation. They have been identified as mediators of distinct platelet functions and being essential in primary and secondary hemostatic processes. Septin-knockout mouse studies show the relevance of septins in several aspects of hemostasis. This is in line with reports that dysregulation of septins is clinically relevant in human bleeding disorders. The precise function of septins in the biology of endothelial cells and platelets remains poorly understood. The following mini-review highlights the current knowledge about the role of septin cytoskeleton in regulating critical functions in these two cell types.
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Affiliation(s)
- Katharina Neubauer
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Barbara Zieger
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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19
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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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20
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Zhovmer AS, Manning A, Smith C, Hayes JB, Burnette DT, Wang J, Cartagena-Rivera AX, Dokholyan NV, Singh RK, Tabdanov ED. Mechanical Counterbalance of Kinesin and Dynein Motors in a Microtubular Network Regulates Cell Mechanics, 3D Architecture, and Mechanosensing. ACS NANO 2021; 15:17528-17548. [PMID: 34677937 PMCID: PMC9291236 DOI: 10.1021/acsnano.1c04435] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Microtubules (MTs) and MT motor proteins form active 3D networks made of unstretchable cables with rod-like bending mechanics that provide cells with a dynamically changing structural scaffold. In this study, we report an antagonistic mechanical balance within the dynein-kinesin microtubular motor system. Dynein activity drives the microtubular network inward compaction, while isolated activity of kinesins bundles and expands MTs into giant circular bands that deform the cell cortex into discoids. Furthermore, we show that dyneins recruit MTs to sites of cell adhesion, increasing the topographic contact guidance of cells, while kinesins antagonize it via retraction of MTs from sites of cell adhesion. Actin-to-microtubule translocation of septin-9 enhances kinesin-MT interactions, outbalances the activity of kinesins over that of dyneins, and induces the discoid architecture of cells. These orthogonal mechanisms of MT network reorganization highlight the existence of an intricate mechanical balance between motor activities of kinesins and dyneins that controls cell 3D architecture, mechanics, and cell-microenvironment interactions.
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Affiliation(s)
- Alexander S. Zhovmer
- Center
for Biologics Evaluation and Research, U.S.
Food and Drug Administration, Silver Spring, Maryland 20903, United States
- . Tel: 1-301-402-1606
| | - Alexis Manning
- Center
for Biologics Evaluation and Research, U.S.
Food and Drug Administration, Silver Spring, Maryland 20903, United States
| | - Chynna Smith
- Section
on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - James B. Hayes
- Department
of Cell and Developmental Biology, Vanderbilt Medical Center, University of Vanderbilt, Nashville, Tennessee 37232, United States
| | - Dylan T. Burnette
- Department
of Cell and Developmental Biology, Vanderbilt Medical Center, University of Vanderbilt, Nashville, Tennessee 37232, United States
| | - Jian Wang
- Department
of Pharmacology, Penn State College of Medicine, Pennsylvania State University, Hummelstown, Pennsylvania 17036, United States
| | - Alexander X. Cartagena-Rivera
- Section
on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
- . Tel: 1-301-503-4033
| | - Nikolay V. Dokholyan
- Department
of Pharmacology, Penn State College of Medicine, Pennsylvania State University, Hummelstown, Pennsylvania 17036, United States
- Department
of Biochemistry & Molecular Biology, Penn State College of Medicine, Pennsylvania State University, Hershey, Pennsylvania 17033, United States
- . Tel: 1-717-531-5177
| | - Rakesh K. Singh
- Department
of Obstetrics and Gynecology, University
of Rochester Medical Center, Rochester, New York 14620, United States
- . Tel: 1-585-276-6281
| | - Erdem D. Tabdanov
- Department
of Pharmacology, Penn State College of Medicine, Pennsylvania State University, Hummelstown, Pennsylvania 17036, United States
- . Tel: 1-717-531-0003 Ext: 4430
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21
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Russo G, Krauss M. Septin Remodeling During Mammalian Cytokinesis. Front Cell Dev Biol 2021; 9:768309. [PMID: 34805175 PMCID: PMC8600141 DOI: 10.3389/fcell.2021.768309] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/18/2021] [Indexed: 01/22/2023] Open
Abstract
Cytokinesis mediates the final separation of a mother cell into two daughter cells. Septins are recruited to the cleavage furrow at an early stage. During cytokinetic progression the septin cytoskeleton is constantly rearranged, ultimately leading to a concentration of septins within the intercellular bridge (ICB), and to the formation of two rings adjacent to the midbody that aid ESCRT-dependent abscission. The molecular mechanisms underlying this behavior are poorly understood. Based on observations that septins can associate with actin, microtubules and associated motors, we review here established roles of septins in mammalian cytokinesis, and discuss, how septins may support cytokinetic progression by exerting their functions at particular sites. Finally, we discuss how this might be assisted by phosphoinositide-metabolizing enzymes.
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Affiliation(s)
- Giulia Russo
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Michael Krauss
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
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22
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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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23
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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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24
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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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25
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Spiliotis ET, Kesisova IA. Spatial regulation of microtubule-dependent transport by septin GTPases. Trends Cell Biol 2021; 31:979-993. [PMID: 34253430 DOI: 10.1016/j.tcb.2021.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/10/2021] [Accepted: 06/14/2021] [Indexed: 01/21/2023]
Abstract
The intracellular long-range transport of membrane vesicles and organelles is mediated by microtubule motors (kinesins, dynein) which move cargo with spatiotemporal accuracy and efficiency. How motors navigate the microtubule network and coordinate their activity on membrane cargo are fundamental but poorly understood questions. New studies show that microtubule-dependent membrane traffic is spatially controlled by septins - a unique family of multimerizing GTPases that associate with microtubules and membrane organelles. We review how septins selectively regulate motor interactions with microtubules and membrane cargo. We posit that septins provide a novel traffic code that specifies the movement and directionality of select motor-cargo complexes on distinct microtubule tracks.
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Affiliation(s)
- Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA.
| | - Ilona A Kesisova
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
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Abstract
PURPOSE OF REVIEW This review focuses on the current insights and developments in neuralgic amyotrophy (NA), an auto-immune multifocal peripheral nervous system disorder that leaves many patients permanently impaired if not recognized and treated properly. RECENT FINDINGS NA is not as rare as previously thought. The phenotype is broad, and recent nerve imaging developments suggest that NA is the most common cause of acute anterior or posterior interosseous nerve palsy. Phrenic nerve involvement occurs in 8% of all NA patients, often with debilitating consequences. Acute phase treatment of NA with steroids or i.v. immunoglobulin may benefit patients. Long-term consequences are the rule, and persisting symptoms are mainly caused by a combination of decreased endurance in the affected nerves and an altered posture and movement pattern, not by the axonal damage itself. Patients benefit from specific rehabilitation treatment. For nerves that do not recover, surgery may be an option. SUMMARY NA is not uncommon, and has a long-term impact on patients' well-being. Early immunomodulating treatment, and identifying phrenic neuropathy or complete nerve paralysis is important for optimal recovery. For persistent symptoms a specific treatment strategy aiming at regaining an energy balance and well-coordinated scapular movement are paramount.
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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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28
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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: 27] [Impact Index Per Article: 9.0] [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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29
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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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30
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Lin YH, Huang CY, Ke CC, Wang YY, Lai TH, Liu HC, Ku WC, Chan CC, Lin YH. ACTN4 Mediates SEPT14 Mutation-Induced Sperm Head Defects. Biomedicines 2020; 8:biomedicines8110518. [PMID: 33228246 PMCID: PMC7699536 DOI: 10.3390/biomedicines8110518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 12/22/2022] Open
Abstract
Septins (SEPTs) are highly conserved GTP-binding proteins and the fourth component of the cytoskeleton. Polymerized SEPTs participate in the modulation of various cellular processes, such as cytokinesis, cell polarity, and membrane dynamics, through their interactions with microtubules, actin, and other cellular components. The main objective of this study was to dissect the molecular pathological mechanism of SEPT14 mutation-induced sperm head defects. To identify SEPT14 interactors, co-immunoprecipitation (co-IP) and nano-liquid chromatography-mass spectrometry/mass spectrometry were applied. Immunostaining showed that SEPT14 was significantly localized to the manchette structure. The SEPT14 interactors were identified and classified as (1) SEPT-, (2) microtubule-, (3) actin-, and (4) sperm structure-related proteins. One interactor, ACTN4, an actin-holding protein, was selected for further study. Co-IP experiments showed that SEPT14 interacts with ACTN4 in a male germ cell line. SEPT14 also co-localized with ACTN4 in the perinuclear and manchette regions of the sperm head in early elongating spermatids. In the cell model, mutated SEPT14 disturbed the localization pattern of ACTN4. In a clinical aspect, sperm with mutant SEPT14, SEPT14A123T (p.Ala123Thr), and SEPT14I333T (p.Ile333Thr), have mislocalized and fragmented ACTN4 signals. Sperm head defects in donors with SEPT14 mutations are caused by disruption of the functions of ACTN4 and actin during sperm head formation.
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Affiliation(s)
- Yu-Hua Lin
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 242, Taiwan;
- Division of Urology, Department of Surgery, Cardinal Tien Hospital, New Taipei City 231, Taiwan
| | - Chia-Yen Huang
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 300, Taiwan;
- Gynecologic Cancer Center, Department of Obstetrics and Gynecology, Cathay General Hospital, Taipei 106, Taiwan
- School of Medicine, Fu Jen Catholic University, New Taipei City 242, Taiwan; (T.-H.L.); (W.-C.K.)
| | - Chih-Chun Ke
- PhD Program in Nutrition & Food Science, Fu Jen Catholic University, New Taipei City 242, Taiwan;
- Department of Urology, En Chu Kong Hospital, New Taipei City 237, Taiwan
| | - Ya-Yun Wang
- Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic University, New Taipei City 242, Taiwan; (Y.-Y.W.); (H.-C.L.)
| | - Tsung-Hsuan Lai
- School of Medicine, Fu Jen Catholic University, New Taipei City 242, Taiwan; (T.-H.L.); (W.-C.K.)
- Department of Obstetrics and Gynecology, Cathay General Hospital, Taipei 106, Taiwan
| | - Hsuan-Che Liu
- Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic University, New Taipei City 242, Taiwan; (Y.-Y.W.); (H.-C.L.)
| | - Wei-Chi Ku
- School of Medicine, Fu Jen Catholic University, New Taipei City 242, Taiwan; (T.-H.L.); (W.-C.K.)
| | - Chying-Chyuan Chan
- Department of Obstetrics and Gynecology, Taipei City Hospital, Renai Branch, Taipei 106, Taiwan;
| | - Ying-Hung Lin
- Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic University, New Taipei City 242, Taiwan; (Y.-Y.W.); (H.-C.L.)
- Correspondence:
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31
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La TM, Tachibana H, Li SA, Abe T, Seiriki S, Nagaoka H, Takashima E, Takeda T, Ogawa D, Makino SI, Asanuma K, Watanabe M, Tian X, Ishibe S, Sakane A, Sasaki T, Wada J, Takei K, Yamada H. Dynamin 1 is important for microtubule organization and stabilization in glomerular podocytes. FASEB J 2020; 34:16449-16463. [PMID: 33070431 DOI: 10.1096/fj.202001240rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 09/24/2020] [Accepted: 10/06/2020] [Indexed: 11/11/2022]
Abstract
Dynamin 1 is a neuronal endocytic protein that participates in vesicle formation by scission of invaginated membranes. Dynamin 1 is also expressed in the kidney; however, its physiological significance to this organ remains unknown. Here, we show that dynamin 1 is crucial for microtubule organization and stabilization in glomerular podocytes. By immunofluorescence and immunoelectron microscopy, dynamin 1 was concentrated at microtubules at primary processes in rat podocytes. By immunofluorescence of differentiated mouse podocytes (MPCs), dynamin 1 was often colocalized with microtubule bundles, which radially arranged toward periphery of expanded podocyte. In dynamin 1-depleted MPCs by RNAi, α-tubulin showed a dispersed linear filament-like localization, and microtubule bundles were rarely observed. Furthermore, dynamin 1 depletion resulted in the formation of discontinuous, short acetylated α-tubulin fragments, and the decrease of microtubule-rich protrusions. Dynamins 1 and 2 double-knockout podocytes showed dispersed acetylated α-tubulin and rare protrusions. In vitro, dynamin 1 polymerized around microtubules and cross-linked them into bundles, and increased their resistance to the disassembly-inducing reagents Ca2+ and podophyllotoxin. In addition, overexpression and depletion of dynamin 1 in MPCs increased and decreased the nocodazole resistance of microtubules, respectively. These results suggest that dynamin 1 supports the microtubule bundle formation and participates in the stabilization of microtubules.
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Affiliation(s)
- The Mon La
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hiromi Tachibana
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Shun-Ai Li
- Center for Innovative Clinical Medicine, Okayama University Hospital, Okayama, Japan
| | - Tadashi Abe
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Sayaka Seiriki
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Tetsuya Takeda
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Daisuke Ogawa
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Shin-Ichi Makino
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba-shi, Japan
| | - Katsuhiko Asanuma
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba-shi, Japan
| | - Masami Watanabe
- Center for Innovative Clinical Medicine, Okayama University Hospital, Okayama, Japan
| | - Xuefei Tian
- Department of Internal Medicine, Section of Nephrology, Yale University School of Medicine, New Haven, CT, USA
| | - Shuta Ishibe
- Department of Internal Medicine, Section of Nephrology, Yale University School of Medicine, New Haven, CT, USA
| | - Ayuko Sakane
- Department of Biochemistry, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan.,Department of Interdisciplinary Researches for Medicine and Photonics, Institute of Post-LED Photonics, Tokushima, Japan
| | - Takuya Sasaki
- Department of Biochemistry, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Jun Wada
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kohji Takei
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hiroshi Yamada
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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Novel Functions of the Septin Cytoskeleton: Shaping Up Tissue Inflammation and Fibrosis. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 191:40-51. [PMID: 33039354 DOI: 10.1016/j.ajpath.2020.09.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/24/2020] [Accepted: 09/16/2020] [Indexed: 12/19/2022]
Abstract
Chronic inflammatory diseases cause profound alterations in tissue homeostasis, including unchecked activation of immune and nonimmune cells leading to disease complications such as aberrant tissue repair and fibrosis. Current anti-inflammatory therapies are often insufficient in preventing or reversing these complications. Remodeling of the intracellular cytoskeleton is critical for cell activation in inflamed and fibrotic tissues; however, the cytoskeleton has not been adequately explored as a therapeutic target in inflammation. Septins are GTP-binding proteins that self-assemble into higher order cytoskeletal structures. The septin cytoskeleton exhibits a number of critical cellular functions, including regulation of cell shape and polarity, cytokinesis, cell migration, vesicle trafficking, and receptor signaling. Surprisingly, little is known about the role of the septin cytoskeleton in inflammation. This article reviews emerging evidence implicating different septins in the regulation of host-pathogen interactions, immune cell functions, and tissue fibrosis. Targeting of the septin cytoskeleton as a potential future therapeutic intervention in human inflammatory and fibrotic diseases is also discussed.
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33
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Blangy A, Bompard G, Guerit D, Marie P, Maurin J, Morel A, Vives V. The osteoclast cytoskeleton - current understanding and therapeutic perspectives for osteoporosis. J Cell Sci 2020; 133:133/13/jcs244798. [PMID: 32611680 DOI: 10.1242/jcs.244798] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Osteoclasts are giant multinucleated myeloid cells specialized for bone resorption, which is essential for the preservation of bone health throughout life. The activity of osteoclasts relies on the typical organization of osteoclast cytoskeleton components into a highly complex structure comprising actin, microtubules and other cytoskeletal proteins that constitutes the backbone of the bone resorption apparatus. The development of methods to differentiate osteoclasts in culture and manipulate them genetically, as well as improvements in cell imaging technologies, has shed light onto the molecular mechanisms that control the structure and dynamics of the osteoclast cytoskeleton, and thus the mechanism of bone resorption. Although essential for normal bone physiology, abnormal osteoclast activity can cause bone defects, in particular their hyper-activation is commonly associated with many pathologies, hormonal imbalance and medical treatments. Increased bone degradation by osteoclasts provokes progressive bone loss, leading to osteoporosis, with the resulting bone frailty leading to fractures, loss of autonomy and premature death. In this context, the osteoclast cytoskeleton has recently proven to be a relevant therapeutic target for controlling pathological bone resorption levels. Here, we review the present knowledge on the regulatory mechanisms of the osteoclast cytoskeleton that control their bone resorption activity in normal and pathological conditions.
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Affiliation(s)
- Anne Blangy
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Guillaume Bompard
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - David Guerit
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Pauline Marie
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Justine Maurin
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Anne Morel
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Virginie Vives
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
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34
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Radler MR, Suber A, Spiliotis ET. Spatial control of membrane traffic in neuronal dendrites. Mol Cell Neurosci 2020; 105:103492. [PMID: 32294508 DOI: 10.1016/j.mcn.2020.103492] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 03/24/2020] [Accepted: 04/01/2020] [Indexed: 02/06/2023] Open
Abstract
Neuronal dendrites are highly branched and specialized compartments with distinct structures and secretory organelles (e.g., spines, Golgi outposts), and a unique cytoskeletal organization that includes microtubules of mixed polarity. Dendritic membranes are enriched with proteins, which specialize in the formation and function of the post-synaptic membrane of the neuronal synapse. How these proteins partition preferentially in dendrites, and how they traffic in a manner that is spatiotemporally accurate and regulated by synaptic activity are long-standing questions of neuronal cell biology. Recent studies have shed new insights into the spatial control of dendritic membrane traffic, revealing new classes of proteins (e.g., septins) and cytoskeleton-based mechanisms with dendrite-specific functions. Here, we review these advances by revisiting the fundamental mechanisms that control membrane traffic at the levels of protein sorting and motor-driven transport on microtubules and actin filaments. Overall, dendrites possess unique mechanisms for the spatial control of membrane traffic, which might have specialized and co-evolved with their highly arborized morphology.
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Affiliation(s)
- Megan R Radler
- Department of Biology, Drexel University, 3245 Chestnut St, Philadelphia, PA 19104, USA
| | - Ayana Suber
- Department of Biology, Drexel University, 3245 Chestnut St, Philadelphia, PA 19104, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, 3245 Chestnut St, Philadelphia, PA 19104, USA.
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35
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Grosse GM, Bauer C, Kopp B, Schrader C, Osmanovic A. Identification of a rare SEPT9 variant in a family with autosomal dominant Charcot-Marie-Tooth disease. BMC MEDICAL GENETICS 2020; 21:45. [PMID: 32122354 PMCID: PMC7050135 DOI: 10.1186/s12881-020-0984-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/25/2020] [Indexed: 12/17/2022]
Abstract
Background Charcot-Marie-Tooth disease (CMT) is one of the most commonly inherited neurological disorders. A growing number of genes, involved in glial and neuronal functions, have been associated with different subtypes of CMT leading to improved diagnostics and understanding of pathophysiological mechanisms. However, some patients and families remain genetically unsolved. Methods We report on a German family including four affected members over three generations with a CMT phenotype accompanied by cognitive deficits, predominantly with regard to visual abilities and episodic memory. Results A comprehensive clinical characterization followed by a sequential diagnostic approach disclosed a heterozygous rare SEPT9 missense variant c.1406 T > C, p.(Val469Ala), that segregates with disease. SEPT9 has been linked to various intracellular functions, such as cytokinesis and membrane trafficking. Interestingly, SEPT9-mutations are known to cause hereditary neuralgic amyotrophy (HNA), a recurrent focal peripheral neuropathy. Conclusion We, for the first time, present a SEPT9 variant associated to a CMT phenotype and suggest SEPT9 as new sufficient candidate gene in CMT.
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Affiliation(s)
- Gerrit M Grosse
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Christine Bauer
- Center for Genomics and Transcriptomics (CeGaT GmbH), Tübingen, Germany
| | - Bruno Kopp
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Christoph Schrader
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Alma Osmanovic
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
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36
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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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37
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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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38
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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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39
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Zeng Y, Cao Y, Liu L, Zhao J, Zhang T, Xiao L, Jia M, Tian Q, Yu H, Chen S, Cai Y. SEPT9_i1 regulates human breast cancer cell motility through cytoskeletal and RhoA/FAK signaling pathway regulation. Cell Death Dis 2019; 10:720. [PMID: 31558699 PMCID: PMC6763430 DOI: 10.1038/s41419-019-1947-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 08/09/2019] [Accepted: 08/26/2019] [Indexed: 02/08/2023]
Abstract
Increasing cell mobility is the basis of tumor invasion and metastasis, and is therefore a therapeutic target for preventing the spread of many types of cancer. Septins are a family of cytoskeletal proteins with GTPase activity, and play a role in many important cellular functions, including cell migration. SEPT9 isoform 1 protein (SEPT9_i1) has been associated with breast tumor development and the enhancement of cell migration; however, the exact mechanism of how SEPT9_i1 might affect breast cancer progression remains to be elucidated. Here, we report that the expression of SEPT9_i1 positively correlated with paxillin, and both were significantly upregulated in invasive breast cancer tissues of patients with lymph node metastases. Lentivirus-mediated shRNA knockdown of SEPT9 in MCF-7 cells diminished tumor cell migration, focal adhesion (FA) maturation and the expression of β-actin, β-tubulin, Cdc42, RhoA, and Rac, whereas overexpression of SEPT9_i1 in SEPT9-knockdown MCF-7 cells promoted cell migration, FA maturation and relevant protein expression. Furthermore, overexpression of SEPT9_i1 in MCF-7 cells markedly increased FAK/Src/paxillin signaling, at least in part through RhoA/ROCK1 upstream activation. Transcriptome profiling suggested that SEPT9_i1 may directly affect “Focal adhesion” and “Regulation of actin cytoskeleton” signaling mechanisms. Finally, overexpression of SEPT9_i1 markedly enhanced lung metastases in vivo 6 weeks after tumor inoculation. These findings suggest that a mechanism of Septin-9-induced aberrant cancer cell migration is through cytoskeletal regulation and FA modulation, and encourages the use of SEPT9 as novel therapeutic target in the prevention of tumor metastasis.
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Affiliation(s)
- Yongqiu Zeng
- Key Laboratory of Obstetric, Gynecologic, and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu, Sichuan, China. .,Department of Medical Cell Biology and Genetics, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China.
| | - Yang Cao
- Department of Physiology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
| | - Lan Liu
- Department of Medical Cell Biology and Genetics, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
| | - Jiao Zhao
- Department of Medical Cell Biology and Genetics, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
| | - Ting Zhang
- Department of Medical Cell Biology and Genetics, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
| | - Lifan Xiao
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
| | - Man Jia
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
| | - Qiang Tian
- Department of Medical Cell Biology and Genetics, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
| | - Hong Yu
- Department of Medical Cell Biology and Genetics, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
| | - Shaokun Chen
- Department of Medical Cell Biology and Genetics, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
| | - Yansen Cai
- Department of Medical Cell Biology and Genetics, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China
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40
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SEPT14 Mutations and Teratozoospermia: Genetic Effects on Sperm Head Morphology and DNA Integrity. J Clin Med 2019; 8:jcm8091297. [PMID: 31450874 PMCID: PMC6780492 DOI: 10.3390/jcm8091297] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 08/16/2019] [Accepted: 08/19/2019] [Indexed: 12/24/2022] Open
Abstract
The main objective of this study was to evaluate the potential genetic effects of SEPT14 on male infertility through sequencing the SEPT14 coding region. To address this research gap, 254 men with sperm abnormalities and 116 normozoospermic men were recruited, and the whole-coding regions of SEPT14 were sequenced. Two heterozygous mutations, p.Ala123Thr (3/254 vs. 0/116) and p.Ile333Thr (3/254 vs. 0/116), were identified in these cases. A high percentage of defective sperm heads was found in sperm with mutated SEPT14. Both mutations are highly evolutionarily conserved among vertebrates. The results of a fine morphological and chromatin structural analysis indicated severely malformed sperm heads with abnormal chromatin packaging through transmission electron microscopy and Toluidine blue staining. Compared with controls, high DNA fragmentation was demonstrated in sperm from cases carrying SEPT14 mutations using the comet assay. In addition, these two mutations in SEPT14 affected its polymerization ability in vitro. These data revels that the two SEPT14 missense mutations impaired sperm head morphology and induced DNA damage. Our study suggests that genetic variant of SEPT14 is one of the effects for human sperm formation and male fertility.
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41
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Septin 9 isoforms promote tumorigenesis in mammary epithelial cells by increasing migration and ECM degradation through metalloproteinase secretion at focal adhesions. Oncogene 2019; 38:5839-5859. [PMID: 31285548 PMCID: PMC6859949 DOI: 10.1038/s41388-019-0844-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 02/07/2023]
Abstract
The cytoskeletal interacting protein Septin 9 (SEPT9), a member of the septin gene family, has been proposed to have oncogenic functions. It is a known hot spot of retroviral tagging insertion and a fusion partner of both de novo and therapy-induced mixed lineage leukemia (MLL). Of all septins, SEPT9 holds the strongest link to cancer, especially breast cancer. Murine models of breast cancer frequently exhibit Sept9 amplification in the form of double minute chromosomes, and about 20% of human breast cancer display genomic amplification and protein over expression at the SEPT9 locus. Yet, a clear mechanism by which SEPT9 elicits tumor-promoting functions is lacking. To obtain unbiased insights on molecular signatures of SEPT9 upregulation in breast tumors, we overexpressed several of its isoforms in breast cancer cell lines. Global transcriptomic profiling supports a role of SEPT9 in invasion. Functional studies reveal that SEPT9 upregulation is sufficient to increase degradation of the extracellular matrix, while SEPT9 downregulation inhibits this process. The degradation pattern is peripheral and associated with focal adhesions (FA), where it is coupled with increased expression of matrix metalloproteinases. SEPT9 overexpression induces MMP upregulation in human tumors and in culture models and promotes MMP3 secretion to the media at FAs. Downregulation of SEPT9 or chemical inhibition of septin filament assembly impairs recruitment of MMP3 to FAs. Our results indicate that SEPT9 promotes upregulation and both trafficking and secretion of MMPs near FAs, thus enhancing migration and invasion of breast cancer cells.
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42
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Karasmanis EP, Hwang D, Nakos K, Bowen JR, Angelis D, Spiliotis ET. A Septin Double Ring Controls the Spatiotemporal Organization of the ESCRT Machinery in Cytokinetic Abscission. Curr Biol 2019; 29:2174-2182.e7. [PMID: 31204162 DOI: 10.1016/j.cub.2019.05.050] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/29/2019] [Accepted: 05/20/2019] [Indexed: 01/01/2023]
Abstract
Abscission is the terminal step of mitosis that physically separates two daughter cells [1, 2]. Abscission requires the endocytic sorting complex required for transport (ESCRT), a molecular machinery of multiple subcomplexes (ESCRT-I/II/III) that promotes membrane remodeling and scission [3-5]. Recruitment of ESCRT-I/II complexes to the midbody of telophase cells initiates ESCRT-III assembly into two rings, which subsequently expand into helices and spirals that narrow down to the incipient site of abscission [6-8]. ESCRT-III assembly is highly dynamic and spatiotemporally ordered, but the underlying mechanisms are poorly understood. Here, we report that, after cleavage furrow closure, septins form a membrane-bound double ring that controls the organization and function of ESCRT-III. The septin double ring demarcates the sites of ESCRT-III assembly into rings and disassembles before ESCRT-III rings expand into helices and spirals. We show that septin 9 (SEPT9) depletion, which abrogates abscission, impairs recruitment of VPS25 (ESCRT-II) and CHMP6 (ESCRT-III). Strikingly, ESCRT-III subunits (CHMP4B and CHMP2A/B) accumulate to the midbody, but they are highly disorganized, failing to form symmetric rings and to expand laterally into the cone-shaped helices and spirals of abscission. We found that SEPT9 interacts directly with the ubiquitin E2 variant (UEV) domain of ESCRT-I protein TSG101 through two N-terminal PTAP motifs, which are required for the recruitment of VPS25 and CHMP6, and the spatial organization of ESCRT-III (CHMP4B and CHMP2B) into functional rings. These results reveal that septins function in the ESCRT-I-ESCRT-II-CHMP6 pathway of ESCRT-III assembly and provide a framework for the spatiotemporal control of the ESCRT machinery of cytokinetic abscission.
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Affiliation(s)
- Eva P Karasmanis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Daniel Hwang
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | | | - Jonathan R Bowen
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Dimitrios Angelis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA.
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43
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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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44
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Banko M, Mucha-Kruczynska I, Weise C, Heyd F, Ewers H. A homozygous genome-edited Sept2-EGFP fibroblast cell line. Cytoskeleton (Hoboken) 2019; 76:73-82. [PMID: 30924304 PMCID: PMC6593442 DOI: 10.1002/cm.21518] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 03/22/2019] [Accepted: 03/23/2019] [Indexed: 01/09/2023]
Abstract
Septins are a conserved, essential family of GTPases that interact with actin, microtubules, and membranes and form scaffolds and diffusion barriers in cells. Several of the 13 known mammalian septins assemble into nonpolar, multimeric complexes that can further polymerize into filamentous structures. While some GFP‐coupled septins have been described, overexpression of GFP‐tagged septins often leads to artifacts in localization and function. To overcome this ubiquitous problem, we have here generated a genome‐edited rat fibroblast cell line expressing Septin 2 (Sept2) coupled to enhanced green fluorescent protein (EGFP) from both chromosomal loci. We characterize these cells by genomic polymerase chain reaction (PCR) for genomic integration, by western blot and reverse transcriptase‐PCR for expression, by immunofluorescence and immunoprecipitation for the colocalization of septins with one another and cellular structures and for complex formation of different septins. By live cell imaging, proliferation and migration assays we investigate proper function of septins in these cells. We find that EGFP is incorporated into both chromosomal loci and only EGFP‐coupled Sept2 is expressed in homozygous cells. We find that endogenous Sept2‐EGFP exhibits expression levels, localization and incorporation into cellular septin complexes similar to the wt in these cells. The expression level of other septins is not perturbed and cell division and cell migration proceed normally. We expect our cell line to be a useful tool for the cell biology of septins, especially for quantitative biology.
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Affiliation(s)
- Monika Banko
- Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.,Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Iwona Mucha-Kruczynska
- Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.,Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Christoph Weise
- Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Florian Heyd
- Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Helge Ewers
- Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.,Department of Biology, ETH Zürich, Zürich, Switzerland.,Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
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45
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Reorganization of Septins Modulates Synaptic Transmission at Neuromuscular Junctions. Neuroscience 2019; 404:91-101. [PMID: 30738855 DOI: 10.1016/j.neuroscience.2019.01.060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 01/27/2019] [Accepted: 01/29/2019] [Indexed: 12/24/2022]
Abstract
Septins (Sept) are highly conserved Guanosine-5'-triphosphate (GTP)-binding cytoskeletal proteins involved in neuronal signaling in the central nervous system but their involvement in signal transmission in peripheral synapses remains unclear. Sept5 and Sept9 proteins were detected in mouse peripheral neuromuscular junctions by immunofluorescence with a greater degree of co-localization with presynaptic than postsynaptic membranes. Preincubation of neuromuscular junction preparations with the inhibitor of Sept dynamics, forchlorfenuron (FCF), decreased co-localization of Sept with presynaptic membranes. FCF introduced ex vivo or in vivo had no effect on the amplitude of the spontaneous endplate currents (EPCs), indicating the absence of postsynaptic effects of FCF. However, FCF decreased acetylcholine (ACh) quantal release in response to nerve stimulation, reduced the amplitude of evoked quantal currents and decreased the number of quanta with long synaptic delays, demonstrating the presynaptic action of FCF. Nevertheless, FCF had no effect on the amplitude of calcium transient in nerve terminals, as detected by calcium-sensitive dye, and slightly decreased the ratio of the second response amplitude to the first one in paired-pulse experiments. These results suggest that FCF-induced decrease in ACh quantal secretion is not due to a decrease in Ca2+ influx but is likely related to the impairment of later stages occurring after Ca2+ entry, such as trafficking, docking or membrane fusion of synaptic vesicles. Therefore, Sept9 and Sept5 are abundantly expressed in presynaptic membranes, and disruption of Sept dynamics suppresses the evoked synchronous and delayed asynchronous quantal release of ACh, strongly suggesting an important role of Sept in the regulation of neurotransmission in peripheral synapses.
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46
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Song K, Gras C, Capin G, Gimber N, Lehmann M, Mohd S, Puchkov D, Rödiger M, Wilhelmi I, Daumke O, Schmoranzer J, Schürmann A, Krauss M. A SEPT1-based scaffold is required for Golgi integrity and function. J Cell Sci 2019; 132:132/3/jcs225557. [PMID: 30709970 PMCID: PMC6382012 DOI: 10.1242/jcs.225557] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/17/2018] [Indexed: 12/13/2022] Open
Abstract
Compartmentalization of membrane transport and signaling processes is of pivotal importance to eukaryotic cell function. While plasma membrane compartmentalization and dynamics are well known to depend on the scaffolding function of septin GTPases, the roles of septins at intracellular membranes have remained largely elusive. Here, we show that the structural and functional integrity of the Golgi depends on its association with a septin 1 (SEPT1)-based scaffold, which promotes local microtubule nucleation and positioning of the Golgi. SEPT1 function depends on the Golgi matrix protein GM130 (also known as GOLGA2) and on centrosomal proteins, including CEP170 and components of γ-tubulin ring complex (γ-Turc), to facilitate the perinuclear concentration of Golgi membranes. Accordingly, SEPT1 depletion triggers a massive fragmentation of the Golgi ribbon, thereby compromising anterograde membrane traffic at the level of the Golgi.
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Affiliation(s)
- Kyungyeun Song
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
| | - Claudia Gras
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
| | - Gabrielle Capin
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
| | - Niclas Gimber
- Charité Universitätsmedizin Berlin, Advanced Medical Bioimaging Core Facility - AMBIO, 10117 Berlin, Germany
| | - Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Cellular Imaging Facility, 13125 Berlin, Germany
| | - Saif Mohd
- Max-Delmbrück-Centrum für Molekulare Medizin, 13125 Berlin, Germany
| | - Dmytro Puchkov
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Cellular Imaging Facility, 13125 Berlin, Germany
| | - Maria Rödiger
- Deutsches Institut für Ernährungsforschung, Potsdam Rehbrücke, and German Center for Diabetes Research (DZD), München-Neuherberg, 14558 Potsdam-Rehbrücke, Germany
| | - Ilka Wilhelmi
- Deutsches Institut für Ernährungsforschung, Potsdam Rehbrücke, and German Center for Diabetes Research (DZD), München-Neuherberg, 14558 Potsdam-Rehbrücke, Germany
| | - Oliver Daumke
- Max-Delmbrück-Centrum für Molekulare Medizin, 13125 Berlin, Germany
| | - Jan Schmoranzer
- Charité Universitätsmedizin Berlin, Advanced Medical Bioimaging Core Facility - AMBIO, 10117 Berlin, Germany
| | - Annette Schürmann
- Deutsches Institut für Ernährungsforschung, Potsdam Rehbrücke, and German Center for Diabetes Research (DZD), München-Neuherberg, 14558 Potsdam-Rehbrücke, Germany
| | - Michael Krauss
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
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47
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Septin filament coalignment with microtubules depends on SEPT9_i1 and tubulin polyglutamylation, and is an early feature of acquired cell resistance to paclitaxel. Cell Death Dis 2019; 10:54. [PMID: 30670682 PMCID: PMC6342940 DOI: 10.1038/s41419-019-1318-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/14/2018] [Accepted: 12/18/2018] [Indexed: 02/06/2023]
Abstract
Cancer cell resistance to taxanes is a complex, multifactorial process, which results from the combination of several molecular and cellular changes. In breast cancer cells adapted to long-term paclitaxel treatment, we previously identified a new adaptive mechanism that contributes to resistance and involves high levels of tubulin tyrosination and long-chain polyglutamylation coupled with high levels of septin expression, especially that of SEPT9_i1. This in turn led to higher CLIP-170 and MCAK recruitment to microtubules to enhance microtubule dynamics and therefore counteract the stabilizing effects of taxanes. Here, we explored to which extent this new mechanism alone could trigger taxane resistance. We show that coupling septins (including SEPT9_i1) overexpression together with long-chain tubulin polyglutamylation induce significant paclitaxel resistance in several naive (taxane-sensitive) cell lines and accordingly stimulate the binding of CLIP-170 and MCAK to microtubules. Strikingly, such resistance was paralleled by a systematic relocalization of septin filaments from actin fibers to microtubules. We further show that this relocalization resulted from the overexpression of septins in a context of enhanced tubulin polyglutamylation and reveal that it could also be promoted by an acute treatment with paclitaxel of sensitve cell displaying a high basal level of SEPT9_i1. These findings point out the functional importance and the complex cellular dynamics of septins in the onset of cell resistance to death caused by microtubule-targeting antimitotic drugs of the taxane family.
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48
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Lin CH, Shen YR, Wang HY, Chiang CW, Wang CY, Kuo PL. Regulation of septin phosphorylation: SEPT12 phosphorylation in sperm septin assembly. Cytoskeleton (Hoboken) 2018; 76:137-142. [PMID: 30160375 DOI: 10.1002/cm.21491] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 08/08/2018] [Accepted: 08/12/2018] [Indexed: 12/11/2022]
Abstract
The sperm annulus, a septin-based ring structure, is important for reproductive physiology. It is composed of SEPT12-based septin core complex followed by assembling as octameric filament. In clinical examinations, mutations of Septin12 result in male infertility, immotile sperm, as well as sperm with defective annuli. The dynamic assembly of septin filaments is regulated by several post-translational modifications, including sumoylation, acetylation, and phosphorylation. Here, we briefly review the biological significance and the regulation of SEPT12 phosphorylation in the mammalian sperm physiology. During mammalian spermiogenesis, the phosphorylation of SEPT12 on Ser198 residue is important in regulating mammalian annulus architectures. SEPT12 phosphomimetic knock-in mice displayed poor male fertility due to weak sperm motility and loss of the sperm annulus. SEPT12 is phosphorylated via Protein kinase A (PKA), and its phosphorylation interfered with SEPT12 polymerization into complexes and filaments. Taken together, the phosphorylation status of SEPT12 is crucial for its function in regulating the mammalian sperm physiology.
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Affiliation(s)
- Chun-Hsiang Lin
- Department of Obstetrics and Gynecology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Ru Shen
- Department of Obstetrics and Gynecology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Han-Yu Wang
- Department of Obstetrics and Gynecology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chi-Wu Chiang
- Institute of Molecular Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chia-Yih Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Pao-Lin Kuo
- Department of Obstetrics and Gynecology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Obstetrics and Gynecology, National Cheng-Kung University Hospital, Tainan, Taiwan
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49
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Krokowski S, Lobato-Márquez D, Chastanet A, Pereira PM, Angelis D, Galea D, Larrouy-Maumus G, Henriques R, Spiliotis ET, Carballido-López R, Mostowy S. Septins Recognize and Entrap Dividing Bacterial Cells for Delivery to Lysosomes. Cell Host Microbe 2018; 24:866-874.e4. [PMID: 30543779 PMCID: PMC6299245 DOI: 10.1016/j.chom.2018.11.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 08/14/2018] [Accepted: 11/05/2018] [Indexed: 12/31/2022]
Abstract
The cytoskeleton occupies a central role in cellular immunity by promoting bacterial sensing and antibacterial functions. Septins are cytoskeletal proteins implicated in various cellular processes, including cell division. Septins also assemble into cage-like structures that entrap cytosolic Shigella, yet how septins recognize bacteria is poorly understood. Here, we discover that septins are recruited to regions of micron-scale membrane curvature upon invasion and division by a variety of bacterial species. Cardiolipin, a curvature-specific phospholipid, promotes septin recruitment to highly curved membranes of Shigella, and bacterial mutants lacking cardiolipin exhibit less septin cage entrapment. Chemically inhibiting cell separation to prolong membrane curvature or reducing Shigella cell growth respectively increases and decreases septin cage formation. Once formed, septin cages inhibit Shigella cell division upon recruitment of autophagic and lysosomal machinery. Thus, recognition of dividing bacterial cells by the septin cytoskeleton is a powerful mechanism to restrict the proliferation of intracellular bacterial pathogens.
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Affiliation(s)
- Sina Krokowski
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK; Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - Damián Lobato-Márquez
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK; Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - Arnaud Chastanet
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas 78350, France
| | - Pedro Matos Pereira
- Quantitative Imaging and NanoBiophysics Group, MRC Laboratory for Molecular Cell Biology and Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Dimitrios Angelis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Dieter Galea
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Gerald Larrouy-Maumus
- Faculty of Natural Sciences, Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Ricardo Henriques
- Quantitative Imaging and NanoBiophysics Group, MRC Laboratory for Molecular Cell Biology and Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Rut Carballido-López
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas 78350, France
| | - Serge Mostowy
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK; Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK.
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50
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Akhmetova KA, Chesnokov IN, Fedorova SA. [Functional Characterization of Septin Complexes]. Mol Biol (Mosk) 2018; 52:155-171. [PMID: 29695686 DOI: 10.7868/s0026898418020015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/27/2016] [Indexed: 12/28/2022]
Abstract
Septins belong to a family of conserved GTP-binding proteins found in majority of eukaryotic species except for higher plants. Septins form nonpolar complexes that further polymerize into filaments and associate with cell membranes, thus comprising newly acknowledged cytoskeletal system. Septins participate in a variety of cell processes and contribute to various pathophysiological states, including tumorigenesis and neurodegeneration. Here, we review the structural and functional properties of septins and the regulation of their dynamics with special emphasis on the role of septin filaments as a cytoskeletal system and its interaction with actin and microtubule cytoskeletons. We also discuss how septins compartmentalize the cell by forming local protein-anchoring scaffolds and by providing barriers for the lateral diffusion of the membrane proteins.
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Affiliation(s)
- K A Akhmetova
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090 Russia.,University of Alabama at Birmingham, Birmingham, 35294 USA.,Novosibirsk National Research State University, Novosibirsk, 630090 Russia
| | - I N Chesnokov
- University of Alabama at Birmingham, Birmingham, 35294 USA
| | - S A Fedorova
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090 Russia.,Novosibirsk National Research State University, Novosibirsk, 630090 Russia.,
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