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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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2
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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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3
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Chen L, Ouyang Y, Gu L, Guo J, Han Z, Wang Z, Hou Y, Schatten H, Sun Q. Septin 9 controls CCNB1 stabilization via APC/C CDC20 during meiotic metaphase I/anaphase I transition in mouse oocytes. Cell Prolif 2022; 56:e13359. [PMID: 36354207 PMCID: PMC9890537 DOI: 10.1111/cpr.13359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/24/2022] [Accepted: 10/28/2022] [Indexed: 11/11/2022] Open
Abstract
The anaphase promoting complex/cyclosome (APC/C) and its cofactors CDH1 and CDC20 regulate the accumulation/degradation of CCNB1 during mouse oocyte meiotic maturation. Generally, the CCNB1 degradation mediated by APC/CCDC20 activity is essential for the transition from metaphase to anaphase. Here, by using siRNA and mRNA microinjection, as well as time-lapse live imaging, we showed that Septin 9, which mediates the binding of septins to microtubules, is critical for oocyte meiotic cell cycle progression. The oocytes were arrested at the MI stage and the connection between chromosome kinetochores and spindle microtubules was disrupted after Septin 9 depletion. As it is well known that spindle assembly checkpoint (SAC) is an important regulator of the MI-AI transition, we thus detected the SAC activity and the expression of CDC20 and CCNB1 which were the downstream proteins of SAC during this critical period. The signals of Mad1 and BubR1 still remained on the kinetochores of chromosomes in Septin 9 siRNA oocytes at 9.5 h of in vitro culture when most control oocytes entered anaphase I. The expression of CCNB1 did not decrease and the expression of CDC20 did not increase at 9.5 h in Septin 9 siRNA oocytes. Microinjection of mRNA encoding Septin 9 or CDC20 could partially rescue MI arrest caused by Septin 9 siRNA. These results suggest that Septin 9 is required for meiotic MI-AI transition by regulating the kinetochore-microtubule connection and SAC protein localization on kinetochores, whose effects are transmitted to APC/CCDC20 activity and CCNB1 degradation in mouse oocytes.
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Affiliation(s)
- Li Chen
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of Zoology, Chinese Academy of SciencesBeijingChina,University of Chinese Academy of SciencesBeijingChina
| | - Ying‐Chun Ouyang
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of Zoology, Chinese Academy of SciencesBeijingChina
| | - Lin‐Jian Gu
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of Zoology, Chinese Academy of SciencesBeijingChina,University of Chinese Academy of SciencesBeijingChina
| | - Jia‐Ni Guo
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of Zoology, Chinese Academy of SciencesBeijingChina,University of Chinese Academy of SciencesBeijingChina
| | - Zhi‐Ming Han
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of Zoology, Chinese Academy of SciencesBeijingChina
| | - Zhen‐Bo Wang
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of Zoology, Chinese Academy of SciencesBeijingChina,University of Chinese Academy of SciencesBeijingChina
| | - Yi Hou
- State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of Zoology, Chinese Academy of SciencesBeijingChina
| | - Heide Schatten
- Department of Veterinary PathobiologyUniversity of MissouriColumbiaMissouriUSA
| | - Qing‐Yuan Sun
- Fertility Preservation Lab, Guangdong‐Hong Kong Metabolism & Reproduction Joint LaboratoryReproductive Medicine Center, Guangdong Second Provincial General HospitalGuangzhouChina
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4
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Ancient Origins of Cytoskeletal Crosstalk: Spectraplakin-like Proteins Precede the Emergence of Cortical Microtubule Stabilization Complexes as Crosslinkers. Int J Mol Sci 2022; 23:ijms23105594. [PMID: 35628404 PMCID: PMC9145010 DOI: 10.3390/ijms23105594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/12/2022] [Accepted: 05/12/2022] [Indexed: 11/17/2022] Open
Abstract
Adhesion between cells and the extracellular matrix (ECM) is one of the prerequisites for multicellularity, motility, and tissue specialization. Focal adhesions (FAs) are defined as protein complexes that mediate signals from the ECM to major components of the cytoskeleton (microtubules, actin, and intermediate filaments), and their mutual communication determines a variety of cellular processes. In this study, human cytoskeletal crosstalk proteins were identified by comparing datasets with experimentally determined cytoskeletal proteins. The spectraplakin dystonin was the only protein found in all datasets. Other proteins (FAK, RAC1, septin 9, MISP, and ezrin) were detected at the intersections of FAs, microtubules, and actin cytoskeleton. Homology searches for human crosstalk proteins as queries were performed against a predefined dataset of proteomes. This analysis highlighted the importance of FA communication with the actin and microtubule cytoskeleton, as these crosstalk proteins exhibit the highest degree of evolutionary conservation. Finally, phylogenetic analyses elucidated the early evolutionary history of spectraplakins and cortical microtubule stabilization complexes (CMSCs) as model representatives of the human cytoskeletal crosstalk. While spectraplakins probably arose at the onset of opisthokont evolution, the crosstalk between FAs and microtubules is associated with the emergence of metazoans. The multiprotein complexes contributing to cytoskeletal crosstalk in animals gradually gained in complexity from the onset of metazoan evolution.
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Effect of ACY-1215 on cytoskeletal remodeling and histone acetylation in bovine somatic cell nuclear transfer embryos. Theriogenology 2022; 183:98-107. [DOI: 10.1016/j.theriogenology.2022.02.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/10/2022] [Accepted: 02/18/2022] [Indexed: 11/23/2022]
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Dhanya SK, Hasan G. Deficits Associated With Loss of STIM1 in Purkinje Neurons Including Motor Coordination Can Be Rescued by Loss of Septin 7. Front Cell Dev Biol 2021; 9:794807. [PMID: 34993201 PMCID: PMC8724567 DOI: 10.3389/fcell.2021.794807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/15/2021] [Indexed: 12/26/2022] Open
Abstract
Septins are cytoskeletal proteins that can assemble to form heteromeric filamentous complexes and regulate a range of membrane-associated cellular functions. SEPT7, a member of the septin family, functions as a negative regulator of the plasma membrane–localized store-operated Ca2+ entry (SOCE) channel, Orai in Drosophila neurons, and in human neural progenitor cells. Knockdown of STIM, a Ca2+ sensor in the endoplasmic reticulum (ER) and an integral component of SOCE, leads to flight deficits in Drosophila that can be rescued by partial loss of SEPT7 in neurons. Here, we tested the effect of reducing and removing SEPT7 in mouse Purkinje neurons (PNs) with the loss of STIM1. Mice with the complete knockout of STIM1 in PNs exhibit several age-dependent changes. These include altered gene expression in PNs, which correlates with increased synapses between climbing fiber (CF) axons and Purkinje neuron (PN) dendrites and a reduced ability to learn a motor coordination task. Removal of either one or two copies of the SEPT7 gene in STIM1KO PNs restored the expression of a subset of genes, including several in the category of neuron projection development. Importantly, the rescue of gene expression in these animals is accompanied by normal CF-PN innervation and an improved ability to learn a motor coordination task in aging mice. Thus, the loss of SEPT7 in PNs further modulates cerebellar circuit function in STIM1KO animals. Our findings are relevant in the context of identifying SEPT7 as a putative therapeutic target for various neurodegenerative diseases caused by reduced intracellular Ca2+ signaling.
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Affiliation(s)
- Sreeja Kumari Dhanya
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
- SASTRA University, Thanjavur, India
| | - Gaiti Hasan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
- *Correspondence: Gaiti Hasan,
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7
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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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8
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Iv F, Martins CS, Castro-Linares G, Taveneau C, Barbier P, Verdier-Pinard P, Camoin L, Audebert S, Tsai FC, Ramond L, Llewellyn A, Belhabib M, Nakazawa K, Di Cicco A, Vincentelli R, Wenger J, Cabantous S, Koenderink GH, Bertin A, Mavrakis M. Insights into animal septins using recombinant human septin octamers with distinct SEPT9 isoforms. J Cell Sci 2021; 134:jcs258484. [PMID: 34350965 DOI: 10.1242/jcs.258484] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 07/02/2021] [Indexed: 01/22/2023] Open
Abstract
Septin GTP-binding proteins contribute essential biological functions that range from the establishment of cell polarity to animal tissue morphogenesis. Human septins in cells form hetero-octameric septin complexes containing the ubiquitously expressed SEPT9 subunit (also known as SEPTIN9). Despite the established role of SEPT9 in mammalian development and human pathophysiology, biochemical and biophysical studies have relied on monomeric SEPT9, thus not recapitulating its native assembly into hetero-octameric complexes. We established a protocol that enabled, for the first time, the isolation of recombinant human septin octamers containing distinct SEPT9 isoforms. A combination of biochemical and biophysical assays confirmed the octameric nature of the isolated complexes in solution. Reconstitution studies showed that octamers with either a long or a short SEPT9 isoform form filament assemblies, and can directly bind and cross-link actin filaments, raising the possibility that septin-decorated actin structures in cells reflect direct actin-septin interactions. Recombinant SEPT9-containing octamers will make it possible to design cell-free assays to dissect the complex interactions of septins with cell membranes and the actin and microtubule cytoskeleton.
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Affiliation(s)
- Francois Iv
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Carla Silva Martins
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Gerard Castro-Linares
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Cyntia Taveneau
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico Chimie Curie, 75005 Paris, France
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Australia; Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, 3800 Clayton, Australia
| | - Pascale Barbier
- Aix-Marseille Univ, CNRS, UMR 7051, Institut de Neurophysiopathologie (INP), 13005 Marseille, France
| | - Pascal Verdier-Pinard
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, 13009 Marseille, France
| | - Luc Camoin
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille Protéomique, Marseille, France
| | - Stéphane Audebert
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille Protéomique, Marseille, France
| | - Feng-Ching Tsai
- Department of Living Matter, AMOLF, 1098 XG Amsterdam, The Netherlands
| | - Laurie Ramond
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Alex Llewellyn
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Mayssa Belhabib
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Koyomi Nakazawa
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico Chimie Curie, 75005 Paris, France
| | - Aurélie Di Cicco
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico Chimie Curie, 75005 Paris, France
| | - Renaud Vincentelli
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS UMR7257, Aix Marseille Univ, 13009 Marseille, France
| | - Jerome Wenger
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - Stéphanie Cabantous
- Centre de Recherche en Cancérologie de Toulouse (CRCT), Inserm, Université Paul Sabatier-Toulouse III, CNRS, 31037 Toulouse, France
| | - Gijsje H Koenderink
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, 2629 HZ Delft, The Netherlands
- Department of Living Matter, AMOLF, 1098 XG Amsterdam, The Netherlands
| | - Aurélie Bertin
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico Chimie Curie, 75005 Paris, France
| | - Manos Mavrakis
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
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Salameh J, Cantaloube I, Benoit B, Poüs C, Baillet A. Cdc42 and its BORG2 and BORG3 effectors control the subcellular localization of septins between actin stress fibers and microtubules. Curr Biol 2021; 31:4088-4103.e5. [PMID: 34329591 DOI: 10.1016/j.cub.2021.07.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 05/28/2021] [Accepted: 07/02/2021] [Indexed: 01/22/2023]
Abstract
Cell resistance to taxanes involves several complementary mechanisms, among which septin relocalization from actin stress fibers to microtubules plays an early role. By investigating the molecular mechanism underlying this relocalization, we found that acute paclitaxel treatment triggers the release from stress fibers and subsequent proteasome-mediated degradation of binder of Rho GTPases 2 (BORG2)/Cdc42 effector protein 3 (Cdc42EP3) and to a lesser extent of BORG3/Cdc42EP5, two Cdc42 effectors that link septins to actin in interphase cells. BORG2 or BORG3 silencing not only caused septin detachment from stress fibers but also mimicked the effects of paclitaxel by triggering both septin relocalization to microtubules and significant drug resistance. Conversely, BORG2 or BORG3 overexpression retained septins on actin fibers even after paclitaxel treatment, without affecting paclitaxel sensitivity. We found that drug-induced inhibition of Cdc42 resulted in a drop in BORG2 level and in the relocalization of septins to microtubules. Accordingly, although septins relocalized when overexpressing an inactive mutant of Cdc42, the expression of a constitutively active mutant acted locally at actin stress fibers to prevent septin release, even after paclitaxel treatment. These findings reveal the role of Cdc42 upstream of BORG2 and BORG3 in controlling the interplay between septins, actin fibers, and microtubules in basal condition and in response to taxanes.
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Affiliation(s)
- Joëlle Salameh
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France
| | - Isabelle Cantaloube
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France
| | - Béatrice Benoit
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France
| | - Christian Poüs
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France; Laboratoire de Biochimie-Hormonologie, Hôpital Antoine Béclère, AP-HP, Clamart, France.
| | - Anita Baillet
- INSERM UMR-S 1193, Faculté de Pharmacie, Université Paris-Saclay, Châtenay-Malabry, France.
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10
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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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11
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Abstract
Septins, a conserved family of GTP-binding proteins, are widely recognized as an essential cytoskeletal component, playing important roles in a variety of biological processes, including division, polarity, and membrane remodeling, in different eukaryotes. Although the roles played by septins were identified in the model organism Saccharomyces cerevisiae, their importance in other fungi, especially pathogenic fungi, have recently been determined. In this review, we summarize the functions of septins in pathogenic fungi in the cell cycle, autophagy, endocytosis and invasion host-microbe interactions that were reported in the last two years in the field of septin cell biology. These new discoveries may be expanded to investigate the functions of septin proteins in fungal pathogenesis and may be of wide interest to the readers of Microbiology and Molecular Pathology.
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Affiliation(s)
- Lin Li
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.,State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Xue-Ming Zhu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Zhen-Zhu Su
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Maurizio Del Poeta
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA.,Division of Infectious Diseases, Stony Brook University, Stony Brook, New York, USA.,Veterans Affairs Medical Center, Northport, New York, USA
| | - Xiao-Hong Liu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Fu-Cheng Lin
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.,State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
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12
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Sun J, Xu J, Sun C, Zheng M, Li Y, Zhu S, Zhang S. Screening and Prognostic Value of Methylated Septin9 and its Association With Clinicopathological and Molecular Characteristics in Colorectal Cancer. Front Mol Biosci 2021; 8:568818. [PMID: 34095214 PMCID: PMC8173126 DOI: 10.3389/fmolb.2021.568818] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 04/22/2021] [Indexed: 12/24/2022] Open
Abstract
Screening of CRC continues to show poor compliance of endoscopy examination. The detection of mSEPT9 in peripheral blood is among the safe and simple early screening methods for CRC. The issue of how to elucidate whether detection of mSEPT9 in peripheral blood can effectively improve compliance of endoscopy and increase the early diagnosis rate of CRC and the relationship between levels of mSEPT9 in the peripheral blood and clinical stage, pathological classification, and expression of characteristic molecules in CRC remains unsolved. A total of 7759 individuals participated in the study that was performed using a questionnaire for screening of high-risk CRC. The endoscopic detection compliance of individuals with high-risk CRC who underwent the fecal occult blood test (FOBT) or mSEPT9 test was compared based on the results of the questionnaire. Additionally, correlation of mSEPT9 levels in the peripheral blood with clinicopathological features, mutation status of TP53, mismatch repair deficiency (dMMR), and KRAS/NRAS/BRAF/PIK3CA genotype was analyzed, and association of biomarkers with cancer-specific survival (CSS) and time to recurrence (TTR) was compared. We also detected levels of mSEPT9 in the peripheral blood of patients with CRC 7 days after surgery and compared the prognostic value of mSEPT9 with CEA. Results of our study showed that the mSEPT9 test could improve compliance of endoscopy and indicated a higher percentage of patients with positive mSEPT9 willing to undergo endoscopy detection than in those with positive FOBT. The specificity and sensitivity of mSEPT9 were better than that of FOBT for the detection of CRC. mSEPT9 was associated with the TNM stage, dMMR, and mutations in TP53, BRAF, and PIK3CA. A Ct value of mSEPT9 ≤ 37.5 was significantly related to poor CSS. mSEPT9 could affect association of dMMR and BRAF and PIK3CA mutations with CSS in a specific stage of CRC. The positive rate of mSEPT9 after surgery was found to correlate with poor TTR, and sensitivity was higher than CEA. The combination of mSEPT9 with CEA had a better prognostic value than that of mSEPT9 alone. The level of mSEPT9 was related to dMMR, mutations in TP53, BRAF, and PIK3CA, and was an effective biomarker for the prognosis of patients with CRC.
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Affiliation(s)
- Jie Sun
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China
| | - Jinling Xu
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China
| | - Chao Sun
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Minying Zheng
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China
| | - Yuwei Li
- Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin, China
| | - Siwei Zhu
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China
| | - Shiwu Zhang
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China
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13
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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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14
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Wang M, Du Y, Gao S, Wang Z, Qu P, Gao Y, Wang J, Liu Z, Zhang J, Zhang Y, Qing S, Wang Y. Sperm-borne miR-202 targets SEPT7 and regulates first cleavage of bovine embryos via cytoskeletal remodeling. Development 2021; 148:dev.189670. [PMID: 33472846 DOI: 10.1242/dev.189670] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 01/08/2021] [Indexed: 01/28/2023]
Abstract
In mammals, sperm-borne regulators can be transferred to oocytes during fertilization and have different effects on the formation of pronuclei, the first cleavage of zygotes, the development of preimplantation embryos and even the metabolism of individuals after birth. The regulatory role of sperm microRNAs (miRNAs) in the development of bovine preimplantation embryos has not been reported in detail. By constructing and screening miRNA expression libraries, we found that miR-202 was highly enriched in bovine sperm. As a target gene of miR-202, co-injection of SEPT7 siRNA can partially reverse the accelerated first cleavage of bovine embryos caused by miR-202 inhibitor. In addition, both a miR-202 mimic and SEPT7 siRNA delayed the first cleavage of somatic cell nuclear transfer (SCNT) embryos, suggesting that miR-202-SEPT7 mediates the delay of first cleavage of bovine embryos. By further exploring the relationship between miR-202/SEPT7, HDAC6 and acetylated α-tubulin during embryonic development, we investigated how sperm-borne miR-202 regulates the first cleavage process of bovine embryos by SEPT7 and demonstrate the potential of sperm-borne miRNAs to improve the efficiency of SCNT.
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Affiliation(s)
- Mengyun Wang
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China.,School of Life Science and Technology, Harbin Institute of Technology, Science Park of Harbin Institute of Technology, Harbin 150000, China
| | - Yue Du
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China.,Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Song Gao
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
| | - Zheng Wang
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
| | - Pengxiang Qu
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
| | - Yang Gao
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
| | - Jingyi Wang
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
| | - Zhengqi Liu
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
| | - Jingcheng Zhang
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
| | - Yong Zhang
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
| | - Suzhu Qing
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
| | - Yongsheng Wang
- College of Veterinary Medicine, Northwest A&F University, Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Yangling 712100, Shaanxi Province, China
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15
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Protein Kinase A-Mediated Septin7 Phosphorylation Disrupts Septin Filaments and Ciliogenesis. Cells 2021; 10:cells10020361. [PMID: 33572403 PMCID: PMC7916176 DOI: 10.3390/cells10020361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 01/22/2023] Open
Abstract
Septins are GTP-binding proteins that form heteromeric filaments for proper cell growth and migration. Among the septins, septin7 (SEPT7) is an important component of all septin filaments. Here we show that protein kinase A (PKA) phosphorylates SEPT7 at Thr197, thus disrupting septin filament dynamics and ciliogenesis. The Thr197 residue of SEPT7, a PKA phosphorylating site, was conserved among different species. Treatment with cAMP or overexpression of PKA catalytic subunit (PKACA2) induced SEPT7 phosphorylation, followed by disruption of septin filament formation. Constitutive phosphorylation of SEPT7 at Thr197 reduced SEPT7‒SEPT7 interaction, but did not affect SEPT7‒SEPT6‒SEPT2 or SEPT4 interaction. Moreover, we noted that SEPT7 interacted with PKACA2 via its GTP-binding domain. Furthermore, PKA-mediated SEPT7 phosphorylation disrupted primary cilia formation. Thus, our data uncover the novel biological function of SEPT7 phosphorylation in septin filament polymerization and primary cilia formation.
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16
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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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17
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Sun J, Zheng MY, Li YW, Zhang SW. Structure and function of Septin 9 and its role in human malignant tumors. World J Gastrointest Oncol 2020; 12:619-631. [PMID: 32699577 PMCID: PMC7340996 DOI: 10.4251/wjgo.v12.i6.619] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/03/2020] [Accepted: 04/25/2020] [Indexed: 02/05/2023] Open
Abstract
The treatment and prognosis of malignant tumors are closely related to the time when the tumors are diagnosed; the earlier the diagnosis of the tumor, the better the prognosis. However, most tumors are not detected in the early stages of screening and diagnosis. It is of great clinical significance to study the correlation between multiple pathogeneses of tumors and explore simple, safe, specific, and sensitive molecular indicators for early screening, diagnosis, and prognosis. The Septin 9 (SEPT9) gene has been found to be associated with a variety of human diseases, and it plays a role in the development of tumors. SEPT9 is a member of the conserved family of cytoskeletal GTPase, which consists of a P-loop-based GTP-binding domain flanked by a variable N-terminal region and a C-terminal region. SEPT9 is involved in many biological processes such as cytokinesis, polarization, vesicle trafficking, membrane reconstruction, deoxyribonucleic acid repair, cell migration, and apoptosis. Several studies have shown that SEPT9 may serve as a marker for early screening, diagnosis, and prognosis of some malignant tumors, and have the potential to become a new target for anti-cancer therapy. This article reviews the progress in research on the SEPT9 gene in early screening, diagnosis, and prognosis of tumors.
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Affiliation(s)
- Jie Sun
- Department of Pathology, Tianjin Union Medical Center, Tianjin 300121, China
| | - Min-Ying Zheng
- Department of Pathology, Tianjin Union Medical Center, Tianjin 300121, China
| | - Yu-Wei Li
- Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin 300121, China
| | - Shi-Wu Zhang
- Department of Pathology, Tianjin Union Medical Center, Tianjin 300121, China
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18
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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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19
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Bashirzadeh Y, Liu AP. Encapsulation of the cytoskeleton: towards mimicking the mechanics of a cell. SOFT MATTER 2019; 15:8425-8436. [PMID: 31621750 DOI: 10.1039/c9sm01669d] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The cytoskeleton of a cell controls all the aspects of cell shape changes and motility from its physiological functions for survival to reproduction to death. The structure and dynamics of the cytoskeletal components: actin, microtubules, intermediate filaments, and septins - recently regarded as the fourth member of the cytoskeleton family - are conserved during evolution. Such conserved and effective control over the mechanics of the cell makes the cytoskeletal components great candidates for in vitro reconstitution and bottom-up synthetic biology studies. Here, we review the recent efforts in reconstitution of the cytoskeleton in and on membrane-enclosed biomimetic systems and argue that co-reconstitution and synergistic interplay between cytoskeletal filaments might be indispensable for efficient mechanical functionality of active minimal cells. Further, mechanical equilibrium in adherent eukaryotic cells is achieved by the formation of integrin-based focal contacts with extracellular matrix (ECM) and the transmission of stresses generated by actomyosin contraction to ECM. Therefore, a minimal mimic of such balance of forces and quasi-static kinetics of the cell by bottom-up reconstitution requires a careful construction of contractile machineries and their link with adhesive contacts. In this review, in addition to cytoskeletal crosstalk, we provide a perspective on reconstruction of cell mechanical equilibrium by reconstitution of cortical actomyosin networks in lipid membrane vesicles adhered on compliant substrates and also discuss future perspectives of this active research area.
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Affiliation(s)
- Yashar Bashirzadeh
- Department of Mechanical Engineering, University of Michigan, 2350 Hayward Street, Ann Arbor, Michigan, USA.
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20
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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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21
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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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22
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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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23
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Swider ZT, Ng RK, Varadarajan R, Fagerstrom CJ, Rusan NM. Fascetto interacting protein ensures proper cytokinesis and ploidy. Mol Biol Cell 2019; 30:992-1007. [PMID: 30726162 PMCID: PMC6589905 DOI: 10.1091/mbc.e18-09-0573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cell division is critical for development, organ growth, and tissue repair. The later stages of cell division include the formation of the microtubule (MT)-rich central spindle in anaphase, which is required to properly define the cell equator, guide the assembly of the acto-myosin contractile ring and ultimately ensure complete separation and isolation of the two daughter cells via abscission. Much is known about the molecular machinery that forms the central spindle, including proteins needed to generate the antiparallel overlapping interzonal MTs. One critical protein that has garnered great attention is the protein regulator of cytokinesis 1, or Fascetto (Feo) in Drosophila, which forms a homodimer to cross-link interzonal MTs, ensuring proper central spindle formation and cytokinesis. Here, we report on a new direct protein interactor and regulator of Feo we named Feo interacting protein (FIP). Loss of FIP results in a reduction in Feo localization, rapid disassembly of interzonal MTs, and several defects related to cytokinesis failure, including polyploidization of neural stem cells. Simultaneous reduction in Feo and FIP results in very large, tumorlike DNA-filled masses in the brain that contain hundreds of centrosomes. In aggregate, our data show that FIP acts directly on Feo to ensure fully accurate cell division.
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Affiliation(s)
- Zachary T Swider
- Graduate Program in Cell and Molecular Biology, University of Wisconsin, Madison, WI 53606
| | - Rachel K Ng
- Cell and Developmental Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Ramya Varadarajan
- Cell and Developmental Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Carey J Fagerstrom
- Cell and Developmental Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Nasser M Rusan
- Cell and Developmental Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
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24
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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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25
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Nakos K, Rosenberg M, Spiliotis ET. Regulation of microtubule plus end dynamics by septin 9. Cytoskeleton (Hoboken) 2018; 76:83-91. [PMID: 30144301 DOI: 10.1002/cm.21488] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/05/2018] [Accepted: 08/10/2018] [Indexed: 12/18/2022]
Abstract
Septins are GTP-binding proteins that associate with the microtubule (MT) and actin cytoskeleton. Septins affect MT organization and posttranslational modifications, but their role in MT dynamics is less understood. Here, we reconstituted MT dynamics in the presence of the MT-binding septin (SEPT9) using an in vitro cell-free assay, which images the polymerization of tubulin from guanosine-5'-[(α,β)-methyleno]triphosphate (GMPCPP)-stabilized MT seeds. We found that submicromolar concentrations of SEPT9 suppress MT catastrophe and enhance the growth of MT plus ends to great lengths, while low micromolar concentrations of SEPT9 stabilize MTs by inhibiting dynamic instability. We show that SEPT9 associates preferentially with the lattice of GMPCPP-stabilized MT seeds and surprisingly recruits soluble tubulin to the MT lattice. Notably, the effects of SEPT9 on MT dynamics are dependent on its G-G dimerization interface, which is formed by the pockets of the GTP-binding domains. A mutation (H530D) that disrupts G-G dimerization abrogates the effects of SEPT9 on MT dynamics and diminishes its ability to recruit tubulin to the MT lattice. Taken together, these results suggest that SEPT9 promotes the formation and maintenance of long stable MTs through a mechanism that may involve recruitment of unpolymerized tubulin to the MT lattice.
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Affiliation(s)
| | | | - Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, Pennsylvania
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26
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Abbey M, Gaestel M, Menon MB. Septins: Active GTPases or just GTP-binding proteins? Cytoskeleton (Hoboken) 2018; 76:55-62. [PMID: 29747238 DOI: 10.1002/cm.21451] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/24/2018] [Accepted: 05/05/2018] [Indexed: 01/19/2023]
Abstract
Septins are conserved cytoskeletal proteins with unique filament forming capabilities and roles in cytokinesis and cell morphogenesis. Septins undergo hetero-oligomerization and assemble into higher order structures including filaments, rings, and cages. Hetero- and homotypic interactions of septin isoforms involve alternating GTPase (G)-domain interfaces and those mediated by N- and C-terminal extensions. While most septins bind GTP, display weak GTP-hydrolysis activity and incorporate guanine nucleotides in their interaction interfaces, studies using GTPase-inactivating mutations have failed to conclusively establish a crucial role for GTPase activity in mediating septin functions. In this mini-review, we will critically assess the role of GTP-binding and -hydrolysis on septin assembly and function. The relevance of G-domain activity will also be discussed in the context of human septin mutations as well as the development of specific small-molecules targeting septin polymerization. As structural determinants of septin oligomer interfaces, G-domains are attractive targets for ligand-based inhibition of septin assembly. Whether such an intervention can predictably alter septin function is a major question for future research.
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Affiliation(s)
- Megha Abbey
- Hannover Medical School, Institute of Cell Biochemistry, Hannover, 30625, Germany
| | - Matthias Gaestel
- Hannover Medical School, Institute of Cell Biochemistry, Hannover, 30625, Germany
| | - Manoj B Menon
- Hannover Medical School, Institute of Cell Biochemistry, Hannover, 30625, Germany
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27
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Wasik AA, Dash SN, Lehtonen S. Septins in kidney: A territory little explored. Cytoskeleton (Hoboken) 2018; 76:154-162. [PMID: 30004646 PMCID: PMC6585700 DOI: 10.1002/cm.21477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/15/2018] [Accepted: 07/03/2018] [Indexed: 12/15/2022]
Abstract
Septins are a conserved family of GTP‐binding proteins that assemble into cytoskeletal filaments to function in a highly sophisticated and physiologically regulated manner. Originally septins were discovered in the budding yeast as membrane‐associated filaments that affect cell polarity and cytokinesis. In the last decades, much progress has been made in understanding the biochemical properties and cell biological functions of septins. In line with this, mammalian septins have been shown to be involved in various cellular processes, including regulation of cell polarity, cytoskeletal organization, vesicle trafficking, ciliogenesis, and cell–pathogen interactions. A growing number of studies have shown that septins play important roles in tissue and organ development and physiology; yet, little is known about their role in the kidney. In the following review, we discuss the structure and functions of septins in general and summarize the evidence for their presence and roles in the kidney.
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Affiliation(s)
- Anita A Wasik
- Department of Pathology, University of Helsinki, Helsinki, Finland
| | - Surjya N Dash
- Department of Pathology, University of Helsinki, Helsinki, Finland
| | - Sanna Lehtonen
- Department of Pathology, University of Helsinki, Helsinki, Finland
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28
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Boddy KC, Gao AD, Truong D, Kim MS, Froese CD, Trimble WS, Brumell JH. Septin-regulated actin dynamics promote Salmonella invasion of host cells. Cell Microbiol 2018; 20:e12866. [PMID: 29885024 PMCID: PMC6175387 DOI: 10.1111/cmi.12866] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 05/26/2018] [Indexed: 01/08/2023]
Abstract
Actin nucleators and their binding partners play crucial roles during Salmonella invasion, but how these factors are dynamically coordinated remains unclear. Here, we show that septins, a conserved family of GTP binding proteins, play a role during the early stages of Salmonella invasion. We demonstrate that septins are rapidly enriched at sites of bacterial entry and contribute to the morphology of invasion ruffles. We found that SEPTIN2, SEPTIN7, and SEPTIN9 are required for efficient bacterial invasion. Septins contributed to the recruitment of ROCK2 kinase during Salmonella invasion, and the downstream activation of the actin nucleating protein FHOD1. In contrast, activation of the ROCK2 substrate myosin II, which is known to be required for Salmonella enterica serovar Typhimurium invasion, did not require septins. Collectively, our studies provide new insight into the mechanisms involved in Salmonella invasion of host cells.
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Affiliation(s)
- Kirsten C Boddy
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Aggie Duan Gao
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Dorothy Truong
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Moshe S Kim
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada
| | - Carol D Froese
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada
| | - William S Trimble
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - John H Brumell
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada.,SickKids IBD Centre, Hospital for Sick Children, Toronto, Canada
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29
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Shindo A, Audrey A, Takagishi M, Takahashi M, Wallingford JB, Kinoshita M. Septin-dependent remodeling of cortical microtubule drives cell reshaping during epithelial wound healing. J Cell Sci 2018; 131:jcs212647. [PMID: 29777035 PMCID: PMC6031381 DOI: 10.1242/jcs.212647] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 05/10/2018] [Indexed: 12/31/2022] Open
Abstract
Wounds in embryos heal rapidly through contraction of the wound edges. Despite well-recognized significance of the actomyosin purse string for wound closure, roles for other cytoskeletal components are largely unknown. Here, we report that the septin cytoskeleton cooperates with actomyosin and microtubules to coordinate circumferential contraction of the wound margin and concentric elongation of wound-proximal cells in Xenopus laevis embryos. Microtubules reoriented radially, forming bundles along lateral cell cortices in elongating wound-proximal cells. Depletion of septin 7 (Sept7) slowed wound closure by attenuating the wound edge contraction and cell elongation. ROCK/Rho-kinase inhibitor-mediated suppression of actomyosin contractility enhanced the Sept7 phenotype, whereas the Sept7 depletion did not affect the accumulation of actomyosin at the wound edge. The cortical microtubule bundles were reduced in wound-proximal cells in Sept7 knockdown (Sept7-KD) embryos, but forced bundling of microtubules mediated by the microtubule-stabilizing protein Map7 did not rescue the Sept7-KD phenotype. Nocodazole-mediated microtubule depolymerization enhanced the Sept7-KD phenotype, suggesting that Sept7 is required for microtubule reorganization during cell elongation. Our findings indicate that septins are required for the rapid wound closure by facilitating cortical microtubule reorganization and the concentric elongation of surrounding cells.
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Affiliation(s)
- Asako Shindo
- Division of Biological Sciences, Department of Molecular Biology, Nagoya University Graduate School of Science, Nagoya 464-8602, Japan
- Department of Molecular Biosciences, University of Texas at Austin, Austin 78712, USA
| | - Anastasia Audrey
- Division of Biological Sciences, Department of Molecular Biology, Nagoya University Graduate School of Science, Nagoya 464-8602, Japan
| | - Maki Takagishi
- Department of Tumor Pathology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Masahide Takahashi
- Department of Tumor Pathology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, Austin 78712, USA
| | - Makoto Kinoshita
- Division of Biological Sciences, Department of Molecular Biology, Nagoya University Graduate School of Science, Nagoya 464-8602, Japan
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30
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Wang X, Fei F, Qu J, Li C, Li Y, Zhang S. The role of septin 7 in physiology and pathological disease: A systematic review of current status. J Cell Mol Med 2018; 22:3298-3307. [PMID: 29602250 PMCID: PMC6010854 DOI: 10.1111/jcmm.13623] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 03/05/2018] [Indexed: 12/22/2022] Open
Abstract
Septins are a conserved family of cytoskeletal GTPases present in different organisms, including yeast, drosophila, Caenorhabditis elegans and humans. In humans, septins are involved in various cellular processes, including exocytosis, apoptosis, leukemogenesis, carcinogenesis and neurodegeneration. Septin 7 is unique out of 13 human septins. Mammalian septin 6, septin 7, septin 2 and septin 9 coisolate together in complexes to form the core unit for the generation of the septin filaments. Physiological septin filaments are hetero‐oligomeric complexes consisting of core septin hexamers and octamers. Furthermore, septin 7 plays a crucial role in cytokinesis and mitosis. Septin 7 is localized to the filopodia and branches of developing hippocampal neurons, and is the most abundant septin in the adult rat forebrain as well as a structural component of the human and mouse sperm annuli. Septin 7 is crucial to the spine morphogenesis and dendrite growth in neurons, and is also a structural constituent of the annulus in human and mouse sperm. It can suppress growth of some tumours such as glioma and papillary thyroid carcinoma. However, the molecular mechanisms of involvement of septin 7 in human disease, especially in the development of cancer, remain unclear. This review focuses on the structure, function and mechanism of septin 7 in vivo, and summarizes the role of septin 7 in cell proliferation, cytokinesis, nervous and reproductive systems, as well as the underlying molecular events linking septin 7 to various diseases, such as Alzheimer's disease, schizophrenia, neuropsychiatric systemic lupus erythematosus, tumour and so on.
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Affiliation(s)
- Xinlu Wang
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Department of Pathology, Tianjin Union Medical Center, Tianjin, China
| | - Fei Fei
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China.,Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Jie Qu
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China.,Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Chunyuan Li
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China.,Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Yuwei Li
- Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin, China
| | - Shiwu Zhang
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China
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31
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Spiliotis ET. Spatial effects - site-specific regulation of actin and microtubule organization by septin GTPases. J Cell Sci 2018; 131:jcs207555. [PMID: 29326311 PMCID: PMC5818061 DOI: 10.1242/jcs.207555] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The actin and microtubule cytoskeletons comprise a variety of networks with distinct architectures, dynamics and protein composition. A fundamental question in eukaryotic cell biology is how these networks are spatially and temporally controlled, so they are positioned in the right intracellular places at the right time. While significant progress has been made in understanding the self-assembly of actin and microtubule networks, less is known about how they are patterned and regulated in a site-specific manner. In mammalian systems, septins are a large family of GTP-binding proteins that multimerize into higher-order structures, which associate with distinct subsets of actin filaments and microtubules, as well as membranes of specific curvature and lipid composition. Recent studies have shed more light on how septins interact with actin and microtubules, and raised the possibility that the cytoskeletal topology of septins is determined by their membrane specificity. Importantly, new functions have emerged for septins regarding the generation, maintenance and positioning of cytoskeletal networks with distinct organization and biochemical makeup. This Review presents new and past findings, and discusses septins as a unique regulatory module that instructs the local differentiation and positioning of distinct actin and microtubule networks.
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Affiliation(s)
- Elias T Spiliotis
- Drexel University, Department of Biology, Drexel University, Philadelphia, PA 19104, USA
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32
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Ribet D, Boscaini S, Cauvin C, Siguier M, Mostowy S, Echard A, Cossart P. SUMOylation of human septins is critical for septin filament bundling and cytokinesis. J Cell Biol 2017; 216:4041-4052. [PMID: 29051266 PMCID: PMC5716278 DOI: 10.1083/jcb.201703096] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/25/2017] [Accepted: 08/23/2017] [Indexed: 01/22/2023] Open
Abstract
Septins are cytoskeletal proteins that assemble into nonpolar filaments. They are critical in diverse cellular functions, acting as scaffolds for protein recruitment and as diffusion barriers for subcellular compartmentalization. Human septins are encoded by 13 different genes and are classified into four groups based on sequence homology (SEPT2, SEPT3, SEPT6, and SEPT7 groups). In yeast, septins were among the first proteins reported to be modified by SUMOylation, a ubiquitin-like posttranslational modification. However, whether human septins could be modified by small ubiquitin-like modifiers (SUMOs) and what roles this modification may have in septin function remains unknown. In this study, we first show that septins from all four human septin groups can be covalently modified by SUMOs. We show in particular that endogenous SEPT7 is constitutively SUMOylated during the cell cycle. We then map SUMOylation sites to the C-terminal domain of septins belonging to the SEPT6 and SEPT7 groups and to the N-terminal domain of septins from the SEPT3 group. We finally demonstrate that expression of non-SUMOylatable septin variants from the SEPT6 and SEPT7 groups leads to aberrant septin bundle formation and defects in cytokinesis after furrow ingression. Altogether, our results demonstrate a pivotal role for SUMOylation in septin filament bundling and cell division.
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Affiliation(s)
- David Ribet
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Institut National de la Santé et de la Recherche Médicale, Institut National de la Recherche Agronomique, Paris, France
| | - Serena Boscaini
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Institut National de la Santé et de la Recherche Médicale, Institut National de la Recherche Agronomique, Paris, France
| | - Clothilde Cauvin
- Unité de Trafic Membranaire et Division Cellulaire, Département de Biologie Cellulaire et Infection, Institut Pasteur, Paris, France
- Centre National de la Recherche Scientifique UMR3691, Paris, France
- Sorbonne Universités, Université Pierre et Marie Curie, Université Paris 06, Institut de Formation Doctorale, Paris, France
| | - Martin Siguier
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Institut National de la Santé et de la Recherche Médicale, Institut National de la Recherche Agronomique, Paris, France
| | - Serge Mostowy
- Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, England, UK
| | - Arnaud Echard
- Unité de Trafic Membranaire et Division Cellulaire, Département de Biologie Cellulaire et Infection, Institut Pasteur, Paris, France
- Centre National de la Recherche Scientifique UMR3691, Paris, France
- Sorbonne Universités, Université Pierre et Marie Curie, Université Paris 06, Institut de Formation Doctorale, Paris, France
| | - Pascale Cossart
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Institut National de la Santé et de la Recherche Médicale, Institut National de la Recherche Agronomique, Paris, France
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33
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Dash SN, Narumanchi S, Paavola J, Perttunen S, Wang H, Lakkisto P, Tikkanen I, Lehtonen S. Sept7b is required for the subcellular organization of cardiomyocytes and cardiac function in zebrafish. Am J Physiol Heart Circ Physiol 2017; 312:H1085-H1095. [DOI: 10.1152/ajpheart.00394.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 02/28/2017] [Accepted: 03/19/2017] [Indexed: 12/22/2022]
Abstract
Myofibrils made up of actin, myosin, and associated proteins generate the contractile force in muscle, and, consequently, mutations in these proteins may lead to heart failure. Septins are a conserved family of small GTPases that associate with actin filaments, microtubules, and cellular membranes. Despite the importance of septins in cytoskeleton organization, their role in cardiomyocyte organization and function is poorly characterized. Here, we show that septin 7 is expressed in both embryonic and adult zebrafish hearts and elucidate the physiological significance of sept7b, the zebrafish ortholog of human septin 7, in the heart in embryonic and larval zebrafish. Knockdown of sept7b reduced F-actin and α-cardiac actin expression in the heart and caused disorganization of actin filaments. Electron microscopy of sept7b-depleted larvae showed disorganization of heart myofibrils and partial detachment from Z-disks. Functional studies revealed that knockdown of sept7b leads to reduced ventricular dimensions, contractility, and cardiac output. Furthermore, we found that depletion of sept7b diminished the expression of retinaldehyde dehydrogenase 2, which catalyzes the synthesis of retinoic acid necessary for heart morphogenesis. We further observed that the sept7b and retinoic acid signaling pathways converge to regulate cardiac function. Together, these results specify an essential role for sept7b in the contractile function of the heart. NEW & NOTEWORTHY Knockdown of the zebrafish ortholog of human septin 7 ( sept7b) destabilizes cardiac actin and reduces ventricular dimensions, contractility, and cardiac output in larval zebrafish, indicating that sept7b is essential for cardiac function. We further found that sept7b and retinoic acid signaling pathways converge to regulate cardiac function. These data prompt further studies defining the role of sept7b in cardiomyopathies.
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Affiliation(s)
| | - Suneeta Narumanchi
- Unit of Cardiovascular Research, Minerva Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland
| | - Jere Paavola
- Unit of Cardiovascular Research, Minerva Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland
- Internal Medicine, Jorvi Hospital, Helsinki University Hospital, Espoo, Finland
| | - Sanni Perttunen
- Unit of Cardiovascular Research, Minerva Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland
| | - Hong Wang
- Department of Pathology, University of Helsinki, Helsinki, Finland
| | - Päivi Lakkisto
- Unit of Cardiovascular Research, Minerva Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland
- Clinical Chemistry and Hematology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; and
| | - Ilkka Tikkanen
- Unit of Cardiovascular Research, Minerva Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland
- Abdominal Center, Nephrology, Helsinki University Hospital, Helsinki, Finland
| | - Sanna Lehtonen
- Department of Pathology, University of Helsinki, Helsinki, Finland
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Septin 9_i2 is downregulated in tumors, impairs cancer cell migration and alters subnuclear actin filaments. Sci Rep 2017; 7:44976. [PMID: 28338090 PMCID: PMC5364497 DOI: 10.1038/srep44976] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 02/20/2017] [Indexed: 01/08/2023] Open
Abstract
Functions of septin cytoskeletal polymers in tumorigenesis are still poorly defined. Their role in the regulation of cytokinesis and cell migration were proposed to contribute to cancer associated aneuploidy and metastasis. Overexpression of Septin 9 (Sept9) promotes migration of cancer cell lines. SEPT9 mRNA and protein expression is increased in breast tumors compared to normal and peritumoral tissues and amplification of SEPT9 gene was positively correlated with breast tumor progression. However, the existence of multiple isoforms of Sept9 is a confounding factor in the analysis of Sept9 functions. In the present study, we analyze the protein expression of Sept9_i2, an uncharacterized isoform, in breast cancer cell lines and tumors and describe its specific impact on cancer cell migration and Sept9 cytoskeletal distribution. Collectively, our results showed that, contrary to Sept9_i1, Sept9_i2 did not support cancer cell migration, and induced a loss of subnuclear actin filaments. These effects were dependent on Sept9_i2 specific N-terminal sequence. Sept9_i2 was strongly down-regulated in breast tumors compared to normal mammary tissues. Thus our data indicate that Sept9_i2 is a negative regulator of breast tumorigenesis. We propose that Sept9 tumorigenic properties depend on the balance between Sept9_i1 and Sept9_i2 expression levels.
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35
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Thieleke-Matos C, Osório DS, Carvalho AX, Morais-de-Sá E. Emerging Mechanisms and Roles for Asymmetric Cytokinesis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 332:297-345. [PMID: 28526136 DOI: 10.1016/bs.ircmb.2017.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cytokinesis completes cell division by physically separating the contents of the mother cell between the two daughter cells. This event requires the highly coordinated reorganization of the cytoskeleton within a precise window of time to ensure faithful genomic segregation. In addition, recent progress in the field highlighted the importance of cytokinesis in providing particularly important cues in the context of multicellular tissues. The organization of the cytokinetic machinery and the asymmetric localization or inheritance of the midbody remnants is critical to define the spatial distribution of mechanical and biochemical signals. After a brief overview of the conserved steps of animal cytokinesis, we review the mechanisms controlling polarized cytokinesis focusing on the challenges of epithelial cytokinesis. Finally, we discuss the significance of these asymmetries in defining embryonic body axes, determining cell fate, and ensuring the correct propagation of epithelial organization during proliferation.
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Affiliation(s)
- C Thieleke-Matos
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Cell Division and Genomic stability, IBMC, Instituto de Biologia Molecular e Celular, and i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - D S Osório
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Cytoskeletal Dynamics, IBMC, Instituto de Biologia Molecular e Celular, and i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - A X Carvalho
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Cytoskeletal Dynamics, IBMC, Instituto de Biologia Molecular e Celular, and i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - E Morais-de-Sá
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Cell Division and Genomic stability, IBMC, Instituto de Biologia Molecular e Celular, and i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
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Abstract
Septins are GTP-binding and membrane-interacting proteins with a highly conserved domain structure involved in various cellular processes, including cytoskeleton organization, cytokinesis, and membrane dynamics. To date, 13 different septin genes have been identified in mammals (SEPT1 to SEPT12 and SEPT14), which can be classified into four distinct subgroups based on the sequence homology of their domain structure (SEPT2, SEPT3, SEPT6, and SEPT7 subgroup). The family members of these subgroups have a strong affinity for other septins and form apolar tri-, hexa-, or octameric complexes consisting of multiple septin polypeptides. The first characterized core complex is the hetero-trimer SEPT2-6-7. Within these complexes single septins can be exchanged in a subgroup-specific manner. Hexamers contain SEPT2 and SEPT6 subgroup members and SEPT7 in two copies each whereas the octamers additionally comprise two SEPT9 subgroup septins. The various isoforms seem to determine the function and regulation of the septin complex. Septins self-assemble into higher-order structures, including filaments and rings in orders, which are typical for different cell types. Misregulation of septins leads to human diseases such as neurodegenerative and bleeding disorders. In non-dividing cells such as neuronal tissue and platelets septins have been associated with exocytosis. However, many mechanistic details and roles attributed to septins are poorly understood. We describe here some important mammalian septin interactions with a special focus on the clinically relevant septin interactions.
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Affiliation(s)
- Katharina Neubauer
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, Medical Center-University of Freiburg Freiburg, Germany
| | - Barbara Zieger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, Medical Center-University of Freiburg Freiburg, Germany
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Liu Z, Wu S, Chen Y, Han X, Gu Q, Yin Y, Ma Z. The microtubule end-binding protein FgEB1 regulates polar growth and fungicide sensitivity via different interactors in Fusarium graminearum. Environ Microbiol 2017; 19:1791-1807. [PMID: 28028881 DOI: 10.1111/1462-2920.13651] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 12/18/2016] [Indexed: 11/30/2022]
Abstract
In yeasts, the end-binding protein 1 (EB1) homologs regulate microtubule dynamics, cell polarization, and chromosome stability. However, functions of EB1 orthologs in plant pathogenic fungi have not been characterized yet. Here, we observed that the FgEB1 deletion mutant (ΔFgEB1) of Fusarium graminearum exhibits twisted hyphae, increased hyphal branching and curved conidia, indicating that FgEB1 is involved in the regulation of cellular polarity. Microscopic examination further showed that the microtubules of ΔFgEB1 exhibited less organized in comparison with those of the wild type. In addition, the lack of FgEB1 also altered the distribution of polarity-related class I myosin via the interaction with the actin. On the other hand, we identified four core septins as FgEB1-interacting proteins, and found that FgEB1 and septins regulated conidial polar growth in the opposite orientation. Interestingly, FgEB1 and FgKar9 constituted another complex that modulated the response to carbendazim, a microtubule-damaging agent specifically. In addition, the deletion of FgEB1 led to dramatically decreased deoxynivalenol (DON) biosynthesis. Taken together, results of this study indicate that FgEB1 regulates cellular polarity, fungicide sensitivity and DON biosynthesis via different interactors in F. graminarum, which provides a novel insight into understanding of the biological functions of EB1 in filamentous fungi.
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Affiliation(s)
- Zunyong Liu
- Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Sisi Wu
- Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yun Chen
- Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Xinyue Han
- Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Qin Gu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yanni Yin
- Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Zhonghua Ma
- Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.,State Key Laboratory of Rice Biology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
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Yamada S, Isogai T, Tero R, Tanaka-Takiguchi Y, Ujihara T, Kinoshita M, Takiguchi K. Septin Interferes with the Temperature-Dependent Domain Formation and Disappearance of Lipid Bilayer Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:12823-12832. [PMID: 27934514 DOI: 10.1021/acs.langmuir.6b03452] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Domain formation or compartmentalization in a lipid bilayer membrane has been thought to take place dynamically in cell membranes and play important roles in the spatiotemporal regulation of their physiological functions. In addition, the membrane skeleton, which is a protein assembly beneath the cell membrane, also regulates the properties as well as the morphology of membranes because of its role as a diffusion barrier against constitutive molecules of the membrane or as a scaffold for physiological reactions. Therefore, it is important to study the relationship between lipid bilayer membranes and proteins that form the membrane skeleton. Among cytoskeletal systems, septin is unique because it forms arrays on liposomes that contain phosphoinositides, and this property is thought to contribute to the formation of the annulus in sperm flagellum. In this study, a supported lipid bilayer (SLB) was used to investigate the effect of septin on lipid bilayers because SLBs rather than liposomes are suitable for observation of the membrane domains formed. We found that SLBs containing phosphatidylinositol (PI) reversibly form domains by decreasing the temperature and that septin affects both the formation and the disappearance of the cooling-induced domain. Septin inhibits the growth of cooling-induced domains during decreases in temperature and inhibits the dispersion and the disappearance of those domains during increases in temperature. These results indicate that septin complexes, i.e., filaments or oligomers assembling on the surface of lipid bilayer membranes, can regulate the dynamics of domain formation via their behavior as an anchor for PI molecules.
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Affiliation(s)
| | | | - Ryugo Tero
- The Electronics-Inspired Interdisciplinary Research Institute, Toyohashi University of Technology , Toyohashi 441-8580, Japan
| | | | | | | | - Kingo Takiguchi
- Structural Biology Research Center, Nagoya University , Nagoya 464-8601, Japan
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Poüs C, Klipfel L, Baillet A. Cancer-Related Functions and Subcellular Localizations of Septins. Front Cell Dev Biol 2016; 4:126. [PMID: 27878118 PMCID: PMC5099157 DOI: 10.3389/fcell.2016.00126] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/24/2016] [Indexed: 12/16/2022] Open
Abstract
Since the initial discovery of septin family GTPases, the understanding of their molecular organization and cellular roles keeps being refined. Septins have been involved in many physiological processes and the misregulation of specific septin gene expression has been implicated in diverse human pathologies, including neurological disorders and cancer. In this minireview, we focus on the importance of the subunit composition and subcellular localization of septins relevant to tumor initiation, progression, and metastasis. We especially underline the importance of septin polymer composition and of their association with the plasma membrane, actin, or microtubules in cell functions involved in cancer and in resistance to cancer therapies. Through their scaffolding role, their function in membrane compartmentalization or through their protective function against protein degradation, septins also emerge as critical organizers of membrane-associated proteins and of signaling pathways implicated in cancer-associated angiogenesis, apoptosis, polarity, migration, proliferation, and in metastasis. Also, the question as to which of the free monomers, hetero-oligomers, or filaments is the functional form of mammalian septins is raised and the control over their spatial and temporal localization is discussed. The increasing amount of crosstalks identified between septins and cellular signaling mediators reinforces the exciting possibility that septins could be new targets in anti-cancer therapies or in therapeutic strategies to limit drug resistance.
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Affiliation(s)
- Christian Poüs
- Institut National de la Santé et de la Recherche Médicale, UMR-S 1193, Université Paris-Sud, Université Paris-SaclayChâtenay-Malabry, France; Laboratoire de Biochimie-Hormonologie, Hôpital Antoine Béclère, AP-HPClamart, France
| | - Laurence Klipfel
- Institut National de la Santé et de la Recherche Médicale, UMR-S 1193, Université Paris-Sud, Université Paris-SaclayChâtenay-Malabry, France; Département de Génétique, Institut de la Vision, Université Pierre et Marie Curie Paris 06, Sorbonne Universités, Institut National de la Santé et de la Recherche Médicale UMR-S 968, Centre National de la Recherche Scientifique UMR 7210Paris, France
| | - Anita Baillet
- Institut National de la Santé et de la Recherche Médicale, UMR-S 1193, Université Paris-Sud, Université Paris-Saclay Châtenay-Malabry, France
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Septin cooperation with tubulin polyglutamylation contributes to cancer cell adaptation to taxanes. Oncotarget 2016; 6:36063-80. [PMID: 26460824 PMCID: PMC4742162 DOI: 10.18632/oncotarget.5373] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/25/2015] [Indexed: 12/05/2022] Open
Abstract
The mechanisms of cancer cell adaptation to the anti-microtubule agents of the taxane family are multifaceted and still poorly understood. Here, in a model of breast cancer cells which display amplified microtubule dynamics to resist Taxol®, we provide evidence that septin filaments containing high levels of SEPT9_i1 bind to microtubules in a way that requires tubulin long chain polyglutamylation. Reciprocally, septin filaments provide a scaffold for elongating and trimming polyglutamylation enzymes to finely tune the glutamate side-chain length on microtubules to an optimal level. We also demonstrate that tubulin retyrosination and/or a high level of tyrosinated tubulin is crucial to allow the interplay between septins and polyglutamylation on microtubules and that together, these modifications result in an enhanced CLIP-170 and MCAK recruitment to microtubules. Finally, the inhibition of tubulin retyrosination, septins, tubulin long chain polyglutamylation or of both CLIP-170 and MCAK allows the restoration of cell sensitivity to taxanes, providing evidence for a new integrated mechanism of resistance.
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Ortore MG, Macedo JNA, Araujo APU, Ferrero C, Mariani P, Spinozzi F, Itri R. Structural and Thermodynamic Properties of Septin 3 Investigated by Small-Angle X-Ray Scattering. Biophys J 2016; 108:2896-902. [PMID: 26083929 DOI: 10.1016/j.bpj.2015.05.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 04/30/2015] [Accepted: 05/11/2015] [Indexed: 01/22/2023] Open
Abstract
Septins comprise a family of proteins involved in a variety of cellular processes and related to several human pathologies. They are constituted by three structural domains: the N- and C-terminal domains, highly variable in length and composition, and the central domain, involved in the guanine nucleotide (GTP) binding. Thirteen different human septins are known to form heterogeneous complexes or homofilaments, which are stabilized by specific interactions between the different interfaces present in the domains. In this work, we have investigated by in-solution small-angle x-ray scattering the structural and thermodynamic properties of a human septin 3 construct, SEPT3-GC, which contains both of both interfaces (G and NC) responsible for septin-septin interactions. In order to shed light on the role of these interactions, small-angle x-ray scattering measurements were performed in a wide range of temperatures, from 2 up to 56°C, both with and without a nonhydrolysable form of GTP (GTPγS). The acquired data show a temperature-dependent coexistence of monomers, dimers, and higher-order aggregates that were analyzed using a global fitting approach, taking into account the crystallographic structure of the recently reported SEPT3 dimer, PDB:3SOP. As a result, the enthalpy, entropy, and heat capacity variations that control the dimer-monomer dissociation equilibrium in solution were derived and GTPγS was detected to increase the enthalpic stability of the dimeric species. Moreover, a temperature increase was observed to induce dissociation of SEPT3-GC dimers into monomers just preceding their reassembling into amyloid aggregates, as revealed by the Thioflavin-T fluorescence assays.
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Affiliation(s)
- Maria Grazia Ortore
- Dipartimento di Scienze della Vita e dell'Ambiente and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Università Politecnica delle Marche, Ancona, Italy
| | - Joci N A Macedo
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, Brazil
| | - Ana Paula U Araujo
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, Brazil
| | | | - Paolo Mariani
- Dipartimento di Scienze della Vita e dell'Ambiente and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Università Politecnica delle Marche, Ancona, Italy
| | - Francesco Spinozzi
- Dipartimento di Scienze della Vita e dell'Ambiente and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Università Politecnica delle Marche, Ancona, Italy.
| | - Rosangela Itri
- Instituto de Física da Universidade de São Paulo, São Paulo, Brazil.
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Fu Q, Li Y, Yang Y, Li C, Yao J, Zeng Q, Qin Z, Liu S, Li D, Liu Z. Septin genes in channel catfish (Ictalurus punctatus) and their involvement in disease defense responses. FISH & SHELLFISH IMMUNOLOGY 2016; 49:110-121. [PMID: 26700173 DOI: 10.1016/j.fsi.2015.12.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/09/2015] [Accepted: 12/12/2015] [Indexed: 06/05/2023]
Abstract
Septins are an evolutionarily conserved family of GTP-binding proteins. They are involved in diverse processes including cytokinesis, apoptosis, infection, neurodegeneration and neoplasia. In this study, through thorough data mining of existed channel catfish genomic resources, we identified a complete set of 15 septin genes. Septins were classified into four subgroups according to phylogenetic analysis. Extensive comparative genomic analysis, including domain and syntenic analysis, supported their annotation and orthologies. The expression patterns of septins in channel catfish were examined in healthy tissues and after infection with two major bacterial pathogens, Edwardsiella ictaluri and Flavobacterium columnare. In healthy channel catfish, most septin genes were ubiquitously expressed and presented diversity patterns in various tissues, especially mucosal tissues, proposing the significant roles septin genes may play in maintaining homeostasis and host immune response activities. After bacterial infections, most septin genes were regulated, but opposite direction in expression profiles were found with the two bacterial pathogens: the differentially expressed septin genes were down-regulated in the intestine after E. ictaluri infection while generally up-regulated in the gill after F. columnare infection, suggesting a pathogen-specific and tissue-specific pattern of regulation. Taken together, these results suggested that septin genes may play complex and important roles in the host immune responses to bacterial pathogens in channel catfish.
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Affiliation(s)
- Qiang Fu
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062, China; The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Yun Li
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Yujia Yang
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Chao Li
- Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China
| | - Jun Yao
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Qifan Zeng
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Zhenkui Qin
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Shikai Liu
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Daoji Li
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062, China
| | - Zhanjiang Liu
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
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43
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Bai X, Karasmanis EP, Spiliotis ET. Septin 9 interacts with kinesin KIF17 and interferes with the mechanism of NMDA receptor cargo binding and transport. Mol Biol Cell 2016; 27:897-906. [PMID: 26823018 PMCID: PMC4791134 DOI: 10.1091/mbc.e15-07-0493] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 01/20/2016] [Indexed: 01/22/2023] Open
Abstract
Kinesin motor interactions with cargo and their regulation are not well understood. Septin 9 (SEPT9) interacts directly with kinesin KIF17 and interferes with binding of the cargo adaptor/scaffold mLin-10/Mint1, which links the NMDA receptor subunit 2B (NR2B) to KIF17. SEPT9 down-regulates NR2B transport without affecting the motile properties of KIF17. Intracellular transport involves the regulation of microtubule motor interactions with cargo, but the underlying mechanisms are not well understood. Septins are membrane- and microtubule-binding proteins that assemble into filamentous, scaffold-like structures. Septins are implicated in microtubule-dependent transport, but their roles are unknown. Here we describe a novel interaction between KIF17, a kinesin 2 family motor, and septin 9 (SEPT9). We show that SEPT9 associates directly with the C-terminal tail of KIF17 and interacts preferentially with the extended cargo-binding conformation of KIF17. In developing rat hippocampal neurons, SEPT9 partially colocalizes and comigrates with KIF17. We show that SEPT9 interacts with the KIF17 tail domain that associates with mLin-10/Mint1, a cargo adaptor/scaffold protein, which underlies the mechanism of KIF17 binding to the NMDA receptor subunit 2B (NR2B). Significantly, SEPT9 interferes with binding of the PDZ1 domain of mLin-10/Mint1 to KIF17 and thereby down-regulates NR2B transport into the dendrites of hippocampal neurons. Measurements of KIF17 motility in live neurons show that SEPT9 does not affect the microtubule-dependent motility of KIF17. These results provide the first evidence of an interaction between septins and a nonmitotic kinesin and suggest that SEPT9 modulates the interactions of KIF17 with membrane cargo.
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Affiliation(s)
- Xiaobo Bai
- Department of Biology, Drexel University, Philadelphia, PA 19104
| | - Eva P Karasmanis
- Department of Biology, Drexel University, Philadelphia, PA 19104
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Abstract
SEPT9 gene methylation has been implicated as a biomarker for colorectal cancer (CRC) for more than 10 years and has been used clinically for more than 6 years. Studies have proven it to be an accurate, reliable, fast, and convenient method for CRC. In this chapter, we will first provide the background on the role of septin9 protein and the theoretical basis of the SEPT9 gene methylation assay. We will then focus on the performance of SEPT9 gene methylation assay for CRC early detection and screening by analyzing the data obtained in clinical trials and comparing its performance with other methods or markers. Finally, we will discuss the future applications of the assay in monitoring cancer recurrence, evaluating surgery, chemotherapy, and predicting long-term survival. We hope this chapter can provide a full overview of the theoretical basis, development, validation, and clinical applications of the SEPT9 assay for both basic science researchers and clinical practitioners.
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Affiliation(s)
- Lele Song
- Department of Radiotherapy, The Chinese PLA 309 Hospital, Beijing, PR China; BioChain (Beijing) Science and Technology, Inc., Economic and Technological Development Area, Beijing, PR China.
| | - Yuemin Li
- Department of Radiotherapy, The Chinese PLA 309 Hospital, Beijing, PR China.
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Li Y, Song L, Gong Y, He B. Detection of colorectal cancer by DNA methylation biomarker SEPT9: past, present and future. Biomark Med 2015; 8:755-69. [PMID: 25123042 DOI: 10.2217/bmm.14.8] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Colorectal cancer has become the third most common cancer in the world. Early diagnosis and treatment can significantly reduce colorectal cancer mortality. The current routinely used fecal-based screening methods do not provide satisfactory sensitivity. Although colonoscopy provides macroscopic diagnosis, the compliance is low due to its inconvenience and complications. Hence, the development of new screening methods is needed urgently. Peripheral blood SEPT9 gene methylation assay has become a potential option with promising future for early detection and screening of colorectal cancer. It is shown to be convenient, reliable with good compliance by several clinical trials. This article will review the theoretical foundation and development of the assay, focusing on its clinical trials, comparing it with other screening methods and discussing its future applications.
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Affiliation(s)
- Yuemin Li
- The Chinese PLA 309 Hospital (General Hospital of the PLA General Staff Headquarters), No. 17, HeiShanHu Road, HaiDian District, Beijing 100091, PR China
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Tong B, Li GP, Sasaki S, Muramatsu Y, Ohta T, Kose H, Yamada T. Association of the expression levels in the skeletal muscle and a SNP in the CDC10 gene with growth-related traits in Japanese Black beef cattle. Anim Genet 2015; 46:200-4. [PMID: 25691006 DOI: 10.1111/age.12274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2014] [Indexed: 11/28/2022]
Abstract
Growth performance, as well as marbling, is the main breeding objective in Japanese Black (JB) cattle, the major beef breed in Japan. The septin 7 (CDC10) gene, involved in cellular proliferation, is located within a genomic region of a quantitative trait locus for growth-related traits. In this study, we first showed that the expression levels of the CDC10 gene in the skeletal muscle were higher in JB steers with extremely high growth performance than in JB steers with extremely low growth, using real-time PCR. Further, a single nucleotide polymorphism (SNP), NC_007302.5:g.63264949G>C, was detected in the promoter region of the CDC10 gene and genotyped in three Japanese cattle breeds (known as 'Wagyu' in Japan) and the Brown Swiss dairy cattle breed. All four cattle populations showed a moderate genetic diversity at the SNP of the CDC10 gene. An association analysis indicated that the SNP was associated with growth-related traits in JB cattle. These findings suggest possible effects of the expression levels in the skeletal muscle and the SNP of the CDC10 gene on growth-related traits in JB cattle. The CDC10 SNP may be useful for effective marker-assisted selection to increase beef productivity in JB beef cattle.
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Affiliation(s)
- B Tong
- Department of Agrobiology, Faculty of Agriculture, Niigata University, Nishi-ku, Niigata, 950-2181, Japan
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47
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Menon MB, Gaestel M. Sep(t)arate or not – how some cells take septin-independent routes through cytokinesis. J Cell Sci 2015; 128:1877-86. [PMID: 25690008 DOI: 10.1242/jcs.164830] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Cytokinesis is the final step of cell division, and is a process that requires a precisely coordinated molecular machinery to fully separate the cytoplasm of the parent cell and to establish the intact outer cell barrier of the daughter cells. Among various cytoskeletal proteins involved, septins are known to be essential mediators of cytokinesis. In this Commentary, we present recent observations that specific cell divisions can proceed in the absence of the core mammalian septin SEPT7 and its Drosophila homolog Peanut (Pnut) and that thus challenge the view that septins have an essential role in cytokinesis. In the pnut mutant neuroepithelium, orthogonal cell divisions are successfully completed. Similarly, in the mouse, Sept7-null mutant early embryonic cells and, more importantly, planktonically growing adult hematopoietic cells undergo productive proliferation. Hence, as discussed here, mechanisms must exist that compensate for the lack of SEPT7 and the other core septins in a cell-type-specific manner. Despite there being crucial non-canonical immune-relevant functions of septins, septin depletion is well tolerated by the hematopoietic system. Thus differential targeting of cytokinesis could form the basis for more specific anti-proliferative therapies to combat malignancies arising from cell types that require septins for cytokinesis, such as carcinomas and sarcomas, without impairing hematopoiesis that is less dependent on septin.
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Affiliation(s)
- Manoj B Menon
- Institute of Physiological Chemistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Matthias Gaestel
- Institute of Physiological Chemistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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48
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MinCD cell division proteins form alternating copolymeric cytomotive filaments. Nat Commun 2014; 5:5341. [PMID: 25500731 PMCID: PMC4338524 DOI: 10.1038/ncomms6341] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 09/20/2014] [Indexed: 11/28/2022] Open
Abstract
During bacterial cell division, filaments of the tubulin-like protein FtsZ assemble at midcell to form the cytokinetic Z-ring. Its positioning is regulated by the oscillation of MinCDE proteins. MinC is activated by MinD through an unknown mechanism and prevents Z-ring assembly anywhere but midcell. Here, using X-ray crystallography, electron microscopy and in vivo analyses we show that MinD activates MinC by forming a new class of alternating copolymeric filaments that show similarity to eukaryotic septin filaments A non-polymerising mutation in MinD causes aberrant cell division in E. coli. MinCD copolymers bind to membrane, interact with FtsZ, and are disassembled by MinE. Imaging a functional msfGFP-MinC fusion protein in MinE deleted cells reveals filamentous structures. EM imaging of our reconstitution of the MinCD-FtsZ interaction on liposome surfaces reveals a plausible mechanism for regulation of FtsZ ring assembly by MinCD copolymers.
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49
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Fung KYY, Dai L, Trimble WS. Cell and molecular biology of septins. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 310:289-339. [PMID: 24725429 DOI: 10.1016/b978-0-12-800180-6.00007-4] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Septins are a family of GTP-binding proteins that assemble into cytoskeletal filaments. Unlike other cytoskeletal components, septins form ordered arrays of defined stoichiometry that can polymerize into long filaments and bundle laterally. Septins associate directly with membranes and have been implicated in providing membrane stability and serving as diffusion barriers for membrane proteins. In addition, septins bind other proteins and have been shown to function as multimolecular scaffolds by recruiting components of signaling pathways. Remarkably, septins participate in a spectrum of cellular processes including cytokinesis, ciliogenesis, cell migration, polarity, and cell-pathogen interactions. Given their breadth of functions, it is not surprising that septin abnormalities have also been linked to human diseases. In this review, we discuss the current knowledge of septin structure, assembly and function, and discuss these in the context of human disease.
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Affiliation(s)
- Karen Y Y Fung
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada; Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Lu Dai
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada; Department of Physiology, University of Toronto, Toronto, Canada
| | - William S Trimble
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada; Department of Biochemistry, University of Toronto, Toronto, Canada; Department of Physiology, University of Toronto, Toronto, Canada.
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50
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Septin6 and Septin7 GTP binding proteins regulate AP-3- and ESCRT-dependent multivesicular body biogenesis. PLoS One 2014; 9:e109372. [PMID: 25380047 PMCID: PMC4224394 DOI: 10.1371/journal.pone.0109372] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 09/04/2014] [Indexed: 11/19/2022] Open
Abstract
Septins (SEPTs) form a family of GTP-binding proteins implicated in cytoskeleton and membrane organization, cell division and host/pathogen interactions. The precise function of many family members remains elusive. We show that SEPT6 and SEPT7 complexes bound to F-actin regulate protein sorting during multivesicular body (MVB) biogenesis. These complexes bind AP-3, an adapter complex sorting cargos destined to remain in outer membranes of maturing endosomes, modulate AP-3 membrane interactions and the motility of AP-3-positive endosomes. These SEPT-AP interactions also influence the membrane interaction of ESCRT (endosomal-sorting complex required for transport)-I, which selects ubiquitinated cargos for degradation inside MVBs. Whereas our findings demonstrate that SEPT6 and SEPT7 function in the spatial, temporal organization of AP-3- and ESCRT-coated membrane domains, they uncover an unsuspected coordination of these sorting machineries during MVB biogenesis. This requires the E3 ubiquitin ligase LRSAM1, an AP-3 interactor regulating ESCRT-I sorting activity and whose mutations are linked with Charcot-Marie-Tooth neuropathies.
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