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Kumar S, Mansson A. Covalent and non-covalent chemical engineering of actin for biotechnological applications. Biotechnol Adv 2017; 35:867-888. [PMID: 28830772 DOI: 10.1016/j.biotechadv.2017.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 08/09/2017] [Accepted: 08/16/2017] [Indexed: 12/26/2022]
Abstract
The cytoskeletal filaments are self-assembled protein polymers with 8-25nm diameters and up to several tens of micrometres length. They have a range of pivotal roles in eukaryotic cells, including transportation of intracellular cargoes (primarily microtubules with dynein and kinesin motors) and cell motility (primarily actin and myosin) where muscle contraction is one example. For two decades, the cytoskeletal filaments and their associated motor systems have been explored for nanotechnological applications including miniaturized sensor systems and lab-on-a-chip devices. Several developments have also revolved around possible exploitation of the filaments alone without their motor partners. Efforts to use the cytoskeletal filaments for applications often require chemical or genetic engineering of the filaments such as specific conjugation with fluorophores, antibodies, oligonucleotides or various macromolecular complexes e.g. nanoparticles. Similar conjugation methods are also instrumental for a range of fundamental biophysical studies. Here we review methods for non-covalent and covalent chemical modifications of actin filaments with focus on critical advantages and challenges of different methods as well as critical steps in the conjugation procedures. We also review potential uses of the engineered actin filaments in nanotechnological applications and in some key fundamental studies of actin and myosin function. Finally, we consider possible future lines of investigation that may be addressed by applying chemical conjugation of actin in new ways.
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Affiliation(s)
- Saroj Kumar
- Department of Biotechnology, Delhi Technological University, Delhi 110042, India; Department of Chemistry and Biomedical Sciences, Faculty of Health and Life Sciences, Linnaeus University, SE-391 82 Kalmar, Sweden.
| | - Alf Mansson
- Department of Chemistry and Biomedical Sciences, Faculty of Health and Life Sciences, Linnaeus University, SE-391 82 Kalmar, Sweden.
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Stumpf M, Müller R, Gaßen B, Wehrstedt R, Fey P, Karow MA, Eichinger L, Glöckner G, Noegel AA. A tripeptidyl peptidase 1 is a binding partner of the Golgi pH regulator (GPHR) in Dictyostelium. Dis Model Mech 2017; 10:897-907. [PMID: 28546289 PMCID: PMC5536908 DOI: 10.1242/dmm.029280] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 05/17/2017] [Indexed: 02/02/2023] Open
Abstract
Mutations in tripeptidyl peptidase 1 (TPP1) have been associated with late infantile neuronal ceroid lipofuscinosis (NCL), a neurodegenerative disorder. TPP1 is a lysosomal serine protease, which removes tripeptides from the N-terminus of proteins and is composed of an N-terminal prodomain and a catalytic domain. It is conserved in mammals, amphibians, fish and the amoeba Dictyostelium discoideum. D. discoideum harbors at least six genes encoding TPP1, tpp1A to tpp1F. We identified TPP1F as binding partner of Dictyostelium GPHR (Golgi pH regulator), which is an evolutionarily highly conserved intracellular transmembrane protein. A region encompassing the DUF3735 (GPHR_N) domain of GPHR was responsible for the interaction. In TPP1F, the binding site is located in the prodomain of the protein. The tpp1F gene is transcribed throughout development and translated into a polypeptide of ∼65 kDa. TPP1 activity was demonstrated for TPP1F-GFP immunoprecipitated from D. discoideum cells. Its activity could be inhibited by addition of the recombinant DUF3735 domain of GPHR. Knockout tpp1F mutants did not display any particular phenotype, and TPP1 activity was not abrogated, presumably because tpp1B compensates as it has the highest expression level of all the TPP1 genes during growth. The GPHR interaction was not restricted to TPP1F but occurred also with TPP1B. As previous reports show that the majority of the TPP1 mutations in NCL resulted in reduction or loss of enzyme activity, we suggest that Dicyostelium could be used as a model system in which to test new reagents that could affect the activity of the protein and ameliorate the disease. Summary: Interaction of Dictyostelium tripeptidyl peptidase 1 with GPHR could be relevant for studies of the human enzyme, which is associated with a neurodegenerative disorder.
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Affiliation(s)
- Maria Stumpf
- Institute of Biochemistry I, Medical Faculty, University Hospital Cologne, Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 52, Köln 50931, Germany
| | - Rolf Müller
- Institute of Biochemistry I, Medical Faculty, University Hospital Cologne, Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 52, Köln 50931, Germany
| | - Berthold Gaßen
- Institute of Biochemistry I, Medical Faculty, University Hospital Cologne, Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 52, Köln 50931, Germany
| | - Regina Wehrstedt
- Institute of Biochemistry I, Medical Faculty, University Hospital Cologne, Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 52, Köln 50931, Germany
| | - Petra Fey
- Dicty Base, Northwestern University, Biomedical Informatics Center and Center for Genetic Medicine, Chicago, IL 60611, USA
| | - Malte A Karow
- Institute of Biochemistry I, Medical Faculty, University Hospital Cologne, Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 52, Köln 50931, Germany
| | - Ludwig Eichinger
- Institute of Biochemistry I, Medical Faculty, University Hospital Cologne, Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 52, Köln 50931, Germany
| | - Gernot Glöckner
- Institute of Biochemistry I, Medical Faculty, University Hospital Cologne, Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 52, Köln 50931, Germany
| | - Angelika A Noegel
- Institute of Biochemistry I, Medical Faculty, University Hospital Cologne, Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 52, Köln 50931, Germany
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Ishikawa-Ankerhold HC, Daszkiewicz W, Schleicher M, Müller-Taubenberger A. Actin-Interacting Protein 1 Contributes to Intranuclear Rod Assembly in Dictyostelium discoideum. Sci Rep 2017; 7:40310. [PMID: 28074884 PMCID: PMC5225641 DOI: 10.1038/srep40310] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 12/02/2016] [Indexed: 12/21/2022] Open
Abstract
Intranuclear rods are aggregates consisting of actin and cofilin that are formed in the nucleus in consequence of chemical or mechanical stress conditions. The formation of rods is implicated in a variety of pathological conditions, such as certain myopathies and some neurological disorders. It is still not well understood what exactly triggers the formation of intranuclear rods, whether other proteins are involved, and what the underlying mechanisms of rod assembly or disassembly are. In this study, Dictyostelium discoideum was used to examine appearance, stages of assembly, composition, stability, and dismantling of rods. Our data show that intranuclear rods, in addition to actin and cofilin, are composed of a distinct set of other proteins comprising actin-interacting protein 1 (Aip1), coronin (CorA), filactin (Fia), and the 34 kDa actin-bundling protein B (AbpB). A finely tuned spatio-temporal pattern of protein recruitment was found during formation of rods. Aip1 is important for the final state of rod compaction indicating that Aip1 plays a major role in shaping the intranuclear rods. In the absence of both Aip1 and CorA, rods are not formed in the nucleus, suggesting that a sufficient supply of monomeric actin is a prerequisite for rod formation.
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Affiliation(s)
| | - Wioleta Daszkiewicz
- Department of Cell Biology (Anatomy III), Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Michael Schleicher
- Department of Cell Biology (Anatomy III), Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
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Xu L, Ji C, Wu H, Tan Q, Wang WX. A comparative proteomic study on the effects of metal pollution in oysters Crassostrea hongkongensis. MARINE POLLUTION BULLETIN 2016; 112:436-442. [PMID: 27402499 DOI: 10.1016/j.marpolbul.2016.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 07/04/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
The metal pollution has posed great risk on the coastal organisms along the Jiulongjiang Estuary in South China. In this work, two-dimensional electrophoresis-based proteomics was applied to the oysters Crassostrea hongkongensis from metal pollution sites to characterize the proteomic responses to metal pollution. Metal accumulation and proteomic responses indicated that the oysters from BJ site were more severely contaminated than those from FG site. Compared with those oyster samples from the clean site (JZ), metal pollution induced cellular injuries, oxidative and immune stresses in oyster heapatopancreas from both BJ and FG sites via differential metabolic pathways. In addition, metal pollution in BJ site induced disturbance in energy and lipid metabolisms in oysters. Results indicated that cathepsin L and ferritin GF1 might be the biomarkers of As and Fe in oyster C. hongkongensis, respectively. This study demonstrates that proteomics is a useful tool for investigating biological effects induced by metal pollution.
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Affiliation(s)
- Lanlan Xu
- Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, YICCAS, Yantai 264003, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Chenglong Ji
- Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, YICCAS, Yantai 264003, P.R. China
| | - Huifeng Wu
- Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, YICCAS, Yantai 264003, P.R. China.
| | - Qiaoguo Tan
- Key Laboratory of the Coastal and Wetland Ecosystems, Ministry of Education, College of Environment and Ecology, Xiamen University, Xiamen 361102, P.R. China
| | - Wen-Xiong Wang
- Division of Life Science, The Hong Kong University of Science and Technology (HKUST), Clearwater Bay, Kowloon, Hong Kong
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Huang L, Li J, Anboukaria H, Luo Z, Zhao M, Wu H. Comparative transcriptome analyses of seven anurans reveal functions and adaptations of amphibian skin. Sci Rep 2016; 6:24069. [PMID: 27040083 PMCID: PMC4819189 DOI: 10.1038/srep24069] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 03/18/2016] [Indexed: 01/06/2023] Open
Abstract
Animal skin, which is the tissue that directly contacts the external surroundings, has evolved diverse functions to adapt to various environments. Amphibians represent the transitional taxon from aquatic to terrestrial life. Exploring the molecular basis of their skin function and adaptation is important to understand the survival and evolutionary mechanisms of vertebrates. However, comprehensive studies on the molecular mechanisms of skin functions in amphibians are scarce. In this study, we sequenced the skin transcriptomes of seven anurans belonging to three families and compared the similarities and differences in expressed genes and proteins. Unigenes and pathways related to basic biological processes and special functions, such as defense, immunity, and respiration, were enriched in functional annotations. A total of 108 antimicrobial peptides were identified. The highly expressed genes were similar in species of the same family but were different among families. Additionally, the positively selected orthologous groups were involved in biosynthesis, metabolism, immunity, and defense processes. This study is the first to generate extensive transcriptome data for the skin of seven anurans and provides unigenes and pathway candidates for further studies on amphibian skin function and adaptation.
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Affiliation(s)
- Li Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, 152 Luoyulu, Hongshan District, Wuhan 430079, China
| | - Jun Li
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, 152 Luoyulu, Hongshan District, Wuhan 430079, China
| | - Housseni Anboukaria
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, 152 Luoyulu, Hongshan District, Wuhan 430079, China
| | - Zhenhua Luo
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, 152 Luoyulu, Hongshan District, Wuhan 430079, China
| | - Mian Zhao
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, 152 Luoyulu, Hongshan District, Wuhan 430079, China
| | - Hua Wu
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, 152 Luoyulu, Hongshan District, Wuhan 430079, China
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Swaminathan K, Stumpf M, Müller R, Horn AC, Schmidbauer J, Eichinger L, Müller-Taubenberger A, Faix J, Noegel AA. Coronin7 regulates WASP and SCAR through CRIB mediated interaction with Rac proteins. Sci Rep 2015; 5:14437. [PMID: 26411260 PMCID: PMC4585930 DOI: 10.1038/srep14437] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 08/28/2015] [Indexed: 11/14/2022] Open
Abstract
Coronin7 (CRN7) stabilizes F-actin and is a regulator of processes associated with the actin cytoskeleton. Its loss leads to defects in phagocytosis, motility and development. It harbors a CRIB (Cdc42- and Rac-interactive binding) domain in each of its WD repeat domains which bind to Rac GTPases preferably in their GDP-loaded forms. Expression of wild type CRN7 in CRN7 deficient cells rescued these defects, whereas proteins with mutations in the CRIB motifs which were associated with altered Rac binding were effective to varying degrees. The presence of one functional CRIB was sufficient to reestablish phagocytosis, cell motility and development. Furthermore, by molecular modeling and mutational analysis we identified the contact regions between CRN7 and the GTPases. We also identified WASP, SCAR and PAKa as downstream effectors in phagocytosis, development and cell surface adhesion, respectively, since ectopic expression rescued these functions.
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Affiliation(s)
- Karthic Swaminathan
- Center for Biochemistry, Medical Faculty, Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Köln, Germany
| | - Maria Stumpf
- Center for Biochemistry, Medical Faculty, Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Köln, Germany
| | - Rolf Müller
- Center for Biochemistry, Medical Faculty, Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Köln, Germany
| | - Anna-Carolin Horn
- Center for Biochemistry, Medical Faculty, Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Köln, Germany
| | - Julia Schmidbauer
- Center for Biochemistry, Medical Faculty, Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Köln, Germany
| | - Ludwig Eichinger
- Center for Biochemistry, Medical Faculty, Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Köln, Germany
| | | | - Jan Faix
- Department of Biophysical Chemistry, Medizinische Hochschule Hannover, 30623 Hannover, Germany
| | - Angelika A Noegel
- Center for Biochemistry, Medical Faculty, Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Köln, Germany
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7
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Biophysical Forces Modulate the Costamere and Z-Disc for Sarcomere Remodeling in Heart Failure. BIOPHYSICS OF THE FAILING HEART 2013. [DOI: 10.1007/978-1-4614-7678-8_7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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8
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Sultana H, Neelakanta G, Eichinger L, Rivero F, Noegel AA. Microarray phenotyping places cyclase associated protein CAP at the crossroad of signaling pathways reorganizing the actin cytoskeleton in Dictyostelium. Exp Cell Res 2009; 315:127-40. [DOI: 10.1016/j.yexcr.2008.10.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Revised: 08/29/2008] [Accepted: 10/14/2008] [Indexed: 01/31/2023]
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Smith J, Diez G, Klemm AH, Schewkunow V, Goldmann WH. CapZ-lipid membrane interactions: a computer analysis. Theor Biol Med Model 2006; 3:30. [PMID: 16914033 PMCID: PMC1564000 DOI: 10.1186/1742-4682-3-30] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2006] [Accepted: 08/16/2006] [Indexed: 12/03/2022] Open
Abstract
Background CapZ is a calcium-insensitive and lipid-dependent actin filament capping protein, the main function of which is to regulate the assembly of the actin cytoskeleton. CapZ is associated with membranes in cells and it is generally assumed that this interaction is mediated by polyphosphoinositides (PPI) particularly PIP2, which has been characterized in vitro. Results We propose that non-PPI lipids also bind CapZ. Data from computer-aided sequence and structure analyses further suggest that CapZ could become partially buried in the lipid bilayer probably under mildly acidic conditions, in a manner that is not only dependent on the presence of PPIs. We show that lipid binding could involve a number of sites that are spread throughout the CapZ molecule i.e., alpha- and beta-subunits. However, a beta-subunit segment between residues 134–151 is most likely to be involved in interacting with and inserting into lipid membrane due to a slighly higher ratio of positively to negatively charged residues and also due to the presence of a small hydrophobic helix. Conclusion CapZ may therefore play an essential role in providing a stable membrane anchor for actin filaments.
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Affiliation(s)
- James Smith
- Friedrich-Alexander-University of Erlangen-Nuremberg Center for Medical Physics and Technology, Biophysics Group Henkestrasse 91, 91052 Erlangen, Germany
| | - Gerold Diez
- Friedrich-Alexander-University of Erlangen-Nuremberg Center for Medical Physics and Technology, Biophysics Group Henkestrasse 91, 91052 Erlangen, Germany
| | - Anna H Klemm
- Friedrich-Alexander-University of Erlangen-Nuremberg Center for Medical Physics and Technology, Biophysics Group Henkestrasse 91, 91052 Erlangen, Germany
| | - Vitali Schewkunow
- Friedrich-Alexander-University of Erlangen-Nuremberg Center for Medical Physics and Technology, Biophysics Group Henkestrasse 91, 91052 Erlangen, Germany
| | - Wolfgang H Goldmann
- Friedrich-Alexander-University of Erlangen-Nuremberg Center for Medical Physics and Technology, Biophysics Group Henkestrasse 91, 91052 Erlangen, Germany
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10
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Schirenbeck A, Bretschneider T, Arasada R, Schleicher M, Faix J. The Diaphanous-related formin dDia2 is required for the formation and maintenance of filopodia. Nat Cell Biol 2005; 7:619-25. [PMID: 15908944 DOI: 10.1038/ncb1266] [Citation(s) in RCA: 207] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2005] [Accepted: 04/29/2005] [Indexed: 12/16/2022]
Abstract
Formins have important roles in the nucleation of actin and the formation of linear actin filaments, but their role in filopodium formation has remained elusive. Dictyostelium discoideum Diaphanous-related formin dDia2 is enriched at the tips of filopodia and interacts with profilin II and Rac1. An FH1FH2 fragment of dDia2 nucleated actin polymerization and removed capping protein from capped filament ends. Genetic studies showed that dDia2 is important for cell migration as well as the formation, elongation and maintenance of filopodia. Here we provide evidence that dDia2 specifically controls filopodial dynamics by regulating actin turnover at the barbed ends of actin filaments.
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Affiliation(s)
- Antje Schirenbeck
- A. Butenandt-Institut/Zellbiologie, Ludwig-Maximilians-Universität, Schillerstr. 42, 80336 München, Germany
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11
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Hart MC, Korshunova YO, Cooper JA. Vertebrates have conserved capping protein alpha isoforms with specific expression patterns. CELL MOTILITY AND THE CYTOSKELETON 2000; 38:120-32. [PMID: 9331217 DOI: 10.1002/(sici)1097-0169(1997)38:2<120::aid-cm2>3.0.co;2-b] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Capping protein (CP), a ubiquitous actin binding protein composed of an alpha and a beta subunit, is important for actin assembly and cell motility. Lower organisms have one gene and one isoform of each subunit. Chickens have two very similar alpha-subunit isoforms. To determine if vertebrates in general contain multiple alpha isoforms and if those alpha isoforms have conserved sequences, we isolated and analyzed alpha subunit cDNA's in mice and humans. Both mice and humans also have two alpha isoforms. Phylogenetic analysis of the alpha isoform sequences reveals that vertebrates have two highly conserved subfamilies, alpha1 and alpha2. The alpha1 and alpha2 subfamilies are very similar to each other but can be defined and distinguished from each other by a small number of key amino acid residues. In addition, 3' untranslated cDNA sequences are conserved within the isoform subfamilies. To investigate the function of the alpha isoforms, we examined their expression in mouse cells and tissues. Endothelial cells contain only the alpha2 isoform, and erythrocytes contain almost exclusively the alpha1 isoform. Most tissues have both alpha1 and alpha2 isoforms but the ratio of alpha1:alpha2 varies widely. Together, these findings support the hypothesis that the CP alpha isoforms have conserved, unique and essential roles in vertebrates.
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Affiliation(s)
- M C Hart
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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12
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Lim RW, Furukawa R, Fechheimer M. Evidence of intramolecular regulation of the Dictyostelium discoideum 34 000 Da F-actin-bundling protein. Biochemistry 1999; 38:16323-32. [PMID: 10587457 DOI: 10.1021/bi991100o] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intramolecular interaction within the Ca(2+)-regulated 34 kDa actin-bundling protein from Dictyostelium discoideum was found to contribute to the regulation of its actin-binding activity. Recombinant N-terminally truncated proteins aa77-295, 124-295, and 139-295 bound actin at > or = 2:1 stoichiometry, which is 5-fold greater than the intact protein aa1-295 as assessed by cosedimentation with F-actin. These proteins also have enhanced cross-linking activity as assessed by viscometry and electron microscopy. All truncated 34 kDa proteins failed to bind (45)Ca(2+) on blots and displayed Ca(2+)-insensitive binding with actin, although most proteins possessed intact putative EF-hand Ca(2+)-binding motifs. An intramolecular interaction within the 34 kDa protein was inferred from direct demonstrations of domain-domain interaction among the truncated 34 kDa proteins both in the presence and absence of actin. The intramolecular interaction between interaction zone 1 (aa71-123) and interaction zone 2 (aa193-254) is proposed to maintain the N-terminal inhibitory region (aa1-76) in close proximity with the strong actin-binding site (aa193-254) in order to modulate the interaction of the intact protein with actin filaments.
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Affiliation(s)
- R W Lim
- Department of Cellular Biology, University of Georgia, Athens 30602, USA
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13
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Abstract
The actin cytoskeleton is an essential structure for most movements at the cellular and intracellular level. Whereas for contraction a muscle cell requires a rather static organisation of cytoskeletal proteins, cell motility of amoeboid cells relies on a tremendously dynamic turnover of filamentous networks in a matter of seconds and at distinct regions inside the cell. The best model system for studying cell motility is Dictyostelium discoideum. The cells live as single amoebae but can also start a developmental program that leads to multicellular stages and differentiation into simple types of tissues. Thus, cell motility can be studied on single cells and on cells in a tissue-like aggregate. The ability to combine protein purification and biochemistry with fairly easy molecular genetics is a unique feature for investigation of the cytoskeleton and cell motility. The actin cytoskeleton in Dictyostelium harbours essentially all classes of actin-binding proteins that have been found throughout eukaryotes. By conventional mutagenesis, gene disruption, antisense approaches, or gene replacements many genes that code for cytoskeletal proteins have been disrupted, and altered phenotypes in transformants that lacked one or more of those cytoskeletal proteins allowed solid conclusions about their in vivo function. In addition, tagging the proteins or selected domains with green fluorescent protein allows the monitoring of protein redistribution during cell movement. Gene tagging by restriction enzyme mediated integration of vectors and the ongoing international genome and cDNA sequencing projects offer the chance to understand the dynamics of the cytoskeleton by identification and functional characterisation of all proteins involved.
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Affiliation(s)
- L Eichinger
- Adolf-Butenandt-Institut/Zellbiologie, Ludwig-Maximilians-Universität, 80336 München, Germany.
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14
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Stocker S, Hiery M, Marriott G. Phototactic migration of Dictyostelium cells is linked to a new type of gelsolin-related protein. Mol Biol Cell 1999; 10:161-78. [PMID: 9880334 PMCID: PMC25161 DOI: 10.1091/mbc.10.1.161] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The molecular and functional characterization of a 125-kDa Ca2+-extractable protein of the Triton X-100-insoluble fraction of Dictyostelium cells identified a new type of a gelsolin-related molecule. In addition to its five gelsolin segments, this gelsolin-related protein of 125 kDa (GRP125) reveals a number of unique domains, two of which are predicted to form coiled-coil regions. Another distinct attribute of GRP125 concerns the lack of sequence elements known to be essential for characteristic activities of gelsolin-like proteins, i.e. the severing, capping, or nucleation of actin filaments. The subcellular distribution of GRP125 to vesicular compartments suggests an activity of GRP125 different from actin-binding, gelsolin-related proteins. GRP125 expression is tightly regulated and peaks at the transition to the multicellular pseudoplasmodial stage of Dictyostelium development. GRP125 was found indispensable for slug phototaxis, because slugs fail to correctly readjust their orientation in the absence of GRP125. Analysis of the GRP125-deficient mutant showed that GRP125 is required for coupling photodetection to the locomotory machinery of slugs. We propose that GRP125 is essential in the natural environment for the propagation of Dictyostelium spores. We also present evidence for further representatives of the GRP125 type in Dictyostelium, as well as in heterologous cells from lower to higher eukaryotes.
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Affiliation(s)
- S Stocker
- Max-Planck-Institute for Biochemistry, D-82152 Martinsried, Germany
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15
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Tardieux I, Baines I, Mossakowska M, Ward GE. Actin-binding proteins of invasive malaria parasites and the regulation of actin polymerization by a complex of 32/34-kDa proteins associated with heat shock protein 70kDa. Mol Biochem Parasitol 1998; 93:295-308. [PMID: 9662713 DOI: 10.1016/s0166-6851(98)00044-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Movement of the malaria parasite into a host erythrocyte during invasion is thought to involve polymerization of parasite actin. We have used F-actin affinity chromatography to isolate actin-binding proteins from Plasmodium knowlesi merozoites, in an attempt to identify proteins responsible for regulating parasite actin polymerization during invasion. Five major proteins, of molecular masses 75, 70, 48, 40 and 34 kDa, were reproducibly eluted from the F-actin columns. The 70 kDa actin-binding protein was identified by tryptic peptide microsequencing as heat shock protein-70 kDa (HSC70); this identification was confirmed by Western blotting with anti-HSC70 antibody, and binding of the protein to ATP-agarose. A doublet of 32/34-kDa proteins coeluted with parasite HSC70 from the F-actin and ATP-agarose columns; a complex of these three proteins was also observed by gel filtration chromatography Highly enriched fractions containing the Plasmodium HSC70/32/34 complex inhibited the polymerization of rabbit skeletal muscle actin, in vitro. This capping activity was calcium-independent, and abrogated by phosphatidylinositol 4,5-bisphosphate. The average length of the actin filaments polymerized in presence of the HSC70/32/34-kDa complex was significantly shorter than in the absence of the complex, consistent with a capping activity. The capping or uncapping of actin filament ends by the HSC70/32/34-kDa complex during invasion could provide a mechanism for localized actin filament growth and movement of the parasite into the host cell.
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Affiliation(s)
- I Tardieux
- Laboratory of Parasitic Diseases, NIAID, NIH, Bethesda 20892, USA.
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16
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Eddy RJ, Han J, Sauterer RA, Condeelis JS. A major agonist-regulated capping activity in Dictyostelium is due to the capping protein, cap32/34. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1314:247-59. [PMID: 8982279 DOI: 10.1016/s0167-4889(96)00108-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Stimulation of starved Dictyostelium amoebae with the chemoattractant cAMP produces a rapid increase in actin nucleation activity at 5 seconds which is cotemporal with an increase in actin assembly and a decrease in Ca(2+)-insensitive capping activity [1]. Further characterization of this capping activity, called aginactin, led to the isolation of an Hsc70 [2]. Here, we demonstrate that purified aginactin contains both Hsc70 and the heterodimeric barbed-end capping protein, cap32/34. Immunoprecipitation of cap32/34 from purified aginactin removes all capping activity while immunoprecipitation of Hsc70 does not, indicating that the capping activity of aginactin is an intrinsic property of cap32/34. Gel filtration and immunoprecipitation assays fail to demonstrate the existence of a stable, high affinity complex between Hsc70 and cap32/34 in either lysate supernatants or aginactin pools but indicate the presence of a transient, ATP-sensitive interaction in cell lysates. Reconstitution experiments with purified Hsc70 and cap32/34 demonstrate that Hsc70 neither stimulates nor inhibits the capping activity of native cap32/34. Furthermore, we measured a Kd of approx. 0.8 nM for the binding of cap32/34 to barbed ends of actin filaments in the absence or presence of Hsc70, in agreement with Kd values measured for purified capping protein from other sources. We conclude, therefore, that cap32/34 is responsible for the capping activity called aginactin and that Hsc70 is not a regulatory cofactor for cap32/34 in Dictyostelium but may function as a chaperone during assembly of the cap32/34 heterodimer.
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Affiliation(s)
- R J Eddy
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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17
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Rivero F, Köppel B, Peracino B, Bozzaro S, Siegert F, Weijer CJ, Schleicher M, Albrecht R, Noegel AA. The role of the cortical cytoskeleton: F-actin crosslinking proteins protect against osmotic stress, ensure cell size, cell shape and motility, and contribute to phagocytosis and development. J Cell Sci 1996; 109 ( Pt 11):2679-91. [PMID: 8937986 DOI: 10.1242/jcs.109.11.2679] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We generated Dictyostelium double mutants lacking the two F-actin crosslinking proteins alpha-actinin and gelation factor by inactivating the corresponding genes via homologous recombination. Here we investigated the consequences of these deficiencies both at the single cell level and at the multicellular stage. We found that loss of both proteins severely affected growth of the mutant cells in shaking suspension, and led to a reduction of cell size from 12 microns in wild-type cells to 9 microns in mutant cells. Moreover the cells did not exhibit the typical polarized morphology of aggregating Dictyostelium cells but had a more rounded cell shape, and also exhibited an increased sensitivity towards osmotic shock and a reduced rate of phagocytosis. Development was heavily impaired and never resulted in the formation of fruiting bodies. Expression of developmentally regulated genes and the final developmental stages that were reached varied, however, with the substrata on which the cells were deposited. On phosphate buffered agar plates the cells were able to form tight aggregates and mounds and to express prespore and prestalk cell specific genes. Under these conditions the cells could perform chemotactic signalling and cell behavior was normal at the onset of multicellular development as revealed by time-lapse video microscopy. Double mutant cells were motile but speed was reduced by approximately 30% as compared to wild type. These changes were reversed by expressing the gelation factor in the mutant cells. We conclude that the actin assemblies that are formed and/or stabilized by both F-actin crosslinking proteins have a protective function during osmotic stress and are essential for proper cell shape and motility.
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Affiliation(s)
- F Rivero
- Max-Planck-Institut für Biochemie, Martinsried, Germany
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18
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Doering DS, Matsudaira P. Cysteine scanning mutagenesis at 40 of 76 positions in villin headpiece maps the F-actin binding site and structural features of the domain. Biochemistry 1996; 35:12677-85. [PMID: 8841111 DOI: 10.1021/bi9615699] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Villin headpiece, the 76 amino acid, C-terminal domain of villin, is one of the two F-actin binding sites in villin necessary for F-actin bundling activity. Expression and study of recombinant headpiece revealed the domain to be remarkably thermostable (Tm = 74 degrees C) for a non-disulfide-bonded domain. Forty independent point mutations to cysteine of headpiece have been purified and tested for their actin binding activity, cysteine reactivity, and thermal stability. These assays identify two segments of headpiece, near amino acids 38 and 70 of headpiece, in which mutations to cysteine significantly disrupt cosedimentation of headpiece with F-actin. Assay of the thermal stability of these mutants and assay of the reactivity of the introduced cysteine show that these amino acids are mutations at the protein surface that do not perturb the overall structure of the domain. The actin binding mutants are replacements to cysteine of Lys38, Glu39, Lys65, Lys70, Lys71, Leu75, and Phe76 of headpiece. We propose that these discontinuous segments of charged amino acids define the F-actin binding contacts of the headpiece domain. The assay of mutants for effects on the thermal stability of helical structure as well as the assay of reactivity of the introduced sulfhydryl group identify candidate positions that are involved in the stabilizing core and internal structure of the domain. The cysteine scanning mutagenesis also identifies an amino-terminal subdomain (Val1-Leu35) and a predominantly helical carboxy-terminal subdomain (Pro36-Phe76).
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Affiliation(s)
- D S Doering
- Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge 02142, USA.
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19
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Abstract
New avenues of cytoskeleton research in Dictyostelium discoideum have opened up with the cloning of the alpha- and beta-tubulin genes and the characterization of kinesins and cytoplasmic dynein. Much research, however, continues to focus on the actin cytoskeleton and its dynamics during chemotaxis, morphogenesis, and other motile processes. New actin-associated proteins are being identified and characterized by biochemical means and through isolation of mutants lacking individual components. This work is shedding light on the roles of specific actin assemblies in various biological processes.
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Affiliation(s)
- A A Noegel
- Max-Planck-Institut für Biochemie, Martinsried, Germany
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20
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Röhrig U, Gerisch G, Morozova L, Schleicher M, Wegner A. Coactosin interferes with the capping of actin filaments. FEBS Lett 1995; 374:284-6. [PMID: 7589554 DOI: 10.1016/0014-5793(95)01130-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Coactosin, a 16 kDa protein associated with the actin cytoskeleton from Dictyostelium discoideum, was purified by an improved method, in which other components of the cytoskeleton were removed. The highly purified coactosin had no effect on the time course of actin polymerization, but when added to actin in presence of capping proteins, coactosin counteracted the capping activity of these proteins. The capping proteins cap32/34 and severin domain 1 retarded actin polymerization, on addition of coactosin to samples containing one of these capping proteins the time course of actin polymerization became close to controls without capping proteins.
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Affiliation(s)
- U Röhrig
- Max-Planck-Institut für Biochemie, Martinsried, Germany
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21
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Barron-Casella EA, Torres MA, Scherer SW, Heng HH, Tsui LC, Casella JF. Sequence analysis and chromosomal localization of human Cap Z. Conserved residues within the actin-binding domain may link Cap Z to gelsolin/severin and profilin protein families. J Biol Chem 1995; 270:21472-9. [PMID: 7665558 DOI: 10.1074/jbc.270.37.21472] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
From a human retinal cDNA library, we have isolated cDNAs that are homologs for the alpha 2 and beta subunits of chicken Cap Z. The derived human alpha subunit shares 95% amino acid identity with the chicken alpha 2 subunit; the beta subunit is 99% identical to the chicken subunit residues 1-243. The remaining portion of the human beta subunit (244-272) diverges significantly with only 8 out of 29 C-terminal amino acids conserved between the two species. This lack of conservation is of particular interest because the chicken C terminus contains an actin-binding domain. Cosedimentation assays with F-actin show that human Cap Z binds actin with an affinity equal that of chicken Cap Z. These results point to the eight shared amino acids as critical for actin binding, three of which are regularly spaced leucines. These apolar residues and one outside the region of divergence align well with those residues of the actin-binding alpha-helix proposed for gelsolin segment 1. The apolar residues as well as three polar amino acids are also conserved in other capping, capping and severing, and monomer-binding proteins. Amino acid substitutions in the chicken beta subunit of the two most highly conserved leucines result in significant decreases in F-actin binding activity. The human alpha 2 gene (CAPZA2) has been mapped to chromosome 7 position q31.2-q31.3 and the beta gene (CAPZB) to chromosome 1 region p36.1.
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Affiliation(s)
- E A Barron-Casella
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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22
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Ivanenkov VV, Jamieson GA, Gruenstein E, Dimlich RV. Characterization of S-100b binding epitopes. Identification of a novel target, the actin capping protein, CapZ. J Biol Chem 1995; 270:14651-8. [PMID: 7540176 DOI: 10.1074/jbc.270.24.14651] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Short amino acid sequences that interact with the Ca2+ binding protein S-100b were identified by screening a bacteriophage random peptide display library. S-100b binding bacteriophages were selected by Ca(2+)-dependent affinity chromatography, and the sequence of the random peptide insert contained in 51 clones was determined. Alignment of the sequence of 44 unique S-100b binding peptides identified a common motif of eight amino acids. A subgroup of peptides that contained sequences with the highest degree of similarity had the consensus motif (K/R)(L/I)XWXXIL, in which predominantly P, S, and N were found in position 3, and S and D were found in position 5. Analysis of sequence databanks identified a similar sequence in the COOH-terminal region of the alpha-subunit of actin capping proteins. The peptide TRTKIDWNKILS (TRTK-12), corresponding to the region of greatest homology within this region of the subunit of actin capping proteins (e.g. amino acids 265-276 in CapZ alpha 1 and CapZ alpha 2), was synthesized and shown by fluorescence spectrophotometry to bind S-100b in a Ca(2+)-dependent manner. Gel overlay and cross-linking experiments demonstrated the interaction of S-100b with CapZ to be Ca2+ dependent. Moreover, this interaction was blocked by addition of TRTK-12 peptide. These results identify Ca(2+)-dependent S-100b target sequence epitopes and designate the carboxyl terminus of the alpha-subunit of actin capping proteins, like CapZ, to be a target of S-100b activity. The high level of conservation within this region of actin capping proteins and the apparent high affinity of this interaction strongly suggest that the interaction between S-100b and the alpha-subunit of actin capping proteins is biologically significant.
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Affiliation(s)
- V V Ivanenkov
- Department of Emergency Medicine, University of Cincinnati College of Medicine, Ohio 45267, USA
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23
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Hug C, Jay PY, Reddy I, McNally JG, Bridgman PC, Elson EL, Cooper JA. Capping protein levels influence actin assembly and cell motility in dictyostelium. Cell 1995; 81:591-600. [PMID: 7758113 DOI: 10.1016/0092-8674(95)90080-2] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Actin assembly is important for cell motility, but the mechanism of assembly and how it relates to motility in vivo is largely unknown. In vitro, actin assembly can be controlled by proteins, such as capping protein, that bind filament ends. To investigate the function of actin assembly in vivo, we altered the levels of capping protein in Dictyostelium cells and found changes in resting and chemoattractant-induced actin assembly that were consistent with the in vitro properties of capping protein in capping but not nucleation. Significantly, overexpressers moved faster and underexpressers moved slower than control cells. Mutants also exhibited changes in cytoskeleton architecture. These results provide insights into in vivo actin assembly and the role of the actin cytoskeleton in motility.
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Affiliation(s)
- C Hug
- Department of Cell Biology and Physiology, Washington University, St. Louis, Missouri 63110, USA
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24
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Witke W, Sharpe AH, Hartwig JH, Azuma T, Stossel TP, Kwiatkowski DJ. Hemostatic, inflammatory, and fibroblast responses are blunted in mice lacking gelsolin. Cell 1995; 81:41-51. [PMID: 7720072 DOI: 10.1016/0092-8674(95)90369-0] [Citation(s) in RCA: 351] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Gelsolin, an 82 kDa actin-binding protein, has potent actin filament-severing activity in vitro. To investigate the in vivo function of gelsolin, transgenic gelsolin-null (Gsn-) mice were generated and found to have normal embryonic development and longevity. However, platelet shape changes are decreased in Gsn- mice, causing prolonged bleeding times. Neutrophil migration in vivo into peritoneal exudates and in vitro is delayed. Gsn- dermal fibroblasts have excessive actin stress fibers and migrate more slowly than wild-type fibroblasts, but have increased contractility in vitro. These observations establish the requirement of gelsolin for rapid motile responses in cell types involved in stress responses such as hemostasis, inflammation, and wound healing. Neither gelsolin nor other proteins with similar actin filament-severing activity are expressed in early embryonic cells, indicating that this mechanism of actin filament dynamics is not essential for motility during early embryogenesis.
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Affiliation(s)
- W Witke
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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25
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Casella J, Torres M. Interaction of Cap Z with actin. The NH2-terminal domains of the alpha 1 and beta subunits are not required for actin capping, and alpha 1 beta and alpha 2 beta heterodimers bind differentially to actin. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37472-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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26
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Jungbluth A, von Arnim V, Biegelmann E, Humbel B, Schweiger A, Gerisch G. Strong increase in the tyrosine phosphorylation of actin upon inhibition of oxidative phosphorylation: correlation with reversible rearrangements in the actin skeleton of Dictyostelium cells. J Cell Sci 1994; 107 ( Pt 1):117-25. [PMID: 7513710 DOI: 10.1242/jcs.107.1.117] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When oxidative phosphorylation is inhibited in cells of Dictyostelium discoideum, the phosphorylation of tyrosine residues on actin is strongly increased. This increase is fully reversible. Under the same conditions the amoeboid cells undergo a series of shape changes. Within three minutes the pseudopods are withdrawn and replaced by cell surface blebs. Subsequently, the cells are rounding up to become immobile. In parallel with the changes in cell shape, the distribution of actin filaments is grossly altered within the cells. The cortical network of actin filaments of normal cells is broken down, and the F-actin forms large, irregular clusters deep within the cytoplasm. In these clusters the actin is associated with myosin II and with the heterodimeric F-actin capping protein cap32/34. After restoration of oxidative phosphorylation the actin returns within less than four minutes to its normal cortical position. A causal relationship between tyrosine phosphorylation and changes in the distribution of actin remains to be established. The rearrangements in the actin system that result from the inhibition of oxidative phosphorylation indicate that the organisation of this system and its maintenance in a functional state depend on the continuous supply of energy by ATP.
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Affiliation(s)
- A Jungbluth
- Max-Planck-Institut für Biochemie, Martinsried, Germany
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27
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Hofmann A, Noegel AA, Bomblies L, Lottspeich F, Schleicher M. The 100 kDa F-actin capping protein of Dictyostelium amoebae is a villin prototype ('protovillin'). FEBS Lett 1993; 328:71-6. [PMID: 8344435 DOI: 10.1016/0014-5793(93)80968-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The 100 kDa actin-binding protein from Dictyostelium amoebae is an F-actin capping protein that displays neither severing nor crosslinking nor nucleating activities [Hofmann et al. (1992) Cell Motil. Cytoskel. 23,133-144]. Cloning and sequencing of the gene revealed that the protein is highly homologous to vertebrate villin, a unique component of brush border microvilli and contains six domains fused to a villin-like headpiece domain via a threonine/proline rich neck region. The functional differences and similarities between the 100 kDa protein and villin are reflected in the amino acid sequences. We draw from the data the following conclusions. (i) The presence of a six domain protein in Dictyostelium suggests that in contrast to the current view gene duplications must have happened before Dictyostelium branched off during evolution. (ii) The villin-like molecule in Dictyostelium appears to be a premature villin ('protovillin') which is able to cap actin filaments but still lacks the other villin-type actin-binding activities. This renders capping of actin filaments as the evolutionarily oldest function of an F-actin binding protein.
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Affiliation(s)
- A Hofmann
- Institute for Cell Biology, Ludwig-Maximilians-University Munich, Germany
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28
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Abstract
Recent research on F-actin capping proteins has concentrated on three main areas. The discovery that controlled actin polymerization is the driving force for intracellular movement suggests an important role for capping proteins in regulating filament number and length. A capping protein from Dictyostelium (related to heat-shock protein HSP70) has been characterized that is activated by external stimuli. This provides a pivotal connection between extracellular signalling, cytoskeletal reorganization and locomotory behaviour. The roles of individual actin-binding sites in the gelsolin family of severing/capping proteins and binding sites for phosphatidylinositol 4,5-bisphosphate have been identified.
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Affiliation(s)
- A Weeds
- MRC Laboratory of Molecular Biology, Cambridge, UK
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29
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Fukui Y. Toward a new concept of cell motility: cytoskeletal dynamics in amoeboid movement and cell division. INTERNATIONAL REVIEW OF CYTOLOGY 1993; 144:85-127. [PMID: 8320063 DOI: 10.1016/s0074-7696(08)61514-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Y Fukui
- Department of Cell, Molecular, and Structural Biology, Northwestern University Medical School, Chicago, Illinois 60611
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30
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Hofmann A, Eichinger L, André E, Rieger D, Schleicher M. Cap100, a novel phosphatidylinositol 4,5-bisphosphate-regulated protein that caps actin filaments but does not nucleate actin assembly. CELL MOTILITY AND THE CYTOSKELETON 1992; 23:133-44. [PMID: 1333365 DOI: 10.1002/cm.970230206] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The fast and transient polymerization of actin in nonmuscle cells after stimulation with chemoattractants requires strong nucleation activities but also components that inhibit this process in resting cells. In this paper, we describe the purification and characterization of a new actin-binding protein from Dictyostelium discoideum that exhibited strong F-actin capping activity but did not nucleate actin assembly independently of the Ca2+ concentration. These properties led at physiological salt conditions to an inhibition of actin polymerization at a molar ratio of capping protein to actin below 1:1,000. The protein is a monomer, with a molecular mass of approximately 100 kDa, and is present in growing and in developing amoebae. Based on its F-actin capping function and its apparent molecular weight, we designated this monomeric protein cap100. As shown by dilution-induced depolymerization and by elongation assays, cap100 capped the barbed ends of actin filaments and did not sever F-actin. In agreement with its capping activity, cap100 increased the critical concentration for actin polymerization. In excitation or emission scans of pyrene-labeled G-actin, the fluorescence was increased in the presence of cap100. This suggests a G-actin binding activity for cap100. The capping activity could be completely inhibited by phosphatidylinositol 4,5-bisphosphate (PIP2), and bound cap100 could be removed by PIP2. The inhibition by phosphatidylinositol and the Ca(2+)-independent down-regulation of spontaneous actin polymerization indicate that cap100 plays a role in balancing the G- and F-actin pools of a resting cell. In the cytoplasm, the equilibrium would be shifted towards G-actin, but, below the membrane where F-actin is required, this activity would be inhibited by PIP2.
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Affiliation(s)
- A Hofmann
- Max-Planck-Institute for Biochemistry, Martinsried, Federal Republic of Germany
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31
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Haus U, Hartmann H, Trommler P, Noegel AA, Schleicher M. F-actin capping by cap32/34 requires heterodimeric conformation and can be inhibited with PIP2. Biochem Biophys Res Commun 1991; 181:833-9. [PMID: 1661590 DOI: 10.1016/0006-291x(91)91265-e] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The heterodimeric F-actin capping protein cap32/34 from Dictyostelium discoideum is a typical member of a widely distributed family of cytoskeletal proteins. To analyze its regulation and structure/function relationships we cloned and expressed the subunits separately in Escherichia coli using the ATG-expression vector pT7-7. Studies on the viscosity of F-actin solutions and the kinetics of actin polymerization in the presence of single subunits or the reconstituted protein showed that capping of F-actin absolutely requires the heterodimeric conformation. This activity can be inhibited by phosphatidyl bisphosphate (PIP2), an important component in signal transduction. The regulation of cap32/34 by PIP2 suggests an involvement of this protein in the re-organization of the actin cytoskeleton upon stimulation of D. discoideum cells with chemoattractant.
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Affiliation(s)
- U Haus
- Max-Planck-Institute for Biochemistry, Martinsried, Federal Republic of Germany
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32
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Purification and cDNA-derived sequence of adenylosuccinate synthetase from Dictyostelium discoideum. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52269-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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33
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Abstract
Much new information on the sequence, structure, and function of filament crosslinking, capping, and severing proteins is now known. Other significant findings include identification of a new abundant monomer-sequestering protein in platelets, and evidence that many actin-binding proteins interact with phosphoinositides and that this interaction may have metabolic consequences.
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Affiliation(s)
- J H Hartwig
- Massachusetts General Hospital, Hematology-Oncology Unit, Charlestown 02129
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34
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Huffaker TC, Bretscher AP. Cloning and analyzing genes encoding cytoskeletal proteins in yeast Saccharomyces cerevisiae. Methods Enzymol 1991; 196:355-68. [PMID: 2034130 DOI: 10.1016/0076-6879(91)96032-m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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35
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Cooper JA, Caldwell JE, Gattermeir DJ, Torres MA, Amatruda JF, Casella JF. Variant cDNAs encoding proteins similar to the alpha subunit of chicken CapZ. CELL MOTILITY AND THE CYTOSKELETON 1991; 18:204-14. [PMID: 1711931 DOI: 10.1002/cm.970180306] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Chicken adult muscle and liver cDNA libraries were screened with a cDNA, alpha 1, previously isolated from a chicken embryo library by screening with antibodies against the alpha subunit of chicken CapZ. cDNAs with a new coding region, called alpha 2, were found in addition to ones with the alpha 1 coding region. alpha 2 predicts a protein sequence that matches exactly the N-terminal sequence of 5 peptides prepared from CapZ alpha purified from chicken muscle, while the protein sequence predicted by alpha 1 matches the peptides well, but not exactly. The predicted protein sequences of alpha 1 and alpha 2 are very similar to each other, and they are similar to those of the alpha subunit of capping protein from Dictyostelium [Hartmann et al., J. Biol. Chem. 163:5254-5254, 1989] and an actin-binding protein from Xenopus [Ankenbauer et al., Nature 342:822-824, 1989]. Other conserved features of the predicted primary and secondary structures are noted. Chicken alpha 1 and alpha 2 are transcribed in all of 7 adult chicken muscle and non-muscle tissues in comparable amounts by Northern analysis. alpha 2 has four poly(A)+RNA transcripts, one of which is rare in liver. alpha 1 has two transcripts. alpha 1 and alpha 2 are encoded by different single-copy genes by Southern analysis of chicken genomic DNA.
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Affiliation(s)
- J A Cooper
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
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36
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Bresnick AR, Condeelis J. Isolation of actin-binding proteins from Dictyostelium discoideum. Methods Enzymol 1991; 196:70-83. [PMID: 1851943 DOI: 10.1016/0076-6879(91)96009-g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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37
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38
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Yu FX, Johnston PA, Südhof TC, Yin HL. gCap39, a calcium ion- and polyphosphoinositide-regulated actin capping protein. Science 1990; 250:1413-5. [PMID: 2255912 DOI: 10.1126/science.2255912] [Citation(s) in RCA: 164] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The polymerization of actin filaments is involved in growth, movement, and cell division. It has been shown that actin polymerization is controlled by gelsolin, whose interactions with actin are activated by calcium ion (Ca2+) and inhibited by membrane polyphosphoinositides (PPI). A smaller Ca2(+)- and PPI-regulated protein, gCap39, which has 49% sequence identity with gelsolin, has been identified by cDNA cloning and protein purification. Like gelsolin, gCap39 binds to the fast-growing (+) end of actin filaments. However, gCap39 does not sever actin filaments and can respond to Ca2+ and PPI transients independently, under conditions in which gelsolin is ineffective. The coexistence of gCap39 with gelsolin should allow precise regulation of actin assembly at the leading edge of the cell.
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Affiliation(s)
- F X Yu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas 75235-9040
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39
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Noegel AA, Gerisch G, Lottspeich F, Schleicher M. A protein with homology to the C-terminal repeat sequence of Octopus rhodopsin and synaptophysin is a member of a multigene family in Dictyostelium discoideum. FEBS Lett 1990; 266:118-22. [PMID: 2114316 DOI: 10.1016/0014-5793(90)81521-o] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Monoclonal antibodies were raised against a protein with a molecular mass of 24 kDa that has been described as a membrane-associated, actin binding protein from Dictyostelium discoideum [( 1985) J. Cell Biol. 100, 727-735]. Using these monoclonal antibodies we isolated from a lambda gt11 expression library cDNA clones coding for this protein. The cDNA deduced amino acid sequence revealed the presence of an unusual carboxy-terminus which has homologies to the C-termini of Octopus rhodopsin and synaptophysin. This part of the protein sequence contains 5 direct repeats with the motif GYP (P)Q(P). Southern and Northern blots showed that this sequence is present in a series of Dictyostelium genes transcribed in all stages of development.
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Affiliation(s)
- A A Noegel
- Max-Planck-Institut für Biochemie, Martinsried, FRG
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40
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Maruyama K, Kurokawa H, Oosawa M, Shimaoka S, Yamamoto H, Ito M, Maruyama K. Beta-actinin is equivalent to Cap Z protein. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38947-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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41
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Wiesmüller L, Noegel AA, Bârzu O, Gerisch G, Schleicher M. cDNA-derived sequence of UMP-CMP kinase from Dictyostelium discoideum and expression of the enzyme in Escherichia coli. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39331-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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42
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Amatruda JF, Cannon JF, Tatchell K, Hug C, Cooper JA. Disruption of the actin cytoskeleton in yeast capping protein mutants. Nature 1990; 344:352-4. [PMID: 2179733 DOI: 10.1038/344352a0] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Capping protein controls the addition of actin subunits to the barbed end of actin filaments and nucleates actin polymerization in vitro. Capping protein has been identified in all eukaryotic cells examined so far; it is a heterodimer with subunits of relative molecular masses 32,000-36,000 (alpha-subunit) and 28,000-32,000 (beta-subunit). In skeletal muscle, capping protein (CapZ) probably binds the barbed ends of actin filaments at the Z line. The in vivo role of this protein in non-muscle cells is not known. We report here the characterization of CAP2, the single gene encoding the beta-subunit of capping protein in Saccharomyces cerevisiae. Yeast cells in which the CAP2 gene was disrupted by an insertion or a deletion had an abnormal actin distribution, including the loss of actin cables. The mutant cells were round and large, with a heterogeneous size distribution, and, although viable, grew more slowly than congenic wild-type cells. Chitin, a cell wall component restricted to the mother-bud junction in wild-type budding yeast, was found on the entire mother cell surface in the mutants. The phenotype of CAP2 disruption resembled that of temperature-sensitive mutations in the yeast actin gene ACT1, indicating that capping protein regulates actin-filament distribution in vivo.
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Affiliation(s)
- J F Amatruda
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110
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43
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Affiliation(s)
- M Way
- MRC Laboratory of Molecular Biology, Cambridge, UK
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44
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Hartmann H, Schleicher M, Noegel AA. Heterodimeric capping proteins constitute a highly conserved group of actin-binding proteins. DEVELOPMENTAL GENETICS 1990; 11:369-76. [PMID: 1710551 DOI: 10.1002/dvg.1020110508] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The two subunits of the heterodimeric protein cap32/34, an actin-binding protein, are encoded by separate single-copy genes. We have established the genomic structure of both genes. A sequence comparison of cap32/34 with capZ from chicken skeletal muscle and two partially known sequences from Saccharomyces cerevisiae and Xenopus laevis show that heterodimeric capping proteins belong to a highly conserved group of actin-binding proteins. This conclusion is supported by the cross-reaction of polyclonal antibodies against cap32 and cap34 with proteins from lower and higher eukaryotes. In addition, a system is presented that allows the expression of truncated cap34 polypeptides under the control of the cap34 promoter.
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Affiliation(s)
- H Hartmann
- Max-Planck-Institut für Biochemie, Martinsried, Federal Republic of Germany
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45
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Luna EJ, Condeelis JS. Actin-associated proteins in Dictyostelium discoideum. DEVELOPMENTAL GENETICS 1990; 11:328-32. [PMID: 2096013 DOI: 10.1002/dvg.1020110503] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The cellular slime mold Dictyostelium discoideum is becoming the premier system for the explication of the biochemical and cellular events that occur during motile processes. Proteins associated with the actin cytoskeleton, in particular, appear to play key roles in cellular responses to many external stimuli. This review summarizes our present understanding of the actin-associated proteins in Dictyostelium, including their in vitro activities and their structural and/or functional analogues in mammalian cells.
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Affiliation(s)
- E J Luna
- Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545
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46
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Ankenbauer T, Kleinschmidt JA, Walsh MJ, Weiner OH, Franke WW. Identification of a widespread nuclear actin binding protein. Nature 1989; 342:822-5. [PMID: 2689884 DOI: 10.1038/342822a0] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The many different cellular functions so far shown to involve actin and to be regulated by specific actin binding proteins are located primarily, if not exclusively, in the cytoplasm. Actin is also found in the nucleus of various cells, but because of the problems of cell fractionation the significance of nuclear actin has remained unclear. The large amphibian oocyte nucleus (germinal vesicle), however, can be isolated manually with little cytoplasmic contamination. This nucleus contains high concentrations (4-6 mg ml-1) of mostly soluble, although polymerization-competent beta- and gamma-actin, which exists in a nucleocytoplasmic exchange pool. The findings that drastic effects on transcription and chromosome morphology are caused by the injection of actin antibodies or actin binding proteins into germinal vesicles, and that a factor required for accurate transcription by RNA polymerase II is actin, suggest that nuclear actin is involved in specific nuclear functions. We have recently identified two main components in Xenopus laevis oocytes with actin binding activities; one of these activities is Ca2+-dependent, is located predominantly, if not exclusively, in the cytoplasm and is attributable to gelsolin. Here we report that the second component, having a Ca2+-independent activity, is a heterodimeric acting binding protein; this protein is markedly enriched in the nuclei of oocytes and somatic cells of amphibia, but also occurs in nuclei of other vertebrate cells.
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Affiliation(s)
- T Ankenbauer
- Division of Membrane Biology and Biochemistry, German Cancer Research Center, Heidelberg
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47
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Noegel AA, Leiting B, Witke W, Gurniak C, Harloff C, Hartmann H, Wiesmüller E, Schleicher M. Biological roles of actin-binding proteins in Dictyostelium discoideum examined using genetic techniques. CELL MOTILITY AND THE CYTOSKELETON 1989; 14:69-74. [PMID: 2684430 DOI: 10.1002/cm.970140114] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- A A Noegel
- Max-Planck-Institut für Biochemie, Martinsried, Federal Republic of Germany
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