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Imoto D, Saito N, Nakajima A, Honda G, Ishida M, Sugita T, Ishihara S, Katagiri K, Okimura C, Iwadate Y, Sawai S. Comparative mapping of crawling-cell morphodynamics in deep learning-based feature space. PLoS Comput Biol 2021; 17:e1009237. [PMID: 34383753 PMCID: PMC8360578 DOI: 10.1371/journal.pcbi.1009237] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 07/03/2021] [Indexed: 12/13/2022] Open
Abstract
Navigation of fast migrating cells such as amoeba Dictyostelium and immune cells are tightly associated with their morphologies that range from steady polarized forms that support high directionality to those more complex and variable when making frequent turns. Model simulations are essential for quantitative understanding of these features and their origins, however systematic comparisons with real data are underdeveloped. Here, by employing deep-learning-based feature extraction combined with phase-field modeling framework, we show that a low dimensional feature space for 2D migrating cell morphologies obtained from the shape stereotype of keratocytes, Dictyostelium and neutrophils can be fully mapped by an interlinked signaling network of cell-polarization and protrusion dynamics. Our analysis links the data-driven shape analysis to the underlying causalities by identifying key parameters critical for migratory morphologies both normal and aberrant under genetic and pharmacological perturbations. The results underscore the importance of deciphering self-organizing states and their interplay when characterizing morphological phenotypes. Migratory cells that move by crawling do so by extending and retracting their plasma membrane. When and where these events take place determine the cell shape, and this is directly linked to the movement patterns. Understanding how the highly plastic and interconvertible morphologies appear from their underlying dynamics remains a challenge partly because their inherent complexity makes quantitatively comparison against the outputs of mathematical models difficult. To this end, we employed machine-learning based classification to extract features that characterize the basic migrating morphologies. The obtained features were then used to compare real cell data with outputs of a conceptual model that we introduced which describes coupling via feedback between local protrusive dynamics and polarity. The feature mapping showed that the model successfully recapitulates the shape dynamics that were not covered by previous related models and also hints at the critical parameters underlying state transitions. The ability of the present approach to compare model outputs with real cell data systematically and objectively is important as it allows outputs of future mathematical models to be quantitatively tested in an accessible and common reference frame.
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Affiliation(s)
- Daisuke Imoto
- Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
| | - Nen Saito
- Universal Biological Institute, University of Tokyo, Tokyo, Japan
- Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Japan
| | - Akihiko Nakajima
- Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
- Research Center for Complex Systems Biology, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
| | - Gen Honda
- Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
| | - Motohiko Ishida
- Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
| | - Toyoko Sugita
- Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
| | - Sayaka Ishihara
- Department of Biosciences, School of Science, Kitasato University, Sagamihara, Japan
| | - Koko Katagiri
- Department of Biosciences, School of Science, Kitasato University, Sagamihara, Japan
| | - Chika Okimura
- Faculty of Science, Yamaguchi University, Yamaguchi, Japan
| | | | - Satoshi Sawai
- Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
- Universal Biological Institute, University of Tokyo, Tokyo, Japan
- Research Center for Complex Systems Biology, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
- Department of Biology, Graduate School of Science, University of Tokyo, Tokyo, Japan
- * E-mail:
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2
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Hilbi H, Kortholt A. Role of the small GTPase Rap1 in signal transduction, cell dynamics and bacterial infection. Small GTPases 2017. [PMID: 28632994 DOI: 10.1080/21541248.2017.1331721] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Rap1 belongs to the Ras family of small GTPases, which are involved in a multitude of cellular signal transduction pathways and have extensively been linked to cancer biogenesis and metastasis. The small GTPase is activated in response to various extracellular and intracellular cues. Rap1 has conserved functions in Dictyostelium discoideum amoeba and mammalian cells, which are important for cell polarity, substrate and cell-cell adhesion and other processes that involve the regulation of cytoskeletal dynamics. Moreover, our recent study has shown that Rap1 is required for the formation of the replication-permissive vacuole of an intracellular bacterial pathogen. Here we review the function and regulation of Rap1 in these distinct processes, and we discuss the underlying signal transduction pathways.
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Affiliation(s)
- Hubert Hilbi
- a Institute of Medical Microbiology, University of Zürich , Zürich , Switzerland
| | - Arjan Kortholt
- b Department of Cell Biochemistry, University of Groningen , Groningen , The Netherlands
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3
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Scavello M, Petlick AR, Ramesh R, Thompson VF, Lotfi P, Charest PG. Protein kinase A regulates the Ras, Rap1 and TORC2 pathways in response to the chemoattractant cAMP in Dictyostelium. J Cell Sci 2017; 130:1545-1558. [PMID: 28302905 PMCID: PMC5450229 DOI: 10.1242/jcs.177170] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 03/06/2017] [Indexed: 12/19/2022] Open
Abstract
Efficient directed migration requires tight regulation of chemoattractant signal transduction pathways in both space and time, but the mechanisms involved in such regulation are not well understood. Here, we investigated the role of protein kinase A (PKA) in controlling signaling of the chemoattractant cAMP in Dictyostelium discoideum We found that cells lacking PKA display severe chemotaxis defects, including impaired directional sensing. Although PKA is an important regulator of developmental gene expression, including the cAMP receptor cAR1, our studies using exogenously expressed cAR1 in cells lacking PKA, cells lacking adenylyl cyclase A (ACA) and cells treated with the PKA-selective pharmacological inhibitor H89, suggest that PKA controls chemoattractant signal transduction, in part, through the regulation of RasG, Rap1 and TORC2. As these pathways control the ACA-mediated production of intracellular cAMP, they lie upstream of PKA in this chemoattractant signaling network. Consequently, we propose that the PKA-mediated regulation of the upstream RasG, Rap1 and TORC2 signaling pathways is part of a negative feedback mechanism controlling chemoattractant signal transduction during Dictyostelium chemotaxis.
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Affiliation(s)
- Margarethakay Scavello
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0088, USA
| | - Alexandra R Petlick
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0088, USA
| | - Ramya Ramesh
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0088, USA
| | - Valery F Thompson
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0088, USA
| | - Pouya Lotfi
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0088, USA
| | - Pascale G Charest
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0088, USA
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4
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A Gα-Stimulated RapGEF Is a Receptor-Proximal Regulator of Dictyostelium Chemotaxis. Dev Cell 2016; 37:458-72. [PMID: 27237792 DOI: 10.1016/j.devcel.2016.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 02/15/2016] [Accepted: 04/29/2016] [Indexed: 12/19/2022]
Abstract
Chemotaxis, or directional movement toward extracellular chemical gradients, is an important property of cells that is mediated through G-protein-coupled receptors (GPCRs). Although many chemotaxis pathways downstream of Gβγ have been identified, few Gα effectors are known. Gα effectors are of particular importance because they allow the cell to distinguish signals downstream of distinct chemoattractant GPCRs. Here we identify GflB, a Gα2 binding partner that directly couples the Dictyostelium cyclic AMP GPCR to Rap1. GflB localizes to the leading edge and functions as a Gα-stimulated, Rap1-specific guanine nucleotide exchange factor required to balance Ras and Rap signaling. The kinetics of GflB translocation are fine-tuned by GSK-3 phosphorylation. Cells lacking GflB display impaired Rap1/Ras signaling and actin and myosin dynamics, resulting in defective chemotaxis. Our observations demonstrate that GflB is an essential upstream regulator of chemoattractant-mediated cell polarity and cytoskeletal reorganization functioning to directly link Gα activation to monomeric G-protein signaling.
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Khanna A, Lotfi P, Chavan AJ, Montaño NM, Bolourani P, Weeks G, Shen Z, Briggs SP, Pots H, Van Haastert PJM, Kortholt A, Charest PG. The small GTPases Ras and Rap1 bind to and control TORC2 activity. Sci Rep 2016; 6:25823. [PMID: 27172998 PMCID: PMC4865869 DOI: 10.1038/srep25823] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 04/22/2016] [Indexed: 02/05/2023] Open
Abstract
Target of Rapamycin Complex 2 (TORC2) has conserved roles in regulating cytoskeleton dynamics and cell migration and has been linked to cancer metastasis. However, little is known about the mechanisms regulating TORC2 activity and function in any system. In Dictyostelium, TORC2 functions at the front of migrating cells downstream of the Ras protein RasC, controlling F-actin dynamics and cAMP production. Here, we report the identification of the small GTPase Rap1 as a conserved binding partner of the TORC2 component RIP3/SIN1, and that Rap1 positively regulates the RasC-mediated activation of TORC2 in Dictyostelium. Moreover, we show that active RasC binds to the catalytic domain of TOR, suggesting a mechanism of TORC2 activation that is similar to Rheb activation of TOR complex 1. Dual Ras/Rap1 regulation of TORC2 may allow for integration of Ras and Rap1 signaling pathways in directed cell migration.
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Affiliation(s)
- Ankita Khanna
- Department of Cell Biochemistry, University of Groningen, Groningen, 9747AG, Netherlands
| | - Pouya Lotfi
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Anita J. Chavan
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Nieves M. Montaño
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Parvin Bolourani
- Department of Microbiology and Immunology, Life Sciences Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Gerald Weeks
- Department of Microbiology and Immunology, Life Sciences Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Zhouxin Shen
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093-0380, USA
| | - Steven P. Briggs
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093-0380, USA
| | - Henderikus Pots
- Department of Cell Biochemistry, University of Groningen, Groningen, 9747AG, Netherlands
| | | | - Arjan Kortholt
- Department of Cell Biochemistry, University of Groningen, Groningen, 9747AG, Netherlands
| | - Pascale G. Charest
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721-0088, USA
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6
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Senoo H, Cai H, Wang Y, Sesaki H, Iijima M. The novel RacE-binding protein GflB sharpens Ras activity at the leading edge of migrating cells. Mol Biol Cell 2016; 27:1596-605. [PMID: 27009206 PMCID: PMC4865317 DOI: 10.1091/mbc.e15-11-0796] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 03/18/2016] [Indexed: 12/25/2022] Open
Abstract
A novel protein, GflB, is found to control both Ras and Rho to optimize the reorganization of actin cytoskeletons for directed cell migration. GflB is subjected to feedback regulation from actin cytoskeletons, allowing cells to detect and control the size of actin-rich pseudopods and navigate their movements with extremely high precision. Directional sensing, a process in which cells convert an external chemical gradient into internal signaling events, is essential in chemotaxis. We previously showed that a Rho GTPase, RacE, regulates gradient sensing in Dictyostelium cells. Here, using affinity purification and mass spectrometry, we identify a novel RacE-binding protein, GflB, which contains a Ras GEF domain and a Rho GAP domain. Using biochemical and gene knockout approaches, we show that GflB balances the activation of Ras and Rho GTPases, which enables cells to precisely orient signaling events toward higher concentrations of chemoattractants. Furthermore, we find that GflB is located at the leading edge of migrating cells, and this localization is regulated by the actin cytoskeleton and phosphatidylserine. Our findings provide a new molecular mechanism that connects directional sensing and morphological polarization.
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Affiliation(s)
- Hiroshi Senoo
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Huaqing Cai
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 State Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yu Wang
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Hiromi Sesaki
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Miho Iijima
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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7
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Plak K, Pots H, Van Haastert PJM, Kortholt A. Direct Interaction between TalinB and Rap1 is necessary for adhesion of Dictyostelium cells. BMC Cell Biol 2016; 17:1. [PMID: 26744136 PMCID: PMC4861126 DOI: 10.1186/s12860-015-0078-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 12/22/2015] [Indexed: 11/10/2022] Open
Abstract
Background The small G-protein Rap1 is an important regulator of cellular adhesion in Dictyostelium, however so far the downstream signalling pathways for cell adhesion are not completely characterized. In mammalian cells talin is crucial for adhesion and Rap1 was shown to be a key regulator of talin signalling. Results In a proteomic screen we identified TalinB as a potential Rap1 effector in Dictyostelium. In subsequent pull-down experiments we demonstrate that the Ras association (RA) domain of TalinB interacts specifically with active Rap1. Studies with a mutated RA domain revealed that the RA domain is essential for TalinB-Rap1 interaction, and that this interaction contributes to cell-substrate adhesion during single-celled growth and is crucial for cell-cell adhesion during multicellular development. Conclusions Dictyostelium Rap1 directly binds to TalinB via the conserved RA domain. This interaction is critical for adhesion, which becomes essential for high adhesive force demanding processes, like morphogenesis during multicellular development of Dictyostelium. In mammalian cells the established Rap1-talin interaction is indirect and acts through the scaffold protein - RIAM. Interestingly, direct binding of mouse Rap1 to the RA domain of Talin1 has recently been demonstrated. Electronic supplementary material The online version of this article (doi:10.1186/s12860-015-0078-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katarzyna Plak
- Department of Cell Biochemistry, University of Groningen, Nijenborgh 7, Groningen, AG 9747, The Netherlands. .,Current address: BIOTEC center, Technical University Dresden, Tatzberg 47/49, 01307, Dresden, Germany.
| | - Henderikus Pots
- Department of Cell Biochemistry, University of Groningen, Nijenborgh 7, Groningen, AG 9747, The Netherlands.
| | - Peter J M Van Haastert
- Department of Cell Biochemistry, University of Groningen, Nijenborgh 7, Groningen, AG 9747, The Netherlands.
| | - Arjan Kortholt
- Department of Cell Biochemistry, University of Groningen, Nijenborgh 7, Groningen, AG 9747, The Netherlands.
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8
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Rho Signaling in Dictyostelium discoideum. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 322:61-181. [DOI: 10.1016/bs.ircmb.2015.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Mohamed W, Ray S, Brazill D, Baskar R. Absence of catalytic domain in a putative protein kinase C (PkcA) suppresses tip dominance in Dictyostelium discoideum. Dev Biol 2015; 405:10-20. [PMID: 26183108 DOI: 10.1016/j.ydbio.2015.05.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 04/06/2015] [Accepted: 05/28/2015] [Indexed: 12/22/2022]
Abstract
A number of organisms possess several isoforms of protein kinase C but little is known about the significance of any specific isoform during embryogenesis and development. To address this we characterized a PKC ortholog (PkcA; DDB_G0288147) in Dictyostelium discoideum. pkcA expression switches from prestalk in mound to prespore in slug, indicating a dynamic expression pattern. Mutants lacking the catalytic domain of PkcA (pkcA(-)) did not exhibit tip dominance. A striking phenotype of pkcA- was the formation of an aggregate with a central hollow, and aggregates later fragmented to form small mounds, each becoming a fruiting body. Optical density wave patterns of cAMP in the late aggregates showed several cAMP wave generation centers. We attribute these defects in pkcA(-) to impaired cAMP signaling, altered cell motility and decreased expression of the cell adhesion molecules - CadA and CsaA. pkcA(-) slugs showed ectopic expression of ecmA in the prespore region. Further, the use of a PKC-specific inhibitor, GF109203X that inhibits the activity of catalytic domain phenocopied pkcA(-).
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Affiliation(s)
- Wasima Mohamed
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Sibnath Ray
- Department of Biological Sciences, Center for Translational and Basic Research, Hunter College and The Graduate Center of the City University of New York, New York, NY 10065, USA
| | - Derrick Brazill
- Department of Biological Sciences, Center for Translational and Basic Research, Hunter College and The Graduate Center of the City University of New York, New York, NY 10065, USA
| | - Ramamurthy Baskar
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India.
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Plak K, Keizer-Gunnink I, van Haastert PJM, Kortholt A. Rap1-dependent pathways coordinate cytokinesis in Dictyostelium. Mol Biol Cell 2014; 25:4195-204. [PMID: 25298405 PMCID: PMC4263460 DOI: 10.1091/mbc.e14-08-1285] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Dictyostelium Rap1 is dynamically activated during cytokinesis and drives cytokinesis progression by coordinating the three major cytoskeletal components: microtubules, actin, and myosin II. Importantly, mutated forms of Rap also affect cytokinesis in other organisms, suggesting a conserved role for Rap in cell division. Cytokinesis is the final step of mitosis when a mother cell is separated into two daughter cells. Major cytoskeletal changes are essential for cytokinesis; it is, however, not well understood how the microtubules and actomyosin cytoskeleton are exactly regulated in time and space. In this paper, we show that during the early stages of cytokinesis, in rounded-up Dictyostelium discoideum cells, the small G-protein Rap1 is activated uniformly at the cell cortex. When cells begin to elongate, active Rap1 becomes restricted from the furrow region, where the myosin contractile ring is subsequently formed. In the final stages of cytokinesis, active Rap1 is only present at the cell poles. Mutant cells with decreased Rap1 activation at the poles showed strongly decreased growth rates. Hyperactivation of Rap1 results in severe growth delays and defective spindle formation in adherent cells and cell death in suspension. Furthermore, Rap mutants show aberrant regulation of the actomyosin cytoskeleton, resulting in extended furrow ingression times and asymmetrical cell division. We propose that Rap1 drives cytokinesis progression by coordinating the three major cytoskeletal components: microtubules, actin, and myosin II. Importantly, mutated forms of Rap also affect cytokinesis in other organisms, suggesting a conserved role for Rap in cell division.
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Affiliation(s)
- Katarzyna Plak
- Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, Netherlands
| | - Ineke Keizer-Gunnink
- Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, Netherlands
| | - Peter J M van Haastert
- Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, Netherlands
| | - Arjan Kortholt
- Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, Netherlands
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Moving towards a paradigm: common mechanisms of chemotactic signaling in Dictyostelium and mammalian leukocytes. Cell Mol Life Sci 2014; 71:3711-47. [PMID: 24846395 DOI: 10.1007/s00018-014-1638-8] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 04/24/2014] [Accepted: 04/29/2014] [Indexed: 12/31/2022]
Abstract
Chemotaxis, or directed migration of cells along a chemical gradient, is a highly coordinated process that involves gradient sensing, motility, and polarity. Most of our understanding of chemotaxis comes from studies of cells undergoing amoeboid-type migration, in particular the social amoeba Dictyostelium discoideum and leukocytes. In these amoeboid cells the molecular events leading to directed migration can be conceptually divided into four interacting networks: receptor/G protein, signal transduction, cytoskeleton, and polarity. The signal transduction network occupies a central position in this scheme as it receives direct input from the receptor/G protein network, as well as feedback from the cytoskeletal and polarity networks. Multiple overlapping modules within the signal transduction network transmit the signals to the actin cytoskeleton network leading to biased pseudopod protrusion in the direction of the gradient. The overall architecture of the networks, as well as the individual signaling modules, is remarkably conserved between Dictyostelium and mammalian leukocytes, and the similarities and differences between the two systems are the subject of this review.
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