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Egger B. Neural Stem Cells and Brain Tumour Models in Drosophila. Neurogenetics 2023. [DOI: 10.1007/978-3-031-07793-7_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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2
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Akturk A, Day M, Tarchini B. RGS12 polarizes the GPSM2-GNAI complex to organize and elongate stereocilia in sensory hair cells. SCIENCE ADVANCES 2022; 8:eabq2826. [PMID: 36260679 PMCID: PMC9581478 DOI: 10.1126/sciadv.abq2826] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/31/2022] [Indexed: 06/10/2023]
Abstract
Inhibitory G proteins (GNAI/Gαi) bind to the scaffold G protein signaling modulator 2 (GPSM2) to form a conserved polarity complex that regulates cytoskeleton organization. GPSM2 keeps GNAI in a guanosine diphosphate (GDP)-bound state, but how GPSM2-GNAI is generated or relates to heterotrimeric G protein signaling remains unclear. We find that RGS12, a GTPase-activating protein (GAP), is required to polarize GPSM2-GNAI at the hair cell apical membrane and to organize mechanosensory stereocilia in rows of graded heights. Accordingly, RGS12 and the guanine nucleotide exchange factor (GEF) DAPLE are asymmetrically co-enriched at the hair cell apical junction, and Rgs12 mouse mutants are deaf. GPSM2 and RGS12 share GoLoco motifs that stabilize GNAI(GDP), and GPSM2 outcompetes RGS12 to bind GNAI. Our results suggest that polarized GEF/GAP junctional activity might dissociate heterotrimeric G proteins, generating free GNAI(GDP) for GPSM2 at the adjacent apical membrane. GPSM2-GNAI(GDP), in turn, imparts asymmetry to the forming stereocilia to enable sensory function in hair cells.
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Affiliation(s)
- Anil Akturk
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Matthew Day
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Basile Tarchini
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
- School of Medicine, Tufts University, Boston, MA 02111, USA
- Graduate School of Biomedical Science and Engineering (GSBSE), University of Maine, Orono, ME 04469, USA
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3
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de Torres-Jurado A, Manzanero-Ortiz S, Carmena A. Glial-secreted Netrins regulate Robo1/Rac1-Cdc42 signaling threshold levels during Drosophila asymmetric neural stem/progenitor cell division. Curr Biol 2022; 32:2174-2188.e3. [DOI: 10.1016/j.cub.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 02/21/2022] [Accepted: 04/01/2022] [Indexed: 01/14/2023]
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4
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Lechler T, Mapelli M. Spindle positioning and its impact on vertebrate tissue architecture and cell fate. Nat Rev Mol Cell Biol 2021; 22:691-708. [PMID: 34158639 PMCID: PMC10544824 DOI: 10.1038/s41580-021-00384-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2021] [Indexed: 12/18/2022]
Abstract
In multicellular systems, oriented cell divisions are essential for morphogenesis and homeostasis as they determine the position of daughter cells within the tissue and also, in many cases, their fate. Early studies in invertebrates led to the identification of conserved core mechanisms of mitotic spindle positioning centred on the Gαi-LGN-NuMA-dynein complex. In recent years, much has been learnt about the way this complex functions in vertebrate cells. In particular, studies addressed how the Gαi-LGN-NuMA-dynein complex dynamically crosstalks with astral microtubules and the actin cytoskeleton, and how it is regulated to orient the spindle according to cellular and tissue-wide cues. We have also begun to understand how dynein motors and actin regulators interact with mechanosensitive adhesion molecules sensing extracellular mechanical stimuli, such as cadherins and integrins, and with signalling pathways so as to respond to extracellular cues instructing the orientation of the division axis in vivo. In this Review, with the focus on epithelial tissues, we discuss the molecular mechanisms of mitotic spindle orientation in vertebrate cells, and how this machinery is regulated by epithelial cues and extracellular signals to maintain tissue cohesiveness during mitosis. We also outline recent knowledge of how spindle orientation impacts tissue architecture in epithelia and its emerging links to the regulation of cell fate decisions. Finally, we describe how defective spindle orientation can be corrected or its effects eliminated in tissues under physiological conditions, and the pathological implications associated with spindle misorientation.
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Affiliation(s)
- Terry Lechler
- Department of Dermatology, Duke University Medical Center, Durham, NC, USA.
- Department of Cell Biology, Duke University Medical Center, Durham, NC, USA.
| | - Marina Mapelli
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy.
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Kubick N, Klimovich P, Bieńkowska I, Poznanski P, Łazarczyk M, Sacharczuk M, Mickael ME. Investigation of Evolutionary History and Origin of the Tre1 Family Suggests a Role in Regulating Hemocytes Cells Infiltration of the Blood-Brain Barrier. INSECTS 2021; 12:insects12100882. [PMID: 34680651 PMCID: PMC8540695 DOI: 10.3390/insects12100882] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 09/23/2021] [Indexed: 12/30/2022]
Abstract
Simple Summary Understanding the evolutionary association between immune cells and the blood–brain barrier (BBB) is vital to develop therapeutic approaches. In Drosophila, glial cells form the BBB that regulates the access of hemocytes to the brain. It is still not known which diapedesis route hemocytes cells follow. In vertebrates, paracellular migration is dependent on PECAM1, while transcellular migration is dependent on the expression of CAV1. The drosophila genome lacks both genes. The Tre1 family (Tre1, moody, and Dmel_CG4313) contribute to regulating transepithelial migration in Drosophila. However, its evolutionary history is not known. We performed phylogenetic analysis to reconstruct the evolutionary history of the Tre1 family. We found Dmel_CG4313 only in insects. Tre1 exists only in invertebrates and is highly conserved. moody evolutionary history is more spread as it appears from Cnidaria up to mammals and is less conserved. The Tre1 family origin seems to be related to opsins. We have identified an SH3 motif in Tre1, moody, and Dmel_CG4313. SH3 regulates actin movement in a Rho-dependent manner in PECAM1. Our results suggest that the Tre1 family could be playing an important role in paracellular diapedesis in Drosophila. Thus, targeting the Tre1 family could help us regulate access to the brain. Abstract Understanding the evolutionary relationship between immune cells and the blood–brain barrier (BBB) is important to devise therapeutic strategies. In vertebrates, immune cells follow either a paracellular or a transcellular pathway to infiltrate the BBB. In Drosophila, glial cells form the BBB that regulates the access of hemocytes to the brain. However, it is still not known which diapedesis route hemocytes cells follow. In vertebrates, paracellular migration is dependent on PECAM1, while transcellular migration is dependent on the expression of CAV1. Interestingly Drosophila genome lacks both genes. Tre1 family (Tre1, moody, and Dmel_CG4313) play a diverse role in regulating transepithelial migration in Drosophila. However, its evolutionary history and origin are not yet known. We performed phylogenetic analysis, together with HH search, positive selection, and ancestral reconstruction to investigate the Tre1 family. We found that Tre1 exists in Mollusca, Arthropoda, Ambulacraria, and Scalidophora. moody is shown to be a more ancient protein and it has existed since Cnidaria emergence and has a homolog (e.g., GPCR84) in mammals. The third family member (Dmel_CG4313) seems to only exist in insects. The origin of the family seems to be related to the rhodopsin-like family and in particular family α. We found that opsin is the nearest receptor to have a common ancestor with the Tre1 family that has diverged in sponges. We investigated the positive selection of the Tre1 family using PAML. Tre1 seems to have evolved under negative selection, whereas moody has evolved during positive selection. The sites that we found under positive selection are likely to play a role in the speciation of function in the case of moody. We have identified an SH3 motif, in Tre1 and, moody and Dmel_CG4313. SH3 is known to play a fundamental role in regulating actin movement in a Rho-dependent manner in PECAM1. Our results suggest that the Tre1 family could be playing an important role in paracellular diapedesis in Drosophila.
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Affiliation(s)
- Norwin Kubick
- Department of Biochemistry and Molecular Cell Biology (IBMZ), University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany;
| | - Pavel Klimovich
- Department of Immunology, PM Forskningscentreum, 17854 Ekerö, Sweden;
| | - Irmina Bieńkowska
- Department of Experimental Genomics, Institute of Animal Biotechnology and Genetics, Polish Academy of Science, Postępu 36A, 05-552 Subcarpathia, Poland; (I.B.); (P.P.); (M.Ł.); (M.S.)
| | - Piotr Poznanski
- Department of Experimental Genomics, Institute of Animal Biotechnology and Genetics, Polish Academy of Science, Postępu 36A, 05-552 Subcarpathia, Poland; (I.B.); (P.P.); (M.Ł.); (M.S.)
| | - Marzena Łazarczyk
- Department of Experimental Genomics, Institute of Animal Biotechnology and Genetics, Polish Academy of Science, Postępu 36A, 05-552 Subcarpathia, Poland; (I.B.); (P.P.); (M.Ł.); (M.S.)
| | - Mariusz Sacharczuk
- Department of Experimental Genomics, Institute of Animal Biotechnology and Genetics, Polish Academy of Science, Postępu 36A, 05-552 Subcarpathia, Poland; (I.B.); (P.P.); (M.Ł.); (M.S.)
| | - Michel-Edwar Mickael
- Department of Immunology, PM Forskningscentreum, 17854 Ekerö, Sweden;
- Department of Experimental Genomics, Institute of Animal Biotechnology and Genetics, Polish Academy of Science, Postępu 36A, 05-552 Subcarpathia, Poland; (I.B.); (P.P.); (M.Ł.); (M.S.)
- Correspondence:
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Kimura K, Motegi F. Fluid flow dynamics in cellular patterning. Semin Cell Dev Biol 2021; 120:3-9. [PMID: 34274213 DOI: 10.1016/j.semcdb.2021.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 06/24/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022]
Abstract
The development of complex forms of multicellular organisms depends on the spatial arrangement of cellular architecture and functions. The interior design of the cell is patterned by spatially biased distributions of molecules and biochemical reactions in the cytoplasm and/or on the plasma membrane. In recent years, a dynamic change in the cytoplasmic fluid flow has emerged as a key physical process of driving long-range transport of molecules to particular destinations within the cell. Here, recent experimental advances in the understanding of the generation of the various types of cytoplasmic flows and contributions to intracellular patterning are reviewed with a particular focus on feedback mechanisms between the mechanical properties of fluid flow and biochemical signaling during animal cell polarization.
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Affiliation(s)
- Kenji Kimura
- School of Science and Technology, Kwansei Gakuin University, Japan.
| | - Fumio Motegi
- Instiute for Genetic Medicine, Hokkaido University, Japan; Temasek Lifesciences Laboratory, Singapore; Mechanobiology Institute, National University of Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore.
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7
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Saad F, Hipfner DR. Extensive crosstalk of G protein-coupled receptors with the Hedgehog signalling pathway. Development 2021; 148:dev189258. [PMID: 33653875 PMCID: PMC10656458 DOI: 10.1242/dev.189258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 02/19/2021] [Indexed: 12/23/2022]
Abstract
Hedgehog (Hh) ligands orchestrate tissue patterning and growth by acting as morphogens, dictating different cellular responses depending on ligand concentration. Cellular sensitivity to Hh ligands is influenced by heterotrimeric G protein activity, which controls production of the second messenger 3',5'-cyclic adenosine monophosphate (cAMP). cAMP in turn activates Protein kinase A (PKA), which functions as an inhibitor and (uniquely in Drosophila) as an activator of Hh signalling. A few mammalian Gαi- and Gαs-coupled G protein-coupled receptors (GPCRs) have been shown to influence Sonic hedgehog (Shh) responses in this way. To determine whether this is a more-general phenomenon, we carried out an RNAi screen targeting GPCRs in Drosophila. RNAi-mediated depletion of more than 40% of GPCRs tested either decreased or increased Hh responsiveness in the developing Drosophila wing, closely matching the effects of Gαs and Gαi depletion, respectively. Genetic analysis indicated that the orphan GPCR Mthl5 lowers cAMP levels to attenuate Hh responsiveness. Our results identify Mthl5 as a new Hh signalling pathway modulator in Drosophila and suggest that many GPCRs may crosstalk with the Hh pathway in mammals.
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Affiliation(s)
- Farah Saad
- Institut de recherches cliniques de Montréal, 110 Pine Avenue West, Montreal H2W 1R7, QC, Canada
- Department of Biology, McGill University, Montreal H3A 1B1, QC, Canada
| | - David R. Hipfner
- Institut de recherches cliniques de Montréal, 110 Pine Avenue West, Montreal H2W 1R7, QC, Canada
- Department of Biology, McGill University, Montreal H3A 1B1, QC, Canada
- Département de médecine, Université de Montréal, Montreal H3C 3J7, QC, Canada
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8
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Kim JH, Hanlon CD, Vohra S, Devreotes PN, Andrew DJ. Hedgehog signaling and Tre1 regulate actin dynamics through PI(4,5)P 2 to direct migration of Drosophila embryonic germ cells. Cell Rep 2021; 34:108799. [PMID: 33657369 PMCID: PMC8023404 DOI: 10.1016/j.celrep.2021.108799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 12/21/2020] [Accepted: 02/05/2021] [Indexed: 01/09/2023] Open
Abstract
The Tre1 G-protein coupled receptor (GPCR) was discovered to be required for Drosophila germ cell (GC) coalescence almost two decades ago, yet the molecular events both upstream and downstream of Tre1 activation remain poorly understood. To gain insight into these events, we describe a bona fide null allele and both untagged and tagged versions of Tre1. We find that the primary defect with complete Tre1 loss is the failure of GCs to properly navigate, with GC mis-migration occurring from early stages. We find that Tre1 localizes with F-actin at the migration front, along with PI(4,5)P2; dPIP5K, an enzyme that generates PI(4,5)P2; and dWIP, a protein that binds activated Wiskott-Aldrich syndrome protein (WASP), which stimulates F-actin polymerization. We show that Tre1 is required for polarized accumulation of F-actin, PI(4,5)P2, and dPIP5K. Smoothened also localizes with F-actin at the migration front, and Hh, through Smo, increases levels of Tre1 at the plasma membrane and Tre1’s association with dPIP5K. Kim et al. uncover molecular and cellular events upstream and downstream of the Tre1 G-protein coupled receptor (GPCR), which is required for germ cell navigation in Drosophila. Hedgehog signaling through Smoothened localizes Tre1 to activate F-actin assembly through dPIP5K, PI(4,5)P2, and WASP.
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Affiliation(s)
- Ji Hoon Kim
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Caitlin D Hanlon
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sunaina Vohra
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter N Devreotes
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Deborah J Andrew
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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9
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Yip JLK, Lee MMK, Leung CCY, Tse MK, Cheung AST, Wong YH. AGS3 and Gα i3 Are Concomitantly Upregulated as Part of the Spindle Orientation Complex during Differentiation of Human Neural Progenitor Cells. Molecules 2020; 25:molecules25215169. [PMID: 33172018 PMCID: PMC7664263 DOI: 10.3390/molecules25215169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 11/16/2022] Open
Abstract
Adult neurogenesis is modulated by many Gi-coupled receptors but the precise mechanism remains elusive. A key step for maintaining the population of neural stem cells in the adult is asymmetric cell division (ACD), a process which entails the formation of two evolutionarily conserved protein complexes that establish the cell polarity and spindle orientation. Since ACD is extremely difficult to monitor in stratified tissues such as the vertebrate brain, we employed human neural progenitor cell lines to examine the regulation of the polarity and spindle orientation complexes during neuronal differentiation. Several components of the spindle orientation complex, but not those of the polarity complex, were upregulated upon differentiation of ENStem-A and ReNcell VM neural progenitor cells. Increased expression of nuclear mitotic apparatus (NuMA), Gαi subunit, and activators of G protein signaling (AGS3 and LGN) coincided with the appearance of a neuronal marker (β-III tubulin) and the concomitant loss of neural progenitor cell markers (nestin and Sox-2). Co-immunoprecipitation assays demonstrated that both Gαi3 and NuMA were associated with AGS3 in differentiated ENStem-A cells. Interestingly, AGS3 appeared to preferentially interact with Gαi3 in ENStem-A cells, and this specificity for Gαi3 was recapitulated in co-immunoprecipitation experiments using HEK293 cells transiently overexpressing GST-tagged AGS3 and different Gαi subunits. Moreover, the binding of Gαi3 to AGS3 was suppressed by GTPγS and pertussis toxin. Disruption of AGS3/Gαi3 interaction by pertussis toxin indicates that AGS3 may recognize the same site on the Gα subunit as G protein-coupled receptors. Regulatory mechanisms controlling the formation of spindle orientation complex may provide novel means to manipulate ACD which in turn may have an impact on neurogenesis.
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Affiliation(s)
- Jackson L. K. Yip
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China; (J.L.K.Y.); (M.M.K.L.); (C.C.Y.L.); (M.K.T.); (A.S.T.C.)
| | - Maggie M. K. Lee
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China; (J.L.K.Y.); (M.M.K.L.); (C.C.Y.L.); (M.K.T.); (A.S.T.C.)
| | - Crystal C. Y. Leung
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China; (J.L.K.Y.); (M.M.K.L.); (C.C.Y.L.); (M.K.T.); (A.S.T.C.)
| | - Man K. Tse
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China; (J.L.K.Y.); (M.M.K.L.); (C.C.Y.L.); (M.K.T.); (A.S.T.C.)
| | - Annie S. T. Cheung
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China; (J.L.K.Y.); (M.M.K.L.); (C.C.Y.L.); (M.K.T.); (A.S.T.C.)
| | - Yung H. Wong
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China; (J.L.K.Y.); (M.M.K.L.); (C.C.Y.L.); (M.K.T.); (A.S.T.C.)
- State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China
- Correspondence: ; Tel.: +852-2358-7328; Fax: +852-2358-1552
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10
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Lin B, Luo J, Lehmann R. Collectively stabilizing and orienting posterior migratory forces disperses cell clusters in vivo. Nat Commun 2020; 11:4477. [PMID: 32901019 PMCID: PMC7479147 DOI: 10.1038/s41467-020-18185-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 08/04/2020] [Indexed: 12/11/2022] Open
Abstract
Individual cells detach from cohesive ensembles during development and can inappropriately separate in disease. Although much is known about how cells separate from epithelia, it remains unclear how cells disperse from clusters lacking apical-basal polarity, a hallmark of advanced epithelial cancers. Here, using live imaging of the developmental migration program of Drosophila primordial germ cells (PGCs), we show that cluster dispersal is accomplished by stabilizing and orienting migratory forces. PGCs utilize a G protein coupled receptor (GPCR), Tre1, to guide front-back migratory polarity radially from the cluster toward the endoderm. Posteriorly positioned myosin-dependent contractile forces pull on cell-cell contacts until cells release. Tre1 mutant cells migrate randomly with transient enrichment of the force machinery but fail to separate, indicating a temporal contractile force threshold for detachment. E-cadherin is retained on the cell surface during cell separation and augmenting cell-cell adhesion does not impede detachment. Notably, coordinated migration improves cluster dispersal efficiency by stabilizing cell-cell interfaces and facilitating symmetric pulling. We demonstrate that guidance of inherent migratory forces is sufficient to disperse cell clusters under physiological settings and present a paradigm for how such events could occur across development and disease.
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Affiliation(s)
- B Lin
- HHMI and Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, NY, USA.
| | - J Luo
- HHMI and Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, NY, USA
| | - R Lehmann
- HHMI and Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, NY, USA.
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Wavreil FDM, Yajima M. Diversity of activator of G-protein signaling (AGS)-family proteins and their impact on asymmetric cell division across taxa. Dev Biol 2020; 465:89-99. [PMID: 32687894 DOI: 10.1016/j.ydbio.2020.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/05/2020] [Accepted: 07/06/2020] [Indexed: 11/18/2022]
Abstract
Asymmetric cell division (ACD) is a cellular process that forms two different cell types through a cell division and is thus critical for the development of all multicellular organisms. Not all but many of the ACD processes are mediated by proper orientation of the mitotic spindle, which segregates the fate determinants asymmetrically into daughter cells. In many cell types, the evolutionarily conserved protein complex of Gαi/AGS-family protein/NuMA-like protein appears to play critical roles in orienting the spindle and/or generating the polarized cortical forces to regulate ACD. Studies in various organisms reveal that this conserved protein complex is slightly modified in each phylum or even within species. In particular, AGS-family proteins appear to be modified with a variable number of motifs in their functional domains across taxa. This apparently creates different molecular interactions and mechanisms of ACD in each developmental program, ultimately contributing to developmental diversity across species. In this review, we discuss how a conserved ACD machinery has been modified in each phylum over the course of evolution with a major focus on the molecular evolution of AGS-family proteins and its impact on ACD regulation.
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Affiliation(s)
- Florence D M Wavreil
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02906, USA
| | - Mamiko Yajima
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02906, USA.
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12
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Rizzelli F, Malabarba MG, Sigismund S, Mapelli M. The crosstalk between microtubules, actin and membranes shapes cell division. Open Biol 2020; 10:190314. [PMID: 32183618 PMCID: PMC7125961 DOI: 10.1098/rsob.190314] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mitotic progression is orchestrated by morphological and mechanical changes promoted by the coordinated activities of the microtubule (MT) cytoskeleton, the actin cytoskeleton and the plasma membrane (PM). MTs assemble the mitotic spindle, which assists sister chromatid separation, and contact the rigid and tensile actomyosin cortex rounded-up underneath the PM. Here, we highlight the dynamic crosstalk between MTs, actin and cell membranes during mitosis, and discuss the molecular connections between them. We also summarize recent views on how MT traction forces, the actomyosin cortex and membrane trafficking contribute to spindle positioning in isolated cells in culture and in epithelial sheets. Finally, we describe the emerging role of membrane trafficking in synchronizing actomyosin tension and cell shape changes with cell–substrate adhesion, cell–cell contacts and extracellular signalling events regulating proliferation.
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Affiliation(s)
| | - Maria Grazia Malabarba
- IEO, Istituto Europeo di Oncologia IRCCS, Milan, Italy.,Dipartimento di Oncologia ed Emato-oncologia, Università degli Studi di Milano, Milan, Italy
| | - Sara Sigismund
- IEO, Istituto Europeo di Oncologia IRCCS, Milan, Italy.,Dipartimento di Oncologia ed Emato-oncologia, Università degli Studi di Milano, Milan, Italy
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13
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Loyer N, Januschke J. Where does asymmetry come from? Illustrating principles of polarity and asymmetry establishment in Drosophila neuroblasts. Curr Opin Cell Biol 2020; 62:70-77. [DOI: 10.1016/j.ceb.2019.07.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 12/22/2022]
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14
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Pirovano L, Culurgioni S, Carminati M, Alfieri A, Monzani S, Cecatiello V, Gaddoni C, Rizzelli F, Foadi J, Pasqualato S, Mapelli M. Hexameric NuMA:LGN structures promote multivalent interactions required for planar epithelial divisions. Nat Commun 2019; 10:2208. [PMID: 31101817 PMCID: PMC6525239 DOI: 10.1038/s41467-019-09999-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 04/11/2019] [Indexed: 12/12/2022] Open
Abstract
Cortical force generators connect epithelial polarity sites with astral microtubules, allowing dynein movement to orient the mitotic spindle as astral microtubules depolymerize. Complexes of the LGN and NuMA proteins, fundamental components of force generators, are recruited to the cortex by Gαi-subunits of heterotrimeric G-proteins. They associate with dynein/dynactin and activate the motor activity pulling on astral microtubules. The architecture of cortical force generators is unknown. Here we report the crystal structure of NuMA:LGN hetero-hexamers, and unveil their role in promoting the assembly of active cortical dynein/dynactin motors that are required in orchestrating oriented divisions in polarized cells. Our work elucidates the basis for the structural organization of essential spindle orientation motors. LGN and NuMA link epithelial polarity sites with astral microtubules and associate with dynein, but the architecture of such cortical force-generating complexes is unknown. Here, the authors report the crystal structure of NuMA:LGN hetero-hexamers, and unveil their role in promoting the assembly of active cortical dynein/dynactin motors.
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Affiliation(s)
- Laura Pirovano
- IEO, European Institute of Oncology IRCCS, 20141, MILANO, Italy
| | - Simone Culurgioni
- IEO, European Institute of Oncology IRCCS, 20141, MILANO, Italy.,Exscientia Ltd., The Schröedinger Building, Heatley Road, Oxford Science Park, Oxford, OX4 4GE, UK
| | - Manuel Carminati
- IEO, European Institute of Oncology IRCCS, 20141, MILANO, Italy.,MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Andrea Alfieri
- IEO, European Institute of Oncology IRCCS, 20141, MILANO, Italy.,Department of Biosciences, Università degli Studi di Milano, 20133, Milan, Italy
| | - Silvia Monzani
- IEO, European Institute of Oncology IRCCS, 20141, MILANO, Italy
| | | | - Chiara Gaddoni
- IEO, European Institute of Oncology IRCCS, 20141, MILANO, Italy
| | | | - James Foadi
- Department of Mathematical Sciences, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | | | - Marina Mapelli
- IEO, European Institute of Oncology IRCCS, 20141, MILANO, Italy.
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15
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Abstract
For over a century, the centrosome has been an organelle more easily tracked than understood, and the study of its peregrinations within the cell remains a chief underpinning of its functional investigation. Increasing attention and new approaches have been brought to bear on mechanisms that control centrosome localization in the context of cleavage plane determination, ciliogenesis, directional migration, and immunological synapse formation, among other cellular and developmental processes. The Golgi complex, often linked with the centrosome, presents a contrasting case of a pleiomorphic organelle for which functional studies advanced somewhat more rapidly than positional tracking. However, Golgi orientation and distribution has emerged as an area of considerable interest with respect to polarized cellular function. This chapter will review our current understanding of the mechanism and significance of the positioning of these organelles.
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16
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Hiraiwa T, Nakai Y, Yamada TG, Tanimoto R, Kimura H, Matsumoto Y, Miki N, Hiroi N, Funahashi A. Quantitative analysis of sensitivity to a Wnt3a gradient in determination of the pole-to-pole axis of mitotic cells by using a microfluidic device. FEBS Open Bio 2018; 8:1920-1935. [PMID: 30524943 PMCID: PMC6275273 DOI: 10.1002/2211-5463.12525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/10/2018] [Accepted: 09/04/2018] [Indexed: 11/22/2022] Open
Abstract
Proper determination of the cell division axis is essential during development. Wnt3a is a known regulator of the cell division axis; however, the sensitivity of cells to Wnt3a signalling and its role in determining the cell division axis have not been measured to date. To address this gap, we took advantage of the asymmetric distribution of outer dense fibre 2 (ODF2/cenexin) proteins on centrosomes in dividing cells. To precisely quantify the sensitivity of cells to Wnt3a signalling, we developed a microfluidic cell culture device, which can produce a quantitative gradient of signalling molecules. We confirmed that mitotic SH‐SY5Y neuroblastoma cells could detect a 2.5 ~ 5 × 10−3 nm·μm−1 Wnt3a concentration gradient and demonstrated that this gradient is sufficient to affect the determination of the pole‐to‐pole axis of cell division during the later stages of mitosis.
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Affiliation(s)
- Takumi Hiraiwa
- Department of Biosciences and Informatics Keio University Yokohama Japan
| | - Yuichiro Nakai
- Department of Biosciences and Informatics Keio University Yokohama Japan
| | - Takahiro G Yamada
- Department of Biosciences and Informatics Keio University Yokohama Japan
| | - Ryuichi Tanimoto
- Department of Biosciences and Informatics Keio University Yokohama Japan
| | - Hiroshi Kimura
- Department of Mechanical Engineering Tokai University Hiratsuka Japan
| | - Yoshinori Matsumoto
- Department of Applied Physics and Physico-Informatics Keio University Yokohama Japan
| | - Norihisa Miki
- Department of Mechanical Engineering Keio University Yokohama Japan
| | - Noriko Hiroi
- Department of Biosciences and Informatics Keio University Yokohama Japan.,Department of Pharmacy Sanyo-Onoda City University Japan
| | - Akira Funahashi
- Department of Biosciences and Informatics Keio University Yokohama Japan
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17
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Liu C, Weng J, Wang D, Yang M, Jia M, Wang W. A Residue outside the Binding Site Determines the Gα Binding Specificity of GoLoco Motifs. Biochemistry 2018; 57:6562-6569. [PMID: 30406994 DOI: 10.1021/acs.biochem.8b00848] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
GoLoco motif-containing proteins regulate the nucleotide-binding state of Gα proteins in various signaling pathways. As guanine nucleotide dissociation inhibitors (GDIs), they bind Gα·GDP and inhibit GDP to GTP exchange. GoLoco proteins show binding selectivity toward different members of the Gα family. Although the Gαi1·GDP/RGS14 crystal structure explains the specific binding selectivity of the RGS14 GoLoco domain well, the mechanism of selective binding has not been understood for the more general features of short GoLoco domains found in tandem arrays in proteins like GPSM2/LGN/ dPins and GPSM1/AGS3. We explored the mechanism of differential interactions of GoLoco protein LGN with hGαi3 and hGαo. By combining mutagenesis experiments and molecular dynamics simulations, we identified a residue (Asp229 in hGαi3) away from the binding interface that remarkably affects the interaction between LGN and hGαi/o. A negatively charged residue at this position is required for high binding affinity. This affinity regulation mechanism was further verified by the cases of hGαi2 and dGαo, suggesting that this pathway is conserved among members of the Gα family.
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Affiliation(s)
- Chunhua Liu
- Multiscale Research Institute of Complex Systems, Department of Chemistry, and Institutes of Biomedical Sciences , Fudan University , Shanghai 200433 , P. R. China
| | - Jingwei Weng
- Multiscale Research Institute of Complex Systems, Department of Chemistry, and Institutes of Biomedical Sciences , Fudan University , Shanghai 200433 , P. R. China
| | - Dan Wang
- Multiscale Research Institute of Complex Systems, Department of Chemistry, and Institutes of Biomedical Sciences , Fudan University , Shanghai 200433 , P. R. China
| | - Maohua Yang
- Multiscale Research Institute of Complex Systems, Department of Chemistry, and Institutes of Biomedical Sciences , Fudan University , Shanghai 200433 , P. R. China
| | - Min Jia
- Multiscale Research Institute of Complex Systems, Department of Chemistry, and Institutes of Biomedical Sciences , Fudan University , Shanghai 200433 , P. R. China
| | - Wenning Wang
- Multiscale Research Institute of Complex Systems, Department of Chemistry, and Institutes of Biomedical Sciences , Fudan University , Shanghai 200433 , P. R. China
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18
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Venkei ZG, Yamashita YM. Emerging mechanisms of asymmetric stem cell division. J Cell Biol 2018; 217:3785-3795. [PMID: 30232100 PMCID: PMC6219723 DOI: 10.1083/jcb.201807037] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 09/06/2018] [Accepted: 09/13/2018] [Indexed: 01/10/2023] Open
Abstract
Venkei and Yamashita summarize recent advances in our understanding of asymmetric stem cell division in tissue homeostasis. The asymmetric cell division of stem cells, which produces one stem cell and one differentiating cell, has emerged as a mechanism to balance stem cell self-renewal and differentiation. Elaborate cellular mechanisms that orchestrate the processes required for asymmetric cell divisions are often shared between stem cells and other asymmetrically dividing cells. During asymmetric cell division, cells must establish asymmetry/polarity, which is guided by varying degrees of intrinsic versus extrinsic cues, and use intracellular machineries to divide in a desired orientation in the context of the asymmetry/polarity. Recent studies have expanded our knowledge on the mechanisms of asymmetric cell divisions, revealing the previously unappreciated complexity in setting up the cellular and/or environmental asymmetry, ensuring binary outcomes of the fate determination. In this review, we summarize recent progress in understanding the mechanisms and regulations of asymmetric stem cell division.
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Affiliation(s)
- Zsolt G Venkei
- Life Sciences Institute, University of Michigan, Ann Arbor, MI
| | - Yukiko M Yamashita
- Life Sciences Institute, University of Michigan, Ann Arbor, MI .,Department of Cell and Developmental Biology, Medical School, University of Michigan, Ann Arbor, MI.,Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI
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19
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Loyer N, Januschke J. The last-born daughter cell contributes to division orientation of Drosophila larval neuroblasts. Nat Commun 2018; 9:3745. [PMID: 30218051 PMCID: PMC6138640 DOI: 10.1038/s41467-018-06276-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 08/17/2018] [Indexed: 01/27/2023] Open
Abstract
Controlling the orientation of cell division is important in the context of cell fate choices and tissue morphogenesis. However, the mechanisms providing the required positional information remain incompletely understood. Here we use stem cells of the Drosophila larval brain that stably maintain their axis of polarity and division between cell cycles to identify cues that orient cell division. Using live cell imaging of cultured brains, laser ablation and genetics, we reveal that division axis maintenance relies on their last-born daughter cell. We propose that, in addition to known intrinsic cues, stem cells in the developing fly brain are polarized by an extrinsic signal. We further find that division axis maintenance allows neuroblasts to maximize their contact area with glial cells known to provide protective and proliferative signals to neuroblasts.
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Affiliation(s)
- Nicolas Loyer
- Cell & Developmental Biology, School of Life Sciences, University of Dundee, MSI/WTB3 Complex, Dow Street, Dundee, DD1 5EH, UK
| | - Jens Januschke
- Cell & Developmental Biology, School of Life Sciences, University of Dundee, MSI/WTB3 Complex, Dow Street, Dundee, DD1 5EH, UK.
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20
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Fielmich LE, Schmidt R, Dickinson DJ, Goldstein B, Akhmanova A, van den Heuvel S. Optogenetic dissection of mitotic spindle positioning in vivo. eLife 2018; 7:38198. [PMID: 30109984 PMCID: PMC6214656 DOI: 10.7554/elife.38198] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/14/2018] [Indexed: 12/25/2022] Open
Abstract
The position of the mitotic spindle determines the plane of cell cleavage, and thereby daughter cell location, size, and content. Spindle positioning is driven by dynein-mediated pulling forces exerted on astral microtubules, which requires an evolutionarily conserved complex of Gα∙GDP, GPR-1/2Pins/LGN, and LIN-5Mud/NuMA proteins. To examine individual functions of the complex components, we developed a genetic strategy for light-controlled localization of endogenous proteins in C. elegans embryos. By replacing Gα and GPR-1/2 with a light-inducible membrane anchor, we demonstrate that Gα∙GDP, Gα∙GTP, and GPR-1/2 are not required for pulling-force generation. In the absence of Gα and GPR-1/2, cortical recruitment of LIN-5, but not dynein itself, induced high pulling forces. The light-controlled localization of LIN-5 overruled normal cell-cycle and polarity regulation and provided experimental control over the spindle and cell-cleavage plane. Our results define Gα∙GDP–GPR-1/2Pins/LGN as a regulatable membrane anchor, and LIN-5Mud/NuMA as a potent activator of dynein-dependent spindle-positioning forces. A cell about to divide must decide where exactly to cut itself in two. Split right down the middle, and the two daughter cells will be identical; offset the cleavage plane to one side, and the resulting siblings will have different sizes, places and fates. In animals, the splitting of cells is dictated by the location of the spindle, a structure that forms when cable-like microtubules stretch from the cell membrane to attach to the chromosomes. At the membrane, a group of proteins tugs on the microtubules to bring the spindle into the correct position. One of these proteins, dynein, is a motor that uses microtubules as its track to pull the spindle into place. What the other parts of the complex do is still unclear, but a general assumption is that they may be serving as an anchor for dynein. To test this model, Fielmich, Schmidt et al. removed one or more proteins from the complex in the developing embryos of the nematode worm Caenorhabditis elegans. A light-activated system then linked the remaining proteins to the membrane by tying them to an artificial anchor. Two of the proteins in the complex could be replaced with the artificial anchor, but pulling forces were absent when dynein was artificially tied to the membrane. This indicates that the motor being anchored at the edge of the cell is not enough for it to pull on microtubules. Instead, the experiments showed that dynein needs to be activated by another component of the complex, a protein called LIN-5. This suggests that individual proteins in the complex have specialized roles that go beyond simply tethering dynein. In fact, steering where LIN-5 was attached on the membrane helped to control the location of the spindle, and therefore of the cleavage plane. As mammals have a protein similar to LIN-5, dissecting the roles of the components involved in positioning the spindle in C. elegans could help to understand normal and abnormal human development. In addition, these results demonstrate that creating artificial interactions between proteins using light is a powerful technique to study biological processes.
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Affiliation(s)
- Lars-Eric Fielmich
- Developmental Biology, Department of Biology, Faculty of Sciences, Utrecht University, Utrecht, Netherlands
| | - Ruben Schmidt
- Developmental Biology, Department of Biology, Faculty of Sciences, Utrecht University, Utrecht, Netherlands.,Cell Biology, Department of Biology, Faculty of Sciences, Utrecht University, Utrecht, Netherlands
| | - Daniel J Dickinson
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Bob Goldstein
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Anna Akhmanova
- Cell Biology, Department of Biology, Faculty of Sciences, Utrecht University, Utrecht, Netherlands
| | - Sander van den Heuvel
- Developmental Biology, Department of Biology, Faculty of Sciences, Utrecht University, Utrecht, Netherlands
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21
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Abstract
Asymmetric cell divisions balance stem cell proliferation and differentiation to sustain tissue morphogenesis and homeostasis. During asymmetric divisions, fate determinants and niche contacts segregate unequally between daughters, but little is known on how this is achieved mechanistically. In Drosophila neuroblasts and murine mammary stem cells, the association of the spindle orientation protein LGN with the stem cell adaptor Inscuteable has been connected to asymmetry. Here we report the crystal structure of Drosophila LGN in complex with the asymmetric domain of Inscuteable, which reveals a tetrameric arrangement of intertwined molecules. We show that Insc:LGN tetramers constitute stable cores of Par3–Insc-LGN-GαiGDP complexes, which cannot be dissociated by NuMA. In mammary stem cells, the asymmetric domain of Insc bound to LGN:GαiGDP suffices to drive asymmetric fate, and reverts aberrant symmetric divisions induced by p53 loss. We suggest a novel role for the Insc-bound pool of LGN acting independently of microtubule motors to promote asymmetric fate specification. During asymmetric divisions fate determinants and niche contacts segregate unequally between daughter cells, but the mechanism is unclear. Here the authors show that Insc:LGN tetramers promote assembly of Par3-Insc-LGN-GαiGDP complexes and asymmetric fate specification independently of microtubule motors.
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22
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Heppert JK, Pani AM, Roberts AM, Dickinson DJ, Goldstein B. A CRISPR Tagging-Based Screen Reveals Localized Players in Wnt-Directed Asymmetric Cell Division. Genetics 2018; 208:1147-1164. [PMID: 29348144 PMCID: PMC5844328 DOI: 10.1534/genetics.117.300487] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/08/2018] [Indexed: 11/18/2022] Open
Abstract
Oriented cell divisions are critical to establish and maintain cell fates and tissue organization. Diverse extracellular and intracellular cues have been shown to provide spatial information for mitotic spindle positioning; however, the molecular mechanisms by which extracellular signals communicate with cells to direct mitotic spindle positioning are largely unknown. In animal cells, oriented cell divisions are often achieved by the localization of force-generating motor protein complexes to discrete cortical domains. Disrupting either these force-generating complexes or proteins that globally affect microtubule stability results in defects in mitotic positioning, irrespective of whether these proteins function as spatial cues for spindle orientation. This poses a challenge to traditional genetic dissection of this process. Therefore, as an alternative strategy to identify key proteins that act downstream of intercellular signaling, we screened the localization of many candidate proteins by inserting fluorescent tags directly into endogenous gene loci, without overexpressing the proteins. We tagged 23 candidate proteins in Caenorhabditis elegans and examined each protein's localization in a well-characterized, oriented cell division in the four-cell-stage embryo. We used cell manipulations and genetic experiments to determine which cells harbor key localized proteins and which signals direct these localizations in vivo We found that Dishevelled and adenomatous polyposis coli homologs are polarized during this oriented cell division in response to a Wnt signal, but two proteins typically associated with mitotic spindle positioning, homologs of NuMA and Dynein, were not detectably polarized. These results suggest an unexpected mechanism for mitotic spindle positioning in this system, they pinpoint key proteins of interest, and they highlight the utility of a screening approach based on analyzing the localization of endogenously tagged proteins.
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Affiliation(s)
- Jennifer K Heppert
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Ariel M Pani
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Allyson M Roberts
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Daniel J Dickinson
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Bob Goldstein
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, North Carolina 27599
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23
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LeBlanc MG, Lehmann R. Domain-specific control of germ cell polarity and migration by multifunction Tre1 GPCR. J Cell Biol 2017; 216:2945-2958. [PMID: 28687666 PMCID: PMC5584160 DOI: 10.1083/jcb.201612053] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 04/28/2017] [Accepted: 06/08/2017] [Indexed: 11/22/2022] Open
Abstract
Migrating cells encounter directional cues to reach their destinations, often using G protein–coupled receptors (GPCRs) to interpret such cues. LeBlanc and Lehmann show that two highly conserved domains in the GPCR Tre1 mediate distinct migratory responses in germ cells via separate signaling pathways, one regulating cell polarization and the other directional migration. The migration of primordial germ cells (PGCs) from their place of origin to the embryonic gonad is an essential reproductive feature in many animal species. In Drosophila melanogaster, a single G protein–coupled receptor, Trapped in endoderm 1 (Tre1), mediates germ cell polarization at the onset of active migration and directs subsequent migration of PGCs through the midgut primordium. How these different aspects of cell behavior are coordinated through a single receptor is not known. We demonstrate that two highly conserved domains, the E/N/DRY and NPxxY motifs, have overlapping and unique functions in Tre1. The Tre1-NRY domain via G protein signaling is required for reading and responding to guidance and survival cues controlled by the lipid phosphate phosphatases Wunen and Wunen2. In contrast, the Tre1-NPIIY domain has a separate role in Rho1- and E-cadherin–mediated polarization at the initiation stage independent of G protein signaling. We propose that this bifurcation of the Tre1 G protein–coupled receptor signaling response via G protein–dependent and independent branches enables distinct spatiotemporal regulation of germ cell migration.
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Affiliation(s)
- Michelle G LeBlanc
- Howard Hughes Medical Institute, Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, NY.,Department of Cell Biology, New York University School of Medicine, New York, NY
| | - Ruth Lehmann
- Howard Hughes Medical Institute, Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, NY .,Department of Cell Biology, New York University School of Medicine, New York, NY
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24
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Chishiki K, Kamakura S, Hayase J, Sumimoto H. Ric-8A, an activator protein of Gαi, controls mammalian epithelial cell polarity for tight junction assembly and cystogenesis. Genes Cells 2017; 22:293-309. [PMID: 28185378 DOI: 10.1111/gtc.12477] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 01/11/2017] [Indexed: 01/04/2023]
Abstract
Correct cyst morphogenesis of epithelial cells requires apical-basal polarization, which is partly regulated by mitotic spindle orientation, a process dependent on the heterotrimeric G protein subunit Gαi and its binding protein LGN. Here, we show that in three-dimensional culture of mammalian epithelial Madin-Darby canine kidney (MDCK) cells, the Gαi-activating protein Ric-8A is crucial for orientation of the mitotic spindle and formation of normal cysts that comprise a single layer of polarized cells with their apical surfaces lining an inner lumen. Consistent with the involvement of LGN, cystogenesis can be well organized by ADP-ribosylated Gαi, retaining the ability to interact with LGN, but not by the interaction-defective mutant protein Gαi2 (N150I). In monolayer culture of MDCK cells, functional tight junction (TJ) assembly, a process associated with epithelial cell polarization, is significantly delayed in Ric-8A-depleted cells as well as in Gαi-depleted cells in a mitosis-independent manner. Ric-8A knockdown results in a delayed cortical delivery of Gαi and the apical membrane protein gp135, and an increased formation of intercellular lumens surrounded by membranes rich in Gαi3 and gp135. TJ development also involves LGN and its related protein AGS3. Thus, Ric-8A regulates mammalian epithelial cell polarity for TJ assembly and cystogenesis probably in concert with Gαi and LGN/AGS3.
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Affiliation(s)
- Kanako Chishiki
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Sachiko Kamakura
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Junya Hayase
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Hideki Sumimoto
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
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25
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Tadenev ALD, Tarchini B. The Spindle Orientation Machinery Beyond Mitosis: When Cell Specialization Demands Polarization. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1002:209-225. [DOI: 10.1007/978-3-319-57127-0_9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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26
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Drosophila melanogaster Neuroblasts: A Model for Asymmetric Stem Cell Divisions. Results Probl Cell Differ 2017; 61:183-210. [PMID: 28409305 DOI: 10.1007/978-3-319-53150-2_8] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Asymmetric cell division (ACD) is a fundamental mechanism to generate cell diversity, giving rise to daughter cells with different developmental potentials. ACD is manifested in the asymmetric segregation of proteins or mRNAs, when the two daughter cells differ in size or are endowed with different potentials to differentiate into a particular cell type (Horvitz and Herskowitz, Cell 68:237-255, 1992). Drosophila neuroblasts, the neural stem cells of the developing fly brain, are an ideal system to study ACD since this system encompasses all of these characteristics. Neuroblasts are intrinsically polarized cells, utilizing polarity cues to orient the mitotic spindle, segregate cell fate determinants asymmetrically, and regulate spindle geometry and physical asymmetry. The neuroblast system has contributed significantly to the elucidation of the basic molecular mechanisms underlying ACD. Recent findings also highlight its usefulness to study basic aspects of stem cell biology and tumor formation. In this review, we will focus on what has been learned about the basic mechanisms underlying ACD in fly neuroblasts.
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27
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di Pietro F, Echard A, Morin X. Regulation of mitotic spindle orientation: an integrated view. EMBO Rep 2016; 17:1106-30. [PMID: 27432284 DOI: 10.15252/embr.201642292] [Citation(s) in RCA: 201] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 06/17/2016] [Indexed: 12/18/2022] Open
Abstract
Mitotic spindle orientation is essential for cell fate decisions, epithelial maintenance, and tissue morphogenesis. In most animal cell types, the dynein motor complex is anchored at the cell cortex and exerts pulling forces on astral microtubules to position the spindle. Early studies identified the evolutionarily conserved Gαi/LGN/NuMA complex as a key regulator that polarizes cortical force generators. In recent years, a combination of genetics, biochemistry, modeling, and live imaging has contributed to decipher the mechanisms of spindle orientation. Here, we highlight the dynamic nature of the assembly of this complex and discuss the molecular regulation of its localization. Remarkably, a number of LGN-independent mechanisms were described recently, whereas NuMA remains central in most pathways involved in recruiting force generators at the cell cortex. We also describe the emerging role of the actin cortex in spindle orientation and discuss how dynamic astral microtubule formation is involved. We further give an overview on instructive external signals that control spindle orientation in tissues. Finally, we discuss the influence of cell geometry and mechanical forces on spindle orientation.
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Affiliation(s)
- Florencia di Pietro
- Cell Division and Neurogenesis Laboratory, Ecole Normale Supérieure CNRS Inserm Institut de Biologie de l'Ecole Normale Supérieure (IBENS) PSL Research University, Paris, France Institute of Doctoral Studies (IFD), Sorbonne Universités Université Pierre et Marie Curie-Université Paris 6, Paris, France
| | - Arnaud Echard
- Membrane Traffic and Cell Division Laboratory, Cell Biology and Infection Department, Institut Pasteur, Paris, France Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3691, Paris, France
| | - Xavier Morin
- Cell Division and Neurogenesis Laboratory, Ecole Normale Supérieure CNRS Inserm Institut de Biologie de l'Ecole Normale Supérieure (IBENS) PSL Research University, Paris, France
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28
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Buckley SJ, Fitzgibbon QP, Smith GG, Ventura T. In silico prediction of the G-protein coupled receptors expressed during the metamorphic molt of Sagmariasus verreauxi (Crustacea: Decapoda) by mining transcriptomic data: RNA-seq to repertoire. Gen Comp Endocrinol 2016; 228:111-127. [PMID: 26850661 DOI: 10.1016/j.ygcen.2016.02.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
Abstract
Against a backdrop of food insecurity, the farming of decapod crustaceans is a rapidly expanding and globally significant source of food protein. Sagmariasus verreauxi spiny lobster, the subject of this study, are decapods of underdeveloped aquaculture potential. Crustacean neuropeptide G-protein coupled receptors (GPCRs) mediate endocrine pathways that are integral to animal fecundity, growth and survival. The potential use of novel biotechnologies to enhance GPCR-mediated physiology may assist in improving the health and productivity of farmed decapod populations. This study catalogues the GPCRs expressed in the early developmental stages, as well as adult tissues, with a view to illuminating key neuropeptide receptors. De novo assembled contiguous sequences generated from transcriptomic reads of metamorphic and post metamorphic S. verreauxi were filtered for seven transmembrane domains, and used as a reference for iterative re-mapping. Subsequent putative GPCR open reading frames (ORFs) were BLAST annotated, categorised, and compared to published orthologues based on phylogenetic analysis. A total of 85 GPCRs were digitally predicted, that represented each of the four arthropod subfamilies. They generally displayed low-level and non-differential metamorphic expression with few exceptions that we examined using RT-PCR and qPCR. Two putative CHH-like neuropeptide receptors were annotated. Three dimensional structural modelling suggests that these receptors exhibit a conserved extracellular ligand binding pocket, providing support to the notion that these receptors co-evolved with their ligands across Decapoda. This perhaps narrows the search for means to increase productivity of farmed decapod populations.
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Affiliation(s)
- Sean J Buckley
- GeneCology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 4 Locked Bag, Maroochydore, Queensland 4558, Australia
| | - Quinn P Fitzgibbon
- Fisheries and Aquaculture, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Gregory G Smith
- Fisheries and Aquaculture, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Tomer Ventura
- GeneCology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 4 Locked Bag, Maroochydore, Queensland 4558, Australia.
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29
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Anderson DP, Whitney DS, Hanson-Smith V, Woznica A, Campodonico-Burnett W, Volkman BF, King N, Thornton JW, Prehoda KE. Evolution of an ancient protein function involved in organized multicellularity in animals. eLife 2016; 5:e10147. [PMID: 26740169 PMCID: PMC4718807 DOI: 10.7554/elife.10147] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/09/2015] [Indexed: 12/30/2022] Open
Abstract
To form and maintain organized tissues, multicellular organisms orient their mitotic spindles relative to neighboring cells. A molecular complex scaffolded by the GK protein-interaction domain (GKPID) mediates spindle orientation in diverse animal taxa by linking microtubule motor proteins to a marker protein on the cell cortex localized by external cues. Here we illuminate how this complex evolved and commandeered control of spindle orientation from a more ancient mechanism. The complex was assembled through a series of molecular exploitation events, one of which - the evolution of GKPID's capacity to bind the cortical marker protein - can be recapitulated by reintroducing a single historical substitution into the reconstructed ancestral GKPID. This change revealed and repurposed an ancient molecular surface that previously had a radically different function. We show how the physical simplicity of this binding interface enabled the evolution of a new protein function now essential to the biological complexity of many animals.
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Affiliation(s)
- Douglas P Anderson
- Institute of Ecology and Evolution, University of Oregon, Eugene, United States.,Department of Chemistry and Biochemistry, University of Oregon, Eugene, United States.,Institute of Molecular Biology, University of Oregon, Eugene, United States
| | - Dustin S Whitney
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, United States
| | - Victor Hanson-Smith
- Institute of Ecology and Evolution, University of Oregon, Eugene, United States
| | - Arielle Woznica
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - William Campodonico-Burnett
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, United States.,Institute of Molecular Biology, University of Oregon, Eugene, United States
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, United States
| | - Nicole King
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | | | - Kenneth E Prehoda
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, United States.,Institute of Molecular Biology, University of Oregon, Eugene, United States
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30
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A Novel Gene Controlling the Timing of Courtship Initiation in Drosophila melanogaster. Genetics 2015; 202:1043-53. [PMID: 26721856 DOI: 10.1534/genetics.115.183061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 12/29/2015] [Indexed: 02/01/2023] Open
Abstract
Over the past 35 years, developmental geneticists have made impressive progress toward an understanding of how genes specify morphology and function, particularly as they relate to the specification of each physical component of an organism. In the last 20 years, male courtship behavior in Drosophila melanogaster has emerged as a robust model system for the study of genetic specification of behavior. Courtship behavior is both complex and innate, and a single gene, fruitless (fru), is both necessary and sufficient for all aspects of the courtship ritual. Typically, loss of male-specific Fruitless protein function results in male flies that perform the courtship ritual incorrectly, slowly, or not at all. Here we describe a novel requirement for fru: we have identified a group of cells in which male Fru proteins are required to reduce the speed of courtship initiation. In addition, we have identified a gene, Trapped in endoderm 1 (Tre1), which is required in these cells for normal courtship and mating behavior. Tre1 encodes a G-protein-coupled receptor required for establishment of cell polarity and cell migration and has previously not been shown to be involved in courtship behavior. We describe the results of feminization of the Tre1-expressing neurons, as well as the effects on courtship behavior of mutation of Tre1. In addition, we show that Tre1 is expressed in a sexually dimorphic pattern in the central and peripheral nervous systems and investigate the role of the Tre1 cells in mate identification.
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31
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Mode of interaction of the Gαo subunit of heterotrimeric G proteins with the GoLoco1 motif of Drosophila Pins is determined by guanine nucleotides. Biosci Rep 2015; 35:BSR20150201. [PMID: 26487707 PMCID: PMC4660580 DOI: 10.1042/bsr20150201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 09/28/2015] [Indexed: 11/17/2022] Open
Abstract
Drosophila GoLoco-containing protein Pins atypically interacts both with GDP- and GTP-loaded forms of Gαo. We show that Pins' GoLoco1 domain ‘rotates’ on Gαo depending on its nucleotide state. This mechanism has important implications for asymmetric cell divisions. Drosophila GoLoco motif-containing protein Pins is unusual in its highly efficient interaction with both GDP- and the GTP-loaded forms of the α-subunit of the heterotrimeric Go protein. We analysed the interactions of Gαo in its two nucleotide forms with GoLoco1–the first of the three GoLoco domains of Pins–and the possible structures of the resulting complexes, through combination of conventional fluorescence and FRET measurements as well as through molecular modelling. Our data suggest that the orientation of the GoLoco1 motif on Gαo significantly differs between the two nucleotide states of the latter. In other words, a rotation of the GoLoco1 peptide in respect with Gαo must accompany the nucleotide exchange in Gαo. The sterical hindrance requiring such a rotation probably contributes to the guanine nucleotide exchange inhibitor activity of GoLoco1 and Pins as a whole. Our data have important implications for the mechanisms of Pins regulation in the process of asymmetric cell divisions.
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32
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Hanlon CD, Andrew DJ. Outside-in signaling--a brief review of GPCR signaling with a focus on the Drosophila GPCR family. J Cell Sci 2015; 128:3533-42. [PMID: 26345366 DOI: 10.1242/jcs.175158] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are the largest family of receptors in many organisms, including worms, mice and humans. GPCRs are seven-transmembrane pass proteins that are activated by binding a stimulus (or ligand) in the extracellular space and then transduce that information to the inside of the cell through conformational changes. The conformational changes activate heterotrimeric G-proteins, which execute the downstream signaling pathways through the recruitment and activation of cellular enzymes. The highly specific ligand-GPCR interaction prompts an efficient cellular response, which is vital for the health of the cell and organism. In this Commentary, we review general features of GPCR signaling and then focus on the Drosophila GPCRs, which are not as well-characterized as their worm and mammalian counterparts. We discuss findings that the Drosophila odorant and gustatory receptors are not bona fide GPCRs as is the case for their mammalian counterparts. We also present here a phylogenetic analysis of the bona fide Drosophila GPCRs that suggest potential roles for several family members. Finally, we discuss recently discovered roles of GPCRs in Drosophila embryogenesis, a field we expect will uncover many previously unappreciated functions for GPCRs.
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Affiliation(s)
- Caitlin D Hanlon
- Department of Cell Biology, The Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2196, USA
| | - Deborah J Andrew
- Department of Cell Biology, The Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2196, USA
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33
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O'Neill PR, Gautam N. Subcellular optogenetic inhibition of G proteins generates signaling gradients and cell migration. Mol Biol Cell 2014; 25:2305-14. [PMID: 24920824 PMCID: PMC4116304 DOI: 10.1091/mbc.e14-04-0870] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cells sense gradients of extracellular cues and generate polarized responses such as cell migration and neurite initiation. There is static information on the intracellular signaling molecules involved in these responses, but how they dynamically orchestrate polarized cell behaviors is not well understood. A limitation has been the lack of methods to exert spatial and temporal control over specific signaling molecules inside a living cell. Here we introduce optogenetic tools that act downstream of native G protein-coupled receptor (GPCRs) and provide direct control over the activity of endogenous heterotrimeric G protein subunits. Light-triggered recruitment of a truncated regulator of G protein signaling (RGS) protein or a Gβγ-sequestering domain to a selected region on the plasma membrane results in localized inhibition of G protein signaling. In immune cells exposed to spatially uniform chemoattractants, these optogenetic tools allow us to create reversible gradients of signaling activity. Migratory responses generated by this approach show that a gradient of active G protein αi and βγ subunits is sufficient to generate directed cell migration. They also provide the most direct evidence so for a global inhibition pathway triggered by Gi signaling in directional sensing and adaptation. These optogenetic tools can be applied to interrogate the mechanistic basis of other GPCR-modulated cellular functions.
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Affiliation(s)
- Patrick R O'Neill
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110
| | - N Gautam
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110
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34
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Januschke J, Näthke I. Stem cell decisions: a twist of fate or a niche market? Semin Cell Dev Biol 2014; 34:116-23. [PMID: 24613913 PMCID: PMC4169664 DOI: 10.1016/j.semcdb.2014.02.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/24/2014] [Accepted: 02/26/2014] [Indexed: 12/28/2022]
Abstract
Extrinsic and intrinsic cues that impact on stem cell biology. The importance to establish methods that allow to compare spindle orientation measurements. Mechanisms of centrosome segregation in asymmetrically dividing cells.
Establishing and maintaining cell fate in the right place at the right time is a key requirement for normal tissue maintenance. Stem cells are at the core of this process. Understanding how stem cells balance self-renewal and production of differentiating cells is key for understanding the defects that underpin many diseases. Both, external cues from the environment and cell intrinsic mechanisms can control the outcome of stem cell division. The role of the orientation of stem cell division has emerged as an important mechanism for specifying cell fate decisions. Although, the alignment of cell divisions can dependent on spatial cues from the environment, maintaining stemness is not always linked to positioning of stem cells in a particular microenvironment or `niche'. Alternate mechanisms that could contribute to cellular memory include differential segregation of centrosomes in asymmetrically dividing cells.
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Affiliation(s)
- Jens Januschke
- Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
| | - Inke Näthke
- Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
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35
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Blumer JB, Lanier SM. Activators of G protein signaling exhibit broad functionality and define a distinct core signaling triad. Mol Pharmacol 2013; 85:388-96. [PMID: 24302560 DOI: 10.1124/mol.113.090068] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Activators of G protein signaling (AGS), initially discovered in the search for receptor-independent activators of G protein signaling, define a broad panel of biologic regulators that influence signal transfer from receptor to G-protein, guanine nucleotide binding and hydrolysis, G protein subunit interactions, and/or serve as alternative binding partners for Gα and Gβγ independently of the classic heterotrimeric Gαβγ. AGS proteins generally fall into three groups based upon their interaction with and regulation of G protein subunits: group I, guanine nucleotide exchange factors (GEF); group II, guanine nucleotide dissociation inhibitors; and group III, entities that bind to Gβγ. Group I AGS proteins can engage all subclasses of G proteins, whereas group II AGS proteins primarily engage the Gi/Go/transducin family of G proteins. A fourth group of AGS proteins with selectivity for Gα16 may be defined by the Mitf-Tfe family of transcription factors. Groups I-III may act in concert, generating a core signaling triad analogous to the core triad for heterotrimeric G proteins (GEF + G proteins + effector). These two core triads may function independently of each other or actually cross-integrate for additional signal processing. AGS proteins have broad functional roles, and their discovery has advanced new concepts in signal processing, cell and tissue biology, receptor pharmacology, and system adaptation, providing unexpected platforms for therapeutic and diagnostic development.
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Affiliation(s)
- Joe B Blumer
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina
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36
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Kamakura S, Nomura M, Hayase J, Iwakiri Y, Nishikimi A, Takayanagi R, Fukui Y, Sumimoto H. The cell polarity protein mInsc regulates neutrophil chemotaxis via a noncanonical G protein signaling pathway. Dev Cell 2013; 26:292-302. [PMID: 23891662 DOI: 10.1016/j.devcel.2013.06.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 05/07/2013] [Accepted: 06/07/2013] [Indexed: 12/15/2022]
Abstract
Successful chemotaxis requires not only increased motility but also sustained directionality. Here, we show that, during neutrophil chemotaxis via receptors coupled with the Gi family of heterotrimeric G proteins, directional movement is regulated by mInsc, a mammalian protein distantly related to the Drosophila polarity-organizer Inscuteable. The GDP-bound, Gβγ-free Gαi subunit accumulates at the front of chemotaxing neutrophils to recruit mInsc-complexed with the Par3-aPKC evolutionarily conserved polarity complex-via LGN/AGS3 that simultaneously binds to Gαi-GDP and mInsc. Both mInsc-deficient and aPKC-blocked neutrophils exhibit a normal motile activity but migrate in an undirected manner. mInsc deficiency prevents neutrophils from efficiently stabilizing pseudopods at the leading edge; the stability is restored by wild-type mInsc, but not by a mutant protein defective in binding to LGN/AGS3. Thus, mInsc controls directional migration via noncanonical G protein signaling, in which Gβγ-free Gαi-GDP, a product from Gαi-GTP released after receptor activation, plays a central role.
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Affiliation(s)
- Sachiko Kamakura
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
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37
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Mapelli M, Gonzalez C. On the inscrutable role of Inscuteable: structural basis and functional implications for the competitive binding of NuMA and Inscuteable to LGN. Open Biol 2013; 2:120102. [PMID: 22977735 PMCID: PMC3438535 DOI: 10.1098/rsob.120102] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 07/20/2012] [Indexed: 11/12/2022] Open
Abstract
Alignment of the mitotic spindle to the cellular polarity axis is a prerequisite for asymmetric cell divisions. The protein network coordinating the spindle position with cortical polarity includes the molecular machinery pulling on astral microtubules, which is assembled on conserved NuMA:LGN:Gαi complexes, the polarity proteins Par3:Par6:aPKC and an adaptor molecule known as Inscuteable (Insc). To date, all these components were assumed to enter a macromolecular complex localized at polarity sites in mitosis. However, recent structural studies revealed the Insc and NuMA are mutually exclusive interactors of LGN, implying that the molecular mechanism of spindle coupling to polarity is more sophisticated than has been believed to date.
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Affiliation(s)
- Marina Mapelli
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy.
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38
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Hartenstein V, Wodarz A. Initial neurogenesis in Drosophila. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2013; 2:701-21. [PMID: 24014455 DOI: 10.1002/wdev.111] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Early neurogenesis comprises the phase of nervous system development during which neural progenitor cells are born. In early development, the embryonic ectoderm is subdivided by a conserved signaling mechanism into two main domains, the epidermal ectoderm and the neurectoderm. Subsequently, cells of the neurectoderm are internalized and form a cell layer of proliferating neural progenitors. In vertebrates, the entire neurectoderm folds into the embryo to give rise to the neural tube. In Drosophila and many other invertebrates, a subset of neurectodermal cells, called neuroblasts (NBs), delaminates and forms the neural primordium inside the embryo where they divide in an asymmetric, stem cell-like mode. The remainder of the neurectodermal cells that stay behind at the surface loose their neurogenic potential and later give rise to the ventral part of the epidermis. The genetic and molecular analysis of the mechanisms controlling specification and proliferation of NBs in the Drosophila embryo, which played a significant part in pioneering the field of modern developmental neurobiology, represents the topic of this review.
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Affiliation(s)
- Volker Hartenstein
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA, USA
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39
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Lai SL, Miller MR, Robinson KJ, Doe CQ. The Snail family member Worniu is continuously required in neuroblasts to prevent Elav-induced premature differentiation. Dev Cell 2013; 23:849-57. [PMID: 23079601 DOI: 10.1016/j.devcel.2012.09.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 07/17/2012] [Accepted: 09/12/2012] [Indexed: 11/17/2022]
Abstract
Snail family transcription factors are best known for regulating epithelial-mesenchymal transition (EMT). The Drosophila Snail family member Worniu is specifically transcribed in neural progenitors (neuroblasts) throughout their lifespan, and worniu mutants show defects in neuroblast delamination (a form of EMT). However, the role of Worniu in neuroblasts beyond their formation is unknown. We performed RNA-seq on worniu mutant larval neuroblasts and observed reduced cell-cycle transcripts and increased neural differentiation transcripts. Consistent with these genomic data, worniu mutant neuroblasts showed a striking delay in prophase/metaphase transition by live imaging and increased levels of the conserved neuronal differentiation splicing factor Elav. Reducing Elav levels significantly suppressed the worniu mutant phenotype. We conclude that Worniu is continuously required in neuroblasts to maintain self-renewal by promoting cell-cycle progression and inhibiting premature differentiation.
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Affiliation(s)
- Sen-Lin Lai
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA
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40
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Homem CCF, Knoblich JA. Drosophila neuroblasts: a model for stem cell biology. Development 2013; 139:4297-310. [PMID: 23132240 DOI: 10.1242/dev.080515] [Citation(s) in RCA: 300] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Drosophila neuroblasts, the stem cells of the developing fly brain, have emerged as a key model system for neural stem cell biology and have provided key insights into the mechanisms underlying asymmetric cell division and tumor formation. More recently, they have also been used to understand how neural progenitors can generate different neuronal subtypes over time, how their cell cycle entry and exit are coordinated with development, and how proliferation in the brain is spared from the growth restrictions that occur in other organs upon starvation. In this Primer, we describe the biology of Drosophila neuroblasts and highlight the most recent advances made using neuroblasts as a model system.
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Affiliation(s)
- Catarina C F Homem
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Dr Bohr Gasse 3-5, 1030 Vienna, Austria
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41
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Sousa-Nunes R, Somers WG. Mechanisms of asymmetric progenitor divisions in the Drosophila central nervous system. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 786:79-102. [PMID: 23696353 DOI: 10.1007/978-94-007-6621-1_6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Drosophila central nervous system develops from polarised asymmetric divisions of precursor cells, called neuroblasts. Decades of research on neuroblasts have resulted in a substantial understanding of the factors and molecular events responsible for fate decisions of neuroblasts and their progeny. Furthermore, the cell-cycle dependent mechanisms responsible for asymmetric cortical protein localisation, resulting in the unequal partitioning between daughters, are beginning to be exposed. Disruption to the appropriate partitioning of proteins between neuroblasts and differentiation-committed daughters can lead to supernumerary neuroblast-like cells and the formation of tumours. Many of the factors responsible for regulating asymmetric division of Drosophila neuroblasts are evolutionarily conserved and, in many cases, have been shown to play a functionally conserved role in mammalian neurogenesis. Recent genome-wide studies coupled with advancements in live-imaging technologies have opened further avenues of research into neuroblast biology. We review our current understanding of the molecular mechanisms regulating neuroblast divisions, a powerful system to model mammalian neurogenesis and tumourigenesis.
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Affiliation(s)
- Rita Sousa-Nunes
- MRC Centre for Developmental Neurobiology, King's College London, New Hunt's House, London, SE1 1UL, UK.
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42
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Stevermann L, Liakopoulos D. Molecular mechanisms in spindle positioning: structures and new concepts. Curr Opin Cell Biol 2012; 24:816-24. [PMID: 23142476 DOI: 10.1016/j.ceb.2012.10.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 10/08/2012] [Accepted: 10/15/2012] [Indexed: 10/27/2022]
Abstract
Coordination of cell cleavage with respect to cell geometry, cell polarity and neighboring tissues is critical for tissue maintenance, malignant transformation and metastasis. The position of the mitotic spindle within the cell determines where cell cleavage occurs. Spindle positioning is often mediated through capture of astral microtubules by motor proteins at the cell cortex. Recently, the core dynein anchor complex has been structurally resolved. Junctional complexes were shown to provide additional capture sites for astral microtubules in proliferating tissues. Finally, latest studies show that signals from centrosomes control spindle positioning and propose novel concepts for generation of centrosome identity.
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Affiliation(s)
- Lea Stevermann
- Heidelberg University Biochemistry Center (BZH) INF 328, 69120 Heidelberg, Germany
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43
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Jia M, Li J, Zhu J, Wen W, Zhang M, Wang W. Crystal structures of the scaffolding protein LGN reveal the general mechanism by which GoLoco binding motifs inhibit the release of GDP from Gαi. J Biol Chem 2012; 287:36766-76. [PMID: 22952234 DOI: 10.1074/jbc.m112.391607] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
GoLoco (GL) motif-containing proteins regulate G protein signaling by binding to Gα subunit and acting as guanine nucleotide dissociation inhibitors. GLs of LGN are also known to bind the GDP form of Gα(i/o) during asymmetric cell division. Here, we show that the C-terminal GL domain of LGN binds four molecules of Gα(i)·GDP. The crystal structures of Gα(i)·GDP in complex with LGN GL3 and GL4, respectively, reveal distinct GL/Gα(i) interaction features when compared with the only high resolution structure known with GL/Gα(i) interaction between RGS14 and Gα(i1.) Only a few residues C-terminal to the conserved GL sequence are required for LGN GLs to bind to Gα(i)·GDP. A highly conserved "double Arg finger" sequence (RΨ(D/E)(D/E)QR) is responsible for LGN GL to bind to GDP bound to Gα(i). Together with the sequence alignment, we suggest that the LGN GL/Gα(i) interaction represents a general binding mode between GL motifs and Gα(i). We also show that LGN GLs are potent guanine nucleotide dissociation inhibitors.
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Affiliation(s)
- Min Jia
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai 200433, China
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44
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Caers J, Verlinden H, Zels S, Vandersmissen HP, Vuerinckx K, Schoofs L. More than two decades of research on insect neuropeptide GPCRs: an overview. Front Endocrinol (Lausanne) 2012; 3:151. [PMID: 23226142 PMCID: PMC3510462 DOI: 10.3389/fendo.2012.00151] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 11/14/2012] [Indexed: 11/30/2022] Open
Abstract
This review focuses on the state of the art on neuropeptide receptors in insects. Most of these receptors are G protein-coupled receptors (GPCRs) and are involved in the regulation of virtually all physiological processes during an insect's life. More than 20 years ago a milestone in invertebrate endocrinology was achieved with the characterization of the first insect neuropeptide receptor, i.e., the Drosophila tachykinin-like receptor. However, it took until the release of the Drosophila genome in 2000 that research on neuropeptide receptors boosted. In the last decade a plethora of genomic information of other insect species also became available, leading to a better insight in the functions and evolution of the neuropeptide signaling systems and their intracellular pathways. It became clear that some of these systems are conserved among all insect species, indicating that they fulfill crucial roles in their physiological processes. Meanwhile, other signaling systems seem to be lost in several insect orders or species, suggesting that their actions were superfluous in those insects, or that other neuropeptides have taken over their functions. It is striking that the deorphanization of neuropeptide GPCRs gets much attention, but the subsequent unraveling of the intracellular pathways they elicit, or their physiological functions are often hardly examined. Especially in insects besides Drosophila this information is scarce if not absent. And although great progress made in characterizing neuropeptide signaling systems, even in Drosophila several predicted neuropeptide receptors remain orphan, awaiting for their endogenous ligand to be determined. The present review gives a précis of the insect neuropeptide receptor research of the last two decades. But it has to be emphasized that the work done so far is only the tip of the iceberg and our comprehensive understanding of these important signaling systems will still increase substantially in the coming years.
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Affiliation(s)
| | | | | | | | | | - Liliane Schoofs
- *Correspondence: Liliane Schoofs, Department of Biology, Research Group of Functional Genomics and Proteomics, Naamsestraat 59, KU Leuven, 3000 Leuven, Belgium. e-mail:
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