51
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Hall ET, Cleverdon ER, Ogden SK. Dispatching Sonic Hedgehog: Molecular Mechanisms Controlling Deployment. Trends Cell Biol 2019; 29:385-395. [PMID: 30852081 DOI: 10.1016/j.tcb.2019.02.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 02/07/2019] [Accepted: 02/08/2019] [Indexed: 11/26/2022]
Abstract
The Hedgehog (Hh) family of morphogens direct cell fate decisions during embryogenesis and signal to maintain tissue homeostasis after birth. Hh ligands harbor dual lipid modifications that anchor the proteins into producing cell membranes, effectively preventing ligand release. The transporter-like protein Dispatched (Disp) functions to release these membrane tethers and mobilize Hh ligands to travel toward distant cellular targets. The molecular mechanisms by which Disp achieves Hh deployment are not yet fully understood, but a number of recent publications provide insight into the complex process of Hh release. Herein we review this literature, integrate key discoveries, and discuss some of the open questions that will drive future studies aimed at understanding Disp-mediated Hh ligand deployment.
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Affiliation(s)
- Eric T Hall
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, MS 340, Memphis, TN 38105, USA
| | - Elizabeth R Cleverdon
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, MS 340, Memphis, TN 38105, USA
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, MS 340, Memphis, TN 38105, USA.
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52
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Caviglia S, Ober EA. Non-conventional protrusions: the diversity of cell interactions at short and long distance. Curr Opin Cell Biol 2018; 54:106-113. [DOI: 10.1016/j.ceb.2018.05.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/18/2018] [Accepted: 05/23/2018] [Indexed: 01/04/2023]
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53
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From intra- to extracellular vesicles: extracellular vesicles in developmental signalling. Essays Biochem 2018; 62:215-223. [DOI: 10.1042/ebc20180001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 03/02/2018] [Accepted: 03/06/2018] [Indexed: 12/12/2022]
Abstract
Signalling from cell-to-cell is fundamental for determining differentiation and patterning. This communication can occur between adjacent and distant cells. Extracellular vesicles (EVs) are membrane-based structures thought to facilitate the long-distance movement of signalling molecules. EVs have recently been found to allow the transport of two major developmental signalling pathways: Hedgehog and Wnt. These signalling molecules undergo crucial post-translational lipid modifications, which anchor them to membranes and impede their free release into the extracellular space. Preparation of these ligands in EVs involves intracellular vesicle sorting in an endocytosis-dependent recycling process before secretion. In the present review, we discuss the most recent advances with regard to EV involvement in developmental signalling at a distance. We focus on the role of the protein complexes involved in EV genesis, and provide a comprehensive perspective of the contribution of these complexes to intracellular vesicle sorting of developmental signals for their extracellular secretion, reception and transduction.
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54
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Abstract
Spatial organization of membrane domains within cells and cells within tissues is key to the development of organisms and the maintenance of adult tissue. Cell polarization is crucial for correct cell-cell signalling, which, in turn, promotes cell differentiation and tissue patterning. However, the mechanisms linking internal cell polarity to intercellular signalling are just beginning to be unravelled. The Hedgehog (Hh) and Wnt pathways are major directors of development and their malfunction can cause severe disorders like cancer. Here we discuss parallel advances into understanding the mechanism of Hedgehog and Wnt signal dissemination and reception. We hypothesize that cell polarization of the signal-sending and signal-receiving cells is crucial for proper signal spreading and activation of the pathway and, thus, fundamental for development of multicellular organisms.
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55
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Schürmann S, Steffes G, Manikowski D, Kastl P, Malkus U, Bandari S, Ohlig S, Ortmann C, Rebollido-Rios R, Otto M, Nüsse H, Hoffmann D, Klämbt C, Galic M, Klingauf J, Grobe K. Proteolytic processing of palmitoylated Hedgehog peptides specifies the 3-4 intervein region of the Drosophila wing. eLife 2018. [PMID: 29522397 PMCID: PMC5844694 DOI: 10.7554/elife.33033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Cell fate determination during development often requires morphogen transport from producing to distant responding cells. Hedgehog (Hh) morphogens present a challenge to this concept, as all Hhs are synthesized as terminally lipidated molecules that form insoluble clusters at the surface of producing cells. While several proposed Hh transport modes tie directly into these unusual properties, the crucial step of Hh relay from producing cells to receptors on remote responding cells remains unresolved. Using wing development in Drosophila melanogaster as a model, we show that Hh relay and direct patterning of the 3–4 intervein region strictly depend on proteolytic removal of lipidated N-terminal membrane anchors. Site-directed modification of the N-terminal Hh processing site selectively eliminated the entire 3–4 intervein region, and additional targeted removal of N-palmitate restored its formation. Hence, palmitoylated membrane anchors restrict morphogen spread until site-specific processing switches membrane-bound Hh into bioactive forms with specific patterning functions. Each cell in a developing embryo receives information that determines what type of body structure it will form. In fruit flies, this information is partly given by a protein called Hedgehog. In the embryo cells that receive it, Hedgehog can trigger a series of events which activate certain genes and thereby regulate structure formation. The Hedgehog proteins are produced by a different organizing group of cells: from there they transport within the embryo, creating a gradient. Depending on where a responding cell is in the embryo, it receives a different amount of Hedgehog, which gives the cell its identity. For example, Hedgehog proteins form a gradient across a fruit fly’s developing wing, which creates a visible vein pattern. How Hedgehog proteins form gradients is enigmatic, however, because once produced, they cling to the cells that created them. The reason for this unusual behavior is that the two ends of the Hedgehog protein are attached to a different fat molecule. In particular, one extremity is linked to a fat molecule called palmitate. These ends’ fatty additions anchor Hedgehog to the cells that produced them. Then, the tethered proteins gather together to form chain-like clusters where they inactivate each other: the extremity with the palmitate ‘hides’ the portion of the neighboring protein that binds to the receiving cells. It is still unclear how Hedgehog can be activated and released to reach these faraway cells. One hypothesis is that an enzyme comes to the clusters and frees the proteins by cutting both of Hedgehog’s fatty anchors. Thanks to how the palmitate tethers Hedgehog to the cell, the protein is positioned in such a way that when the enzyme makes its snip, the binding site on the neighboring Hedgehog gets exposed: this protein is activated and, when also cut by the enzyme, released. Here, Schürmann et al. create an array of mutant Hedgehog proteins – for example some without palmitate, some with palmitate that cannot be removed by the enzyme – and study how they affect the development of the wing’s pattern in the fruit fly. Coupled with the imaging of the clusters, these experiments support the hypothesis that the palmitate anchor is necessary so that Hedgehog proteins can be turned on before diffusing away. The Hedgehog family of proteins is also present in humans, where it presides over the development of the embryo but is also involved in cancer. Understanding how Hedgehog works in the fruit fly could lead to new discoveries in humans too.
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Affiliation(s)
- Sabine Schürmann
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany
| | - Georg Steffes
- Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany.,Institute of Neurobiology, University of Münster, Münster, Germany
| | - Dominique Manikowski
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany
| | - Philipp Kastl
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany
| | - Ursula Malkus
- Institute of Medical Physics and Biophysics, University of Münster, Münster, Germany
| | - Shyam Bandari
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany
| | - Stefanie Ohlig
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany
| | - Corinna Ortmann
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany
| | | | - Mandy Otto
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany
| | - Harald Nüsse
- Institute of Medical Physics and Biophysics, University of Münster, Münster, Germany
| | - Daniel Hoffmann
- Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Christian Klämbt
- Institute of Neurobiology, University of Münster, Münster, Germany
| | - Milos Galic
- Institute of Medical Physics and Biophysics, University of Münster, Münster, Germany
| | - Jürgen Klingauf
- Institute of Medical Physics and Biophysics, University of Münster, Münster, Germany
| | - Kay Grobe
- Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Münster, Germany
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56
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Parchure A, Vyas N, Mayor S. Wnt and Hedgehog: Secretion of Lipid-Modified Morphogens. Trends Cell Biol 2018; 28:157-170. [PMID: 29132729 PMCID: PMC6941938 DOI: 10.1016/j.tcb.2017.10.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 09/07/2017] [Accepted: 10/17/2017] [Indexed: 12/27/2022]
Abstract
Morphogens are signaling molecules produced by a localized source, specifying cell fate in a graded manner. The source secretes morphogens into the extracellular milieu to activate various target genes in an autocrine or paracrine manner. Here we describe various secreted forms of two canonical morphogens, the lipid-anchored Hedgehog (Hh) and Wnts, indicating the involvement of multiple carriers in the transport of these morphogens. These different extracellular secreted forms are likely to have distinct functions. Here we evaluate newly identified mechanisms that morphogens use to traverse the required distance to activate discrete paracrine signaling.
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Affiliation(s)
- Anup Parchure
- National Centre for Biological Sciences, Tata Institute of Fundamental Research and Institute for Stem Cell Science and Regenerative Medicine, Bangalore 560065, India; Current address: Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Neha Vyas
- St John's Research Institute, St John's National Academy of Health Sciences, Bangalore 560034, India.
| | - Satyajit Mayor
- National Centre for Biological Sciences, Tata Institute of Fundamental Research and Institute for Stem Cell Science and Regenerative Medicine, Bangalore 560065, India.
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57
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Manikowski D, Kastl P, Grobe K. Taking the Occam's Razor Approach to Hedgehog Lipidation and Its Role in Development. J Dev Biol 2018; 6:jdb6010003. [PMID: 29615552 PMCID: PMC5875562 DOI: 10.3390/jdb6010003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/24/2018] [Accepted: 01/25/2018] [Indexed: 01/01/2023] Open
Abstract
All Hedgehog (Hh) proteins signal from producing cells to distant receiving cells despite being synthesized as N-and C-terminally lipidated, membrane-tethered molecules. To explain this paradoxical situation, over the past 15 years, several hypotheses have been postulated that tie directly into this property, such as Hh transport on cellular extensions called cytonemes or on secreted vesicles called lipophorins and exosomes. The alternative situation that tight membrane association merely serves to prevent unregulated Hh solubilization has been addressed by biochemical and structural studies suggesting Hh extraction from the membrane or proteolytic Hh release. While some of these models may act in different organisms, tissues or developmental programs, others may act together to specify Hh short- and long-range signaling in the same tissues. To test and rank these possibilities, we here review major models of Hh release and transport and hypothesize that the (bio)chemical and physical properties of firmly established, homologous, and functionally essential biochemical Hh modifications are adapted to specify and determine interdependent steps of Hh release, transport and signaling, while ruling out other steps. This is also described by the term “congruence”, meaning that the logical combination of biochemical Hh modifications can reveal their true functional implications. This combined approach reveals potential links between models of Hh release and transport that were previously regarded as unrelated, thereby expanding our view of how Hhs can steer development in a simple, yet extremely versatile, manner.
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Affiliation(s)
- Dominique Manikowski
- Institute of Physiological Chemistry and Pathobiochemistry and Cells-in-Motion Cluster of Excellence, University of Münster, D-48149 Münster, Germany.
| | - Philipp Kastl
- Institute of Physiological Chemistry and Pathobiochemistry and Cells-in-Motion Cluster of Excellence, University of Münster, D-48149 Münster, Germany.
| | - Kay Grobe
- Institute of Physiological Chemistry and Pathobiochemistry and Cells-in-Motion Cluster of Excellence, University of Münster, D-48149 Münster, Germany.
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58
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Stewart DP, Marada S, Bodeen WJ, Truong A, Sakurada SM, Pandit T, Pruett-Miller SM, Ogden SK. Cleavage activates dispatched for Sonic Hedgehog ligand release. eLife 2018; 7:31678. [PMID: 29359685 PMCID: PMC5811216 DOI: 10.7554/elife.31678] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/22/2018] [Indexed: 12/12/2022] Open
Abstract
Hedgehog ligands activate an evolutionarily conserved signaling pathway that provides instructional cues during tissue morphogenesis, and when corrupted, contributes to developmental disorders and cancer. The transmembrane protein Dispatched is an essential component of the machinery that deploys Hedgehog family ligands from producing cells, and is absolutely required for signaling to long-range targets. Despite this crucial role, regulatory mechanisms controlling Dispatched activity remain largely undefined. Herein, we reveal vertebrate Dispatched is activated by proprotein convertase-mediated cleavage at a conserved processing site in its first extracellular loop. Dispatched processing occurs at the cell surface to instruct its membrane re-localization in polarized epithelial cells. Cleavage site mutation alters Dispatched membrane trafficking and reduces ligand release, leading to compromised pathway activity in vivo. As such, convertase-mediated cleavage is required for Dispatched maturation and functional competency in Hedgehog ligand-producing cells.
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Affiliation(s)
- Daniel P Stewart
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Suresh Marada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - William J Bodeen
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States.,Integrated Program in Biomedical Sciences, University of Tennessee Health Sciences Center, Memphis, United States
| | - Ashley Truong
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Sadie Miki Sakurada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States.,Center for Advanced Genome Engineering, St. Jude Children's Research Hospital, Memphis, United States
| | - Tanushree Pandit
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Shondra M Pruett-Miller
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States.,Center for Advanced Genome Engineering, St. Jude Children's Research Hospital, Memphis, United States
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
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59
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Chen W, Huang H, Hatori R, Kornberg TB. Essential basal cytonemes take up Hedgehog in the Drosophila wing imaginal disc. Development 2017; 144:3134-3144. [PMID: 28743798 PMCID: PMC5611956 DOI: 10.1242/dev.149856] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 07/19/2017] [Indexed: 01/25/2023]
Abstract
Morphogen concentration gradients that extend across developmental fields form by dispersion from source cells. In the Drosophila wing disc, Hedgehog (Hh) produced by posterior compartment cells distributes in a concentration gradient to adjacent cells of the anterior compartment. We monitored Hh:GFP after pulsed expression, and analyzed the movement and colocalization of Hh, Patched (Ptc) and Smoothened (Smo) proteins tagged with GFP or mCherry and expressed at physiological levels from bacterial artificial chromosome transgenes. Hh:GFP moved to basal subcellular locations prior to release from posterior compartment cells that express it, and was taken up by basal cytonemes that extend to the source cells. Hh and Ptc were present in puncta that moved along the basal cytonemes and formed characteristic apical-basal distributions in the anterior compartment cells. The basal cytonemes required diaphanous, SCAR, Neuroglian and Synaptobrevin, and both the Hh gradient and Hh signaling declined under conditions in which the cytonemes were compromised. These findings show that in the wing disc, Hh distributions and signaling are dependent upon basal release and uptake, and on cytoneme-mediated movement. No evidence for apical dispersion was obtained.
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Affiliation(s)
- Weitao Chen
- Cardiovascular Research Institute, University of California, San Francisco, CA 94143, USA
| | - Hai Huang
- Cardiovascular Research Institute, University of California, San Francisco, CA 94143, USA
| | - Ryo Hatori
- Cardiovascular Research Institute, University of California, San Francisco, CA 94143, USA
| | - Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, CA 94143, USA
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60
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González-Méndez L, Seijo-Barandiarán I, Guerrero I. Cytoneme-mediated cell-cell contacts for Hedgehog reception. eLife 2017; 6:e24045. [PMID: 28825565 PMCID: PMC5565369 DOI: 10.7554/elife.24045] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 07/17/2017] [Indexed: 01/04/2023] Open
Abstract
Morphogens regulate tissue patterning through their distribution in concentration gradients. Emerging research establishes a role for specialized signalling filopodia, or cytonemes, in morphogen dispersion and signalling. Previously we demonstrated that Hedgehog (Hh) morphogen is transported via vesicles along cytonemes emanating from signal-producing cells to form a gradient in Drosophila epithelia. However, the mechanisms for signal reception and transfer are still undefined. Here, we demonstrate that cytonemes protruding from Hh-receiving cells contribute to Hh gradient formation. The canonical Hh receptor Patched is localized in these cellular protrusions and Hh reception takes place in membrane contact sites between Hh-sending and Hh-receiving cytonemes. These two sets of cytonemes have similar dynamics and both fall in two different dynamic behaviours. Furthermore, both the Hh co-receptor Interference hedgehog (Ihog) and the glypicans are critical for this cell-cell cytoneme mediated interaction. These findings suggest that the described contact sites might facilitate morphogen presentation and reception.
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Affiliation(s)
- Laura González-Méndez
- Centro de Biología Molecular 'Severo Ochoa', Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Isabel Guerrero
- Centro de Biología Molecular 'Severo Ochoa', Universidad Autónoma de Madrid, Madrid, Spain
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61
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Bodeen WJ, Marada S, Truong A, Ogden SK. A fixation method to preserve cultured cell cytonemes facilitates mechanistic interrogation of morphogen transport. Development 2017; 144:3612-3624. [PMID: 28827391 PMCID: PMC5665483 DOI: 10.1242/dev.152736] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 08/14/2017] [Indexed: 12/11/2022]
Abstract
During development, extracellular cues guiding cell fate determination are provided by morphogens. One mechanism by which morphogens are proposed to traverse extracellular space is by traveling along specialized filopodia called cytonemes. These cellular highways extend between signal-producing and -receiving cells to enable direct morphogen delivery. Although genetic studies support cytoneme involvement in morphogen transport, mechanistic insight into how they are regulated is limited owing to technical challenges associated with performing cell biological analysis of the delicate filopodial structures. Here, we introduce a fixation method whereby cultured cell cytonemes can be preserved for imaging studies, allowing investigation of cytoneme regulation using standard cell biological techniques. Using this method, we examined Hedgehog-containing cytonemes and identified a role for the Hedgehog deployment protein Dispatched in cytoneme stabilization. We demonstrate that Hedgehog and Dispatched colocalize in cytonemes, and that cholesterol-modified Hedgehog acts through Dispatched to increase cytoneme occurrence. Live imaging suggests that this occurs through Dispatched-mediated slowing of cytoneme retraction rates. Dispatched-induced cytoneme modulation was recapitulated in wing imaginal discs of transgenic Drosophila, providing evidence that cultured cell cytoneme analysis is predictive of in vivo functionality. Summary: A new fixation method for preserving cultured cell cytonemes, used in combination with live cell imaging, reveals that the Hedgehog deployment protein Dispatched promotes cytoneme occurrence by slowing retraction rates.
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Affiliation(s)
- William J Bodeen
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.,Integrated Program in Biomedical Sciences, University of Tennessee Health Sciences Center, Memphis, TN, 38163, USA
| | - Suresh Marada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Ashley Truong
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
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62
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Abstract
Communication between cells pervades the development and physiology of metazoans. In animals, this process is carried out by a relatively small number of signaling pathways, each consisting of a chain of biochemical events through which extracellular stimuli control the behavior of target cells. One such signaling system is the Hedgehog pathway, which is crucial in embryogenesis and is implicated in many birth defects and cancers. Although Hedgehog pathway components were identified by genetic analysis more than a decade ago, our understanding of the molecular mechanisms of signaling is far from complete. In this review, we focus on the biochemistry and cell biology of the Hedgehog pathway. We examine the unique biosynthesis of the Hedgehog ligand, its specialized release from cells into extracellular space, and the poorly understood mechanisms involved in ligand reception and pathway activation at the surface of target cells. We highlight several critical questions that remain open.
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Affiliation(s)
- Kostadin Petrov
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115; ,
| | - Bradley M Wierbowski
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115; ,
| | - Adrian Salic
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115; ,
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63
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Cayuso J, Dzementsei A, Fischer JC, Karemore G, Caviglia S, Bartholdson J, Wright GJ, Ober EA. EphrinB1/EphB3b Coordinate Bidirectional Epithelial-Mesenchymal Interactions Controlling Liver Morphogenesis and Laterality. Dev Cell 2017; 39:316-328. [PMID: 27825440 PMCID: PMC5107609 DOI: 10.1016/j.devcel.2016.10.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/24/2016] [Accepted: 10/10/2016] [Indexed: 11/25/2022]
Abstract
Positioning organs in the body often requires the movement of multiple tissues, yet the molecular and cellular mechanisms coordinating such movements are largely unknown. Here, we show that bidirectional signaling between EphrinB1 and EphB3b coordinates the movements of the hepatic endoderm and adjacent lateral plate mesoderm (LPM), resulting in asymmetric positioning of the zebrafish liver. EphrinB1 in hepatoblasts regulates directional migration and mediates interactions with the LPM, where EphB3b controls polarity and movement of the LPM. EphB3b in the LPM concomitantly repels hepatoblasts to move leftward into the liver bud. Cellular protrusions controlled by Eph/Ephrin signaling mediate hepatoblast motility and long-distance cell-cell contacts with the LPM beyond immediate tissue interfaces. Mechanistically, intracellular EphrinB1 domains mediate EphB3b-independent hepatoblast extension formation, while EpB3b interactions cause their destabilization. We propose that bidirectional short- and long-distance cell interactions between epithelial and mesenchyme-like tissues coordinate liver bud formation and laterality via cell repulsion.
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Affiliation(s)
- Jordi Cayuso
- Division of Developmental Biology, Mill Hill Laboratories, The Francis Crick Institute, London NW7 1AA, UK
| | - Aliaksandr Dzementsei
- Danish Stem Cell Center (DanStem), University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Johanna C Fischer
- Division of Developmental Biology, Mill Hill Laboratories, The Francis Crick Institute, London NW7 1AA, UK
| | - Gopal Karemore
- Novo Nordisk Foundation Center for Protein Research, Protein Imaging Platform, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Sara Caviglia
- Danish Stem Cell Center (DanStem), University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Josefin Bartholdson
- Wellcome Trust Sanger Institute, Cell Surface Signalling Laboratory, Cambridge CB10 1HH, UK
| | - Gavin J Wright
- Wellcome Trust Sanger Institute, Cell Surface Signalling Laboratory, Cambridge CB10 1HH, UK
| | - Elke A Ober
- Division of Developmental Biology, Mill Hill Laboratories, The Francis Crick Institute, London NW7 1AA, UK; Danish Stem Cell Center (DanStem), University of Copenhagen, 2200 Copenhagen N, Denmark.
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64
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Wilcockson SG, Sutcliffe C, Ashe HL. Control of signaling molecule range during developmental patterning. Cell Mol Life Sci 2017; 74:1937-1956. [PMID: 27999899 PMCID: PMC5418326 DOI: 10.1007/s00018-016-2433-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/24/2016] [Accepted: 12/05/2016] [Indexed: 12/22/2022]
Abstract
Tissue patterning, through the concerted activity of a small number of signaling pathways, is critical to embryonic development. While patterning can involve signaling between neighbouring cells, in other contexts signals act over greater distances by traversing complex cellular landscapes to instruct the fate of distant cells. In this review, we explore different strategies adopted by cells to modulate signaling molecule range to allow correct patterning. We describe mechanisms for restricting signaling range and highlight how such short-range signaling can be exploited to not only control the fate of adjacent cells, but also to generate graded signaling within a field of cells. Other strategies include modulation of signaling molecule action by tissue architectural properties and the use of cellular membranous structures, such as signaling filopodia and exosomes, to actively deliver signaling ligands to target cells. Signaling filopodia can also be deployed to reach out and collect particular signals, thereby precisely controlling their site of action.
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Affiliation(s)
- Scott G Wilcockson
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Catherine Sutcliffe
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Hilary L Ashe
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK.
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65
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Daniele JR, Chu T, Kunes S. A novel proteolytic event controls Hedgehog intracellular sorting and distribution to receptive fields. Biol Open 2017; 6:540-550. [PMID: 28298318 PMCID: PMC5450321 DOI: 10.1242/bio.024083] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The patterning activity of a morphogen depends on secretion and dispersal mechanisms that shape its distribution to the cells of a receptive field. In the case of the protein Hedgehog (Hh), these mechanisms of secretion and transmission remain unclear. In the developing Drosophila visual system, Hh is partitioned for release at opposite poles of photoreceptor neurons. Release into the retina regulates the progression of eye development; axon transport and release at axon termini trigger the development of postsynaptic neurons in the brain. Here we show that this binary targeting decision is controlled by a C-terminal proteolysis. Hh with an intact C-terminus undergoes axonal transport, whereas a C-terminal proteolysis enables Hh to remain in the retina, creating a balance between eye and brain development. Thus, we define a novel mechanism for the apical/basal targeting of this developmentally important protein and posit that similar post-translational regulation could underlie the polarity of related ligands.
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Affiliation(s)
- Joseph R Daniele
- Department of Molecular & Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA
| | - Tehyen Chu
- Department of Molecular & Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA
| | - Sam Kunes
- Department of Molecular & Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA
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Suijkerbuijk SJE, van Rheenen J. From good to bad: Intravital imaging of the hijack of physiological processes by cancer cells. Dev Biol 2017; 428:328-337. [PMID: 28473106 DOI: 10.1016/j.ydbio.2017.04.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 04/21/2017] [Accepted: 04/23/2017] [Indexed: 12/23/2022]
Abstract
Homeostasis of tissues is tightly regulated at the cellular, tissue and organismal level. Interestingly, tumor cells have found ways to hijack many of these physiological processes at all the different levels. Here we review how intravital microscopy techniques have provided new insights into our understanding of tissue homeostasis and cancer progression. In addition, we highlight the different strategies that tumor cells have adopted to use these physiological processes for their own benefit. We describe how visualization of these dynamic processes in living mice has broadened to our view on cancer initiation and progression.
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Affiliation(s)
- Saskia J E Suijkerbuijk
- Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Center Utrecht, 3584 CT Utrecht, The Netherlands; Cancer Genomics Netherlands, 3584 CG Utrecht, The Netherlands
| | - Jacco van Rheenen
- Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Center Utrecht, 3584 CT Utrecht, The Netherlands; Cancer Genomics Netherlands, 3584 CG Utrecht, The Netherlands.
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67
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EGFR/ARF6 regulation of Hh signalling stimulates oncogenic Ras tumour overgrowth. Nat Commun 2017; 8:14688. [PMID: 28281543 PMCID: PMC5353614 DOI: 10.1038/ncomms14688] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 01/20/2017] [Indexed: 12/15/2022] Open
Abstract
Multiple signalling events interact in cancer cells. Oncogenic Ras cooperates with Egfr, which cannot be explained by the canonical signalling paradigm. In turn, Egfr cooperates with Hedgehog signalling. How oncogenic Ras elicits and integrates Egfr and Hedgehog signals to drive overgrowth remains unclear. Using a Drosophila tumour model, we show that Egfr cooperates with oncogenic Ras via Arf6, which functions as a novel regulator of Hh signalling. Oncogenic Ras induces the expression of Egfr ligands. Egfr then signals through Arf6, which regulates Hh transport to promote Hh signalling. Blocking any step of this signalling cascade inhibits Hh signalling and correspondingly suppresses the growth of both, fly and human cancer cells harbouring oncogenic Ras mutations. These findings highlight a non-canonical Egfr signalling mechanism, centered on Arf6 as a novel regulator of Hh signalling. This explains both, the puzzling requirement of Egfr in oncogenic Ras-mediated overgrowth and the cooperation between Egfr and Hedgehog. EGFR signalling is required for oncogenic Ras driven tumorigenesis. In this study, using a Drosophila tumour model the authors demonstrate that depletion of Arf6, a Ras-related GTP-binding protein activated by EGFR, supresses oncogenic Ras driven overgrowth via modulation of Hedgehog signalling.
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68
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Kornberg TB. Distributing signaling proteins in space and time: the province of cytonemes. Curr Opin Genet Dev 2017; 45:22-27. [PMID: 28242479 DOI: 10.1016/j.gde.2017.02.010] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/10/2017] [Accepted: 02/14/2017] [Indexed: 12/12/2022]
Abstract
During development, cells use specialized filopodia called cytonemes to deploy the signaling proteins that coordinate growth and direct morphogenesis. Cytonemes are dynamic structures that can extend long distances across tissues to either deliver or take up signaling proteins. Signaling proteins transfer between cells at the tips of cytonemes where specific contacts termed morphogenetic synapses form. This review summarizes our current understanding of the roles and functions of cytonemes, and it explores some of the conceptual issues relevant to the cytoneme mechanism of contact-dependent cell-cell signaling.
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Affiliation(s)
- Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, CA 94143, United States.
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69
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Simon E, Aguirre-Tamaral A, Aguilar G, Guerrero I. Perspectives on Intra- and Intercellular Trafficking of Hedgehog for Tissue Patterning. J Dev Biol 2016; 4:jdb4040034. [PMID: 29615597 PMCID: PMC5831803 DOI: 10.3390/jdb4040034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/07/2016] [Accepted: 11/08/2016] [Indexed: 12/14/2022] Open
Abstract
Intercellular communication is a fundamental process for correct tissue development. The mechanism of this process involves, among other things, the production and secretion of signaling molecules by specialized cell types and the capability of these signals to reach the target cells in order to trigger specific responses. Hedgehog (Hh) is one of the best-studied signaling pathways because of its importance during morphogenesis in many organisms. The Hh protein acts as a morphogen, activating its targets at a distance in a concentration-dependent manner. Post-translational modifications of Hh lead to a molecule covalently bond to two lipid moieties. These lipid modifications confer Hh high affinity to lipidic membranes, and intense studies have been carried out to explain its release into the extracellular matrix. This work reviews Hh molecule maturation, the intracellular recycling needed for its secretion and the proposed carriers to explain Hh transportation to the receiving cells. Special focus is placed on the role of specialized filopodia, also named cytonemes, in morphogen transport and gradient formation.
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Affiliation(s)
- Eléanor Simon
- Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid, CSIC-UAM, Nicolás Cabrera 1, Cantoblanco, 28049 Madrid, Spain.
| | - Adrián Aguirre-Tamaral
- Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid, CSIC-UAM, Nicolás Cabrera 1, Cantoblanco, 28049 Madrid, Spain.
| | - Gustavo Aguilar
- Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid, CSIC-UAM, Nicolás Cabrera 1, Cantoblanco, 28049 Madrid, Spain.
| | - Isabel Guerrero
- Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid, CSIC-UAM, Nicolás Cabrera 1, Cantoblanco, 28049 Madrid, Spain.
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70
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Sena E, Feistel K, Durand BC. An Evolutionarily Conserved Network Mediates Development of the zona limitans intrathalamica, a Sonic Hedgehog-Secreting Caudal Forebrain Signaling Center. J Dev Biol 2016; 4:jdb4040031. [PMID: 29615594 PMCID: PMC5831802 DOI: 10.3390/jdb4040031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 09/29/2016] [Accepted: 10/13/2016] [Indexed: 12/16/2022] Open
Abstract
Recent studies revealed new insights into the development of a unique caudal forebrain-signaling center: the zona limitans intrathalamica (zli). The zli is the last brain signaling center to form and the first forebrain compartment to be established. It is the only part of the dorsal neural tube expressing the morphogen Sonic Hedgehog (Shh) whose activity participates in the survival, growth and patterning of neuronal progenitor subpopulations within the thalamic complex. Here, we review the gene regulatory network of transcription factors and cis-regulatory elements that underlies formation of a shh-expressing delimitated domain in the anterior brain. We discuss evidence that this network predates the origin of chordates. We highlight the contribution of Shh, Wnt and Notch signaling to zli development and discuss implications for the fact that the morphogen Shh relies on primary cilia for signal transduction. The network that underlies zli development also contributes to thalamus induction, and to its patterning once the zli has been set up. We present an overview of the brain malformations possibly associated with developmental defects in this gene regulatory network (GRN).
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Affiliation(s)
- Elena Sena
- Institut Curie, Université Paris Sud, INSERM U1021, CNRS UMR3347, Centre Universitaire, Bâtiment 110, F-91405 Orsay Cedex, France.
| | - Kerstin Feistel
- Institute of Zoology, University of Hohenheim, Garbenstr. 30, 70593 Stuttgart, Germany.
| | - Béatrice C Durand
- Institut Curie, Université Paris Sud, INSERM U1021, CNRS UMR3347, Centre Universitaire, Bâtiment 110, F-91405 Orsay Cedex, France.
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71
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Campbell C, Beug S, Nickerson PEB, Peng J, Mazerolle C, Bassett EA, Ringuette R, Jama FA, Morales C, Christ A, Wallace VA. Sortilin regulates sorting and secretion of Sonic hedgehog. J Cell Sci 2016; 129:3832-3844. [PMID: 27632999 DOI: 10.1242/jcs.183541] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 08/26/2016] [Indexed: 01/03/2023] Open
Abstract
Sonic Hedgehog (Shh) is a secreted morphogen that is an essential regulator of patterning and growth. The Shh full-length protein undergoes autocleavage in the endoplasmic reticulum to generate the biologically active N-terminal fragment (ShhN), which is destined for secretion. We identified sortilin (Sort1), a member of the VPS10P-domain receptor family, as a new Shh trafficking receptor. We demonstrate that Sort-Shh interact by performing coimmunoprecipitation and proximity ligation assays in transfected cells and that they colocalize at the Golgi. Sort1 overexpression causes re-distribution of ShhN and, to a lesser extent, of full-length Shh to the Golgi and reduces Shh secretion. We show loss of Sort1 can partially rescue Hedgehog-associated patterning defects in a mouse model that is deficient in Shh processing, and we show that Sort1 levels negatively regulate anterograde Shh transport in axons in vitro and Hedgehog-dependent axon-glial interactions in vivo Taken together, we conclude that Shh and Sort1 can interact at the level of the Golgi and that Sort1 directs Shh away from the pathways that promote its secretion.
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Affiliation(s)
- Charles Campbell
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6 Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5
| | - Shawn Beug
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6 Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5
| | - Philip E B Nickerson
- Vision Science Division, Krembil Research Institute, University Health Network and Department of Ophthalmology and Vision Sciences, University of Toronto, 60 Leonard Street, Toronto ON M5T 2S8
| | - Jimmy Peng
- Department of Biology, McGill University, 1205 Ave Docteur Penfield Room W4/8, Montreal, Quebec, Canada H3A 1B1 Institut de recherches cliniques de Montréal (IRCM), 110 Avenue des Pins Ouest, Montréal, Quebec, Canada H2W 1R7
| | - Chantal Mazerolle
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6
| | - Erin A Bassett
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6
| | - Randy Ringuette
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6 Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5
| | - Fadumo A Jama
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6 Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5
| | - Carlos Morales
- Department of Anatomy and Cell Biology, McGill University, 3640 Rue University, Montréal, Quebec, Canada H3A 0C7
| | - Annabel Christ
- Max-Delbrück-Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Valerie A Wallace
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6 Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5 Vision Science Division, Krembil Research Institute, University Health Network and Department of Ophthalmology and Vision Sciences, University of Toronto, 60 Leonard Street, Toronto ON M5T 2S8
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Huang H, Kornberg TB. Cells must express components of the planar cell polarity system and extracellular matrix to support cytonemes. eLife 2016; 5. [PMID: 27591355 PMCID: PMC5030081 DOI: 10.7554/elife.18979] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/31/2016] [Indexed: 01/10/2023] Open
Abstract
Drosophila dorsal air sac development depends on Decapentaplegic (Dpp) and Fibroblast growth factor (FGF) proteins produced by the wing imaginal disc and transported by cytonemes to the air sac primordium (ASP). Dpp and FGF signaling in the ASP was dependent on components of the planar cell polarity (PCP) system in the disc, and neither Dpp- nor FGF-receiving cytonemes extended over mutant disc cells that lacked them. ASP cytonemes normally navigate through extracellular matrix (ECM) composed of collagen, laminin, Dally and Dally-like (Dlp) proteins that are stratified in layers over the disc cells. However, ECM over PCP mutant cells had reduced levels of laminin, Dally and Dlp, and whereas Dpp-receiving ASP cytonemes navigated in the Dally layer and required Dally (but not Dlp), FGF-receiving ASP cytonemes navigated in the Dlp layer, requiring Dlp (but not Dally). These findings suggest that cytonemes interact directly and specifically with proteins in the stratified ECM.
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Affiliation(s)
- Hai Huang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
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73
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Abstract
In order to achieve coordinated growth and patterning during development, cells must communicate with one another, sending and receiving signals that regulate their activities. Such developmental signals can be soluble, bound to the extracellular matrix, or tethered to the surface of adjacent cells. Cells can also signal by releasing exosomes – extracellular vesicles containing bioactive molecules such as RNA, DNA and enzymes. Recent work has suggested that exosomes can also carry signalling proteins, including ligands of the Notch receptor and secreted proteins of the Hedgehog and WNT families. Here, we describe the various types of exosomes and their biogenesis. We then survey the experimental strategies used so far to interfere with exosome formation and critically assess the role of exosomes in developmental signalling.
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Affiliation(s)
- Ian John McGough
- Laboratory of Epithelial Interactions, The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK
| | - Jean-Paul Vincent
- Laboratory of Epithelial Interactions, The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK
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74
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Deshpande G, Manry D, Jourjine N, Mogila V, Mozes H, Bialistoky T, Gerlitz O, Schedl P. Role of the ABC transporter Mdr49 in Hedgehog signaling and germ cell migration. Development 2016; 143:2111-20. [PMID: 27122170 DOI: 10.1242/dev.133587] [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: 11/30/2015] [Accepted: 04/12/2016] [Indexed: 01/20/2023]
Abstract
Coalescence of the embryonic gonad in Drosophila melanogaster requires directed migration of primordial germ cells (PGCs) towards somatic gonadal precursor cells (SGPs). It was recently proposed that the ATP-binding cassette (ABC) transporter Mdr49 functions in the embryonic mesoderm to facilitate the transmission of the PGC attractant from the SGPs; however, the precise molecular identity of the Mdr49-dependent guidance signal remained elusive. Employing the loss- and gain-of-function strategies, we show that Mdr49 is a component of the Hedgehog (hh) pathway and it potentiates the signaling activity. This function is direct because in Mdr49 mutant embryos the Hh ligand is inappropriately sequestered in the hh-expressing cells. Our data also suggest that the role of Mdr49 is to provide cholesterol for the correct processing of the Hh precursor protein. Supporting this conclusion, PGC migration defects in Mdr49 embryos are substantially ameliorated by a cholesterol-rich diet.
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Affiliation(s)
- Girish Deshpande
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Diane Manry
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Nicholas Jourjine
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Vladic Mogila
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Henny Mozes
- Department of Developmental Biology and Cancer Research, IMRIC, The Hebrew University, Jerusalem 91120, Israel
| | - Tzofia Bialistoky
- Department of Developmental Biology and Cancer Research, IMRIC, The Hebrew University, Jerusalem 91120, Israel
| | - Offer Gerlitz
- Department of Developmental Biology and Cancer Research, IMRIC, The Hebrew University, Jerusalem 91120, Israel
| | - Paul Schedl
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
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75
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Yamazaki Y, Palmer L, Alexandre C, Kakugawa S, Beckett K, Gaugue I, Palmer RH, Vincent JP. Godzilla-dependent transcytosis promotes Wingless signalling in Drosophila wing imaginal discs. Nat Cell Biol 2016; 18:451-7. [PMID: 26974662 PMCID: PMC4817240 DOI: 10.1038/ncb3325] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 02/05/2016] [Indexed: 12/18/2022]
Abstract
The apical and basolateral membranes of epithelia are insulated from each other, preventing the transfer of extracellular proteins from one side to the other. Thus, a signalling protein produced apically is not expected to reach basolateral receptors. Evidence suggests that Wingless, the main Drosophila Wnt, is secreted apically in the embryonic epidermis. However, in the wing imaginal disc epithelium, Wingless is mostly seen on the basolateral membrane where it spreads from secreting to receiving cells. Here we examine the apico-basal movement of Wingless in Wingless-producing cells of wing imaginal discs. We find that it is presented first on the apical surface before making its way to the basolateral surface, where it is released and allowed to interact with signalling receptors. We show that Wingless transcytosis involves dynamin-dependent endocytosis from the apical surface. Subsequent trafficking from early apical endosomes to the basolateral surface requires Godzilla, a member of the RNF family of membrane-anchored E3 ubiquitin ligases. Without such transport, Wingless signalling is strongly reduced in this tissue.
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Affiliation(s)
- Yasuo Yamazaki
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 9A, 40539 Gothenburg, Sweden
| | - Lucy Palmer
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Cyrille Alexandre
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Satoshi Kakugawa
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Karen Beckett
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Isabelle Gaugue
- Polarity, Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Ruth H Palmer
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 9A, 40539 Gothenburg, Sweden
| | - Jean-Paul Vincent
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
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76
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Reassessing ecdysteroidogenic cells from the cell membrane receptors' perspective. Sci Rep 2016; 6:20229. [PMID: 26847502 PMCID: PMC4742824 DOI: 10.1038/srep20229] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/23/2015] [Indexed: 02/06/2023] Open
Abstract
Ecdysteroids secreted by the prothoracic gland (PG) cells of insects control the
developmental timing of their immature life stages. These cells have been
historically considered as carrying out a single function in insects, namely the
biochemical conversion of cholesterol to ecdysteroids and their secretion. A growing
body of evidence shows that PG cells receive multiple cues during insect development
so we tested the hypothesis that they carry out more than just one function in
insects. We characterised the molecular nature and developmental profiles of cell
membrane receptors in PG cells of Bombyx mori during the final larval stage
and determined what receptors decode nutritional, developmental and physiological
signals. Through iterative approaches we identified a complex repertoire of cell
membrane receptors that are expressed in intricate patterns and activate previously
unidentified signal transduction cascades in PG cells. The expression patterns of
some of these receptors explain precisely the mechanisms that are known to control
ecdysteroidogenesis. However, the presence of receptors for the notch, hedgehog and
wingless signalling pathways and the expression of innate immunity-related receptors
such as phagocytosis receptors, receptors for microbial ligands and Toll-like
receptors call for a re-evaluation of the role these cells play in insects.
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Abstract
The field of developmental biology is not the same one that I entered in 1975. At that time, it seemed that most of its practitioners used various kinds of microscopes to watch animals as they matured, described morphological details with impressive temporal and spatial resolution, and recorded responses to physical and genetic insults. The number of genes whose mutant phenotypes offered insights into developmental mechanisms was small, the expression and functionalities of these genes were unknown, and because the extent of evolutionary conservation between different animals or even different organs in the same animal was also unknown, the vocabularies that were used to describe development were unique to each system. The distance between the descriptors and inferred molecular mechanisms was vast; it was a descriptive discipline. Today genome sequences are available for the animals that developmental biologists study, saturation genetic screens are possible, transgenesis offers powerful ways to modify genomes, and the proteins that direct and implement developmental processes can be imaged in real time. These advances have transformed the field into one that merges with cell biology, physiology, neurobiology, and immunology, and they have transformed our understanding of development. In this essay, I offer my perspectives and my sense of some principles that have emerged.
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Affiliation(s)
- Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, California, USA.
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78
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Parchure A, Vyas N, Ferguson C, Parton RG, Mayor S. Oligomerization and endocytosis of Hedgehog is necessary for its efficient exovesicular secretion. Mol Biol Cell 2015; 26:4700-17. [PMID: 26490120 PMCID: PMC4678025 DOI: 10.1091/mbc.e15-09-0671] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 10/14/2015] [Indexed: 12/14/2022] Open
Abstract
Hedgehog (Hh) is a secreted morphogen involved in both short- and long-range signaling necessary for tissue patterning during development. It is unclear how this dually lipidated protein is transported over a long range in the aqueous milieu of interstitial spaces. We previously showed that the long-range signaling of Hh requires its oligomerization. Here we show that Hh is secreted in the form of exovesicles. These are derived by the endocytic delivery of cell surface Hh to multivesicular bodies (MVBs) via an endosomal sorting complex required for transport (ECSRT)-dependent process. Perturbations of ESCRT proteins have a selective effect on long-range Hh signaling in Drosophila wing imaginal discs. Of importance, oligomerization-defective Hh is inefficiently incorporated into exovesicles due to its poor endocytic delivery to MVBs. These results provide evidence that nanoscale organization of Hh regulates the secretion of Hh on ESCRT-derived exovesicles, which in turn act as a vehicle for long-range signaling.
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Affiliation(s)
- Anup Parchure
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Neha Vyas
- Institute for Stem Cell Biology and Regenerative Medicine, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Charles Ferguson
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane St Lucia 4072, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane St Lucia 4072, Australia
| | - Satyajit Mayor
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India Institute for Stem Cell Biology and Regenerative Medicine, Tata Institute of Fundamental Research, Bangalore 560065, India
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Marada S, Truong A, Ogden SK. The small GTPase Rap1 is a modulator of Hedgehog signaling. Dev Biol 2015; 409:84-94. [PMID: 26481064 DOI: 10.1016/j.ydbio.2015.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 12/31/2022]
Abstract
During development, the evolutionarily conserved Hedgehog (Hh) morphogen provides instructional cues that influence cell fate, cell affinity and tissue morphogenesis. To do so, the Hh signaling cascade must coordinate its activity with other morphogenetic signals. This can occur through engagement of or response to effectors that do not typically function as core Hh pathway components. Given the ability of small G proteins of the Ras family to impact cell survival, differentiation, growth and adhesion, we wanted to determine whether Hh and Ras signaling might intersect during development. We performed genetic modifier tests in Drosophila to examine the ability of select Ras family members to influence Hh signal output, and identified Rap1 as a positive modulator of Hh pathway activity. Our results suggest that Rap1 is activated to its GTP-bound form in response to Hh ligand, and that the GTPase exchange factor C3G likely contributes to this activation. The Rap1 effector Canoe (Cno) also impacts Hh signal output, suggesting that a C3G-Rap1-Cno axis intersects the Hh pathway during tissue morphogenesis.
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Affiliation(s)
- Suresh Marada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States
| | - Ashley Truong
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States; Rhodes College Summer Plus Program, Rhodes College, Memphis, TN 38112, United States
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States.
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80
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Fleming J, Chiang C. The Purkinje neuron: A central orchestrator of cerebellar neurogenesis. NEUROGENESIS 2015; 2:e1025940. [PMID: 27604220 PMCID: PMC4973588 DOI: 10.1080/23262133.2015.1025940] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 01/29/2015] [Accepted: 03/02/2015] [Indexed: 11/02/2022]
Abstract
Within the cyto-architecture of the brain is an often complex, but balanced, neuronal circuitry, the successful construction of which relies on the coordinated generation of functionally opposed neurons. Indeed, deregulated production of excitatory/inhibitory interneurons can greatly disrupt the integrity of excitatory/inhibitory neuronal transmission, which is a hallmark of neurodevelopmental disorders such as autism. Recent work has demonstrated that the Purkinje neuron, the central integrator of signaling within the cerebellar system, acts during development to ensure that neurogenesis occurring in spatially opposed domains reaches completion by transmitting the Sonic hedgehog ligand bi-directionally. In addition to a classic role in driving granule cell precursor proliferation, we now know that Purkinje neuron-derived Sonic hedgehog is simultaneously disseminated to the neonatal white matter. Within this neurogenic niche a lineage of Shh-responding stem and progenitor cells expand pools of GABAergic interneuron and astrocyte precursors. These recent findings advance our understanding of how Purkinje neurons function dynamically to oversee completion of a balanced cerebellar circuit.
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Affiliation(s)
- Jonathan Fleming
- Department of Cell and Developmental Biology; Vanderbilt University ; Nashville TN USA
| | - Chin Chiang
- Department of Cell and Developmental Biology; Vanderbilt University ; Nashville TN USA
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81
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Sánchez Ó, Calvo J, Ibáñez C, Guerrero I, Soler J. Modeling Hedgehog Signaling Through Flux-Saturated Mechanisms. Methods Mol Biol 2015; 1322:19-33. [PMID: 26179036 DOI: 10.1007/978-1-4939-2772-2_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Hedgehog (Hh) molecules act as morphogens directing cell fate during development by activating various target genes in a concentration dependent manner. Hitherto, modeling morphogen gradient formation in multicellular systems has employed linear diffusion, which is very far from physical reality and needs to be replaced by a deeper understanding of nonlinearities. We have developed a novel mathematical approach by applying flux-limited spreading (FLS) to Hh morphogenetic actions. In the new model, the characteristic velocity of propagation of each morphogen is a new key biological parameter. Unlike in linear diffusion models, FLS modeling predicts concentration fronts and correct patterns and cellular responses over time. In addition, FLS considers not only extracellular binding partners influence, but also channels or bridges of information transfer, such as specialized filopodia or cytonemes as a mechanism of Hh transport. We detect and measure morphogen particle velocity in cytonemes in the Drosophila wing imaginal disc. Indeed, this novel approach to morphogen gradient formation can contribute to future research in the field.
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Affiliation(s)
- Óscar Sánchez
- Departamento de Matemática Aplicada, Universidad de Granada, Campus de Fuentenueva, Granada, 18071, Spain
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82
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Huang H, Kornberg TB. Myoblast cytonemes mediate Wg signaling from the wing imaginal disc and Delta-Notch signaling to the air sac primordium. eLife 2015; 4:e06114. [PMID: 25951303 PMCID: PMC4423120 DOI: 10.7554/elife.06114] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 04/16/2015] [Indexed: 12/17/2022] Open
Abstract
The flight muscles, dorsal air sacs, wing blades, and thoracic cuticle of the Drosophila adult function in concert, and their progenitor cells develop together in the wing imaginal disc. The wing disc orchestrates dorsal air sac development by producing decapentaplegic and fibroblast growth factor that travel via specific cytonemes in order to signal to the air sac primordium (ASP). Here, we report that cytonemes also link flight muscle progenitors (myoblasts) to disc cells and to the ASP, enabling myoblasts to relay signaling between the disc and the ASP. Frizzled (Fz)-containing myoblast cytonemes take up Wingless (Wg) from the disc, and Delta (Dl)-containing myoblast cytonemes contribute to Notch activation in the ASP. Wg signaling negatively regulates Dl expression in the myoblasts. These results reveal an essential role for cytonemes in Wg and Notch signaling and for a signal relay system in the myoblasts.
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Affiliation(s)
- Hai Huang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
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83
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Legent K, Liu HH, Treisman JE. Drosophila Vps4 promotes Epidermal growth factor receptor signaling independently of its role in receptor degradation. Development 2015; 142:1480-91. [PMID: 25790850 DOI: 10.1242/dev.117960] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 02/20/2015] [Indexed: 12/12/2022]
Abstract
Endocytic trafficking of signaling receptors is an important mechanism for limiting signal duration. Components of the Endosomal Sorting Complexes Required for Transport (ESCRT), which target ubiquitylated receptors to intra-lumenal vesicles (ILVs) of multivesicular bodies, are thought to terminate signaling by the epidermal growth factor receptor (EGFR) and direct it for lysosomal degradation. In a genetic screen for mutations that affect Drosophila eye development, we identified an allele of Vacuolar protein sorting 4 (Vps4), which encodes an AAA ATPase that interacts with the ESCRT-III complex to drive the final step of ILV formation. Photoreceptors are largely absent from Vps4 mutant clones in the eye disc, and even when cell death is genetically prevented, the mutant R8 photoreceptors that develop fail to recruit surrounding cells to differentiate as R1-R7 photoreceptors. This recruitment requires EGFR signaling, suggesting that loss of Vps4 disrupts the EGFR pathway. In imaginal disc cells mutant for Vps4, EGFR and other receptors accumulate in endosomes and EGFR target genes are not expressed; epistasis experiments place the function of Vps4 at the level of the receptor. Surprisingly, Vps4 is required for EGFR signaling even in the absence of Shibire, the Dynamin that internalizes EGFR from the plasma membrane. In ovarian follicle cells, in contrast, Vps4 does not affect EGFR signaling, although it is still essential for receptor degradation. Taken together, these findings indicate that Vps4 can promote EGFR activity through an endocytosis-independent mechanism.
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Affiliation(s)
- Kevin Legent
- Kimmel Center for Biology and Medicine of the Skirball Institute and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Hui Hua Liu
- Kimmel Center for Biology and Medicine of the Skirball Institute and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Jessica E Treisman
- Kimmel Center for Biology and Medicine of the Skirball Institute and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
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84
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Long J, Tokhunts R, Old WM, Houel S, Rodgriguez-Blanco J, Singh S, Schilling N, J Capobianco A, Ahn NG, Robbins DJ. Identification of a family of fatty-acid-speciated sonic hedgehog proteins, whose members display differential biological properties. Cell Rep 2015; 10:1280-1287. [PMID: 25732819 DOI: 10.1016/j.celrep.2015.01.058] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 01/14/2015] [Accepted: 01/26/2015] [Indexed: 01/25/2023] Open
Abstract
Hedgehog (HH) proteins are proteolytically processed into a biologically active form that is covalently modified by cholesterol and palmitate. However, most studies of HH biogenesis have characterized protein from cells in which HH is overexpressed. We purified Sonic Hedgehog (SHH) from cells expressing physiologically relevant levels and showed that it was more potent than SHH isolated from overexpressing cells. Furthermore, the SHH in our preparations was modified with a diverse spectrum of fatty acids on its amino termini, and this spectrum of fatty acids varied dramatically depending on the growth conditions of the cells. The fatty acid composition of SHH affected its trafficking to lipid rafts as well as its potency. Our results suggest that HH proteins exist as a family of diverse lipid-speciated proteins that might be altered in different physiological and pathological contexts in order to regulate distinct properties of HH proteins.
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Affiliation(s)
- Jun Long
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136.,The Sheila and David Fuente Graduate Program in Cancer Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Robert Tokhunts
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136.,Program in Experimental and Molecular Medicine, Dartmouth Medical School, Hanover, New Hampshire 03755
| | - William M Old
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Stephane Houel
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309
| | - Jezabel Rodgriguez-Blanco
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Samer Singh
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Neal Schilling
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136.,Program in Experimental and Molecular Medicine, Dartmouth Medical School, Hanover, New Hampshire 03755
| | - Anthony J Capobianco
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136.,Sylvester Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida 33136.,Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida 33136
| | - Natalie G Ahn
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309.,Howard Hughes Medical Institute, University of Colorado, Boulder, Colorado 80309
| | - David J Robbins
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136.,Sylvester Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida 33136.,Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida 33136
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85
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D'Angelo G, Matusek T, Pizette S, Thérond PP. Endocytosis of Hedgehog through dispatched regulates long-range signaling. Dev Cell 2015; 32:290-303. [PMID: 25619925 DOI: 10.1016/j.devcel.2014.12.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 09/22/2014] [Accepted: 12/01/2014] [Indexed: 01/20/2023]
Abstract
The proteins of the Hedgehog (Hh) family are secreted proteins exerting short- and long-range control over various cell fates in developmental patterning. The Hh gradient in Drosophila wing imaginal discs consists of apical and basolateral secreted pools, but the mechanisms governing the overall establishment of the gradient remain unclear. We investigated the relative contributions of endocytosis and recycling to control the Hh gradient. We show that, upon its initial apical secretion, Hh is re-internalized. We examined the effect of the resistance-nodulation-division transporter Dispatched (Disp) on long-range Hh signaling and unexpectedly found that Disp is specifically required for apical endocytosis of Hh. Re-internalized Hh is then regulated in a Rab5- and Rab4-dependent manner to ensure its long-range activity. We propose that Hh-producing cells integrate endocytosis and recycling as two instrumental mechanisms contributing to regulate the long-range activity of Hh.
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Affiliation(s)
- Gisela D'Angelo
- Institut de Biologie de Valrose - iBV, Centre de Biochimie, Université Nice Sophia Antipolis, CNRS UMR7277, INSERM 1091, Parc Valrose, 06108 Nice Cedex 2, France.
| | - Tamás Matusek
- Institut de Biologie de Valrose - iBV, Centre de Biochimie, Université Nice Sophia Antipolis, CNRS UMR7277, INSERM 1091, Parc Valrose, 06108 Nice Cedex 2, France
| | - Sandrine Pizette
- Institut de Biologie de Valrose - iBV, Centre de Biochimie, Université Nice Sophia Antipolis, CNRS UMR7277, INSERM 1091, Parc Valrose, 06108 Nice Cedex 2, France
| | - Pascal P Thérond
- Institut de Biologie de Valrose - iBV, Centre de Biochimie, Université Nice Sophia Antipolis, CNRS UMR7277, INSERM 1091, Parc Valrose, 06108 Nice Cedex 2, France.
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86
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Seijo-Barandiarán I, Guerrero I, Bischoff M. In Vivo Imaging of Hedgehog Transport in Drosophila Epithelia. Methods Mol Biol 2015; 1322:9-18. [PMID: 26179035 DOI: 10.1007/978-1-4939-2772-2_2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The Hedgehog (Hh) signaling pathway is a regulator of patterning, cell migration and axon guidance during development as well as of homeostatic events in adult organs. It is highly conserved from Drosophila to humans. In many contexts during development, Hh appears to function as a morphogen; it spreads from producing cells to trigger concentration dependent responses in target cells, leading to their specification. During production, Hh undergoes two lipid modifications resulting in a highly hydrophobic molecule. The processes that create lipid-modified Hh for release from producing cells and that move it to target cells in a graded manner are complex. While most of the work done trying to explain Hh gradient formation is based on immunohistochemical studies in steady state, in vivo imaging in intact organisms is the finest technique to study gradient formation in real time. Both the wing imaginal disc epithelium and the adult abdominal epidermis of Drosophila are well suited for in vivo imaging. They allow us to observe the behavior of cells and fluorescently labeled proteins, without interfering with development. Here, we describe in vivo imaging methods for these two epithelia, which allowed us to study Hh transport along specialized cytoplasmic protrusions called cytonemes.
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Affiliation(s)
- Irene Seijo-Barandiarán
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Nicolas Cabrera 1, Cantoblanco, Madrid, 28049, Spain
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87
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Abstract
Recent findings in several organ systems show that cytoneme-mediated signaling transports signaling proteins along cellular extensions and targets cell-to-cell exchanges to synaptic contacts. This mechanism of paracrine signaling may be a general one that is used by many (or all) cell types in many (or all) organs. We briefly review these findings in this perspective. We also describe the properties of several signaling systems that have previously been interpreted to support a passive diffusion mechanism of signaling protein dispersion, but can now be understood in the context of the cytoneme mechanism. Also watch the Video Abstract.
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Affiliation(s)
- Sougata Roy
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Thomas B. Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
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88
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Vyas N, Walvekar A, Tate D, Lakshmanan V, Bansal D, Lo Cicero A, Raposo G, Palakodeti D, Dhawan J. Vertebrate Hedgehog is secreted on two types of extracellular vesicles with different signaling properties. Sci Rep 2014; 4:7357. [PMID: 25483805 PMCID: PMC4258658 DOI: 10.1038/srep07357] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 11/18/2014] [Indexed: 12/29/2022] Open
Abstract
Hedgehog (Hh) is a secreted morphogen that elicits differentiation and patterning in developing tissues. Multiple proposed mechanisms to regulate Hh dispersion includes lipoprotein particles and exosomes. Here we report that vertebrate Sonic Hedgehog (Shh) is secreted on two types of extracellular-vesicles/exosomes, from human cell lines and primary chick notochord cells. Although largely overlapping in size as estimated from electron micrographs, the two exosomal fractions exhibited distinct protein and RNA composition. We have probed the functional properties of these vesicles using cell-based assays of Hh-elicited gene expression. Our results suggest that while both Shh-containing exo-vesicular fractions can activate an ectopic Gli-luciferase construct, only exosomes co-expressing Integrins can activate endogenous Shh target genes HNF3β and Olig2 during the differentiation of mouse ES cells to ventral neuronal progenitors. Taken together, our results demonstrate that primary vertebrate cells secrete Shh in distinct vesicular forms, and support a model where packaging of Shh along with other signaling proteins such as Integrins on exosomes modulates target gene activation. The existence of distinct classes of Shh-containing exosomes also suggests a previously unappreciated complexity for fine-tuning of Shh-mediated gradients and pattern formation.
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Affiliation(s)
- Neha Vyas
- Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, India
| | - Ankita Walvekar
- Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, India
| | - Dhananjay Tate
- Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, India
| | | | - Dhiru Bansal
- Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, India
| | - Alessandra Lo Cicero
- 1] Institut Curie, UMR 144, CNRS, F-75248 Paris, France [2] Structure and Membrane Compartments, Centre National de la Recherche Scientifique, UMR144, Paris F-75248, France [3] Cell and Tissue Imaging Facility, Infrastructures en Biologie Sante et Agronomie (IBiSA), Paris F-75248, France
| | - Graca Raposo
- 1] Institut Curie, UMR 144, CNRS, F-75248 Paris, France [2] Structure and Membrane Compartments, Centre National de la Recherche Scientifique, UMR144, Paris F-75248, France [3] Cell and Tissue Imaging Facility, Infrastructures en Biologie Sante et Agronomie (IBiSA), Paris F-75248, France
| | | | - Jyotsna Dhawan
- 1] Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, India [2] CSIR-Center for Cellular and Molecular Biology, Hyderabad, India
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89
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Exosomes as Hedgehog carriers in cytoneme-mediated transport and secretion. Nat Commun 2014; 5:5649. [DOI: 10.1038/ncomms6649] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 10/22/2014] [Indexed: 12/12/2022] Open
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90
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Kornberg TB. Cytonemes and the dispersion of morphogens. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2014; 3:445-63. [PMID: 25186102 PMCID: PMC4199865 DOI: 10.1002/wdev.151] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 07/10/2014] [Accepted: 07/25/2014] [Indexed: 01/07/2023]
Abstract
Filopodia are cellular protrusions that have been implicated in many types of mechanosensory activities. Morphogens are signaling proteins that regulate the patterned development of embryos and tissues. Both have long histories that date to the beginnings of cell and developmental biology in the early 20th century, but recent findings tie specialized filopodia called cytonemes to morphogen movement and morphogen signaling. This review explores the conceptual and experimental background for a model of paracrine signaling in which the exchange of morphogens between cells is directed to sites where cytonemes directly link cells that produce morphogens to cells that receive and respond to them.
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Affiliation(s)
- Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
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91
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Kornberg TB. The contrasting roles of primary cilia and cytonemes in Hh signaling. Dev Biol 2014; 394:1-5. [PMID: 25072627 DOI: 10.1016/j.ydbio.2014.07.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 07/11/2014] [Accepted: 07/19/2014] [Indexed: 12/16/2022]
Abstract
Hedgehog (Hh) is a paracrine signaling protein with major roles in development and disease. In vertebrates and invertebrates, Hh signal transduction is carried out almost entirely by evolutionarily conserved components, and in both, intercellular movement of Hh is mediated by cytonemes - specialized filopodia that serve as bridges that bring distant cells into contact. A significant difference is the role of the primary cilium, a slender, tubulin-based protuberance of many vertebrate cells. Although the primary cilium is essential for Hh signaling in cells that have one, most Drosophila cells lack a primary cilium. This perspective addresses the roles of primary cilia and cytonemes, and proposes that for Hh signaling, the role of primary cilia is to provide a specialized hydrophobic environment that hosts lipid-modified Hh and other components of Hh signal transduction after Hh has traveled from elsewhere in the cell. Implicit in this model is the idea that initial binding and uptake of Hh is independent of and segregated from the processes of signal transduction and activation.
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Affiliation(s)
- Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, United States.
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92
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Cdon acts as a Hedgehog decoy receptor during proximal-distal patterning of the optic vesicle. Nat Commun 2014; 5:4272. [PMID: 25001599 PMCID: PMC4102123 DOI: 10.1038/ncomms5272] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 05/26/2014] [Indexed: 02/06/2023] Open
Abstract
Patterning of the vertebrate optic vesicle into proximal/optic stalk and distal/neural retina involves midline-derived Hedgehog (Hh) signalling, which promotes stalk specification. In the absence of Hh signalling, the stalks are not specified, causing cyclopia. Recent studies showed that the cell adhesion molecule Cdon forms a heteromeric complex with the Hh receptor Patched 1 (Ptc1). This receptor complex binds Hh and enhances signalling activation, indicating that Cdon positively regulates the pathway. Here we show that in the developing zebrafish and chick optic vesicle, in which cdon and ptc1 are expressed with a complementary pattern, Cdon acts as a negative Hh signalling regulator. Cdon predominantly localizes to the basolateral side of neuroepithelial cells, promotes the enlargement of the neuroepithelial basal end-foot and traps Hh protein, thereby limiting its dispersion. This Ptc-independent function protects the retinal primordium from Hh activity, defines the stalk/retina boundary and thus the correct proximo-distal patterning of the eye. The Drosophila homologue of the vertebrate cell surface glycoprotein Cdon binds Hedgehog ligand and thereby prevents its diffusion. Here, the authors provide evidence for a similar mechanism during vertebrate optic vesicle patterning, where Cdon acts as a negative regulator of Hedgehog signalling to define the boundary between the optic stalk and the retina.
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93
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Guerrero I, Kornberg TB. Hedgehog and its circuitous journey from producing to target cells. Semin Cell Dev Biol 2014; 33:52-62. [PMID: 24994598 DOI: 10.1016/j.semcdb.2014.06.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 06/23/2014] [Indexed: 12/12/2022]
Abstract
The hedgehog (Hh) signaling protein has essential roles in the growth, development and regulation of many vertebrate and invertebrate organs. The processes that make Hh and prepare it for release from producing cells and that move it to target cells are both diverse and complex. This article reviews the essential features of these processes and highlights recent work that provides a novel framework to understand how these processes contribute to an integrated pathway.
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Affiliation(s)
- Isabel Guerrero
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain.
| | - Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA.
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94
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Kornberg TB, Roy S. Communicating by touch--neurons are not alone. Trends Cell Biol 2014; 24:370-6. [PMID: 24560610 PMCID: PMC4037336 DOI: 10.1016/j.tcb.2014.01.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 01/02/2014] [Accepted: 01/24/2014] [Indexed: 10/25/2022]
Abstract
Long-distance cell-cell communication is essential for organ development and function. Whereas neurons communicate at long distances by transferring signals at sites of direct contact (i.e., at synapses), it has been presumed that the only way other cell types signal is by dispersing signals through extracellular fluid--indirectly. Recent evidence from Drosophila suggests that non-neuronal cells also exchange signaling proteins at sites of direct contact, even when long distances separate the cells. We review here contact-mediated signaling in neurons and discuss how this signaling mechanism is shared by other cell types.
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Affiliation(s)
- Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA.
| | - Sougata Roy
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
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95
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Hartl TA, Scott MP. Wing tips: The wing disc as a platform for studying Hedgehog signaling. Methods 2014; 68:199-206. [PMID: 24556557 DOI: 10.1016/j.ymeth.2014.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 02/03/2014] [Accepted: 02/06/2014] [Indexed: 12/26/2022] Open
Abstract
Hedgehog (Hh) signal transduction is necessary for the development of most mammalian tissues and can go awry and cause birth defects or cancer. Hh signaling was initially described in Drosophila, and much of what we know today about mammalian Hh signaling was directly guided by discoveries in the fly. Indeed, Hh signaling is a wonderful example of the use of non-vertebrate model organisms to make basic discoveries that lead to new disease treatment. The first pharmaceutical to treat hyperactive Hh signaling in Basal Cell Carcinoma was released in 2012, approximately 30 years after the isolation of Hh mutants in Drosophila. The study of Hh signaling has been greatly facilitated by the imaginal wing disc, a tissue with terrific experimental advantages. Studies using the wing disc have led to an understanding of Hh ligand processing, packaging into particles for transmission, secretion, reception, signal transduction, target gene activation, and tissue patterning. Here we describe the imaginal wing disc, how Hh patterns this tissue, and provide methods to use wing discs to study Hh signaling in Drosophila. The tools and approaches we highlight form the cornerstone of research efforts in many laboratories that use Drosophila to study Hh signaling, and are essential for ongoing discoveries.
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Affiliation(s)
- Tom A Hartl
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Matthew P Scott
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University School of Medicine, Stanford, CA 94305, USA.
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96
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Abstract
Development creates a vast array of forms and patterns with elegant economy, using a small vocabulary of pattern-generating proteins such as BMPs, FGFs and Hh in similar ways in many different contexts. Despite much theoretical and experimental work, the signaling mechanisms that disperse these morphogen signaling proteins remain controversial. Here, we review the conceptual background and evidence that establishes a fundamental and essential role for cytonemes as specialized filopodia that transport signaling proteins between signaling cells. This evidence suggests that cytoneme-mediated signaling is a dispersal mechanism that delivers signaling proteins directly at sites of cell-cell contact.
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Affiliation(s)
- Thomas B. Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, CA 94156, USA
| | - Sougata Roy
- Cardiovascular Research Institute, University of California, San Francisco, CA 94156, USA
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97
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Abstract
In vivo time-lapse imaging and functional tests bring fresh evidence that the morphogen Hedgehog is conveyed to target cells via long filopodia extensions, dubbed cytonemes. This study provides the tools and conceptual framework to understand how cytonemes form and carry morphogens.
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Affiliation(s)
- James Briscoe
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, UK
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98
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Filmus J, Capurro M. The role of glypicans in Hedgehog signaling. Matrix Biol 2014; 35:248-52. [PMID: 24412155 DOI: 10.1016/j.matbio.2013.12.007] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 12/18/2013] [Accepted: 12/18/2013] [Indexed: 01/13/2023]
Abstract
Glypicans (GPCs) are a family of proteoglycans that are bound to the cell surface by a glycosylphosphatidylinositol anchor. Six glypicans have been found in the mammalian genome (GPC1 to GPC6). GPCs regulate several signaling pathways, including the pathway triggered by Hedgehogs (Hhs). This regulation, which could be stimulatory or inhibitory, occurs at the signal reception level. In addition, GPCs have been shown to be involved in the formation of Hh gradients in the imaginal wing disks in Drosophila. In this review we will discuss the role of various glypicans in specific developmental events in the embryo that are regulated by Hh signaling. In addition, we will discuss the mechanism by which loss-of-function GPC3 mutations alter Hh signaling in the Simpson-Golabi-Behmel overgrowth syndrome, and the molecular basis of the GPC5-induced stimulation of Hh signaling and tumor progression in rhabdomyosarcomas.
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Affiliation(s)
- Jorge Filmus
- Platform of Biological Sciences, Sunnybrook Research Institute, ON, Canada; Dept. of Medical Biophysics, University of Toronto, ON, Canada.
| | - Mariana Capurro
- Platform of Biological Sciences, Sunnybrook Research Institute, ON, Canada; Dept. of Medical Biophysics, University of Toronto, ON, Canada
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99
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Roy S, Huang H, Liu S, Kornberg TB. Cytoneme-mediated contact-dependent transport of the Drosophila decapentaplegic signaling protein. Science 2014; 343:1244624. [PMID: 24385607 DOI: 10.1126/science.1244624] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Decapentaplegic (Dpp), a Drosophila morphogen signaling protein, transfers directly at synapses made at sites of contact between cells that produce Dpp and cytonemes that extend from recipient cells. The Dpp that cytonemes receive moves together with activated receptors toward the recipient cell body in motile puncta. Genetic loss-of-function conditions for diaphanous, shibire, neuroglian, and capricious perturbed cytonemes by reducing their number or only the synapses they make with cells they target, and reduced cytoneme-mediated transport of Dpp and Dpp signaling. These experiments provide direct evidence that cells use cytonemes to exchange signaling proteins, that cytoneme-based exchange is essential for signaling and normal development, and that morphogen distribution and signaling can be contact-dependent, requiring cytoneme synapses.
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Affiliation(s)
- Sougata Roy
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
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100
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Bischoff M, Gradilla AC, Seijo I, Andrés G, Rodríguez-Navas C, González-Méndez L, Guerrero I. Cytonemes are required for the establishment of a normal Hedgehog morphogen gradient in Drosophila epithelia. Nat Cell Biol 2013; 15:1269-81. [PMID: 24121526 PMCID: PMC3840581 DOI: 10.1038/ncb2856] [Citation(s) in RCA: 167] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Accepted: 08/29/2013] [Indexed: 12/13/2022]
Abstract
Hedgehog (Hh) signalling is important in development, stem cell biology and disease. In a variety of tissues, Hh acts as a morphogen to regulate growth and cell fate specification. Several hypotheses have been proposed to explain morphogen movement, one of which is transport along filopodia-like protrusions called cytonemes. Here, we analyse the mechanism underlying Hh movement in the wing disc and the abdominal epidermis of Drosophila melanogaster. We show that, in both epithelia, cells generate cytonemes in regions of Hh signalling. These protrusions are actin-based and span several cell diameters. Various Hh signalling components localize to cytonemes, as well as to punctate structures that move along cytonemes and are probably exovesicles. Using in vivo imaging, we show that cytonemes are dynamic structures and that Hh gradient establishment correlates with cytoneme formation in space and time. Indeed, mutant conditions that affect cytoneme formation reduce both cytoneme length and Hh gradient length. Our results suggest that cytoneme-mediated Hh transport is the mechanistic basis for Hh gradient formation.
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Affiliation(s)
- Marcus Bischoff
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
| | - Ana-Citlali Gradilla
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Nicolas Cabrera 1, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
| | - Irene Seijo
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Nicolas Cabrera 1, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
| | - Germán Andrés
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Nicolas Cabrera 1, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
| | - Carmen Rodríguez-Navas
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Nicolas Cabrera 1, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
| | - Laura González-Méndez
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Nicolas Cabrera 1, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
| | - Isabel Guerrero
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Nicolas Cabrera 1, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
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