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Kravec M, Šedo O, Nedvědová J, Micka M, Šulcová M, Zezula N, Gömöryová K, Potěšil D, Sri Ganji R, Bologna S, Červenka I, Zdráhal Z, Harnoš J, Tripsianes K, Janke C, Bařinka C, Bryja V. Carboxy-terminal polyglutamylation regulates signaling and phase separation of the Dishevelled protein. EMBO J 2024; 43:5635-5666. [PMID: 39349846 PMCID: PMC11574253 DOI: 10.1038/s44318-024-00254-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 08/15/2024] [Accepted: 09/16/2024] [Indexed: 11/20/2024] Open
Abstract
Polyglutamylation is a reversible posttranslational modification that is catalyzed by enzymes of the tubulin tyrosine ligase-like (TTLL) family. Here, we found that TTLL11 generates a previously unknown type of polyglutamylation that is initiated by the addition of a glutamate residue to the free C-terminal carboxyl group of a substrate protein. TTLL11 efficiently polyglutamylates the Wnt signaling protein Dishevelled 3 (DVL3), thereby changing the interactome of DVL3. Polyglutamylation increases the capacity of DVL3 to get phosphorylated, to undergo phase separation, and to act in the noncanonical Wnt pathway. Both carboxy-terminal polyglutamylation and the resulting reduction in phase separation capacity of DVL3 can be reverted by the deglutamylating enzyme CCP6, demonstrating a causal relationship between TTLL11-mediated polyglutamylation and phase separation. Thus, C-terminal polyglutamylation represents a new type of posttranslational modification, broadening the range of proteins that can be modified by polyglutamylation and providing the first evidence that polyglutamylation can modulate protein phase separation.
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Affiliation(s)
- Marek Kravec
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ondrej Šedo
- Central European Institute of Technology (CEITEC), Brno, Czech Republic
| | - Jana Nedvědová
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Miroslav Micka
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Central European Institute of Technology (CEITEC), Brno, Czech Republic
| | - Marie Šulcová
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Nikodém Zezula
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Kristína Gömöryová
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - David Potěšil
- Central European Institute of Technology (CEITEC), Brno, Czech Republic
| | - Ranjani Sri Ganji
- Central European Institute of Technology (CEITEC), Brno, Czech Republic
| | - Sara Bologna
- Central European Institute of Technology (CEITEC), Brno, Czech Republic
| | - Igor Červenka
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Zbyněk Zdráhal
- Central European Institute of Technology (CEITEC), Brno, Czech Republic
| | - Jakub Harnoš
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | | | - Carsten Janke
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France
- Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Cyril Bařinka
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic
| | - Vítězslav Bryja
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.
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2
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Hou XN, Tang C. The pros and cons of ubiquitination on the formation of protein condensates. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1084-1098. [PMID: 37294105 PMCID: PMC10423694 DOI: 10.3724/abbs.2023096] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 03/19/2023] [Indexed: 06/10/2023] Open
Abstract
Ubiquitination, a post-translational modification that attaches one or more ubiquitin (Ub) molecules to another protein, plays a crucial role in the phase-separation processes. Ubiquitination can modulate the formation of membrane-less organelles in two ways. First, a scaffold protein drives phase separation, and Ub is recruited to the condensates. Second, Ub actively phase-separates through the interactions with other proteins. Thus, the role of ubiquitination and the resulting polyUb chains ranges from bystanders to active participants in phase separation. Moreover, long polyUb chains may be the primary driving force for phase separation. We further discuss that the different roles can be determined by the lengths and linkages of polyUb chains which provide preorganized and multivalent binding platforms for other client proteins. Together, ubiquitination adds a new layer of regulation for the flow of material and information upon cellular compartmentalization of proteins.
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Affiliation(s)
- Xue-Ni Hou
- Beijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China
| | - Chun Tang
- Beijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China
- Center for Quantitate BiologyPKU-Tsinghua Center for Life ScienceAcademy for Advanced Interdisciplinary StudiesPeking UniversityBeijing100871China
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3
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Jiang Y, Huang M, Qin R, Jiang D, Chang D, Xie Y, Li C, Wang C. Full-Length Transcriptome Analysis of Soybean Cyst Nematode ( Heterodera glycines) Reveals an Association of Behaviors in Response to Attractive pH and Salt Solutions with Activation of Transmembrane Receptors, Ion Channels, and Ca 2+ Transporters. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37267587 DOI: 10.1021/acs.jafc.3c00908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Soybean cyst nematode (Heterodera glycines Ichinohe), a devastating pathogen in soybean, was chosen as a model system to investigate nematode behavior and gene expression changes in response to acidic and basic pH and salt signals (pH 4.5, 5.25, 8.6, and 10 and NaCl) through full-length transcriptome sequencing of 18 samples. An average of 4.36 Gbp of clean reads per sample were generated, and 3972 novel genes and 29,529 novel transcripts were identified. Sequence structural variation during or after transcription may be associated with the nematode's behavioral response. The functional analysis of 1817/4962 differentially expressed genes/transcripts showed that signal transduction pathways, including transmembrane receptors, ion channels, and Ca2+ transporters, were activated, but pathways involved in nematode development (e.g., ribosome) and energy production (e.g., oxidative phosphorylation) were inhibited. A corresponding model was established. Our findings suggest that these receptors and ion channels might be potential targets for nematicides or drug discovery.
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Affiliation(s)
- Ye Jiang
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081 Heilongjiang, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Minghui Huang
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081 Heilongjiang, P. R. China
| | - Ruifeng Qin
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081 Heilongjiang, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Dan Jiang
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081 Heilongjiang, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Doudou Chang
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081 Heilongjiang, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yifan Xie
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081 Heilongjiang, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Chunjie Li
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081 Heilongjiang, P. R. China
| | - Congli Wang
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081 Heilongjiang, P. R. China
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4
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Cell polarity control by Wnt morphogens. Dev Biol 2022; 487:34-41. [DOI: 10.1016/j.ydbio.2022.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 04/12/2022] [Accepted: 04/18/2022] [Indexed: 02/04/2023]
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5
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Heppert JK, Pani AM, Roberts AM, Dickinson DJ, Goldstein B. A CRISPR Tagging-Based Screen Reveals Localized Players in Wnt-Directed Asymmetric Cell Division. Genetics 2018; 208:1147-1164. [PMID: 29348144 PMCID: PMC5844328 DOI: 10.1534/genetics.117.300487] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/08/2018] [Indexed: 11/18/2022] Open
Abstract
Oriented cell divisions are critical to establish and maintain cell fates and tissue organization. Diverse extracellular and intracellular cues have been shown to provide spatial information for mitotic spindle positioning; however, the molecular mechanisms by which extracellular signals communicate with cells to direct mitotic spindle positioning are largely unknown. In animal cells, oriented cell divisions are often achieved by the localization of force-generating motor protein complexes to discrete cortical domains. Disrupting either these force-generating complexes or proteins that globally affect microtubule stability results in defects in mitotic positioning, irrespective of whether these proteins function as spatial cues for spindle orientation. This poses a challenge to traditional genetic dissection of this process. Therefore, as an alternative strategy to identify key proteins that act downstream of intercellular signaling, we screened the localization of many candidate proteins by inserting fluorescent tags directly into endogenous gene loci, without overexpressing the proteins. We tagged 23 candidate proteins in Caenorhabditis elegans and examined each protein's localization in a well-characterized, oriented cell division in the four-cell-stage embryo. We used cell manipulations and genetic experiments to determine which cells harbor key localized proteins and which signals direct these localizations in vivo We found that Dishevelled and adenomatous polyposis coli homologs are polarized during this oriented cell division in response to a Wnt signal, but two proteins typically associated with mitotic spindle positioning, homologs of NuMA and Dynein, were not detectably polarized. These results suggest an unexpected mechanism for mitotic spindle positioning in this system, they pinpoint key proteins of interest, and they highlight the utility of a screening approach based on analyzing the localization of endogenously tagged proteins.
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Affiliation(s)
- Jennifer K Heppert
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Ariel M Pani
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Allyson M Roberts
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Daniel J Dickinson
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Bob Goldstein
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, North Carolina 27599
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6
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Sugioka K, Fielmich LE, Mizumoto K, Bowerman B, van den Heuvel S, Kimura A, Sawa H. Tumor suppressor APC is an attenuator of spindle-pulling forces during C. elegans asymmetric cell division. Proc Natl Acad Sci U S A 2018; 115:E954-E963. [PMID: 29348204 PMCID: PMC5798331 DOI: 10.1073/pnas.1712052115] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The adenomatous polyposis coli (APC) tumor suppressor has dual functions in Wnt/β-catenin signaling and accurate chromosome segregation and is frequently mutated in colorectal cancers. Although APC contributes to proper cell division, the underlying mechanisms remain poorly understood. Here we show that Caenorhabditis elegans APR-1/APC is an attenuator of the pulling forces acting on the mitotic spindle. During asymmetric cell division of the C. elegans zygote, a LIN-5/NuMA protein complex localizes dynein to the cell cortex to generate pulling forces on astral microtubules that position the mitotic spindle. We found that APR-1 localizes to the anterior cell cortex in a Par-aPKC polarity-dependent manner and suppresses anterior centrosome movements. Our combined cell biological and mathematical analyses support the conclusion that cortical APR-1 reduces force generation by stabilizing microtubule plus-ends at the cell cortex. Furthermore, APR-1 functions in coordination with LIN-5 phosphorylation to attenuate spindle-pulling forces. Our results document a physical basis for the attenuation of spindle-pulling force, which may be generally used in asymmetric cell division and, when disrupted, potentially contributes to division defects in cancer.
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Affiliation(s)
- Kenji Sugioka
- Multicellular Organization Laboratory, National Institute of Genetics, 411-8540 Mishima, Japan
- RIKEN Center for Developmental Biology, Chuo-ku, 650-0047 Kobe, Japan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Lars-Eric Fielmich
- Developmental Biology, Biology Department, Science 4 Life, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Kota Mizumoto
- RIKEN Center for Developmental Biology, Chuo-ku, 650-0047 Kobe, Japan
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Sander van den Heuvel
- Developmental Biology, Biology Department, Science 4 Life, Utrecht University, 3584 CH Utrecht, The Netherlands;
| | - Akatsuki Kimura
- Cell Architecture Laboratory, National Institute of Genetics, 411-8540 Mishima, Japan;
- Department of Genetics, School of Life Science, Sokendai, 411-8540 Mishima, Japan
| | - Hitoshi Sawa
- Multicellular Organization Laboratory, National Institute of Genetics, 411-8540 Mishima, Japan;
- RIKEN Center for Developmental Biology, Chuo-ku, 650-0047 Kobe, Japan
- Department of Genetics, School of Life Science, Sokendai, 411-8540 Mishima, Japan
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7
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Structural basis for Ccd1 auto-inhibition in the Wnt pathway through homomerization of the DIX domain. Sci Rep 2017; 7:7739. [PMID: 28798413 PMCID: PMC5552852 DOI: 10.1038/s41598-017-08019-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/05/2017] [Indexed: 11/08/2022] Open
Abstract
Wnt signaling plays an important role in governing cell fate decisions. Coiled-coil-DIX1 (Ccd1), Dishevelled (Dvl), and Axin are signaling proteins that regulate the canonical pathway by controlling the stability of a key signal transducer β-catenin. These proteins contain the DIX domain with a ubiquitin-like fold, which mediates their interaction in the β-catenin destruction complex through dynamic head-to-tail polymerization. Despite high sequence similarities, mammalian Ccd1 shows weaker stimulation of β-catenin transcriptional activity compared with zebrafish (z) Ccd1 in cultured cells. Here, we show that the mouse (m) Ccd1 DIX domain displays weaker ability for homopolymerization than that of zCcd1. Furthermore, X-ray crystallographic analysis of mCcd1 and zCcd1 DIX domains revealed that mCcd1 was assembled into a double-helical filament by the insertion of the β1-β2 loop into the head-to-tail interface, whereas zCcd1 formed a typical single-helical polymer similar to Dvl1 and Axin. The mutation in the contact interface of mCcd1 double-helical polymer changed the hydrodynamic properties of mCcd1 so that it acquired the ability to induce Wnt-specific transcriptional activity similar to zCcd1. These findings suggest a novel regulatory mechanism by which mCcd1 modulates Wnt signaling through auto-inhibition of dynamic head-to-tail homopolymerization.
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8
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Baldwin AT, Clemons AM, Phillips BT. Unique and redundant β-catenin regulatory roles of two Dishevelled paralogs during C. elegans asymmetric cell division. J Cell Sci 2016; 129:983-93. [PMID: 26795562 DOI: 10.1242/jcs.175802] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 01/13/2016] [Indexed: 12/18/2022] Open
Abstract
The Wnt/β-catenin signaling pathway is utilized across metazoans. However, the mechanism of signal transduction, especially dissociation of the β-catenin destruction complex by Dishevelled proteins, remains controversial. Here, we describe the function of the Dishevelled paralogs DSH-2 and MIG-5 in the Wnt/β-catenin asymmetry (WβA) pathway in Caenorhabditis elegans, where WβA drives asymmetric cell divisions throughout development. We find that DSH-2 and MIG-5 redundantly regulate cell fate in hypodermal seam cells. Similarly, both DSH-2 and MIG-5 are required for positive regulation of SYS-1 (a C. elegans β-catenin), but MIG-5 has a stronger effect on the polarity of SYS-1 localization. We show that MIG-5 controls cortical APR-1 (the C. elegans APC) localization. DSH-2 and MIG-5 both regulate the localization of WRM-1 (another C. elegans β-catenin), acting together as negative regulators of WRM-1 nuclear localization. Finally, we demonstrate that overexpression of DSH-2 or MIG-5 in seam cells leads to stabilization of SYS-1 in the anterior seam daughter, solidifying the Dishevelled proteins as positive regulators of SYS-1. Overall, we have further defined the role of Dishevelled in the WβA signaling pathway, and demonstrated that DSH-2 and MIG-5 regulate cell fate, β-catenin nuclear levels and the polarity of β-catenin regulation.
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Affiliation(s)
- Austin T Baldwin
- Department of Biology, University of Iowa, 143 Biology Building, Iowa City, IA 52242-1324, USA
| | - Amy M Clemons
- Department of Biology, University of Iowa, 143 Biology Building, Iowa City, IA 52242-1324, USA
| | - Bryan T Phillips
- Department of Biology, University of Iowa, 143 Biology Building, Iowa City, IA 52242-1324, USA
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9
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Abstract
The ability to dictate cell fate decisions is critical during animal development. Moreover, faithful execution of this process ensures proper tissue homeostasis throughout adulthood, whereas defects in the molecular machinery involved may contribute to disease. Evolutionarily conserved protein complexes control cell fate decisions across diverse tissues. Maintaining proper daughter cell inheritance patterns of these determinants during mitosis is therefore a fundamental step of the cell fate decision-making process. In this review, we will discuss two key aspects of this fate determinant segregation activity, cortical cell polarity and mitotic spindle orientation, and how they operate together to produce oriented cell divisions that ultimately influence daughter cell fate. Our focus will be directed at the principal underlying molecular mechanisms and the specific cell fate decisions they have been shown to control.
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Affiliation(s)
| | | | - Christopher A. Johnston
- Author to whom correspondence should be addressed; ; Tel.: +1-505-277-1567; Fax: +1-505-277-0304
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10
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Asymmetric neuroblast divisions producing apoptotic cells require the cytohesin GRP-1 in Caenorhabditis elegans. Genetics 2014; 198:229-47. [PMID: 25053664 DOI: 10.1534/genetics.114.167189] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cytohesins are Arf guanine nucleotide exchange factors (GEFs) that regulate membrane trafficking and actin cytoskeletal dynamics. We report here that GRP-1, the sole Caenorhabditis elegans cytohesin, controls the asymmetric divisions of certain neuroblasts that divide to produce a larger neuronal precursor or neuron and a smaller cell fated to die. In the Q neuroblast lineage, loss of GRP-1 led to the production of daughter cells that are more similar in size and to the transformation of the normally apoptotic daughter into its sister, resulting in the production of extra neurons. Genetic interactions suggest that GRP-1 functions with the previously described Arf GAP CNT-2 and two other Arf GEFs, EFA-6 and BRIS-1, to regulate the activity of Arf GTPases. In agreement with this model, we show that GRP-1's GEF activity, mediated by its SEC7 domain, is necessary for the posterior Q cell (Q.p) neuroblast division and that both GRP-1 and CNT-2 function in the Q.posterior Q daughter cell (Q.p) to promote its asymmetry. Although functional GFP-tagged GRP-1 proteins localized to the nucleus, the extra cell defects were rescued by targeting the Arf GEF activity of GRP-1 to the plasma membrane, suggesting that GRP-1 acts at the plasma membrane. The detection of endogenous GRP-1 protein at cytokinesis remnants, or midbodies, is consistent with GRP-1 functioning at the plasma membrane and perhaps at the cytokinetic furrow to promote the asymmetry of the divisions that require its function.
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11
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Wnt and CDK-1 regulate cortical release of WRM-1/β-catenin to control cell division orientation in early Caenorhabditis elegans embryos. Proc Natl Acad Sci U S A 2013; 110:E918-27. [PMID: 23431196 DOI: 10.1073/pnas.1300769110] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In early Caenorhabditis elegans embryos, the Wingless/int (Wnt)- and Src-signaling pathways function in parallel to induce both the division orientation of the endomesoderm (EMS) blastomere and the endoderm fate of the posterior EMS daughter cell, called E. Here, we show that, in addition to its role in endoderm specification, the β-catenin-related protein Worm armadillo 1 (WRM-1) also plays a role in controlling EMS division orientation. WRM-1 localizes to the cortex of cells in both embryos and larvae and is released from the cortex in a Wnt-responsive manner. We show that WRM-1 cortical release is disrupted in a hypomorphic cyclin-dependent protein kinase 1 (cdk-1) mutant and that WRM-1 lacking potential CDK-1 phosphoacceptor sites is retained at the cortex. In both cases, cortical WRM-1 interferes with EMS spindle rotation without affecting endoderm specification. Finally, we show that removal of WRM-1 from the cortex can restore WT division orientation, even when both Wnt- and Src-signaling pathways are compromised. Our findings are consistent with a model in which Wnt signaling and CDK-1 modify WRM-1 in a temporal and spatial manner to unmask an intrinsic polarity cue required for proper orientation of the EMS cell division axis.
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12
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Munro E, Bowerman B. Cellular symmetry breaking during Caenorhabditis elegans development. Cold Spring Harb Perspect Biol 2010; 1:a003400. [PMID: 20066102 DOI: 10.1101/cshperspect.a003400] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The nematode worm Caenorhabditis elegans has produced a wellspring of insights into mechanisms that govern cellular symmetry breaking during animal development. Here we focus on two highly conserved systems that underlie many of the key symmetry-breaking events that occur during embryonic and larval development in the worm. One involves the interplay between Par proteins, Rho GTPases, and the actomyosin cytoskeleton and mediates asymmetric cell divisions that establish the germline. The other uses elements of the Wnt signaling pathway and a highly reiterative mechanism that distinguishes anterior from posterior daughter cell fates. Much of what we know about these systems comes from intensive study of a few key events-Par/Rho/actomyosin-mediated polarization of the zygote in response to a sperm-derived cue and the Wnt-mediated induction of endoderm at the four-cell stage. However, a growing body of work is revealing how C. elegans exploits elements/variants of these systems to accomplish a diversity of symmetry-breaking tasks throughout embryonic and larval development.
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Affiliation(s)
- Edwin Munro
- Center for Cell Dynamics, Friday Harbor Labs, 620 University Rd, Friday Harbor WA 98250, USA.
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13
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Hoffmann M, Segbert C, Helbig G, Bossinger O. Intestinal tube formation in Caenorhabditis elegans requires vang-1 and egl-15 signaling. Dev Biol 2010; 339:268-79. [DOI: 10.1016/j.ydbio.2009.12.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 11/26/2009] [Accepted: 12/01/2009] [Indexed: 10/20/2022]
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14
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Hingwing K, Lee S, Nykilchuk L, Walston T, Hardin J, Hawkins N. CWN-1 functions with DSH-2 to regulate C. elegans asymmetric neuroblast division in a β-catenin independent Wnt pathway. Dev Biol 2009; 328:245-56. [DOI: 10.1016/j.ydbio.2009.01.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 01/14/2009] [Accepted: 01/17/2009] [Indexed: 12/30/2022]
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15
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Bertrand V, Hobert O. Linking asymmetric cell division to the terminal differentiation program of postmitotic neurons in C. elegans. Dev Cell 2009; 16:563-75. [PMID: 19386265 PMCID: PMC2691723 DOI: 10.1016/j.devcel.2009.02.011] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 01/09/2009] [Accepted: 02/13/2009] [Indexed: 01/02/2023]
Abstract
How asymmetric divisions are connected to the terminal differentiation program of neuronal subtypes is poorly understood. In C. elegans, two homeodomain transcription factors, TTX-3 (a LHX2/9 ortholog) and CEH-10 (a CHX10 ortholog), directly activate a large battery of terminal differentiation genes in the cholinergic interneuron AIY. We establish here a transcriptional cascade linking asymmetric division to this differentiation program. A transient lineage-specific input formed by the Zic factor REF-2 and the bHLH factor HLH-2 directly activates ttx-3 expression in the AIY mother. During the terminal division of the AIY mother, an asymmetric Wnt/beta-catenin pathway cooperates with TTX-3 to directly restrict ceh-10 expression to only one of the two daughter cells. TTX-3 and CEH-10 automaintain their expression, thereby locking in the differentiation state. Our study establishes how transient lineage and asymmetric division inputs are integrated and suggests that the Wnt/beta-catenin pathway is widely used to control the identity of neuronal lineages.
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Affiliation(s)
- Vincent Bertrand
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University Medical Center, New York, NY 10032, USA.
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16
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Schlessinger K, Hall A, Tolwinski N. Wnt signaling pathways meet Rho GTPases. Genes Dev 2009; 23:265-77. [PMID: 19204114 DOI: 10.1101/gad.1760809] [Citation(s) in RCA: 292] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Wnt ligands and their receptors orchestrate many essential cellular and physiological processes. During development they control differentiation, proliferation, migration, and patterning, while in the adult, they regulate tissue homeostasis, primarily through their effects on stem cell proliferation and differentiation. Underpinning these diverse biological activities is a complex set of intracellular signaling pathways that are still poorly understood. Rho GTPases have emerged as key mediators of Wnt signals, most notably in the noncanonical pathways that involve polarized cell shape changes and migrations, but also more recently in the canonical pathway leading to beta-catenin-dependent transcription. It appears that Rho GTPases integrate Wnt-induced signals spatially and temporally to promote morphological and transcriptional changes affecting cell behavior.
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Affiliation(s)
- Karni Schlessinger
- Cell Biology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
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17
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The N- or C-terminal domains of DSH-2 can activate the C. elegans Wnt/beta-catenin asymmetry pathway. Dev Biol 2009; 328:234-44. [PMID: 19298786 DOI: 10.1016/j.ydbio.2009.01.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 01/12/2009] [Accepted: 01/13/2009] [Indexed: 12/25/2022]
Abstract
Dishevelleds are modular proteins that lie at the crossroads of divergent Wnt signaling pathways. The DIX domain of dishevelleds modulates a beta-catenin destruction complex, and thereby mediates cell fate decisions through differential activation of Tcf transcription factors. The DEP domain of dishevelleds mediates planar polarity of cells within a sheet through regulation of actin modulators. In Caenorhabditis elegans asymmetric cell fate decisions are regulated by asymmetric localization of signaling components in a pathway termed the Wnt/beta-catenin asymmetry pathway. Which domain(s) of Disheveled regulate this pathway is unknown. We show that C. elegans embryos from dsh-2(or302) mutant mothers fail to successfully undergo morphogenesis, but transgenes containing either the DIX or the DEP domain of DSH-2 are sufficient to rescue the mutant phenotype. Embryos lacking zygotic function of SYS-1/beta-catenin, WRM-1/beta-catenin, or POP-1/Tcf show defects similar to dsh-2 mutants, including a loss of asymmetry in some cell fate decisions. Removal of two dishevelleds (dsh-2 and mig-5) leads to a global loss of POP-1 asymmetry, which can be rescued by addition of transgenes containing either the DIX or DEP domain of DSH-2. These results indicate that either the DIX or DEP domain of DSH-2 is capable of activating the Wnt/beta-catenin asymmetry pathway and regulating anterior-posterior fate decisions required for proper morphogenesis.
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18
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Hardin J, King RS. The long and the short of Wnt signaling in C. elegans. Curr Opin Genet Dev 2008; 18:362-7. [PMID: 18625312 DOI: 10.1016/j.gde.2008.06.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 06/04/2008] [Accepted: 06/14/2008] [Indexed: 10/21/2022]
Abstract
The simplicity of C. elegans makes it an outstanding system to study the role of Wnt signaling in development. Many asymmetric cell divisions in C. elegans require the Wnt/beta-catenin asymmetry pathway. Recent studies confirm that SYS-1 is a structurally and functionally divergent beta-catenin, and implicate lipids and retrograde trafficking in maintenance of WRM-1/beta-catenin asymmetry. Wnts also regulate short-range events such as spindle rotation and gastrulation, and a PCP-like pathway regulates asymmetric divisions. Long-range, cell non-autonomous Wnt signals regulate vulval induction. Both short-range and long-range Wnt signal s are regulated by recycling of MIG-14/Wntless via the retromer complex. These studies indicate that C. elegans continues to be useful for identifying new, conserved mechanisms underlying Wnt signaling in metazoans.
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Affiliation(s)
- Jeff Hardin
- Graduate Program in Cellular and Molecular Biology, Department of Zoology, University of Wisconsin, 1117 W. Johnson Street, Madison, WI 53706, USA.
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19
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Abstract
Asymmetric cell division and apoptosis (programmed cell death) are two fundamental processes that are important for the development and function of multicellular organisms. We have found that the processes of asymmetric cell division and apoptosis can be functionally linked. Specifically, we show that asymmetric cell division in the nematode Caenorhabditis elegans is mediated by a pathway involving three genes, dnj-11 MIDA1, ces-2 HLF, and ces-1 Snail, that directly control the enzymatic machinery responsible for apoptosis. Interestingly, the MIDA1-like protein GlsA of the alga Volvox carteri, as well as the Snail-related proteins Snail, Escargot, and Worniu of Drosophila melanogaster, have previously been implicated in asymmetric cell division. Therefore, C. elegans dnj-11 MIDA1, ces-2 HLF, and ces-1 Snail may be components of a pathway involved in asymmetric cell division that is conserved throughout the plant and animal kingdoms. Furthermore, based on our results, we propose that this pathway directly controls the apoptotic fate in C. elegans, and possibly other animals as well. Asymmetric cell division and apoptosis (programmed cell death) are two fundamental processes that are important for the development and function of multicellular organisms. Asymmetric cell division creates daughter cells of different fates, and this is critical for the generation of cellular diversity. Apoptosis eliminates superfluous cells from the organism, which is critical for cellular homeostasis. We found that the processes of asymmetric cell division and apoptosis can be functionally linked. Specifically, we show that asymmetric cell division in the nematode Caenorhabditis elegans is mediated by a pathway involving three genes, dnj-11 MIDA1, ces-2 HLF, and ces-1 Snail, that directly control the enzymatic machinery responsible for apoptosis. Interestingly, the role of this pathway in asymmetric cell division and the control of apoptosis might be evolutionarily conserved. Furthermore, it might have an unexpected role in stem cell biology: the process of asymmetric cell division plays an essential role in the ability of stem cells to self-renew, and the mammalian counterparts of two components of the dnj-11 MIDA1, ces-2 HLF, ces-1 Snail pathway have recently been implicated in stem cell function. For this reason, we speculate that a dnj-11 MIDA1, ces-2 HLF, ces-1 Snail–like pathway might function in stem cells to coordinate self-renewal and apoptosis and, hence, the number of stem cells. A pathway involved in asymmetric cell division in the nematode Caenorhabditis elegans, the dnj-11 MIDA1, ces-2 HLF, ces-1 Snail pathway, directly controls the enzymatic machinery responsible for apoptosis.
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Affiliation(s)
- Julia Hatzold
- Department of Genetics, Norris Cotton Cancer Center, Dartmouth Medical School, Hanover, New Hampshire, United States of America
- Max Planck Institute of Neurobiology, Planegg-Martinsried, Germany
| | - Barbara Conradt
- Department of Genetics, Norris Cotton Cancer Center, Dartmouth Medical School, Hanover, New Hampshire, United States of America
- * To whom correspondence should be addressed. E-mail:
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20
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Ren J, Wang L, Liu G, Zhang W, Sheng Z, Wang Z, Fei J. Improved method to raise polyclonal antibody using enhanced green fluorescent protein transgenic mice. Acta Biochim Biophys Sin (Shanghai) 2008; 40:111-5. [PMID: 18235972 PMCID: PMC7109985 DOI: 10.1111/j.1745-7270.2008.00381.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Recombinant fusion protein is widely used as an antigen to raise antibodies against the epitope of a target protein. However, the concomitant anticarrier antibody in resulting antiserum reduces the production of the desired antibody and brings about unwanted non-specific immune reactions. It is proposed that the carrier protein transgenic animal could be used to solve this problem. To validate this hypothesis, enhanced green fluorescent protein (EGFP) transgenic mice were produced. By immunizing the mice with fusion protein His6HAtag-EGFP, we showed that the antiserum from the transgenic mice had higher titer antibody against His6HA tag and lower titer antibody against EGFP compared with that from wild-type mice. Therefore, this report describes an improved method to raise high titer antipeptide polyclonal antibody using EGFP transgenic mice that could have application potential in antibody preparation.
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Affiliation(s)
- Jianke Ren
- Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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21
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Wu Z, Ghosh-Roy A, Yanik MF, Zhang JZ, Jin Y, Chisholm AD. Caenorhabditis elegans neuronal regeneration is influenced by life stage, ephrin signaling, and synaptic branching. Proc Natl Acad Sci U S A 2007; 104:15132-7. [PMID: 17848506 PMCID: PMC1975853 DOI: 10.1073/pnas.0707001104] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Indexed: 11/18/2022] Open
Abstract
We previously reported functional regeneration of Caenorhabditis elegans motor neurons after femtosecond laser axotomy. We report here that multiple neuronal types can regrow after laser axotomy using a variety of lasers. The precise pattern of regrowth varies with cell type, stage of animal, and position of axotomy. Mechanosensory axons cut in late larval or adult stages displayed extensive regrowth, yet failed to reach their target area because of guidance errors in the anteroposterior axis. By contrast, mechanosensory axons cut in early larval stages regrew at the same rate but with fewer anteroposterior guidance errors, and were more likely to reach their target area. In adult animals lacking the VAB-1 Eph receptor tyrosine kinase, mechanosensory axon regrowth was more accurate than in the wild type, suggesting that guidance errors of regrowing touch neuron axons are the result of Eph signaling. Kinase-dependent and kinase-independent Eph signaling influenced outgrowth and guidance of regrowing touch neurons, respectively. Mechanosensory neurons regrew when severed proximal to their collateral synaptic branch but did not regrow when severed distal to the branch point. However, the distal axon could regrow if the branch is removed surgically at the same time as distal axotomy, or at a later time. The touch neuron synaptic branch point may act as a sorting area to regulate growth. These findings reveal that multiple influences affect regenerative growth in C. elegans neurons.
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Affiliation(s)
- Zilu Wu
- *Division of Biological Sciences, Center for Molecular Genetics, and
- Howard Hughes Medical Institute, University of California at San Diego, La Jolla, CA 92093
- Department of Molecular, Cell, and Developmental Biology, Sinsheimer Laboratories, University of California, Santa Cruz, CA 95064
| | - Anindya Ghosh-Roy
- *Division of Biological Sciences, Center for Molecular Genetics, and
| | | | - Jin Z. Zhang
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA 95064
| | - Yishi Jin
- *Division of Biological Sciences, Center for Molecular Genetics, and
- Howard Hughes Medical Institute, University of California at San Diego, La Jolla, CA 92093
- Department of Molecular, Cell, and Developmental Biology, Sinsheimer Laboratories, University of California, Santa Cruz, CA 95064
| | - Andrew D. Chisholm
- *Division of Biological Sciences, Center for Molecular Genetics, and
- Department of Molecular, Cell, and Developmental Biology, Sinsheimer Laboratories, University of California, Santa Cruz, CA 95064
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22
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Schwarz-Romond T, Fiedler M, Shibata N, Butler PJG, Kikuchi A, Higuchi Y, Bienz M. The DIX domain of Dishevelled confers Wnt signaling by dynamic polymerization. Nat Struct Mol Biol 2007; 14:484-92. [PMID: 17529994 DOI: 10.1038/nsmb1247] [Citation(s) in RCA: 340] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Accepted: 04/06/2007] [Indexed: 12/14/2022]
Abstract
The Wnt signaling pathway controls numerous cell fates in animal development and is also a major cancer pathway. Dishevelled (Dvl) transduces the Wnt signal by interacting with the cytoplasmic Axin complex. Dvl and Axin each contain a DIX domain whose molecular properties and structure are unknown. Here, we demonstrate that the DIX domain of Dvl2 mediates dynamic polymerization, which is essential for the signaling activity of Dvl2. The purified domain polymerizes gradually, reversibly and in a concentration dependent manner, ultimately forming fibrils. The Axin DIX domain has a novel structural fold largely composed of beta-strands that engage in head-to-tail self-interaction to form filaments in the crystal. The DIX domain thus seems to mediate the formation of a dynamic interaction platform with a high local concentration of binding sites for transient Wnt signaling partners; this represents a previously uncharacterized mechanistic principle, signaling by reversible polymerization.
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Affiliation(s)
- Thomas Schwarz-Romond
- Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK
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23
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Sear RP. Dishevelled: a protein that functions in living cells by phase separating. SOFT MATTER 2007; 3:680-684. [PMID: 32900127 DOI: 10.1039/b618126k] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We review experimental work on a protein called Dishevelled. The unusual name derives from the fact that some mutations in Dishevelled cause fruit flies to develop with misaligned hairs on their bodies. Dishevelled apparently phase separates inside the cytosol of cells. As mutant variants of this protein that cannot phase separate also cannot perform their biological function, phase separation appears to be functional. The mechanism by which Dishevelled functions is poorly understood. We suggest that physical scientists may be able to contribute to the effort to understand how Dishevelled functions, by applying their knowledge of phase separation behaviour. We start to do this by comparing the predictions of a simple model of phase separation to the experimental data.
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Affiliation(s)
- Richard P Sear
- Department of Physics, University of Surrey, Guildford, Surrey, United KingdomGU2 7XH.
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24
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Wu M, Herman MA. Asymmetric localizations of LIN-17/Fz and MIG-5/Dsh are involved in the asymmetric B cell division in C. elegans. Dev Biol 2006; 303:650-62. [PMID: 17196955 PMCID: PMC1858672 DOI: 10.1016/j.ydbio.2006.12.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 11/21/2006] [Accepted: 12/02/2006] [Indexed: 10/23/2022]
Abstract
LIN-44/Wnt and LIN-17/Frizzled (Fz) function in a planar cell polarity (PCP)-like pathway to regulate the asymmetric B cell division in Caenorhabditis elegans. We observed asymmetric localization of LIN-17/Frizzled (Fz) and MIG-5/Dishevelled (Dsh) during the B cell division. LIN-17::GFP was asymmetrically localized within the B cell prior to and after the B cell division and correlated with B cell polarity. Asymmetric localization of LIN-17::GFP was dependent upon LIN-44/Wnt and MIG-5/Dsh function. The LIN-17 transmembrane domain and a portion of the cysteine-rich domain (CRD) were required for LIN-17 function and asymmetric distribution to the B cell daughters, while the conserved KTXXXW motif was only required for function. MIG-5::GFP was also asymmetrically localized within the B cell prior to and after the B cell division in a LIN-17- and LIN-44-dependent manner. Functions of the MIG-5 DEP, PDZ and DIX domains were also conserved. Thus, a novel PCP-like pathway, in which LIN-17 and MIG-5 are asymmetrically localized, is involved in the regulation of B cell polarity.
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Affiliation(s)
| | - Michael A. Herman
- *Author for correspondence: , Phone number: 785-532-6773, Fax: 785-532-6653
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Hao L, Johnsen R, Lauter G, Baillie D, Bürglin TR. Comprehensive analysis of gene expression patterns of hedgehog-related genes. BMC Genomics 2006; 7:280. [PMID: 17076889 PMCID: PMC1636047 DOI: 10.1186/1471-2164-7-280] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Accepted: 10/31/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Caenorhabditis elegans genome encodes ten proteins that share sequence similarity with the Hedgehog signaling molecule through their C-terminal autoprocessing Hint/Hog domain. These proteins contain novel N-terminal domains, and C. elegans encodes dozens of additional proteins containing only these N-terminal domains. These gene families are called warthog, groundhog, ground-like and quahog, collectively called hedgehog (hh)-related genes. Previously, the expression pattern of seventeen genes was examined, which showed that they are primarily expressed in the ectoderm. RESULTS With the completion of the C. elegans genome sequence in November 2002, we reexamined and identified 61 hh-related ORFs. Further, we identified 49 hh-related ORFs in C. briggsae. ORF analysis revealed that 30% of the genes still had errors in their predictions and we improved these predictions here. We performed a comprehensive expression analysis using GFP fusions of the putative intergenic regulatory sequence with one or two transgenic lines for most genes. The hh-related genes are expressed in one or a few of the following tissues: hypodermis, seam cells, excretory duct and pore cells, vulval epithelial cells, rectal epithelial cells, pharyngeal muscle or marginal cells, arcade cells, support cells of sensory organs, and neuronal cells. Using time-lapse recordings, we discovered that some hh-related genes are expressed in a cyclical fashion in phase with molting during larval development. We also generated several translational GFP fusions, but they did not show any subcellular localization. In addition, we also studied the expression patterns of two genes with similarity to Drosophila frizzled, T23D8.1 and F27E11.3A, and the ortholog of the Drosophila gene dally-like, gpn-1, which is a heparan sulfate proteoglycan. The two frizzled homologs are expressed in a few neurons in the head, and gpn-1 is expressed in the pharynx. Finally, we compare the efficacy of our GFP expression effort with EST, OST and SAGE data. CONCLUSION No bona-fide Hh signaling pathway is present in C. elegans. Given that the hh-related gene products have a predicted signal peptide for secretion, it is possible that they constitute components of the extracellular matrix (ECM). They might be associated with the cuticle or be present in soluble form in the body cavity. They might interact with the Patched or the Patched-related proteins in a manner similar to the interaction of Hedgehog with its receptor Patched.
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Affiliation(s)
- Limin Hao
- Department of Biosciences and Nutrition, and Center for Genomics and Bioinformatics, Karolinska Institutet, SE-141 57 Huddinge, Sweden
| | - Robert Johnsen
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, B.C. Canada
| | - Gilbert Lauter
- Department of Biosciences and Nutrition, and Center for Genomics and Bioinformatics, Karolinska Institutet, SE-141 57 Huddinge, Sweden
- School of Life Sciences, Södertörns Högskola, Alfred Nobels Allé 7, SE-141 89 Huddinge, Sweden
| | - David Baillie
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, B.C. Canada
| | - Thomas R Bürglin
- Department of Biosciences and Nutrition, and Center for Genomics and Bioinformatics, Karolinska Institutet, SE-141 57 Huddinge, Sweden
- School of Life Sciences, Södertörns Högskola, Alfred Nobels Allé 7, SE-141 89 Huddinge, Sweden
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26
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Cordes S, Frank CA, Garriga G. The C. elegans MELK ortholog PIG-1 regulates cell size asymmetry and daughter cell fate in asymmetric neuroblast divisions. Development 2006; 133:2747-56. [PMID: 16774992 DOI: 10.1242/dev.02447] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the nematode Caenorhabditis elegans, neurons are generated from asymmetric divisions in which a mother cell divides to produce daughters that differ in fate. Here, we demonstrate that the gene pig-1 regulates the asymmetric divisions of neuroblasts that divide to produce an apoptotic cell and either a neural precursor or a neuron. In pig-1 mutants, these neuroblasts divide to produce daughters that are more equal in size, and their apoptotic daughters are transformed into their sisters, leading to the production of extra neurons. PIG-1 is orthologous to MELK, a conserved member of the polarity-regulating PAR-1/Kin1/SAD-1 family of serine/threonine kinases. Although MELK has been implicated in regulating the cell cycle, our data suggest that PIG-1, like other PAR-1 family members, regulates cell polarity.
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Affiliation(s)
- Shaun Cordes
- Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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