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1.
PLoS Genet ; 12(8): e1006276, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27564576

RESUMO

Mg2+ serves as an essential cofactor for numerous enzymes and its levels are tightly regulated by various Mg2+ transporters. Here, we analyzed Caenorhabditis elegans strains carrying mutations in genes encoding cyclin M (CNNM) Mg2+ transporters. We isolated inactivating mutants for each of the five Caenorhabditis elegans cnnm family genes, cnnm-1 through cnnm-5. cnnm-1; cnnm-3 double mutant worms showed various phenotypes, among which the sterile phenotype was rescued by supplementing the media with Mg2+. This sterility was caused by a gonadogenesis defect with severely attenuated proliferation of germ cells. Using this gonadogenesis defect as an indicator, we performed genome-wide RNAi screening, to search for genes associated with this phenotype. The results revealed that RNAi-mediated inactivation of several genes restores gonad elongation, including aak-2, which encodes the catalytic subunit of AMP-activated protein kinase (AMPK). We then generated triple mutant worms for cnnm-1; cnnm-3; aak-2 and confirmed that the aak-2 mutation also suppressed the defective gonadal elongation in cnnm-1; cnnm-3 mutant worms. AMPK is activated under low-energy conditions and plays a central role in regulating cellular metabolism to adapt to the energy status of cells. Thus, we provide genetic evidence linking Mg2+ homeostasis to energy metabolism via AMPK.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Proteínas de Transporte de Cátions/genética , Ciclinas/genética , Longevidade/genética , Complexos Multiproteicos/genética , Proteínas Serina-Treonina Quinases/genética , Serina-Treonina Quinases TOR/genética , Proteínas Quinases Ativadas por AMP , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/metabolismo , Ciclinas/biossíntese , Células Germinativas/crescimento & desenvolvimento , Células Germinativas/metabolismo , Gônadas/crescimento & desenvolvimento , Gônadas/metabolismo , Mucosa Intestinal/crescimento & desenvolvimento , Mucosa Intestinal/metabolismo , Magnésio/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Família Multigênica/genética , Mutação , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , Transdução de Sinais/genética
2.
Development ; 141(1): 209-18, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24346701

RESUMO

The stable maintenance of acquired cell fates is important during development and for maintaining tissue homeostasis. Although histone modification is one of the major strategies used by cells to maintain their fates, the mechanisms by which histone variants maintain cell fates are not well understood. In C. elegans, the acetylated-histone-H4 (AcH4)-binding protein BET-1 acts downstream of the MYST family histone acetyltransferases MYS-1 and MYS-2 to establish and maintain cell fates in multiple cell lineages. Here we show that, in the bet-1 pathway, the histone H2A variant HTZ-1/H2A.z and MYS-1 are required for the maintenance of cell fates in a redundant manner. BET-1 controlled the subnuclear localization of HTZ-1. HTZ-1 and MYS-1 maintained the fates of the somatic gonadal cells (SGCs) through the repression of a target, ceh-22/Nkx2.5, which induced the formation of the leader cells of the gonad. H3K27 demethylase, UTX-1, had an antagonistic effect relative to HTZ-1 in the regulation of ceh-22. Nuclear spot assay revealed that HTZ-1 localized to the ceh-22 locus in SGCs in an utx-1-dependent manner. We propose that HTZ-1 and MYS-1 repress ceh-22 when UTX-1 removes its silencing mark, H3K27 methylation on the ceh-22 locus, thereby maintaining the fates of SGCs.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/citologia , Gônadas/embriologia , Histona Acetiltransferases/metabolismo , Histona Desmetilases/metabolismo , Histonas/metabolismo , Proteínas de Homeodomínio/metabolismo , Fatores de Transcrição/metabolismo , Adenosina Trifosfatases/genética , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/biossíntese , Proteínas de Caenorhabditis elegans/genética , Diferenciação Celular , Linhagem da Célula , Proteínas Cromossômicas não Histona/genética , DNA Helicases/genética , Metilação de DNA , Regulação da Expressão Gênica no Desenvolvimento , Gônadas/citologia , Histona Desmetilases/genética , Proteínas de Homeodomínio/biossíntese , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , Transativadores/genética , Fatores de Transcrição/biossíntese
3.
PLoS Genet ; 10(6): e1004428, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24968003

RESUMO

Spatiotemporal regulation of cell migration is crucial for animal development and organogenesis. Compared to spatial signals, little is known about temporal signals and the mechanisms integrating the two. In the Caenorhabditis elegans hermaphrodite, the stereotyped migration pattern of two somatic distal tip cells (DTCs) is responsible for shaping the gonad. Guidance receptor UNC-5 is necessary for the dorsalward migration of DTCs. We found that BLMP-1, similar to the mammalian zinc finger transcription repressor Blimp-1/PRDI-BF1, prevents precocious dorsalward turning by inhibiting precocious unc-5 transcription and is only expressed in DTCs before they make the dorsalward turn. Constitutive expression of blmp-1 when BLMP-1 would normally disappear delays unc-5 transcription and causes turn retardation, demonstrating the functional significance of blmp-1 down-regulation. Correct timing of BLMP-1 down-regulation is redundantly regulated by heterochronic genes daf-12, lin-29, and dre-1, which regulate the temporal fates of various tissues. DAF-12, a steroid hormone receptor, and LIN-29, a zinc finger transcription factor, repress blmp-1 transcription, while DRE-1, the F-Box protein of an SCF ubiquitin ligase complex, binds to BLMP-1 and promotes its degradation. We have therefore identified a gene circuit that integrates the temporal and spatial signals and coordinates with overall development of the organism to direct cell migration during organogenesis. The tumor suppressor gene product FBXO11 (human DRE-1 ortholog) also binds to PRDI-BF1 in human cell cultures. Our data suggest evolutionary conservation of these interactions and underscore the importance of DRE-1/FBXO11-mediated BLMP-1/PRDI-BF1 degradation in cellular state transitions during metazoan development.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Proteínas F-Box/genética , Organogênese/genética , Proteínas Repressoras/genética , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Movimento Celular/genética , Evolução Molecular , Proteínas F-Box/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Gônadas/crescimento & desenvolvimento , Gônadas/metabolismo , Humanos , Fator 1 de Ligação ao Domínio I Regulador Positivo , Proteólise , Receptores de Superfície Celular/genética
4.
Dev Biol ; 397(2): 151-61, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25446539

RESUMO

Organs are often formed by the extension and branching of epithelial tubes. An appropriate termination of epithelial tube extension is important for generating organs of the proper size and morphology. However, the mechanism by which epithelial tubes terminate their extension is mostly unknown. Here we show that the BED-finger domain protein MIG-39 acts to stop epithelial tube extension in Caenorhabditis elegans. The gonadal leader cells, called distal tip cells (DTCs), migrate in a U-shaped pattern during larval development and stop migrating at the young adult stage, generating a gonad with anterior and posterior U-shaped arms. In mig-39 mutants, however, DTCs overshot their normal stopping position. MIG-39 promoted the deceleration of DTCs, leading to the proper timing and positioning of the cessation of DTC migration. Among three Rac GTPase genes, mutations in ced-10 and rac-2 enhanced the overshoot of anterior DTCs, while they suppressed that of posterior DTCs of mig-39 mutants. On the other hand, the mutation in mig-2 suppressed both the anterior and posterior DTC defects of mig-39. Genetic analyses suggested that MIG-39 acts in parallel with Rac GTPases in stopping DTC migration. We propose a model in which the anterior and posterior DTCs respond in an opposite manner to the levels of Rac activities in the cessation of DTC migration.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/embriologia , Movimento Celular/fisiologia , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/fisiologia , Gônadas/embriologia , Animais , Animais Geneticamente Modificados , Proteínas de Caenorhabditis elegans/genética , Movimento Celular/genética , Primers do DNA/genética , Proteínas de Ligação a DNA/genética , Gônadas/citologia , Imuno-Histoquímica , Modelos Biológicos , Mutação/genética , Plasmídeos/genética , Interferência de RNA , Proteínas rac de Ligação ao GTP/genética
5.
Development ; 140(16): 3435-44, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23900541

RESUMO

Cell migration and axon guidance require proper regulation of the actin cytoskeleton in response to extracellular guidance cues. Rho/Rac small GTPases are essential regulators of actin remodeling. Caenorhabditis elegans CED-10 is a Rac1 homolog that is required for various cellular morphological changes and migration events and is under the control of several guidance signaling pathways. There is still considerable uncertainty regarding events following the activation of guidance receptors by extracellular signals and the regulation of actin dynamics based on spatiotemporally restricted Rac activity. Here we show that the VPS9 domain protein RIN-1 acts as a novel effector for CED-10 in C. elegans. The orthologous mammalian Rin1 protein has previously been identified as an effector for Ras GTPase and is now known to function as a guanine nucleotide exchange factor for Rab5 GTPase. We found that RIN-1 specifically binds to the GTP-bound form of CED-10 and that mutations in rin-1 cause significant defects in migration and axon guidance of restricted neuronal cell types including AVM and HSN neurons, in contrast to the various defects observed in ced-10 mutants. Our analyses place RIN-1 in the Slit-Robo genetic pathway that regulates repulsive signaling for dorsoventral axon guidance. In rin-1 mutants, actin accumulated on both the ventral and dorsal sides of the developing HSN neuron, in contrast to its ventral accumulation in wild type. These results strongly suggest that RIN-1 acts as an effector for CED-10/Rac1 and regulates actin remodeling in response to restricted guidance cues.


Assuntos
Axônios/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Movimento Celular , Regulação da Expressão Gênica no Desenvolvimento , Neurônios/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Citoesqueleto de Actina/metabolismo , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Clonagem Molecular , Dados de Sequência Molecular , Mutação , Ligação Proteica , Mapeamento de Interação de Proteínas , Transporte Proteico , Pseudópodes/metabolismo , Transdução de Sinais , Proteínas rac de Ligação ao GTP/genética
6.
Development ; 138(18): 4013-23, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21831923

RESUMO

Cytoskeletal regulation is important in cell migration. The Caenorhabditis elegans gonadal distal tip cells (DTCs) offer a simple model with which to investigate the mechanism of cell migration in organogenesis. Here, we report that one of the spectraplakin isoforms, VAB-10B1, plays an essential role in cell and nuclear migration of DTCs by regulating the actin and microtubule (MT) cytoskeleton. In the vab-10(tk27) mutant, which lacks VAB-10B1, alignment of filamentous (F)-actin and MTs was weakly and severely disorganized, respectively, which resulted in a failure to translocate the DTC nucleus and a premature termination of DTC migration. An MT growing-tip marker, EBP-2-GFP, revealed that polarized outgrowth of MTs towards the nuclei of migrating DTCs was strikingly impaired in tk27 animals. A vab-10 mini-gene encoding only the actin- and MT-binding domains significantly rescued the gonadal defects, suggesting that VAB-10B1 has a role in linking actin and MT filaments. These results suggest that VAB-10B1/spectraplakin regulates the polarized alignment of MTs, possibly by linking F-actin and MTs, which enables normal nuclear translocation and cell migration of DTCs.


Assuntos
Proteínas de Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Movimento Celular/genética , Núcleo Celular/fisiologia , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/fisiologia , Actinas/metabolismo , Animais , Animais Geneticamente Modificados , Padronização Corporal/genética , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/ultraestrutura , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Embrião não Mamífero , Gônadas/metabolismo , Gônadas/fisiologia , Microtúbulos/metabolismo , Microtúbulos/fisiologia , Modelos Biológicos , Plaquinas/genética , Plaquinas/metabolismo , Plaquinas/fisiologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/fisiologia
7.
Sci Rep ; 14(1): 4813, 2024 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-38413743

RESUMO

Chondroitin, a class of glycosaminoglycan polysaccharides, is found as proteoglycans in the extracellular matrix, plays a crucial role in tissue morphogenesis during development and axonal regeneration. Ingestion of chondroitin prolongs the lifespan of C. elegans. However, the roles of endogenous chondroitin in regulating lifespan and healthspan mostly remain to be investigated. Here, we demonstrate that a gain-of-function mutation in MIG-22, the chondroitin polymerizing factor (ChPF), results in elevated chondroitin levels and a significant extension of both the lifespan and healthspan in C. elegans. Importantly, the remarkable longevity observed in mig-22(gf) mutants is dependent on SQV-5/chondroitin synthase (ChSy), highlighting the pivotal role of chondroitin in controlling both lifespan and healthspan. Additionally, the mig-22(gf) mutation effectively suppresses the reduced healthspan associated with the loss of MIG-17/ADAMTS metalloprotease, a crucial for factor in basement membrane (BM) remodeling. Our findings suggest that chondroitin functions in the control of healthspan downstream of MIG-17, while regulating lifespan through a pathway independent of MIG-17.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Condroitina/metabolismo , Longevidade/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Glicosaminoglicanos/metabolismo , Metaloendopeptidases/metabolismo , Desintegrinas/metabolismo
8.
Dev Biol ; 361(2): 349-57, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22119053

RESUMO

The SWI/SNF-like chromatin remodeling complexes consist of two evolutionarily conserved subclasses, which are characterized by specific accessory components, the OSA/BAF250 and Polybromo proteins. These complexes regulate the expressions of distinct sets of target genes, with some overlap, and the regulatory components are thought to determine the target specificity for each complex. Here we isolated C. elegans mutants of the genes for the OSA/BAF250 homolog, LET-526, and the Polybromo homolog, PBRM-1, in a screen for the abnormal asymmetric cell division phenotype. In the asymmetric division of the T cell, both LET-526 and PBRM-1 regulated the asymmetric expression of psa-3/Meis between the T cell daughters, suggesting that the two subclasses share the same target. In the gonad, PBRM-1 regulated gonad primordium formation during embryogenesis, whereas LET-526 was required post-embryonically for distal tip cell (DTC) production from the gonad primordium, suggesting that these proteins have distinct targets for DTC development. Thus, the same cellular process is regulated by LET-526 and PBRM-1 in the asymmetric division of the T cell, but they regulate distinct cellular processes in the gonad morphogenesis. Although disruption of the core component PSA-1 or PSA-4 caused similar defects in the gonad and T cell, it also caused early embryonic arrest, which was not observed in the let-526, pbrm-1, or let-526 pbrm-1 double mutants, suggesting that some targets of SWI/SNF-like complexes do not require LET-526 or PBRM-1 for their transcription. Our results show that the target selection by SWI/SNF-like complexes during C. elegans development is intricately regulated by accessory components.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/metabolismo , Montagem e Desmontagem da Cromatina , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Linhagem da Célula , Proteínas Cromossômicas não Histona/metabolismo , Clonagem Molecular , Desenvolvimento Embrionário/genética , Genes de Helmintos/genética , Gônadas/citologia , Gônadas/crescimento & desenvolvimento , Gônadas/metabolismo , Mitose/genética , Mutação/genética , Fenótipo , Transporte Proteico , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt/genética
9.
J Biol Chem ; 285(44): 34155-67, 2010 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-20729547

RESUMO

Chondroitin sulfate (CS) is a polysaccharide consisting of repeating disaccharide units of N-acetyl-D-galactosamine and d-glucuronic acid residues, modified with sulfated residues at various positions. To date six glycosyltransferases for chondroitin synthesis have been identified, and the complex of chondroitin sulfate synthase-1 (CSS1)/chondroitin synthase-1 (ChSy-1) and chondroitin sulfate synthase-2 (CSS2)/chondroitin polymerizing factor is assumed to play a major role in CS biosynthesis. We found an alternative splice variant of mouse CSS2 in a data base that lacks the N-terminal transmembrane domain, contrasting to the original CSS2. Here, we investigated the roles of CSS2 variants. Both the original enzyme and the splice variant, designated CSS2A and CSS2B, respectively, were expressed at different levels and ratios in tissues. Western blot analysis of cultured mouse embryonic fibroblasts confirmed that both enzymes were actually synthesized as proteins and were localized in both the endoplasmic reticulum and the Golgi apparatus. Pulldown assays revealed that either of CSS2A, CSS2B, and CSS1/ChSy-1 heterogeneously and homogeneously interacts with each other, suggesting that they form a complex of multimers. In vitro glycosyltransferase assays demonstrated a reduced glucuronyltransferase activity in CSS2B and no polymerizing activity in CSS2B co-expressed with CSS1, in contrast to CSS2A co-expressed with CSS1. Radiolabeling analysis of cultured COS-7 cells overexpressing each variant revealed that, whereas CSS2A facilitated CS biosynthesis, CSS2B inhibited it. Molecular modeling of CSS2A and CSS2B provided support for their properties. These findings, implicating regulation of CS chain polymerization by CSS2 variants, provide insight in elucidating the mechanisms of CS biosynthesis.


Assuntos
Hexosiltransferases/fisiologia , N-Acetilgalactosaminiltransferases/química , Processamento Alternativo , Sequência de Aminoácidos , Animais , Células COS , Chlorocebus aethiops , Glicosaminoglicanos/química , Hexosiltransferases/química , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Células NIH 3T3 , Homologia de Sequência de Aminoácidos
10.
Dev Cell ; 10(4): 473-82, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16563875

RESUMO

C. elegans diapause, gonadal outgrowth, and life span are regulated by a lipophilic hormone, which serves as a ligand to the nuclear hormone receptor DAF-12. A key step in hormone production is catalyzed by the CYP450 DAF-9, but the extent of the biosynthetic pathway is unknown. Here, we identify a conserved Rieske-like oxygenase, DAF-36, as a component in hormone metabolism. Mutants display larval developmental and adult aging phenotypes, as well as patterns of epistasis similar to that of daf-9. Larval phenotypes are potently reversed by crude lipid extracts, 7-dehydrocholesterol, and a recently identified DAF-12 sterol ligand, suggesting that DAF-36 works early in the hormone biosynthetic pathway. DAF-36 is expressed primarily within the intestine, a major organ of metabolic and endocrine control, distinct from DAF-9. These results imply that C. elegans hormone production has multiple steps and is distributed, and that it may provide one way that tissues register their current physiological state during organismal commitments.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/fisiologia , Desidrocolesteróis/farmacologia , Longevidade/efeitos dos fármacos , Oxigenases/metabolismo , Sequência de Aminoácidos , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/efeitos dos fármacos , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Catálise , Desidrocolesteróis/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Larva/enzimologia , Larva/fisiologia , Ligantes , Longevidade/fisiologia , Dados de Sequência Molecular , Estrutura Molecular , Mutação , Oxigenases/química , Oxigenases/genética , Fenótipo , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
11.
Nat Cell Biol ; 6(1): 31-7, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14688791

RESUMO

In the nematode Caenorhabditis elegans, the gonad acquires two U-shaped arms through the directed migration of its distal tip cells (DTCs), which are located at the tip of the growing gonad arms. A member of the ADAM (a disintegrin and metalloprotease) family, MIG-17, regulates directional migration of DTCs: MIG-17 is synthesized and secreted from the muscle cells of the body wall, and diffuses to the gonad where it is required for DTC migration. The mig-23 mutation causes defective migration of DTCs and interacts genetically with mig-17. Here, we report that mig-23 encodes a membrane-bound nucleoside diphosphatase (NDPase) required for glycosylation and proper localization of MIG-17. Our findings indicate that an NDPase affects organ morphogenesis through glycosylation of the MIG-17 ADAM protease.


Assuntos
Hidrolases Anidrido Ácido/isolamento & purificação , Hidrolases Anidrido Ácido/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/embriologia , Desintegrinas/metabolismo , Gônadas/embriologia , Metaloendopeptidases/metabolismo , Organogênese/fisiologia , Hidrolases Anidrido Ácido/genética , Animais , Animais Geneticamente Modificados , Sequência de Bases/genética , Caenorhabditis elegans/citologia , Caenorhabditis elegans/enzimologia , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/isolamento & purificação , Diferenciação Celular/genética , Linhagem da Célula/genética , Movimento Celular/fisiologia , DNA Complementar/análise , DNA Complementar/genética , Glicoproteínas/metabolismo , Glicosilação , Gônadas/citologia , Gônadas/metabolismo , Dados de Sequência Molecular , Células Musculares/metabolismo , Mutação/genética , Células-Tronco/citologia , Células-Tronco/metabolismo
12.
Proc Natl Acad Sci U S A ; 105(52): 20804-9, 2008 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-19104038

RESUMO

Mutations in the a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS) family of secreted proteases cause diseases linked to ECM abnormalities. However, the mechanisms by which these enzymes modulate the ECM during development are mostly unexplored. The Caenorhabditis elegans MIG-17/ADAMTS protein is secreted from body wall muscle cells and localizes to the basement membrane (BM) of the developing gonad where it controls directional migration of gonadal leader cells. Here we show that specific amino acid changes in the ECM proteins fibulin-1C (FBL-1C) and type IV collagen (LET-2) result in bypass of the requirement for MIG-17 activity in gonadal leader cell migration in a nidogen (NID-1)-dependent and -independent manner, respectively. The MIG-17, FBL-1C and LET-2 activities are required for proper accumulation of NID-1 at the gonadal BM. However, mutant FBL-1C or LET-2 in the absence of MIG-17 promotes NID-1 localization. Furthermore, overexpression of NID-1 in mig-17 mutants substantially rescues leader cell migration defects. These results suggest that functional interactions among BM molecules are important for MIG-17 control of gonadal leader cell migration. We propose that FBL-1C and LET-2 act downstream of MIG-17-dependent proteolysis to recruit NID-1 and that LET-2 also activates a NID-1-independent pathway, thereby inducing the remodeling of the BM required for directional control of leader cell migration.


Assuntos
Membrana Basal/enzimologia , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Movimento Celular/fisiologia , Desintegrinas/metabolismo , Gônadas/enzimologia , Glicoproteínas de Membrana/metabolismo , Metaloendopeptidases/metabolismo , Animais , Membrana Basal/citologia , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Desintegrinas/genética , Feminino , Gônadas/citologia , Masculino , Glicoproteínas de Membrana/genética , Metaloendopeptidases/genética , Células Musculares/citologia , Células Musculares/enzimologia , Mutação , Transporte Proteico/fisiologia
13.
Sci Rep ; 11(1): 22370, 2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34785759

RESUMO

Repulsive guidance molecules (RGMs) are evolutionarily conserved proteins implicated in repulsive axon guidance. Here we report the function of the Caenorhabditis elegans ortholog DRAG-1 in axon branching. The axons of hermaphrodite-specific neurons (HSNs) extend dorsal branches at the region abutting the vulval muscles. The drag-1 mutants exhibited defects in HSN axon branching in addition to a small body size phenotype. DRAG-1 expression in the hypodermal cells was required for the branching of the axons. Although DRAG-1 is normally expressed in the ventral hypodermis excepting the vulval region, its ectopic expression in vulval precursor cells was sufficient to induce the branching. The C-terminal glycosylphosphatidylinositol anchor of DRAG-1 was important for its function, suggesting that DRAG-1 should be anchored to the cell surface. Genetic analyses suggested that the membrane receptor UNC-40 acts in the same pathway with DRAG-1 in HSN branching. We propose that DRAG-1 expressed in the ventral hypodermis signals via the UNC-40 receptor expressed in HSNs to elicit branching activity of HSN axons.


Assuntos
Orientação de Axônios , Axônios/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Regulação da Expressão Gênica , Proteínas do Tecido Nervoso/metabolismo , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas do Tecido Nervoso/genética
15.
PLoS One ; 15(12): e0240571, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33264296

RESUMO

During development of the Caenorhabditis elegans gonad, the gonadal leader cells, called distal tip cells (DTCs), migrate in a U-shaped pattern to form the U-shaped gonad arms. The ADAMTS (a disintegrin and metalloprotease with thrombospondin motifs) family metalloproteases MIG-17 and GON-1 are required for correct DTC migration. Mutations in mig-17 result in misshapen gonads due to the misdirected DTC migration, and mutations in gon-1 result in shortened and swollen gonads due to the premature termination of DTC migration. Although the phenotypes shown by mig-17 and gon-1 mutants are very different from one another, mutations that result in amino acid substitutions in the same basement membrane protein genes, emb-9/collagen IV a1, let-2/collagen IV a2 and fbl-1/fibulin-1, were identified as genetic suppressors of mig-17 and gon-1 mutants. To understand the roles shared by these two proteases, we examined the effects of the mig-17 suppressors on gon-1 and the effects of the gon-1 suppressors and enhancers on mig-17 gonadal defects. Some of the emb-9, let-2 and fbl-1 mutations suppressed both mig-17 and gon-1, whereas others acted only on mig-17 or gon-1. These results suggest that mig-17 and gon-1 have their specific functions as well as functions commonly shared between them for gonad formation. The levels of collagen IV accumulation in the DTC basement membrane were significantly higher in the gon-1 mutants as compared with wild type and were reduced to the wild-type levels when combined with suppressor mutations, but not with enhancer mutations, suggesting that the ability to reduce collagen IV levels is important for gon-1 suppression.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Movimento Celular/genética , Desintegrinas/genética , Gônadas/crescimento & desenvolvimento , Metaloendopeptidases/genética , Proteínas ADAMTS/genética , Proteínas ADAMTS/metabolismo , Substituição de Aminoácidos , Animais , Membrana Basal/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Desintegrinas/metabolismo , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica no Desenvolvimento , Gônadas/citologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Metaloendopeptidases/metabolismo , Mutação
16.
Biol Open ; 8(1)2019 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-30635266

RESUMO

Cell-fate maintenance is important to preserve the variety of cell types that are essential for the formation and function of tissues. We previously showed that the acetylated histone-binding protein BET-1 maintains cell fate by recruiting the histone variant H2A.z. Here, we report that Caenorhabditis elegans TLK-1 and the histone H3 chaperone CAF1 prevent the accumulation of histone variant H3.3. In addition, TLK-1 and CAF1 maintain cell fate by repressing ectopic expression of transcription factors that induce cell-fate specification. Genetic analyses suggested that TLK-1 and BET-1 act in parallel pathways. In tlk-1 mutants, the loss of SIN-3, which promotes histone acetylation, suppressed a defect in cell-fate maintenance in a manner dependent on MYST family histone acetyltransferase MYS-2 and BET-1. sin-3 mutation also suppressed abnormal H3.3 incorporation. Thus, we propose a hypothesis that the regulation and interaction of histone variants play crucial roles in cell-fate maintenance through the regulation of selector genes.

17.
Genetics ; 212(2): 523-535, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30992386

RESUMO

Remodeling of the extracellular matrix supports tissue and organ development, by regulating cellular morphology and tissue integrity. However, proper extracellular matrix remodeling requires spatiotemporal regulation of extracellular metalloproteinase activity. Members of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family, including MIG-17 and GON-1, are evolutionarily conserved, secreted, zinc-requiring metalloproteinases. Although these proteases are required for extracellular matrix remodeling during gonadogenesis in Caenorhabditis elegans, their in vivo regulatory mechanisms remain to be delineated. Therefore, we focused on the C. elegans tissue inhibitors of metalloproteinases (TIMPs), TIMP-1 and CRI-2 Analysis of the transcription and translation products for GFP/Venus fusions, with TIMP-1 or CRI-2, indicated that these inhibitors were secreted and localized to the basement membrane of gonads and the plasma membrane of germ cells. A timp-1 deletion mutant exhibited gonadal growth defects and sterility, and the phenotypes of this mutant were fully rescued by a TIMP-1::Venus construct, but not by a TIMP-1(C21S)::Venus mutant construct, in which the inhibitor coding sequence had been mutated. Moreover, genetic data suggested that TIMP-1 negatively regulates proteolysis of the α1 chain of type IV collagen. We also found that the loss-of-function observed for the mutants timp-1 and cri-2 involves a partial suppression of gonadal defects found for the mutants mig-17/ADAMTS and gon-1/ADAMTS, and that this suppression was canceled upon overexpression of gon-1 or mig-17, respectively. Based on these results, we propose that both TIMP-1 and CRI-2 act as inhibitors of MIG-17 and GON-1 ADAMTSs to regulate gonad development in a noncell-autonomous manner.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Desintegrinas/metabolismo , Gônadas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Metaloendopeptidases/metabolismo , Inibidor Tecidual de Metaloproteinase-1/fisiologia , Inibidores Teciduais de Metaloproteinases/metabolismo , Animais , Membrana Basal/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Membrana Celular/metabolismo , Colágeno Tipo IV/metabolismo , Desintegrinas/genética , Matriz Extracelular/metabolismo , Células Germinativas/metabolismo , Gônadas/crescimento & desenvolvimento , Peptídeos e Proteínas de Sinalização Intercelular/genética , Metaloendopeptidases/genética , Morfogênese/genética , Morfogênese/fisiologia , Inibidor Tecidual de Metaloproteinase-1/genética , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Inibidores Teciduais de Metaloproteinases/genética
18.
FEBS J ; 275(17): 4296-305, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18637819

RESUMO

The activation of ADAMTS (a disintegrin and metalloprotease with thrombospondin motifs) family proteases depends on removal of the prodomain. Although several studies suggest that ADAMTS activities play roles in development, homeostasis and disease, it remains unclear when and where the enzymes are activated in vivo. MIG-17, a Caenorhabditis elegans glycoprotein belonging to the ADAMTS family, is secreted from the body wall muscle cells and localizes to the gonadal basement membrane to control the migration of gonadal distal tip cells. Here, we developed a monoclonal antibody that recognizes the N-terminal neo-epitope of the activated MIG-17. In western blotting, the antibody specifically detected the activated form, the signal for which dramatically increased during the third and fourth larval stages, when MIG-17 is required to direct distal tip cell migration. In in situ staining, the monoclonal antibody recognized the activated form in the basement membrane, whereas it failed to detect a processing-resistant mutant form localized to the basement membrane. MIG-17 was activated in the basement membranes of the muscle, intestine and gonad in the third larval stage, and downregulated in nongonadal basement membranes in young adults and in gonadal basement membranes in older adults. Thus, the activation of MIG-17 is regulated in a spatiotemporal manner during C. elegans development. This is the first report demonstrating the regulated activation of an ADAMTS protein in vivo. Our results suggest that monoclonal antibodies against neo-epitopes have potential as powerful tools for detecting activation of ADAMTSs during development and in disease pathogenesis.


Assuntos
Proteínas de Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/citologia , Movimento Celular/fisiologia , Desintegrinas/fisiologia , Metaloendopeptidases/fisiologia , Animais , Western Blotting , Proteínas de Caenorhabditis elegans/imunologia , Desintegrinas/imunologia , Metaloendopeptidases/imunologia
19.
Curr Biol ; 14(22): 2011-8, 2004 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-15556863

RESUMO

ADAM (a disintegrin and metalloprotease) family proteins play important roles in animal development and pathogenesis. In C. elegans, a secreted ADAM protein, MIG-17, acts from outside the gonad to control the migration of gonadal distal tip cells (DTCs) that promote gonad morphogenesis. Here, we report that dominant mutations in the fbl-1 gene encoding fibulin-1 spliced isoforms, which are calcium binding extracellular matrix proteins, bypass the requirement for MIG-17 activity in directing DTC migration. Specific amino acid substitutions in the third EGF-like motif of one of the two isoforms, FBL-1C, which corresponds to mammalian fibulin-1C, suppress mig-17 mutations. FBL-1C is synthesized in the gut cells and localizes strongly to the gonadal basement membrane in a MIG-17-dependent manner. Localization of mutant FBL-1C is weaker than that of the wild-type protein and is insensitive to MIG-17 activity, suggesting that it gains a novel function that compensates for its reduced molecular density. We propose that proteolysis by MIG-17 recruits FBL-1C to the gonadal basement membrane, where it is required for the guidance of DTCs, and that mutant FBL-1C acts in a manner that mimics the downstream events of MIG-17-mediated proteolysis.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Ligação ao Cálcio/metabolismo , Desintegrinas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Gônadas/crescimento & desenvolvimento , Metaloendopeptidases/metabolismo , Organogênese/fisiologia , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Proteínas de Ligação ao Cálcio/genética , Movimento Celular/fisiologia , Primers do DNA , Microscopia de Fluorescência , Mutação/genética , Plasmídeos/genética , Isoformas de Proteínas , Transdução de Sinais/fisiologia
20.
G3 (Bethesda) ; 6(5): 1449-57, 2016 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-26994289

RESUMO

MIG-17, a secreted protease of the ADAMTS family, acts in the directed migration of gonadal distal tip cells (DTCs) through regulation of the gonadal basement membrane in Caenorhabditis elegans Here, we show that MIG-17 is also required for the control of pharynx elongation during animal growth. We found that the pharynx was elongated in mig-17 mutants compared with wild type. MIG-17 localized to the pharyngeal basement membrane as well as to the gonadal basement membrane. The number of nuclei in the pharynx, and the pumping rate of the pharynx, were not affected in mig-17 mutants, suggesting that cells constituting the pharynx are elongated, although the pharynx functions normally in these mutants. In contrast to the control of DTC migration, MIG-18, a secreted cofactor of MIG-17, was not essential for pharynx length regulation. In addition, the downstream pathways of MIG-17 involving LET-2/type IV collagen, FBL-1/fibulin-1, and NID-1/nidogen, partly diverged from those in gonad development. These results indicate that basement membrane remodeling is important for organ length regulation, and suggest that MIG-17/ADAMTS functions in similar but distinct molecular machineries in pharyngeal and gonadal basement membranes.


Assuntos
Proteínas ADAMTS/genética , Proteínas ADAMTS/metabolismo , Caenorhabditis elegans/anatomia & histologia , Caenorhabditis elegans/genética , Estudos de Associação Genética , Característica Quantitativa Herdável , Proteínas ADAMTS/química , Animais , Membrana Basal/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Catálise , Glicosilação , Gônadas/metabolismo , Mutação , Fenótipo , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico
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