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Xiong T, Zhang Z, Fan T, Ye F, Ye Z. Origin, evolution, and diversification of inositol 1,4,5-trisphosphate 3-kinases in plants and animals. BMC Genomics 2024; 25:350. [PMID: 38589807 PMCID: PMC11000326 DOI: 10.1186/s12864-024-10257-7] [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: 01/25/2024] [Accepted: 03/26/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND In Eukaryotes, inositol polyphosphates (InsPs) represent a large family of secondary messengers and play crucial roes in various cellular processes. InsPs are synthesized through a series of pohophorylation reactions catalyzed by various InsP kinases in a sequential manner. Inositol 1,4,5-trisphosphate 3-kinase (IP3 3-kinase/IP3K), one member of InsP kinase, plays important regulation roles in InsPs metabolism by specifically phosphorylating inositol 1,4,5-trisphosphate (IP3) to inositol 1,3,4,5-tetrakisphosphate (IP4) in animal cells. IP3Ks were widespread in fungi, plants and animals. However, its evolutionary history and patterns have not been examined systematically. RESULTS A total of 104 and 31 IP3K orthologues were identified across 57 plant genomes and 13 animal genomes, respectively. Phylogenetic analyses indicate that IP3K originated in the common ancestor before the divergence of fungi, plants and animals. In most plants and animals, IP3K maintained low-copy numbers suggesting functional conservation during plant and animal evolution. In Brassicaceae and vertebrate, IP3K underwent one and two duplication events, respectively, resulting in multiple gene copies. Whole-genome duplication (WGD) was the main mechanism for IP3K duplications, and the IP3K duplicates have experienced functional divergence. Finally, a hypothetical evolutionary model for the IP3K proteins is proposed based on phylogenetic theory. CONCLUSION Our study reveals the evolutionary history of IP3K proteins and guides the future functions of animal, plant, and fungal IP3K proteins.
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Affiliation(s)
- Tao Xiong
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China
- College of Life Science, Xinyang Normal University, Xinyang, Henan, China
| | - Zaibao Zhang
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China.
- College of Life Science, Xinyang Normal University, Xinyang, Henan, China.
| | - Tianyu Fan
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China
| | - Fan Ye
- College of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou, Zhejiang, China
| | - Ziyi Ye
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China
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2
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Rathor L, Curry S, Park Y, McElroy T, Robles B, Sheng Y, Chen WW, Min K, Xiao R, Lee MH, Han SM. Mitochondrial stress in GABAergic neurons non-cell autonomously regulates organismal health and aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.20.585932. [PMID: 38585797 PMCID: PMC10996468 DOI: 10.1101/2024.03.20.585932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Mitochondrial stress within the nervous system can trigger non-cell autonomous responses in peripheral tissues. However, the specific neurons involved and their impact on organismal aging and health have remained incompletely understood. Here, we demonstrate that mitochondrial stress in γ-aminobutyric acid-producing (GABAergic) neurons in Caenorhabditis elegans ( C. elegans ) is sufficient to significantly alter organismal lifespan, stress tolerance, and reproductive capabilities. This mitochondrial stress also leads to significant changes in mitochondrial mass, energy production, and levels of reactive oxygen species (ROS). DAF-16/FoxO activity is enhanced by GABAergic neuronal mitochondrial stress and mediates the induction of these non-cell-autonomous effects. Moreover, our findings indicate that GABA signaling operates within the same pathway as mitochondrial stress in GABAergic neurons, resulting in non-cell-autonomous alterations in organismal stress tolerance and longevity. In summary, these data suggest the crucial role of GABAergic neurons in detecting mitochondrial stress and orchestrating non-cell-autonomous changes throughout the organism.
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3
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Ko A, Hasanain M, Oh YT, D'Angelo F, Sommer D, Frangaj B, Tran S, Bielle F, Pollo B, Paterra R, Mokhtari K, Soni RK, Peyre M, Eoli M, Papi L, Kalamarides M, Sanson M, Iavarone A, Lasorella A. LZTR1 Mutation Mediates Oncogenesis through Stabilization of EGFR and AXL. Cancer Discov 2023; 13:702-723. [PMID: 36445254 DOI: 10.1158/2159-8290.cd-22-0376] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 09/23/2022] [Accepted: 11/21/2022] [Indexed: 12/02/2022]
Abstract
LZTR1 is the substrate-specific adaptor of a CUL3-dependent ubiquitin ligase frequently mutated in sporadic and syndromic cancer. We combined biochemical and genetic studies to identify LZTR1 substrates and interrogated their tumor-driving function in the context of LZTR1 loss-of-function mutations. Unbiased screens converged on EGFR and AXL receptor tyrosine kinases as LZTR1 interactors targeted for ubiquitin-dependent degradation in the lysosome. Pathogenic cancer-associated mutations of LZTR1 failed to promote EGFR and AXL degradation, resulting in dysregulated growth factor signaling. Conditional inactivation of Lztr1 and Cdkn2a in the mouse nervous system caused tumors in the peripheral nervous system including schwannoma-like tumors, thus recapitulating aspects of schwannomatosis, the prototype tumor predisposition syndrome sustained by LZTR1 germline mutations. Lztr1- and Cdkn2a-deleted tumors aberrantly accumulated EGFR and AXL and exhibited specific vulnerability to EGFR and AXL coinhibition. These findings explain tumorigenesis by LZTR1 inactivation and offer therapeutic opportunities to patients with LZTR1-mutant cancer. SIGNIFICANCE EGFR and AXL are substrates of LZTR1-CUL3 ubiquitin ligase. The frequent somatic and germline mutations of LZTR1 in human cancer cause EGFR and AXL accumulation and deregulated signaling. LZTR1-mutant tumors show vulnerability to concurrent inhibition of EGFR and AXL, thus providing precision targeting to patients affected by LZTR1-mutant cancer. This article is highlighted in the In This Issue feature, p. 517.
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Affiliation(s)
- Aram Ko
- Institute for Cancer Genetics, Columbia University Medical Center, New York, New York
| | - Mohammad Hasanain
- Institute for Cancer Genetics, Columbia University Medical Center, New York, New York
| | - Young Taek Oh
- Institute for Cancer Genetics, Columbia University Medical Center, New York, New York
| | - Fulvio D'Angelo
- Institute for Cancer Genetics, Columbia University Medical Center, New York, New York
| | - Danika Sommer
- Institute for Cancer Genetics, Columbia University Medical Center, New York, New York
| | - Brulinda Frangaj
- Institute for Cancer Genetics, Columbia University Medical Center, New York, New York
| | - Suzanne Tran
- Sorbonne Université, INSERM U1127, CNRS UMR 7225, Brain Institute, ICM, AP-HP, University Hospital La Pitié Salpêtrière-Charles Foix, Laboratory of Neuropathology, Paris, France
| | - Franck Bielle
- Sorbonne Université, INSERM U1127, CNRS UMR 7225, Brain Institute, ICM, AP-HP, University Hospital La Pitié Salpêtrière-Charles Foix, Laboratory of Neuropathology, Paris, France
| | - Bianca Pollo
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Rosina Paterra
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Karima Mokhtari
- Sorbonne Université, INSERM U1127, CNRS UMR 7225, Brain Institute, ICM, AP-HP, University Hospital La Pitié Salpêtrière-Charles Foix, Neurosurgery Service, Paris, France
| | - Rajesh Kumar Soni
- Proteomics Shared Resource, Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Matthieu Peyre
- Sorbonne Université, INSERM U1127, CNRS UMR 7225, Brain Institute, ICM, AP-HP, University Hospital La Pitié Salpêtrière-Charles Foix, Neurosurgery Service, Paris, France
- Sorbonne Université, INSERM U1127, CNRS UMR 7225, Brain Institute, ICM, AP-HP, University Hospital La Pitié Salpêtrière-Charles Foix, Service of Neurology 2-Mazarin, Equipe lLNCC, Paris, France
| | - Marica Eoli
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Laura Papi
- The Department of Experimental and Clinical, Medical Genetics Unit, Biomedical Sciences "Mario Serio," University of Florence, Florence, Italy
| | - Michel Kalamarides
- Sorbonne Université, INSERM U1127, CNRS UMR 7225, Brain Institute, ICM, AP-HP, University Hospital La Pitié Salpêtrière-Charles Foix, Neurosurgery Service, Paris, France
- Sorbonne Université, INSERM U1127, CNRS UMR 7225, Brain Institute, ICM, AP-HP, University Hospital La Pitié Salpêtrière-Charles Foix, Service of Neurology 2-Mazarin, Equipe lLNCC, Paris, France
| | - Marc Sanson
- Sorbonne Université, INSERM U1127, CNRS UMR 7225, Brain Institute, ICM, AP-HP, University Hospital La Pitié Salpêtrière-Charles Foix, Service of Neurology 2-Mazarin, Equipe lLNCC, Paris, France
- Onconeurotek Tumor Bank, Brain and Spinal Cord Institute ICM, 75013 Paris, France
| | - Antonio Iavarone
- Institute for Cancer Genetics, Columbia University Medical Center, New York, New York
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
- Department of Neurology, Columbia University Medical Center, New York, New York
- Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Anna Lasorella
- Institute for Cancer Genetics, Columbia University Medical Center, New York, New York
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
- Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
- Department of Pediatrics, Columbia University Medical Center, New York, New York
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4
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Dridi H, Forrester F, Umanskaya A, Xie W, Reiken S, Lacampagne A, Marks A. Role of oxidation of excitation-contraction coupling machinery in age-dependent loss of muscle function in C. elegans. eLife 2022; 11:75529. [PMID: 35506650 PMCID: PMC9113742 DOI: 10.7554/elife.75529] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 04/27/2022] [Indexed: 11/13/2022] Open
Abstract
Age-dependent loss of body wall muscle function and impaired locomotion occur within 2 weeks in C. elegans; however, the underlying mechanism has not been fully elucidated. In humans, age-dependent loss of muscle function occurs at about 80 years of age and has been linked to dysfunction of ryanodine receptor (RyR)/intracellular calcium (Ca2+) release channels on the sarcoplasmic reticulum (SR). Mammalian skeletal muscle RyR1 channels undergo age-related remodeling due to oxidative overload, leading to loss of the stabilizing subunit calstabin1 (FKBP12) from the channel macromolecular complex. This destabilizes the closed state of the channel resulting in intracellular Ca2+ leak, reduced muscle function, and impaired exercise capacity. We now show that the C. elegans RyR homolog, UNC-68, exhibits a remarkable degree of evolutionary conservation with mammalian RyR channels and similar age-dependent dysfunction. Like RyR1 in mammals UNC-68 encodes a protein that comprises a macromolecular complex which includes the calstabin1 homolog FKB-2 and is immunoreactive with antibodies raised against the RyR1 complex. Further, as in aged mammals, UNC-68 is oxidized and depleted of FKB-2 in an age-dependent manner, resulting in 'leaky' channels, depleted SR Ca2+ stores, reduced body wall muscle Ca2+ transients, and age-dependent muscle weakness. FKB-2 (ok3007)-deficient worms exhibit reduced exercise capacity. Pharmacologically induced oxidization of UNC-68 and depletion of FKB-2 from the channel independently caused reduced body wall muscle Ca2+ transients. Preventing FKB-2 depletion from the UNC-68 macromolecular complex using the Rycal drug S107 improved muscle Ca2+ transients and function. Taken together, these data suggest that UNC-68 oxidation plays a role in age-dependent loss of muscle function. Remarkably, this age-dependent loss of muscle function induced by oxidative overload, which takes ~2 years in mice and ~80 years in humans, occurs in less than 2-3 weeks in C. elegans, suggesting that reduced antioxidant capacity may contribute to the differences in life span amongst species.
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Affiliation(s)
- Haikel Dridi
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, United States
| | - Frances Forrester
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, United States
| | - Alisa Umanskaya
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, United States
| | - Wenjun Xie
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, United States
| | - Steven Reiken
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, United States
| | - Alain Lacampagne
- U1046, Montpellier University, INSERM, CNRS, Montpellier, France
| | - Andrew Marks
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, United States
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5
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Lirakis M, Nolte V, Schlötterer C. Pool-GWAS on reproductive dormancy in Drosophila simulans suggests a polygenic architecture. G3 GENES|GENOMES|GENETICS 2022; 12:6523974. [PMID: 35137042 PMCID: PMC8895979 DOI: 10.1093/g3journal/jkac027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 12/29/2021] [Indexed: 11/29/2022]
Abstract
The genetic basis of adaptation to different environments has been of long-standing interest to evolutionary biologists. Dormancy is a well-studied adaptation to facilitate overwintering. In Drosophila melanogaster, a moderate number of genes with large effects have been described, which suggests a simple genetic basis of dormancy. On the other hand, genome-wide scans for dormancy suggest a polygenic architecture in insects. In D. melanogaster, the analysis of the genetic architecture of dormancy is complicated by the presence of cosmopolitan inversions. Here, we performed a genome-wide scan to characterize the genetic basis of this ecologically extremely important trait in the sibling species of D. melanogaster, D. simulans that lacks cosmopolitan inversions. We performed Pool-GWAS in a South African D. simulans population for dormancy incidence at 2 temperature regimes (10 and 12°C, LD 10:14). We identified several genes with SNPs that showed a significant association with dormancy (P-value < 1e-13), but the overall modest response suggests that dormancy is a polygenic trait with many loci of small effect. Our results shed light on controversies on reproductive dormancy in Drosophila and have important implications for the characterization of the genetic basis of this trait.
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Affiliation(s)
- Manolis Lirakis
- Institut für Populationsgenetik, Vetmeduni Vienna, 1210 Wien, Austria
- Vienna Graduate School of Population Genetics, Vetmeduni Vienna, 1210 Wien, Austria
| | - Viola Nolte
- Institut für Populationsgenetik, Vetmeduni Vienna, 1210 Wien, Austria
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6
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Spiri S, Berger S, Mereu L, DeMello A, Hajnal A. Reciprocal EGFR signaling in the anchor cell ensures precise inter-organ connection during Caenorhabditis elegans vulval morphogenesis. Development 2022; 149:273883. [PMID: 34982813 PMCID: PMC8783044 DOI: 10.1242/dev.199900] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 11/30/2021] [Indexed: 01/01/2023]
Abstract
During Caenorhabditis elegans vulval development, the uterine anchor cell (AC) first secretes an epidermal growth factor (EGF) to specify the vulval cell fates and then invades the underlying vulval epithelium. By doing so, the AC establishes direct contact with the invaginating primary vulF cells and attaches the developing uterus to the vulva. The signals involved and the exact sequence of events joining these two organs are not fully understood. Using a conditional let-23 EGF receptor (EGFR) allele along with novel microfluidic short- and long-term imaging methods, we discovered a specific function of the EGFR in the AC during vulval lumen morphogenesis. Tissue-specific inactivation of let-23 in the AC resulted in imprecise alignment of the AC with the primary vulval cells, delayed AC invasion and disorganized adherens junctions at the contact site forming between the AC and the dorsal vulF toroid. We propose that EGFR signaling, activated by a reciprocal EGF cue from the primary vulval cells, positions the AC at the vulval midline, guides it during invasion and assembles a cytoskeletal scaffold organizing the adherens junctions that connect the developing uterus to the dorsal vulF toroid. Thus, EGFR signaling in the AC ensures the precise alignment of the two developing organs. Summary: A reciprocal EGF signal from the vulval precursor cells positions the invading anchor cell during Caenorhabditis elegans vulval development to link the vulva and uterus as they form.
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Affiliation(s)
- Silvan Spiri
- Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.,Molecular Life Science PhD Program, University and ETH Zürich, CH-8057 Zürich, Switzerland
| | - Simon Berger
- Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.,Institute for Chemical- and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Louisa Mereu
- Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.,Molecular Life Science PhD Program, University and ETH Zürich, CH-8057 Zürich, Switzerland
| | - Andrew DeMello
- Institute for Chemical- and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Alex Hajnal
- Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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7
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Crook M, Hanna-Rose W. Overactive EGF signaling suppresses a C. elegans pnc-1 egg-laying phenotype independent of known signaling mediators. MICROPUBLICATION BIOLOGY 2021; 2021. [PMID: 34723146 PMCID: PMC8553428 DOI: 10.17912/micropub.biology.000482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 11/28/2022]
Abstract
Nicotinamide recycling is critical to the development and function of Caenorhabditis elegans. Excess nicotinamide in a pnc-1 nicotinamidase mutant causes the necrosis of uv1 and OLQ cells and a highly penetrant egg laying defect. An EGF receptor (let-23) gain-of-function mutation suppresses the Egl phenotype in pnc-1 animals. However, gain-of-function mutations in either of the known downstream mediators, let-60/ Ras or itr-1, are not sufficient. Phosphatidylcholine synthesis is neither required nor sufficient, in contrast to its role in the let-23gf rescue of uv1 necrosis. The mechanism behind the let-23gf suppression of the pnc-1 Egl phenotype is unknown.
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8
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p21-Activated kinase 1 (PAK1) in aging and longevity: An overview. Ageing Res Rev 2021; 71:101443. [PMID: 34390849 DOI: 10.1016/j.arr.2021.101443] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/26/2021] [Accepted: 08/10/2021] [Indexed: 02/08/2023]
Abstract
The p21-activated kinases (PAKs) belong to serine/threonine kinases family, regulated by ∼21 kDa small signaling G proteins RAC1 and CDC42. The mammalian PAK family comprises six members (PAK1-6) that are classified into two groups (I and II) based on their domain architecture and regulatory mechanisms. PAKs are implicated in a wide range of cellular functions. PAK1 has recently attracted increasing attention owing to its involvement in oncogenesis, tumor progression, and metastasis as well as several life-limiting diseases and pathological conditions. In Caenorhabditis elegans, PAK1 functions limit the lifespan under basal conditions by inhibiting forkhead transcription factor DAF-16. Interestingly, PAK depletion extended longevity and attenuated the onset of age-related phenotypes in a premature-aging mouse model and delayed senescence in mammalian fibroblasts. These observations implicate PAKs as not only oncogenic but also aging kinases. Therefore, PAK-targeting genetic and/or pharmacological interventions, particularly PAK1-targeting, could be a viable strategy for developing cancer therapies with relatively no side effects and promoting healthy longevity. This review describes PAK family proteins, their biological functions, and their role in regulating aging and longevity using C. elegans. Moreover, we discuss the effect of small-molecule PAK1 inhibitors on the lifespan and healthspan of C. elegans.
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9
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Robinson-Thiewes S, Dufour B, Martel PO, Lechasseur X, Brou AAD, Roy V, Chen Y, Kimble J, Narbonne P. Non-autonomous regulation of germline stem cell proliferation by somatic MPK-1/MAPK activity in C. elegans. Cell Rep 2021; 35:109162. [PMID: 34038716 PMCID: PMC8182673 DOI: 10.1016/j.celrep.2021.109162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 02/17/2021] [Accepted: 04/30/2021] [Indexed: 11/03/2022] Open
Abstract
Extracellular-signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) is a major positive regulator of cell proliferation, which is often upregulated in cancer. However, few studies have addressed ERK/MAPK regulation of proliferation within a complete organism. The Caenorhabditis elegans ERK/MAPK ortholog MPK-1 is best known for its control of somatic organogenesis and germline differentiation, but it also stimulates germline stem cell proliferation. Here, we show that the germline-specific MPK-1B isoform promotes germline differentiation but has no apparent role in germline stem cell proliferation. By contrast, the soma-specific MPK-1A isoform promotes germline stem cell proliferation non-autonomously. Indeed, MPK-1A functions in the intestine or somatic gonad to promote germline proliferation independent of its other known roles. We propose that a non-autonomous role of ERK/MAPK in stem cell proliferation may be conserved across species and various tissue types, with major clinical implications for cancer and other diseases. The prevailing paradigm is that ERK/MAPK functions autonomously to promote cell proliferation upon mitogen stimulation. Robinson-Thiewes et al. now demonstrate that C. elegans ERK/MAPK acts within somatic tissues to non-autonomously promote the proliferation of germline stem cells. Germline ERK/MAPK is thus dispensable for germline stem cell proliferation.
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Affiliation(s)
| | - Benjamin Dufour
- Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada
| | - Pier-Olivier Martel
- Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada
| | - Xavier Lechasseur
- Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada
| | - Amani Ange Danielle Brou
- Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada
| | - Vincent Roy
- Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada; Département de Biologie Moléculaire, de Biochimie Médicale et de pathologie, Faculté de Médecine, Université Laval, QC G1R 3S3, Canada
| | - Yunqing Chen
- Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada
| | - Judith Kimble
- Department of Genetics, University of Wisconsin-Madison, Madison, WI 53706-1580, USA
| | - Patrick Narbonne
- Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada; Département de Biologie Moléculaire, de Biochimie Médicale et de pathologie, Faculté de Médecine, Université Laval, QC G1R 3S3, Canada.
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10
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Haeussler S, Yeroslaviz A, Rolland SG, Luehr S, Lambie EJ, Conradt B. Genome-wide RNAi screen for regulators of UPRmt in Caenorhabditis elegans mutants with defects in mitochondrial fusion. G3-GENES GENOMES GENETICS 2021; 11:6204483. [PMID: 33784383 PMCID: PMC8495942 DOI: 10.1093/g3journal/jkab095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/18/2021] [Indexed: 01/22/2023]
Abstract
Mitochondrial dynamics plays an important role in mitochondrial quality control and the adaptation of metabolic activity in response to environmental changes. The disruption of mitochondrial dynamics has detrimental consequences for mitochondrial and cellular homeostasis and leads to the activation of the mitochondrial unfolded protein response (UPRmt), a quality control mechanism that adjusts cellular metabolism and restores homeostasis. To identify genes involved in the induction of UPRmt in response to a block in mitochondrial fusion, we performed a genome-wide RNAi screen in Caenorhabditis elegans mutants lacking the gene fzo-1, which encodes the ortholog of mammalian Mitofusin, and identified 299 suppressors and 86 enhancers. Approximately 90% of these 385 genes are conserved in humans, and one third of the conserved genes have been implicated in human disease. Furthermore, many have roles in developmental processes, which suggests that mitochondrial function and the response to stress are defined during development and maintained throughout life. Our dataset primarily contains mitochondrial enhancers and non-mitochondrial suppressors of UPRmt, indicating that the maintenance of mitochondrial homeostasis has evolved as a critical cellular function, which, when disrupted, can be compensated for by many different cellular processes. Analysis of the subsets 'non-mitochondrial enhancers' and 'mitochondrial suppressors' suggests that organellar contact sites, especially between the ER and mitochondria, are of importance for mitochondrial homeostasis. In addition, we identified several genes involved in IP3 signaling that modulate UPRmt in fzo-1 mutants and found a potential link between pre-mRNA splicing and UPRmt activation.
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Affiliation(s)
- Simon Haeussler
- Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Assa Yeroslaviz
- Computational Biology Group, Max Planck Institute of Biochemistry, 82152 Planegg-Martinsried, Germany
| | - Stéphane G Rolland
- Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany.,Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, South Korea
| | - Sebastian Luehr
- Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Eric J Lambie
- Center for Integrated Protein Science, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Barbara Conradt
- Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany.,Center for Integrated Protein Science, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany.,Research Department of Cell and Developmental Biology, Division of Biosciences, University College London, London WC1E 6AP, United Kingdom
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11
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Yang ZL, Chen JN, Lu YY, Lu M, Wan QL, Wu GS, Luo HR. Inositol polyphosphate multikinase IPMK-1 regulates development through IP3/calcium signaling in Caenorhabditis elegans. Cell Calcium 2020; 93:102327. [PMID: 33316585 DOI: 10.1016/j.ceca.2020.102327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/25/2020] [Accepted: 11/27/2020] [Indexed: 01/17/2023]
Abstract
Inositol polyphosphate multikinase (IPMK) is a conserved protein that initiates the production of inositol phosphate intracellular messengers and is critical for regulating a variety of cellular processes. Here, we report that the C. elegans IPMK-1, which is homologous to the mammalian inositol polyphosphate multikinase, plays a crucial role in regulating rhythmic behavior and development. The deletion mutant ipmk-1(tm2687) displays a long defecation cycle period and retarded postembryonic growth. The expression of functional ipmk-1::GFP was detected in the pharyngeal muscles, amphid sheath cells, the intestine, excretory (canal) cells, proximal gonad, and spermatheca. The expression of IPMK-1 in the intestine was sufficient for the wild-type phenotype. The IP3-kinase activity of IPMK-1 is required for defecation rhythms and postembryonic development. The defective phenotypes of ipmk-1(tm2687) could be rescued by a loss-of-function mutation in type I inositol 5-phosphatase homolog (IPP-5) and improved by a supplemental Ca2+ in the medium. Our work demonstrates that IPMK-1 and the signaling molecule inositol triphosphate (IP3) pathway modulate rhythmic behaviors and development by dynamically regulating the concentration of intracellular Ca2+ in C. elegans. Advances in understanding the molecular regulation of Ca2+ homeostasis and regulation of organism development may lead to therapeutic strategies that modulate Ca2+ signaling to enhance function and counteract disease processes. Unraveling the physiological role of IPMK and the underlying functional mechanism in C. elegans would contribute to understanding the role of IPMK in other species, especially in mammals, and benefit further research on the involvement of IPMK in disease.
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Affiliation(s)
- Zhong-Lin Yang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Science, Kunming, Yunnan 650201, China; Graduate University of the Chinese Academy of Science, Beijing, 100049, China
| | - Jian-Ning Chen
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Yu-Yang Lu
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Min Lu
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Qin-Li Wan
- The Center for Precision Medicine of First Affiliated Hospital, Biomedical Translational Research Institute, Jinan University, Guangzhou, Guangdong 510632, China
| | - Gui-Sheng Wu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Science, Kunming, Yunnan 650201, China; Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China.
| | - Huai-Rong Luo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Science, Kunming, Yunnan 650201, China; Graduate University of the Chinese Academy of Science, Beijing, 100049, China; Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China.
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12
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Cellular Expression and Functional Roles of All 26 Neurotransmitter GPCRs in the C. elegans Egg-Laying Circuit. J Neurosci 2020; 40:7475-7488. [PMID: 32847964 DOI: 10.1523/jneurosci.1357-20.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/28/2020] [Accepted: 08/13/2020] [Indexed: 01/06/2023] Open
Abstract
Maps of the synapses made and neurotransmitters released by all neurons in model systems, such as Caenorhabditis elegans have left still unresolved how neural circuits integrate and respond to neurotransmitter signals. Using the egg-laying circuit of C. elegans as a model, we mapped which cells express each of the 26 neurotransmitter GPCRs of this organism and also genetically analyzed the functions of all 26 GPCRs. We found that individual neurons express many distinct receptors, epithelial cells often express neurotransmitter receptors, and receptors are often positioned to receive extrasynaptic signals. Receptor knockouts reveal few egg-laying defects under standard laboratory conditions, suggesting that the receptors function redundantly or regulate egg-laying only in specific conditions; however, increasing receptor signaling through overexpression more efficiently reveals receptor functions. This map of neurotransmitter GPCR expression and function in the egg-laying circuit provides a model for understanding GPCR signaling in other neural circuits.SIGNIFICANCE STATEMENT Neurotransmitters signal through GPCRs to modulate activity of neurons, and changes in such signaling can underlie conditions such as depression and Parkinson's disease. To determine how neurotransmitter GPCRs together help regulate function of a neural circuit, we analyzed the simple egg-laying circuit in the model organism C. elegans We identified all the cells that express every neurotransmitter GPCR and genetically analyzed how each GPCR affects the behavior the circuit produces. We found that many neurotransmitter GPCRs are expressed in each neuron, that neurons also appear to use these receptors to communicate with other cell types, and that GPCRs appear to often act redundantly or only under specific conditions to regulate circuit function.
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13
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Bai X, Bouffard J, Lord A, Brugman K, Sternberg PW, Cram EJ, Golden A. Caenorhabditis elegans PIEZO channel coordinates multiple reproductive tissues to govern ovulation. eLife 2020; 9:e53603. [PMID: 32490809 PMCID: PMC7340503 DOI: 10.7554/elife.53603] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 06/02/2020] [Indexed: 01/15/2023] Open
Abstract
PIEZO1 and PIEZO2 are newly identified mechanosensitive ion channels that exhibit a preference for calcium in response to mechanical stimuli. In this study, we discovered the vital roles of pezo-1, the sole PIEZO ortholog in Caenorhabditiselegans, in regulating reproduction. A number of deletion alleles, as well as a putative gain-of-function mutant, of PEZO-1 caused a severe reduction in brood size. In vivo observations showed that oocytes undergo a variety of transit defects as they enter and exit the spermatheca during ovulation. Post-ovulation oocytes were frequently damaged during spermathecal contraction. However, the calcium signaling was not dramatically changed in the pezo-1 mutants during ovulation. Loss of PEZO-1 also led to an inability of self-sperm to navigate back to the spermatheca properly after being pushed out of the spermatheca during ovulation. These findings suggest that PEZO-1 acts in different reproductive tissues to promote proper ovulation and fertilization in C. elegans.
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Affiliation(s)
- Xiaofei Bai
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaUnited States
| | - Jeff Bouffard
- Department of Bioengineering, Northeastern UniversityBostonUnited States
| | - Avery Lord
- Department of Biology, Northeastern UniversityBostonUnited States
| | - Katherine Brugman
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Erin J Cram
- Department of Biology, Northeastern UniversityBostonUnited States
| | - Andy Golden
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaUnited States
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14
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Nair A, Chauhan P, Saha B, Kubatzky KF. Conceptual Evolution of Cell Signaling. Int J Mol Sci 2019; 20:E3292. [PMID: 31277491 PMCID: PMC6651758 DOI: 10.3390/ijms20133292] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/26/2019] [Accepted: 06/28/2019] [Indexed: 12/27/2022] Open
Abstract
During the last 100 years, cell signaling has evolved into a common mechanism for most physiological processes across systems. Although the majority of cell signaling principles were initially derived from hormonal studies, its exponential growth has been supported by interdisciplinary inputs, e.g., from physics, chemistry, mathematics, statistics, and computational fields. As a result, cell signaling has grown out of scope for any general review. Here, we review how the messages are transferred from the first messenger (the ligand) to the receptor, and then decoded with the help of cascades of second messengers (kinases, phosphatases, GTPases, ions, and small molecules such as cAMP, cGMP, diacylglycerol, etc.). The message is thus relayed from the membrane to the nucleus where gene expression ns, subsequent translations, and protein targeting to the cell membrane and other organelles are triggered. Although there are limited numbers of intracellular messengers, the specificity of the response profiles to the ligands is generated by the involvement of a combination of selected intracellular signaling intermediates. Other crucial parameters in cell signaling are its directionality and distribution of signaling strengths in different pathways that may crosstalk to adjust the amplitude and quality of the final effector output. Finally, we have reflected upon its possible developments during the coming years.
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Affiliation(s)
- Arathi Nair
- National Center for Cell Science (NCCS), Ganeshkhind, Pune 411007, India
| | - Prashant Chauhan
- National Center for Cell Science (NCCS), Ganeshkhind, Pune 411007, India
| | - Bhaskar Saha
- National Center for Cell Science (NCCS), Ganeshkhind, Pune 411007, India.
| | - Katharina F Kubatzky
- Zentrum für Infektiologie, Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany.
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15
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Bouffard J, Cecchetelli AD, Clifford C, Sethi K, Zaidel-Bar R, Cram EJ. The RhoGAP SPV-1 regulates calcium signaling to control the contractility of the Caenorhabditis elegans spermatheca during embryo transits. Mol Biol Cell 2019; 30:907-922. [PMID: 30726159 PMCID: PMC6589790 DOI: 10.1091/mbc.e18-10-0633] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 01/25/2019] [Accepted: 01/31/2019] [Indexed: 01/30/2023] Open
Abstract
Contractility of the nonmuscle and smooth muscle cells that comprise biological tubing is regulated by the Rho-ROCK (Rho-associated protein kinase) and calcium signaling pathways. Although many molecular details about these signaling pathways are known, less is known about how they are coordinated spatiotemporally in biological tubes. The spermatheca of the Caenorhabditis elegans reproductive system enables study of the signaling pathways regulating actomyosin contractility in live adult animals. The RhoGAP (GTPase--activating protein toward Rho family small GTPases) SPV-1 was previously identified as a negative regulator of RHO-1/Rho and spermathecal contractility. Here, we uncover a role for SPV-1 as a key regulator of calcium signaling. spv-1 mutants expressing the calcium indicator GCaMP in the spermatheca exhibit premature calcium release, elevated calcium levels, and disrupted spatial regulation of calcium signaling during spermathecal contraction. Although RHO-1 is required for spermathecal contractility, RHO-1 does not play a significant role in regulating calcium. In contrast, activation of CDC-42 recapitulates many aspects of spv-1 mutant calcium signaling. Depletion of cdc-42 by RNA interference does not suppress the premature or elevated calcium signal seen in spv-1 mutants, suggesting other targets remain to be identified. Our results suggest that SPV-1 works through both the Rho-ROCK and calcium signaling pathways to coordinate cellular contractility.
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Affiliation(s)
- Jeff Bouffard
- Department of Bioengineering, Northeastern University, Boston, MA 02143
| | | | - Coleman Clifford
- Department of Biology, Northeastern University, Boston, MA 02143
| | - Kriti Sethi
- Mechanobiology Institute, National University of Singapore, Singapore 117411
| | - Ronen Zaidel-Bar
- Mechanobiology Institute, National University of Singapore, Singapore 117411
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - Erin J. Cram
- Department of Biology, Northeastern University, Boston, MA 02143
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16
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Regulation of Actin Dynamics in the C. elegans Somatic Gonad. J Dev Biol 2019; 7:jdb7010006. [PMID: 30897735 PMCID: PMC6473838 DOI: 10.3390/jdb7010006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 03/13/2019] [Accepted: 03/15/2019] [Indexed: 11/25/2022] Open
Abstract
The reproductive system of the hermaphroditic nematode C. elegans consists of a series of contractile cell types—including the gonadal sheath cells, the spermathecal cells and the spermatheca–uterine valve—that contract in a coordinated manner to regulate oocyte entry and exit of the fertilized embryo into the uterus. Contraction is driven by acto-myosin contraction and relies on the development and maintenance of specialized acto-myosin networks in each cell type. Study of this system has revealed insights into the regulation of acto-myosin network assembly and contractility in vivo.
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17
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Nguyen RL, Medvedeva YV, Ayyagari TE, Schmunk G, Gargus JJ. Intracellular calcium dysregulation in autism spectrum disorder: An analysis of converging organelle signaling pathways. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1718-1732. [PMID: 30992134 DOI: 10.1016/j.bbamcr.2018.08.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/18/2018] [Accepted: 08/02/2018] [Indexed: 12/14/2022]
Abstract
Autism spectrum disorder (ASD) is a group of complex, neurological disorders that affect early cognitive, social, and verbal development. Our understanding of ASD has vastly improved with advances in genomic sequencing technology and genetic models that have identified >800 loci with variants that increase susceptibility to ASD. Although these findings have confirmed its high heritability, the underlying mechanisms by which these genes produce the ASD phenotypes have not been defined. Current efforts have begun to "functionalize" many of these variants and envisage how these susceptibility factors converge at key biochemical and biophysical pathways. In this review, we discuss recent work on intracellular calcium signaling in ASD, including our own work, which begins to suggest it as a compelling candidate mechanism in the pathophysiology of autism and a potential therapeutic target. We consider how known variants in the calcium signaling genomic architecture of ASD may exert their deleterious effects along pathways particularly involving organelle dysfunction including the endoplasmic reticulum (ER), a major calcium store, and the mitochondria, a major calcium ion buffer, and theorize how many of these pathways intersect.
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Affiliation(s)
- Rachel L Nguyen
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA; UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Yuliya V Medvedeva
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA; UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA; Department of Neurology, University of California, Irvine, Irvine, CA, USA
| | - Tejasvi E Ayyagari
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA; UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Galina Schmunk
- UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - John Jay Gargus
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA; UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA; Department of Pediatrics, Section of Human Genetics and Genomics, University of California, Irvine, Irvine, CA, USA.
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18
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McGovern M, Castaneda PG, Pekar O, Vallier LG, Cram EJ, Hubbard EJA. The DSL ligand APX-1 is required for normal ovulation in C. elegans. Dev Biol 2018; 435:162-169. [PMID: 29371032 DOI: 10.1016/j.ydbio.2018.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/14/2017] [Accepted: 01/11/2018] [Indexed: 01/13/2023]
Abstract
DSL ligands activate the Notch receptor in many cellular contexts across metazoa to specify cell fate. In addition, Notch receptor activity is implicated in post-mitotic morphogenesis and neuronal function. In C. elegans, the DSL family ligand APX-1 is expressed in a subset of cells of the proximal gonad lineage, where it can act as a latent proliferation-promoting signal to maintain proximal germline tumors. Here we examine apx-1 in the proximal gonad and uncover a role in the maintenance of normal ovulation. Depletion of apx-1 causes an endomitotic oocyte (Emo) phenotype and ovulation defects. We find that lag-2 can substitute for apx-1 in this role, that the ovulation defect is partially suppressed by loss of ipp-5, and that lin-12 depletion causes a similar phenotype. In addition, we find that the ovulation defects are often accompanied by a delay of spermathecal distal neck closure after oocyte entry. Although calcium oscillations occur in the spermatheca, calcium signals are abnormal when the distal neck does not close completely. Moreover, oocytes sometimes cannot properly transit through the spermatheca, leading to fragmentation of oocytes once the neck closes. Finally, abnormal oocytes and neck closure defects are seen occasionally when apx-1 or lin-12 activity is reduced in adult animals, suggesting a possible post-developmental role for APX-1 and LIN-12 signaling in ovulation.
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Affiliation(s)
- Marie McGovern
- Department of Biological Sciences, Kingsborough Community College, City University of New York, 2001 Oriental Blvd, Brooklyn, NY 11235, United States; Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016, United States
| | | | - Olga Pekar
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016, United States
| | - Laura G Vallier
- Department of Biology, Hofstra University, Hempstead, NY 11549, United States
| | - Erin J Cram
- Department of Biology, Northeastern University, Boston, MA 02115, United States
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016, United States.
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19
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Rios C, Warren D, Olson B, Abbott AL. Functional analysis of microRNA pathway genes in the somatic gonad and germ cells during ovulation in C. elegans. Dev Biol 2017; 426:115-125. [PMID: 28461238 DOI: 10.1016/j.ydbio.2017.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 03/19/2017] [Accepted: 04/17/2017] [Indexed: 01/09/2023]
Abstract
MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression that play critical roles in animal development and physiology, though functions for most miRNAs remain unknown. Worms with reduced miRNA biogenesis due to loss of Drosha or Pasha/DGCR8 activity are sterile and fail to ovulate, indicating that miRNAs are required for the process of oocyte maturation and ovulation. Starting with this penetrant sterile phenotype and using new strains created to perform tissue specific RNAi, we characterized the roles of the C. elegans Pasha, pash-1, and two miRNA-specific Argonautes, alg-1 and alg-2, in somatic gonad cells and in germ cells in the regulation of ovulation. Conditional loss of pash-1 activity resulted in a reduced rate of ovulation and in basal and ovulatory sheath contractions. Similarly, knockdown of miRNA-specific Argonautes in the cells of the somatic gonad by tissue-specific RNAi results in a reduction of the ovulation rate and in basal and ovulatory sheath contractions. Reduced miRNA pathway gene activity resulted in a range of defects, including oocytes that were pinched upon entry of the oocyte into the distal end of the spermatheca in about 42% of the ovulation events observed following alg-1 RNAi. This phenotype was not observed on worms exposed to control RNAi. In contrast, knockdown of alg-1 and alg-2 in germ cells results in few defects in oocyte maturation and ovulation. These data identify specific steps in the process of ovulation that require miRNA pathway gene activity in the somatic gonad cells.
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Affiliation(s)
- Carmela Rios
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, United States
| | - David Warren
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, United States
| | - Benjamin Olson
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, United States
| | - Allison L Abbott
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, United States.
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20
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Wirshing ACE, Cram EJ. Myosin activity drives actomyosin bundle formation and organization in contractile cells of the Caenorhabditis elegans spermatheca. Mol Biol Cell 2017; 28:1937-1949. [PMID: 28331075 PMCID: PMC5541844 DOI: 10.1091/mbc.e17-01-0029] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/14/2017] [Accepted: 03/17/2017] [Indexed: 12/04/2022] Open
Abstract
The contractile myoepithelial cells of the Caenorhabditis elegans somatic gonad are stretched by oocyte entry and subsequently contract to expel the fertilized embryo into the uterus. Formation of aligned, parallel actomyosin bundles during the first ovulation is triggered by oocyte entry and regulated by myosin contractility. Stress fibers—contractile actomyosin bundles—are important for cellular force production and adaptation to physical stress and have been well studied within the context of cell migration. However, less is known about actomyosin bundle formation and organization in vivo and in specialized contractile cells, such as smooth muscle and myoepithelial cells. The Caenorhabditis elegans spermatheca is a bag-like organ of 24 myoepithelial cells that houses the sperm and is the site of fertilization. During ovulation, spermathecal cells are stretched by oocyte entry and then coordinately contract to expel the fertilized embryo into the uterus. Here we use four-dimensional confocal microscopy of live animals to observe changes to spermathecal actomyosin network organization during cell stretch and contraction. Oocyte entry is required to trigger cell contraction and concomitant production of parallel actomyosin bundles. Actomyosin bundle size, connectivity, spacing, and orientation are regulated by myosin activity. We conclude that myosin drives actomyosin bundle production and that myosin activity is tightly regulated during ovulation to produce an optimally organized actomyosin network in C. elegans spermathecae.
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Affiliation(s)
| | - Erin J Cram
- Department of Biology, Northeastern University, Boston, MA 02115
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21
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Epidermal Growth Factor Receptor Cell Survival Signaling Requires Phosphatidylcholine Biosynthesis. G3-GENES GENOMES GENETICS 2016; 6:3533-3540. [PMID: 27605519 PMCID: PMC5100852 DOI: 10.1534/g3.116.034850] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Identification of pro-cell survival signaling pathways has implications for cancer, cardiovascular, and neurodegenerative disease. We show that the Caenorhabditis elegans epidermal growth factor receptor LET-23 (LET-23 EGFR) has a prosurvival function in counteracting excitotoxicity, and we identify novel molecular players required for this prosurvival signaling. uv1 sensory cells in the C. elegans uterus undergo excitotoxic death in response to activation of the OSM-9/OCR-4 TRPV channel by the endogenous agonist nicotinamide. Activation of LET-23 EGFR can effectively prevent this excitotoxic death. We investigate the roles of signaling pathways known to act downstream of LET-23 EGFR in C. elegans and find that the LET-60 Ras/MAPK pathway, but not the IP3 receptor pathway, is required for efficient LET-23 EGFR activity in its prosurvival function. However, activation of LET-60 Ras/MAPK pathway does not appear to be sufficient to fully mimic LET-23 EGFR activity. We screen for genes that are required for EGFR prosurvival function and uncover a role for phosphatidylcholine biosynthetic enzymes in EGFR prosurvival function. Finally, we show that exogenous application of phosphatidylcholine is sufficient to prevent some deaths in this excitotoxicity model. Our work implicates regulation of lipid synthesis downstream of EGFR in cell survival and death decisions.
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22
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Twists and turns—How we stepped into and had fun in the “boring” lipid field. SCIENCE CHINA-LIFE SCIENCES 2015; 58:1073-83. [DOI: 10.1007/s11427-015-4949-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/28/2015] [Indexed: 11/25/2022]
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23
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Schmunk G, Boubion BJ, Smith IF, Parker I, Gargus JJ. Shared functional defect in IP₃R-mediated calcium signaling in diverse monogenic autism syndromes. Transl Psychiatry 2015; 5:e643. [PMID: 26393489 PMCID: PMC5068815 DOI: 10.1038/tp.2015.123] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 07/13/2015] [Accepted: 07/27/2015] [Indexed: 01/03/2023] Open
Abstract
Autism spectrum disorder (ASD) affects 2% of children, and is characterized by impaired social and communication skills together with repetitive, stereotypic behavior. The pathophysiology of ASD is complex due to genetic and environmental heterogeneity, complicating the development of therapies and making diagnosis challenging. Growing genetic evidence supports a role of disrupted Ca(2+) signaling in ASD. Here, we report that patient-derived fibroblasts from three monogenic models of ASD-fragile X and tuberous sclerosis TSC1 and TSC2 syndromes-display depressed Ca(2+) release through inositol trisphosphate receptors (IP3Rs). This was apparent in Ca(2+) signals evoked by G protein-coupled receptors and by photoreleased IP3 at the levels of both global and local elementary Ca(2+) events, suggesting fundamental defects in IP3R channel activity in ASD. Given the ubiquitous involvement of IP3R-mediated Ca(2+) signaling in neuronal excitability, synaptic plasticity, gene expression and neurodevelopment, we propose dysregulated IP3R signaling as a nexus where genes altered in ASD converge to exert their deleterious effect. These findings highlight potential pharmaceutical targets, and identify Ca(2+) screening in skin fibroblasts as a promising technique for early detection of individuals susceptible to ASD.
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Affiliation(s)
- G Schmunk
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA,Center for Autism Research and Translation, University of California, Irvine, CA, USA
| | - B J Boubion
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California, Irvine, CA, USA
| | - I F Smith
- Center for Autism Research and Translation, University of California, Irvine, CA, USA,Department of Neurobiology and Behavior, School of Biological Sciences, University of California, Irvine, CA, USA
| | - I Parker
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA,Center for Autism Research and Translation, University of California, Irvine, CA, USA,Department of Neurobiology and Behavior, School of Biological Sciences, University of California, Irvine, CA, USA
| | - J J Gargus
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA,Center for Autism Research and Translation, University of California, Irvine, CA, USA,Division of Human Genetics & Genomics, Department of Pediatrics, School of Medicine, University of California, Irvine, CA, USA,Department of Physiology and Biophysics, School of Medicine, University of California, 2056 Hewitt Hall, 843 Health Sciences Road, Irvine, CA 92697-3940, USA. E-mail:
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24
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Qin Z, Hubbard EJA. Non-autonomous DAF-16/FOXO activity antagonizes age-related loss of C. elegans germline stem/progenitor cells. Nat Commun 2015; 6:7107. [PMID: 25960195 PMCID: PMC4432587 DOI: 10.1038/ncomms8107] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 04/07/2015] [Indexed: 12/20/2022] Open
Abstract
Stem cells maintain tissues and organs over the lifespan of individuals. How aging influences this process is unclear. Here we investigate the effects of aging on C. elegans germline stem/progenitor cells and show that the progenitor pool is depleted over time in a manner dependent on inhibition of DAF-16/FOXO by insulin/IGF-1 signalling (IIS). Our data indicate that DAF-16/FOXO activity in certain somatic gonad cells is required for germline progenitor maintenance, and that this role is separable from the effect of DAF-16/FOXO on organismal aging. In addition, blocking germ cell flux, similar to reducing IIS, maintains germline progenitors. This effect is partially dependent on gonadal DAF-16/FOXO activity. Our results imply that (1) longevity pathways can regulate aging stem cells through anatomically separable mechanisms, (2) stem cell maintenance is not necessarily prioritized and (3) stem cell regulation can occur at the level of an entire organ system such as the reproductive system. The number of germline stem/progenitor cells in C. elegans declines with age. Here the authors show this cell loss is mediated by the transcription factor DAF-16/FOXO acting in specific somatic gonad cells, demonstrating that stem cell aging can be anatomically uncoupled from organismal aging.
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Affiliation(s)
- Zhao Qin
- Departments of Cell Biology and Pathology, The Helen L. and Martin S. Kimmel Center for Stem Cell Biology, Skirball Institute for Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, New York, USA
| | - E Jane Albert Hubbard
- Departments of Cell Biology and Pathology, The Helen L. and Martin S. Kimmel Center for Stem Cell Biology, Skirball Institute for Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, New York, USA
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Mendes TK, Novakovic S, Raymant G, Bertram SE, Esmaillie R, Nadarajan S, Breugelmans B, Hofmann A, Gasser RB, Colaiácovo MP, Boag PR. Investigating the role of RIO protein kinases in Caenorhabditis elegans. PLoS One 2015; 10:e0117444. [PMID: 25688864 PMCID: PMC4331490 DOI: 10.1371/journal.pone.0117444] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Accepted: 12/24/2014] [Indexed: 12/30/2022] Open
Abstract
RIO protein kinases (RIOKs) are a relatively conserved family of enzymes implicated in cell cycle control and ribosomal RNA processing. Despite their functional importance, they remain a poorly understood group of kinases in multicellular organisms. Here, we show that the C. elegans genome contains one member of each of the three RIOK sub-families and that each of the genes coding for them has a unique tissue expression pattern. Our analysis showed that the gene encoding RIOK-1 (riok-1) was broadly and strongly expressed. Interestingly, the intestinal expression of riok-1 was dependent upon two putative binding sites for the oxidative and xenobiotic stress response transcription factor SKN-1. RNA interference (RNAi)-mediated knock down of riok-1 resulted in germline defects, including defects in germ line stem cell proliferation, oocyte maturation and the production of endomitotic oocytes. Taken together, our findings indicate new functions for RIOK-1 in post mitotic tissues and in reproduction.
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Affiliation(s)
- Tasha K. Mendes
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Stevan Novakovic
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Greta Raymant
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | | | - Reza Esmaillie
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Saravanapriah Nadarajan
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Bert Breugelmans
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria, Australia
| | - Andreas Hofmann
- Eskitis Institute for Cell & Drug Discovery, Griffith University, Brisbane, Australia
| | - Robin B. Gasser
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria, Australia
| | - Monica P. Colaiácovo
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Peter R. Boag
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
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Caenorhabditis elegans Models to Study the Molecular Biology of Ataxias. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00068-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Tan P, Zaidel-Bar R. Transient Membrane Localization of SPV-1 Drives Cyclical Actomyosin Contractions in the C. elegans Spermatheca. Curr Biol 2015; 25:141-151. [DOI: 10.1016/j.cub.2014.11.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 10/27/2014] [Accepted: 11/13/2014] [Indexed: 12/25/2022]
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Aprison EZ, Ruvinsky I. Balanced trade-offs between alternative strategies shape the response of C. elegans reproduction to chronic heat stress. PLoS One 2014; 9:e105513. [PMID: 25165831 PMCID: PMC4148340 DOI: 10.1371/journal.pone.0105513] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 07/24/2014] [Indexed: 11/18/2022] Open
Abstract
To ensure long-term reproductive success organisms have to cope with harsh environmental extremes. A reproductive strategy that simply maximizes offspring production is likely to be disadvantageous because it could lead to a catastrophic loss of fecundity under unfavorable conditions. To understand how an appropriate balance is achieved, we investigated reproductive performance of C. elegans under conditions of chronic heat stress. We found that following even prolonged exposure to temperatures at which none of the offspring survive, worms could recover and resume reproduction. The likelihood of producing viable offspring falls precipitously after exposure to temperatures greater than 28°C primarily due to sperm damage. Surprisingly, we found that worms that experienced higher temperatures can recover considerably better, provided they did not initiate ovulation. Therefore mechanisms controlling this process must play a crucial role in determining the probability of recovery. We show, however, that suppressing ovulation is only beneficial under relatively long stresses, whereas it is a disadvantageous strategy under shorter stresses of the same intensity. This is because the benefit of shutting down egg laying, and thus protecting the reproductive system, is negated by the cost associated with implementing this strategy--it takes considerable time to recover and produce offspring. We interpret these balanced trade-offs as a dynamic response of the C. elegans reproductive system to stress and an adaptation to life in variable and unpredictable conditions.
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Affiliation(s)
- Erin Z. Aprison
- Department of Ecology and Evolution and Institute for Genomics and Systems Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Ilya Ruvinsky
- Department of Ecology and Evolution and Institute for Genomics and Systems Biology, The University of Chicago, Chicago, Illinois, United States of America
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, Illinois, United States of America
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LIN-3/EGF promotes the programmed cell death of specific cells in Caenorhabditis elegans by transcriptional activation of the pro-apoptotic gene egl-1. PLoS Genet 2014; 10:e1004513. [PMID: 25144461 PMCID: PMC4140636 DOI: 10.1371/journal.pgen.1004513] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 06/05/2014] [Indexed: 12/13/2022] Open
Abstract
Programmed cell death (PCD) is the physiological death of a cell mediated by an intracellular suicide program. Although key components of the PCD execution pathway have been identified, how PCD is regulated during development is poorly understood. Here, we report that the epidermal growth factor (EGF)-like ligand LIN-3 acts as an extrinsic signal to promote the death of specific cells in Caenorhabditis elegans. The loss of LIN-3 or its receptor, LET-23, reduced the death of these cells, while excess LIN-3 or LET-23 signaling resulted in an increase in cell deaths. Our molecular and genetic data support the model that the LIN-3 signal is transduced through LET-23 to activate the LET-60/RAS-MPK-1/ERK MAPK pathway and the downstream ETS domain-containing transcription factor LIN-1. LIN-1 binds to, and activates transcription of, the key pro-apoptotic gene egl-1, which leads to the death of specific cells. Our results provide the first evidence that EGF induces PCD at the whole organism level and reveal the molecular basis for the death-promoting function of LIN-3/EGF. In addition, the level of LIN-3/EGF signaling is important for the precise fine-tuning of the life-versus-death fate. Our data and the previous cell culture studies that say EGF triggers apoptosis in some cell lines suggest that the EGF-mediated modulation of PCD is likely conserved in C. elegans and humans. Programmed cell death (PCD) is an evolutionarily conserved cellular process that is important for metazoan development and homeostasis. The epidermal growth factor (EGF) promotes cell proliferation, differentiation and survival during animal development. Surprisingly, we found that the EGF-like ligand LIN-3 also promotes the death of specific cells in Caenorhabditis elegans. We found that the LIN-3/EGF signal can be secreted from a cell to facilitate the demise of cells at a distance by activating the transcription of the PCD-promoting gene egl-1 in the doomed cells through the transcription factor LIN-1. LIN-1 binds to the egl-1 promoter in vitro and is positively regulated by the LIN-3/EGF, LET-23/EGF receptor, and the downstream MAPK signaling pathway. To our knowledge, LIN-3/EGF is the first extrinsic signal that has been shown to regulate the intrinsic PCD machinery during C. elegans development. In addition, the transcription factor LIN-31, which binds to LIN-1 and acts downstream of LIN-3/EGF, LET-23/EGF receptor, and the MAPK signaling pathway during vulval development, is dispensable for PCD. Thus, LIN-3/EGF promotes cell proliferation, differentiation, and PCD through common downstream signaling molecules but acts via distinct sets of transcription factors for different target gene expression.
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Cram EJ. Mechanotransduction in C. elegans morphogenesis and tissue function. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 126:281-316. [PMID: 25081623 DOI: 10.1016/b978-0-12-394624-9.00012-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mechanobiology is an emerging field that investigates how living cells sense and respond to their physical surroundings. Recent interest in the field has been sparked by the finding that stem cells differentiate along different lineages based on the stiffness of the cell surroundings (Engler et al., 2006), and that metastatic behavior of cancer cells is strongly influenced by the mechanical properties of the surrounding tissue (Kumar and Weaver, 2009). Many questions remain about how cells convert mechanical information, such as viscosity, stiffness of the substrate, or stretch state of the cells, into the biochemical signals that control tissue function. Caenorhabditis elegans researchers are making significant contributions to the understanding of mechanotransduction in vivo. This review summarizes recent insights into the role of mechanical forces in morphogenesis and tissue function. Examples of mechanical regulation across length scales, from the single-celled zygote, to the intercellular coordination that enables cohesive tissue function, to the mechanical influences between tissues, are considered. The power of the C. elegans system as a gene discovery and in vivo quantitative bioimaging platform is enabling an important discoveries in this exciting field.
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Affiliation(s)
- Erin J Cram
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
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Ono K, Ono S. Two actin-interacting protein 1 isoforms function redundantly in the somatic gonad and are essential for reproduction in Caenorhabditis elegans. Cytoskeleton (Hoboken) 2013; 71:36-45. [PMID: 24130131 DOI: 10.1002/cm.21152] [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] [Received: 08/13/2013] [Revised: 09/17/2013] [Accepted: 10/10/2013] [Indexed: 11/11/2022]
Abstract
The somatic gonad of the nematode Caenorhabditis elegans exhibits highly regulated contractility during ovulation, which is essential for successful reproduction. Nonstriated actin filament networks in the myoepithelial sheath at the proximal ovary provide contractile forces to push a mature oocyte for ovulation, but the mechanism of assembly and regulation of the contractile actin networks is poorly understood. Here, we show that actin-interacting protein 1 (AIP1) is essential for the assembly of the contractile actin networks in the myoepithelial sheath. AIP1 promotes disassembly of actin filaments in the presence of actin depolymerizing factor (ADF)/cofilin. C. elegans has two AIP1 genes, unc-78 and aipl-1. Mutation or RNA interference of a single AIP1 isoform causes only minor impacts on reproduction. However, simultaneous depletion of the two AIP1 isoforms causes sterility. AIP1-depleted animals show very weak contractility of the myoepithelial sheath and fail to ovulate a mature oocyte, which results in accumulation of endomitotic oocytes in the ovary. Depletion of AIP1 prevents assembly of actin networks and causes abnormal aggregation of actin as well as ADF/cofilin in the myoepithelial sheath. These results indicate that two AIP1 isoforms have redundant roles in assembly of the contractile apparatuses necessary for C. elegans reproduction.
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Affiliation(s)
- Kanako Ono
- Department of Pathology and Department of Cell Biology, Emory University, Atlanta, Georgia
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33
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Kovacevic I, Cram EJ. Filamin and Phospholipase C-ε are required for calcium signaling in the Caenorhabditis elegans Spermatheca. WORM 2013; 2:e25717. [PMID: 24778940 PMCID: PMC3875652 DOI: 10.4161/worm.25717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 07/10/2013] [Indexed: 11/23/2022]
Abstract
Mechanical properties of the microenvironment are fundamental in orchestrating normal tissue function, disease progression, and organismal development. Studies of mechanotransduction in cultured cells on artificial substrates have revealed underlying principles, but the in vivo roles of mechanotransduction remain unclear. We recently reported that the Caenorhabditis elegans spermatheca—a myoepithelial tube composed of a cell monolayer—may be mechanosensitive. Live imaging with the genetically encoded calcium indicator GCaMP revealed that oocyte-induced stretching of the spermatheca resulted in calcium oscillations and constriction of the tube. FLN-1/filamin, a mechanosensitive cytoskeletal scaffolding protein, is required to correctly trigger the calcium transients. PLC-1/phospholipase C-epsilon and ITR-1/IP3 receptor are required to produce the calcium transients, and may function downstream of filamin. In addition to providing important insights into the biology of C. elegans, our studies offer a novel and genetically tractable model for studying mechanotransduction in a myoepithelial tissue.
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Affiliation(s)
- Ismar Kovacevic
- Department of Biology; Northeastern University; Boston, MA USA
| | - Erin J Cram
- Department of Biology; Northeastern University; Boston, MA USA
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Abstract
Receptor Tyrosine Kinase (RTK)-Ras-Extracellular signal-regulated kinase (ERK) signaling pathways control many aspects of C. elegans development and behavior. Studies in C. elegans helped elucidate the basic framework of the RTK-Ras-ERK pathway and continue to provide insights into its complex regulation, its biological roles, how it elicits cell-type appropriate responses, and how it interacts with other signaling pathways to do so. C. elegans studies have also revealed biological contexts in which alternative RTK- or Ras-dependent pathways are used instead of the canonical pathway.
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Affiliation(s)
- Meera V Sundaram
- Dept. of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6145, USA.
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Praitis V, Simske J, Kniss S, Mandt R, Imlay L, Feddersen C, Miller MB, Mushi J, Liszewski W, Weinstein R, Chakravorty A, Ha DG, Schacht Farrell A, Sullivan-Wilson A, Stock T. The secretory pathway calcium ATPase PMR-1/SPCA1 has essential roles in cell migration during Caenorhabditis elegans embryonic development. PLoS Genet 2013; 9:e1003506. [PMID: 23696750 PMCID: PMC3656159 DOI: 10.1371/journal.pgen.1003506] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 03/26/2013] [Indexed: 01/22/2023] Open
Abstract
Maintaining levels of calcium in the cytosol is important for many cellular events, including cell migration, where localized regions of high calcium are required to regulate cytoskeletal dynamics, contractility, and adhesion. Studies show inositol-trisphosphate receptors (IP3R) and ryanodine receptors (RyR), which release calcium into the cytosol, are important regulators of cell migration. Similarly, proteins that return calcium to secretory stores are likely to be important for cell migration. The secretory protein calcium ATPase (SPCA) is a Golgi-localized protein that transports calcium from the cytosol into secretory stores. SPCA has established roles in protein processing, metal homeostasis, and inositol-trisphosphate signaling. Defects in the human SPCA1/ATP2C1 gene cause Hailey-Hailey disease (MIM# 169600), a genodermatosis characterized by cutaneous blisters and fissures as well as keratinocyte cell adhesion defects. We have determined that PMR-1, the Caenorhabditis elegans ortholog of SPCA1, plays an essential role in embryogenesis. Pmr-1 strains isolated from genetic screens show terminal phenotypes, such as ventral and anterior enclosure failures, body morphogenesis defects, and an unattached pharynx, which are caused by earlier defects during gastrulation. In Pmr-1 embryos, migration rates are significantly reduced for cells moving along the embryo surface, such as ventral neuroblasts, C-derived, and anterior-most blastomeres. Gene interaction experiments show changing the activity of itr-1/IP3R and unc-68/RyR modulates levels of embryonic lethality in Pmr-1 strains, indicating pmr-1 acts with these calcium channels to regulate cell migration. This analysis reveals novel genes involved in C. elegans cell migration, as well as a new role in cell migration for the highly conserved SPCA gene family. During growth or regeneration after damage, skin cells migrate from basal to superficial layers, forming tight attachments that protect an individual from environmental assaults. Proteins that remove calcium from the cell cytosol into secretory stores, where it is available for future release, play a key role in skin cell integrity. Defects in these secretory pathway calcium ATPase (SPCA) channels in humans cause Hailey-Hailey disease, a chronic disorder marked by skin lesions in areas of high-stress. Our study of the SPCA gene pmr-1 in Caenorhabditis elegans indicates the gene is essential for viability. Embryos with defective PMR-1 die with cell attachment defects superficially similar to those of Hailey-Hailey disease patients. To better understand this phenotype, we tracked the position of individual cells during development of pmr-1 mutant embryos. This analysis revealed that the cell attachment defects are caused by primary failures in cell migration. We also identified other calcium channel proteins involved in this process, indicating proper regulation of calcium is crucial for cell migration in C. elegans. If SPCA proteins act similarly in humans, this research will lead to better understanding of the molecules important for skin cell regeneration, as well as help to explain the defects observed in Hailey-Hailey disease patients.
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Affiliation(s)
- Vida Praitis
- Biology Department, Grinnell College, Grinnell, IA, USA.
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Filamin and phospholipase C-ε are required for calcium signaling in the Caenorhabditis elegans spermatheca. PLoS Genet 2013; 9:e1003510. [PMID: 23671426 PMCID: PMC3650001 DOI: 10.1371/journal.pgen.1003510] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 03/30/2013] [Indexed: 12/05/2022] Open
Abstract
The Caenorhabditis elegans spermatheca is a myoepithelial tube that stores sperm and undergoes cycles of stretching and constriction as oocytes enter, are fertilized, and exit into the uterus. FLN-1/filamin, a stretch-sensitive structural and signaling scaffold, and PLC-1/phospholipase C-ε, an enzyme that generates the second messenger IP3, are required for embryos to exit normally after fertilization. Using GCaMP, a genetically encoded calcium indicator, we show that entry of an oocyte into the spermatheca initiates a distinctive series of IP3-dependent calcium oscillations that propagate across the tissue via gap junctions and lead to constriction of the spermatheca. PLC-1 is required for the calcium release mechanism triggered by oocyte entry, and FLN-1 is required for timely initiation of the calcium oscillations. INX-12, a gap junction subunit, coordinates propagation of the calcium transients across the spermatheca. Gain-of-function mutations in ITR-1/IP3R, an IP3-dependent calcium channel, and loss-of-function mutations in LFE-2, a negative regulator of IP3 signaling, increase calcium release and suppress the exit defect in filamin-deficient animals. We further demonstrate that a regulatory cassette consisting of MEL-11/myosin phosphatase and NMY-1/non-muscle myosin is required for coordinated contraction of the spermatheca. In summary, this study answers long-standing questions concerning calcium signaling dynamics in the C. elegans spermatheca and suggests FLN-1 is needed in response to oocyte entry to trigger calcium release and coordinated contraction of the spermathecal tissue. During organism development and normal physiological function cells sense, integrate, and respond to a variety of cues or signals including biochemical and mechanical stimuli. In this study we used Caenorhabditis elegans, a small transparent worm, to study filamin (FLN-1), a structural protein that may act as a molecular strain gauge. The C. elegans spermatheca is a contractile tube that is stretched during normal function, making it an ideal candidate for study of how cells respond to stretch. Oocytes are ovulated into the spermatheca, fertilized, and then pushed into the uterus by constriction of the spermatheca. The ability of the spermatheca to constrict depends on inositol 1,4,5-triphosphate (IP3), a signaling molecule produced by the enzyme phospholipase C (PLC-1) that triggers calcium release within cells. In animals with mutated FLN-1 or PLC-1 the spermathecal cells fail to constrict. Using genetic analysis and a calcium-sensitive fluorescent protein, we show that FLN-1 functions with PLC-1 to regulate IP3 production, calcium release, and contraction of the spermatheca. Filamin may function to sense stretch caused by entering oocytes and to trigger constriction. These findings establish a link between filamin and calcium signaling that may apply to similar signaling pathways in other systems.
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Zhang D, Liu X, Chan JD, Marchant JS. Characterization of a flatworm inositol (1,4,5) trisphosphate receptor (IP₃R) reveals a role in reproductive physiology. Cell Calcium 2013; 53:307-14. [PMID: 23481272 PMCID: PMC3665645 DOI: 10.1016/j.ceca.2013.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/22/2013] [Accepted: 01/29/2013] [Indexed: 11/15/2022]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP₃Rs) are intracellular Ca²⁺ channels that elevate cytoplasmic Ca²⁺ in response to the second messenger IP3. Here, we describe the identification and in vivo functional characterization of the planarian IP₃R, the first intracellular Ca²⁺ channel to be defined in flatworms. A single IP₃R gene in Dugesia japonica encoded a 2666 amino acid protein (Dj.IP₃R) that shared well conserved structural features with vertebrate IP₃R counterparts. Expression of an NH₂-terminal Dj.IP₃R region (amino acid residues 223-585) recovered high affinity ³H-IP₃ binding (0.9±0.1 nM) which was abolished by a single point mutation of an arginine residue (R495L) important for IP₃ coordination. In situ hybridization revealed that Dj.IP₃R mRNA was most strongly expressed in the pharynx and optical nerve system as well as the reproductive system in sexualized planarians. Consistent with this observed tissue distribution, in vivo RNAi of Dj.IP₃R resulted in a decreased egg-laying behavior suggesting Dj.IP₃R plays an upstream role in planarian reproductive physiology.
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Affiliation(s)
- Dan Zhang
- Department of Pharmacology, University of Minnesota Medical School, MN 55455, USA
| | - Xiaolong Liu
- Department of Pharmacology, University of Minnesota Medical School, MN 55455, USA
| | - John D. Chan
- Department of Pharmacology, University of Minnesota Medical School, MN 55455, USA
| | - Jonathan S. Marchant
- Department of Pharmacology, University of Minnesota Medical School, MN 55455, USA
- The Stem Cell Institute, University of Minnesota Medical School, MN 55455, USA
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A genetic program promotes C. elegans longevity at cold temperatures via a thermosensitive TRP channel. Cell 2013; 152:806-17. [PMID: 23415228 DOI: 10.1016/j.cell.2013.01.020] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Revised: 10/23/2012] [Accepted: 01/11/2013] [Indexed: 12/26/2022]
Abstract
Both poikilotherms and homeotherms live longer at lower body temperatures, highlighting a general role of temperature reduction in lifespan extension. However, the underlying mechanisms remain unclear. One prominent model is that cold temperatures reduce the rate of chemical reactions, thereby slowing the rate of aging. This view suggests that cold-dependent lifespan extension is simply a passive thermodynamic process. Here, we challenge this view in C. elegans by showing that genetic programs actively promote longevity at cold temperatures. We find that TRPA-1, a cold-sensitive TRP channel, detects temperature drop in the environment to extend lifespan. This effect requires cold-induced, TRPA-1-mediated calcium influx and a calcium-sensitive PKC that signals to the transcription factor DAF-16/FOXO. Human TRPA1 can functionally substitute for worm TRPA-1 in promoting longevity. Our results reveal a previously unrecognized function for TRP channels, link calcium signaling to longevity, and, importantly, demonstrate that genetic programs contribute to lifespan extension at cold temperatures.
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A neuronal signaling pathway of CaMKII and Gqα regulates experience-dependent transcription of tph-1. J Neurosci 2013; 33:925-35. [PMID: 23325232 DOI: 10.1523/jneurosci.2355-12.2013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dynamic serotonin biosynthesis is important for serotonin function; however, the mechanisms that underlie experience-dependent transcriptional regulation of the rate-limiting serotonin biosynthetic enzyme tryptophan hydroxylase (TPH) are poorly understood. Here, we characterize the molecular and cellular mechanisms that regulate increased transcription of Caenorhabditis elegans tph-1 in a pair of serotonergic neurons ADF during an aversive experience with pathogenic bacteria, a common environmental peril for worms. Training with pathogenic bacteria induces a learned aversion to the smell of the pathogen, a behavioral plasticity that depends on the serotonin signal from ADF neurons. We demonstrate that pathogen training increases ADF neuronal activity. While activating ADF increases tph-1 transcription, inhibiting ADF activity abolishes the training effect on tph-1, demonstrating the dependence of tph-1 transcriptional regulation on ADF neural activity. At the molecular level, the C. elegans homolog of CaMKII, UNC-43, functions cell-autonomously in ADF neurons to generate training-dependent enhancement in neuronal activity and tph-1 transcription, and this cell-autonomous function of UNC-43 is required for learning. Furthermore, selective expression of an activated form of UNC-43 in ADF neurons is sufficient to increase ADF activity and tph-1 transcription, mimicking the training effect. Upstream of ADF, the Gqα protein EGL-30 facilitates training-dependent induction of tph-1 by functional regulation of olfactory sensory neurons, which underscores the importance of sensory experience. Together, our work elucidates the molecular and cellular mechanisms whereby experience modulates tph-1 transcription.
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Schumacher JA, Hsieh YW, Chen S, Pirri JK, Alkema MJ, Li WH, Chang C, Chuang CF. Intercellular calcium signaling in a gap junction-coupled cell network establishes asymmetric neuronal fates in C. elegans. Development 2013; 139:4191-201. [PMID: 23093425 DOI: 10.1242/dev.083428] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The C. elegans left and right AWC olfactory neurons specify asymmetric subtypes, one default AWC(OFF) and one induced AWC(ON), through a stochastic, coordinated cell signaling event. Intercellular communication between AWCs and non-AWC neurons via a NSY-5 gap junction network coordinates AWC asymmetry. However, the nature of intercellular signaling across the network and how individual non-AWC cells in the network influence AWC asymmetry is not known. Here, we demonstrate that intercellular calcium signaling through the NSY-5 gap junction neural network coordinates a precise 1AWC(ON)/1AWC(OFF) decision. We show that NSY-5 gap junctions in C. elegans cells mediate small molecule passage. We expressed vertebrate calcium-buffer proteins in groups of cells in the network to reduce intracellular calcium levels, thereby disrupting intercellular communication. We find that calcium in non-AWC cells of the network promotes the AWC(ON) fate, in contrast to the autonomous role of calcium in AWCs to promote the AWC(OFF) fate. In addition, calcium in specific non-AWCs promotes AWC(ON) side biases through NSY-5 gap junctions. Our results suggest a novel model in which calcium has dual roles within the NSY-5 network: autonomously promoting AWC(OFF) and non-autonomously promoting AWC(ON).
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Affiliation(s)
- Jennifer A Schumacher
- Division of Developmental Biology, Children's Hospital Medical Center Research Foundation, 240 Albert Sabin Way, Cincinnati, OH 45229, USA
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Control of oocyte growth and meiotic maturation in Caenorhabditis elegans. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 757:277-320. [PMID: 22872481 DOI: 10.1007/978-1-4614-4015-4_10] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
In sexually reproducing animals, oocytes arrest at diplotene or diakinesis and resume meiosis (meiotic maturation) in response to hormones. Chromosome segregation errors in female meiosis I are the leading cause of human birth defects, and age-related changes in the hormonal environment of the ovary are a suggested cause. Caenorhabditis elegans is emerging as a genetic paradigm for studying hormonal control of meiotic maturation. The meiotic maturation processes in C. elegans and mammals share a number of biological and molecular similarities. Major sperm protein (MSP) and luteinizing hormone (LH), though unrelated in sequence, both trigger meiotic resumption using somatic Gα(s)-adenylate cyclase pathways and soma-germline gap-junctional communication. At a molecular level, the oocyte responses apparently involve the control of conserved protein kinase pathways and post-transcriptional gene regulation in the oocyte. At a cellular level, the responses include cortical cytoskeletal rearrangement, nuclear envelope breakdown, assembly of the acentriolar meiotic spindle, chromosome segregation, and likely changes important for fertilization and the oocyte-to-embryo transition. This chapter focuses on signaling mechanisms required for oocyte growth and meiotic maturation in C. elegans and discusses how these mechanisms coordinate the completion of meiosis and the oocyte-to-embryo transition.
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Singaravelu G, Singson A. Calcium signaling surrounding fertilization in the nematode Caenorhabditis elegans. Cell Calcium 2012; 53:2-9. [PMID: 23218668 DOI: 10.1016/j.ceca.2012.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 11/02/2012] [Accepted: 11/03/2012] [Indexed: 01/17/2023]
Abstract
Calcium plays a prominent role during fertilization in many animals. This review focuses on roles of Ca(2+) during the events around fertilization in the model organism, Caenorhabditis elegans. Specifically, the role of Ca(2+) in sperm, oocytes and the surrounding somatic tissues during fertilization will be discussed, with the focus on sperm activation, meiotic maturation of oocytes, ovulation, sperm-egg interaction and fertilization.
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Kniazeva M, Shen H, Euler T, Wang C, Han M. Regulation of maternal phospholipid composition and IP(3)-dependent embryonic membrane dynamics by a specific fatty acid metabolic event in C. elegans. Genes Dev 2012; 26:554-66. [PMID: 22426533 DOI: 10.1101/gad.187054.112] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Natural fatty acids (FAs) exhibit vast structural diversity, but the functional importance of FA variations and the mechanism by which they contribute to a healthy lipid composition in animals remain largely unexplored. A large family of acyl-CoA synthetases (ACSs) regulates FA metabolism by esterifying FA to coenyzme A. However, little is known about how particular FA-ACS combinations affect lipid composition and specific cellular functions. We analyzed how the activity of ACS-1 on branched chain FA C17ISO impacts maternal lipid content, signal transduction, and development in Caenorhabditis elegans embryos. We show that expression of ACS-1 in the somatic gonad guides the incorporation of C17ISO into certain phospholipids and thus regulates the phospholipid composition in the zygote. Disrupting this ACS-1 function causes striking defects in complex membrane dynamics, including exocytosis and cytokinesis, leading to early embryonic lethality. These defects are suppressed by hyperactive IP(3) signaling, suggesting that C17ISO and ACS-1 functions are necessary for optimal IP(3) signaling essential for early embryogenesis. This study shows a novel role of branched chain FAs whose functions in humans and animals are unknown and uncovers a novel intercellular regulatory pathway linking a specific FA-ACS interaction to specific developmental events.
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Affiliation(s)
- Marina Kniazeva
- Howard Hughes Medical Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80309, USA
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The atypical calpains: evolutionary analyses and roles in Caenorhabditis elegans cellular degeneration. PLoS Genet 2012; 8:e1002602. [PMID: 22479198 PMCID: PMC3315469 DOI: 10.1371/journal.pgen.1002602] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 02/04/2012] [Indexed: 01/17/2023] Open
Abstract
The calpains are physiologically important Ca2+-activated regulatory proteases, which are divided into typical or atypical sub-families based on constituent domains. Both sub-families are present in mammals, but our understanding of calpain function is based primarily on typical sub-family members. Here, we take advantage of the model organism Caenorhabditis elegans, which expresses only atypical calpains, to extend our knowledge of the phylogenetic evolution and function of calpains. We provide evidence that a typical human calpain protein with a penta EF hand, detected using custom profile hidden Markov models, is conserved in ancient metazoans and a divergent clade. These analyses also provide evidence for the lineage-specific loss of typical calpain genes in C. elegans and Ciona, and they reveal that many calpain-like genes lack an intact catalytic triad. Given the association between the dysregulation of typical calpains and human degenerative pathologies, we explored the phenotypes, expression profiles, and consequences of inappropriate reduction or activation of C. elegans atypical calpains. These studies show that the atypical calpain gene, clp-1, contributes to muscle degeneration and reveal that clp-1 activity is sensitive to genetic manipulation of [Ca2+]i. We show that CLP-1 localizes to sarcomeric sub-structures, but is excluded from dense bodies (Z-disks). We find that the muscle degeneration observed in a C. elegans model of dystrophin-based muscular dystrophy can be suppressed by clp-1 inactivation and that nemadipine-A inhibition of the EGL-19 calcium channel reveals that Ca2+ dysfunction underlies the C. elegans MyoD model of myopathy. Taken together, our analyses highlight the roles of calcium dysregulation and CLP-1 in muscle myopathies and suggest that the atypical calpains could retain conserved roles in myofilament turnover. Calpains are calcium activated non-lysosomal proteases that cleave proteins with exquisite selectivity. Proteins can be activated by calpain cleavage, because they are released from inhibitory constraints, or they can be targeted for further degradation to facilitate their normal physiological turnover or to promote cellular remodelling. Inappropriate calpain activity can lead to degenerative pathologies and cancers. Our understanding of calpain function is based primarily on typical calpains, which carry EF hand motifs that bind Ca2+ or mediate dimerization; however, typical and atypical calpains, which lack EF hand motifs, are both present in mammals. Hence, any therapeutic intervention designed to suppress degenerative conditions, particularly those caused by elevated Ca2+ levels, should also consider the potential involvement of atypical calpains. We have taken advantage of the model organism C. elegans, which only encodes atypical calpain proteins, to gain an understanding of the evolution and activities of these proteins. We show that the CLP-1 atypical calpain is normally expressed in muscle and localizes to sarcomeric sub-structures. We find that CLP-1 contributes to the muscle degeneration observed in a model of Duchenne muscular dystrophy. Our studies also highlight the importance of calcium dysregulation in promoting CLP-1 activity and muscle degeneration.
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Rongo C. Epidermal growth factor and aging: a signaling molecule reveals a new eye opening function. Aging (Albany NY) 2012; 3:896-905. [PMID: 21931179 PMCID: PMC3227454 DOI: 10.18632/aging.100384] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Epidermal Growth Factor (EGF) is known for its role in promoting cell division and cellular differentiation in developing animals, but we know surprising little about what EGF does in vivo in mature adult animals. Here I review EGF signaling, emphasizing several recent studies that uncovered an unexpected role for EGF in promoting longevity and healthspan in mature adult C. elegans. EGF, acting through phospholipase Cγ and the IP3 receptor signaling, maintains pharyngeal and body wall muscle function in aging adults, and delays the accumulation of lipofuscin-enriched aging pigments within intestinal cells. EGF also acts through the Ras/ERK pathway to regulate protein homeostasis by promoting the expression of antioxidant genes, stimulating the activity of the Ubiquitin Proteasome System (UPS), and repressing the expression of small heat shock protein chaperones. The effects of EGF signaling on lifespan are largely independent of Insulin/IGF-like Signaling (IIS), as the effects of EGF signaling mutants on lifespan and heathspan are not affected by mutations in the DAF-2 insulin receptor or the DAF-16 FOXO transcription factor. Nevertheless, these two signal pathways have multiple points of overlap, coordination, and cross regulation. I propose that the IIS and EGF signaling pathways respond to environment and to developmental timing, respectively, so as to coordinate the appropriate physiological strategy that cells use to maintain protein homeostasis.
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Affiliation(s)
- Christopher Rongo
- The Waksman Institute, Department of Genetics, Rutgers The State University of New Jersey, Piscataway, New Jersey, USA.
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White A, Fearon A, Johnson CM. HLH-29 regulates ovulation in C. elegans by targeting genes in the inositol triphosphate signaling pathway. Biol Open 2012; 1:261-8. [PMID: 23213416 PMCID: PMC3507288 DOI: 10.1242/bio.2012046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The reproductive cycle in the nematode Caenorhabditis elegans depends in part on the ability of the mature oocyte to ovulate into the spermatheca, fuse with the sperm during fertilization, and then exit the spermatheca as a fertilized egg. This cycle requires the integration of signals between the germ cells and the somatic gonad and relies heavily on the precise control of inositol 1,4,5 triphosphate (IP3)levels. The HLH-29 protein, one of five Hairy/Enhancer of Split (HES) homologs in C. elegans, was previously shown to affect development of the somatic gonad. Here we show that HLH-29 expression in the adult spermatheca is strongly localized to the distal spermatheca valve and to the spermatheca-uterine valve, and that loss of hlh-29 activity interferes with oocyte entry into and egg exit from the spermatheca. We show that HLH-29 can regulate the transcriptional activity of the IP3 signaling pathway genes ppk-1, ipp-5, and plc-1 and provide evidence that hlh-29 acts in a genetic pathway with each of these genes. We propose that the HES-like protein HLH-29 acts in the spermatheca of larval and adult animals to effectively increase IP3 levels during the reproductive cycle.
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Affiliation(s)
- Ana White
- Department of Biology, College of Arts and Sciences, Georgia State University , Atlanta, GA 30303 , USA
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Hoegg MB, Robbins SM, McGhee JD. Characterization of the C. elegans erlin homologue. BMC Cell Biol 2012; 13:2. [PMID: 22269071 PMCID: PMC3292932 DOI: 10.1186/1471-2121-13-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 01/23/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Erlins are highly conserved proteins associated with lipid rafts within the endoplasmic reticulum (ER). Biochemical studies in mammalian cell lines have shown that erlins are required for ER associated protein degradation (ERAD) of activated inositol-1,4,5-trisphosphate receptors (IP3Rs), implying that erlin proteins might negatively regulate IP3R signalling. In humans, loss of erlin function appears to cause progressive intellectual disability, motor dysfunction and joint contractures. However, it is unknown if defects in IP3R ERAD are the underlying cause of this disease phenotype, whether ERAD of activated IP3Rs is the only function of erlin proteins, and what role ERAD plays in regulating IP3R-dependent processes in the context of an intact animal or embryo. In this study, we characterize the erlin homologue of the nematode Caenorhabditis elegans and examine erlin function in vivo. We specifically set out to test whether C. elegans erlin modulates IP3R-dependent processes, such as egg laying, embryonic development and defecation rates. We also explore the possibility that erlin might play a more general role in the ERAD pathway of C. elegans. RESULTS We first show that the C. elegans erlin homologue, ERL-1, is highly similar to mammalian erlins with respect to amino acid sequence, domain structure, biochemical properties and subcellular location. ERL-1 is present throughout the C. elegans embryo; in adult worms, ERL-1 appears restricted to the germline. The expression pattern of ERL-1 thus only partially overlaps with that of ITR-1, eliminating the possibility of ERL-1 being a ubiquitous and necessary regulator of ITR-1. We show that loss of ERL-1 does not affect overall phenotype, or alter brood size, embryonic development or defecation cycle length in either wild type or sensitized itr-1 mutant animals. Moreover we show that ERL-1 deficient worms respond normally to ER stress conditions, suggesting that ERL-1 is not an essential component of the general ERAD pathway. CONCLUSIONS Although loss of erlin function apparently causes a strong phenotype in humans, no such effect is seen in C. elegans. C. elegans erlin does not appear to be a ubiquitous major modulator of IP3 receptor activity nor does erlin appear to play a major role in ERAD.
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Affiliation(s)
- Maja B Hoegg
- Department of Biochemistry & Molecular Biology, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
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Baylis HA, Vázquez-Manrique RP. Genetic analysis of IP3 and calcium signalling pathways in C. elegans. Biochim Biophys Acta Gen Subj 2011; 1820:1253-68. [PMID: 22146231 DOI: 10.1016/j.bbagen.2011.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 11/15/2011] [Accepted: 11/16/2011] [Indexed: 01/02/2023]
Abstract
BACKGROUND The nematode, Caenorhabditis elegans is an established model system that is particularly well suited to genetic analysis. C. elegans is easily manipulated and we have an in depth knowledge of many aspects of its biology. Thus, it is an attractive system in which to pursue integrated studies of signalling pathways. C. elegans has a complement of calcium signalling molecules similar to that of other animals. SCOPE OF REVIEW We focus on IP3 signalling. We describe how forward and reverse genetic approaches, including RNAi, have resulted in a tool kit which enables the analysis of IP3/Ca2+ signalling pathways. The importance of cell and tissue specific manipulation of signalling pathways and the use of epistasis analysis are highlighted. We discuss how these tools have increased our understanding of IP3 signalling in specific developmental, physiological and behavioural roles. Approaches to imaging calcium signals in C. elegans are considered. MAJOR CONCLUSIONS A wide selection of tools is available for the analysis of IP3/Ca2+ signalling in C. elegans. This has resulted in detailed descriptions of the function of IP3/Ca2+ signalling in the animal's biology. Nevertheless many questions about how IP3 signalling regulates specific processes remain. GENERAL SIGNIFICANCE Many of the approaches described may be applied to other calcium signalling systems. C. elegans offers the opportunity to dissect pathways, perform integrated studies and to test the importance of the properties of calcium signalling molecules to whole animal function, thus illuminating the function of calcium signalling in animals. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signalling.
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Affiliation(s)
- Howard A Baylis
- Department of Zoology, University of Cambridge, Cambridge, UK.
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Kang J, Bai Z, Zegarek MH, Grant BD, Lee J. Essential roles of snap-29 in C. elegans. Dev Biol 2011; 355:77-88. [PMID: 21545795 DOI: 10.1016/j.ydbio.2011.04.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 03/29/2011] [Accepted: 04/14/2011] [Indexed: 12/29/2022]
Abstract
SNARE domain proteins are key molecules mediating intracellular fusion events. SNAP25 family proteins are unique target-SNAREs possessing two SNARE domains. Here we report the genetic, molecular, and cell biological characterization of C. elegans SNAP-29. We found that snap-29 is an essential gene required throughout the life-cycle. Depletion of snap-29 by RNAi in adults results in sterility associated with endomitotic oocytes and pre-meiotic maturation of the oocytes. Many of the embryos that are produced are multinucleated, indicating a defect in embryonic cytokinesis. A profound defect in secretion by oocytes and early embryos in animals lacking SNAP-29 appears to be the underlying defect connecting these phenotypes. Further analysis revealed defects in basolateral and apical secretion by intestinal epithelial cells in animals lacking SNAP-29, indicating a broad requirement for this protein in the secretory pathway. A SNAP-29-GFP fusion protein was enriched on recycling endosomes, and loss of SNAP-29 disrupted recycling endosome morphology. Taken together these results suggest a requirement for SNAP-29 in the fusion of post-Golgi vesicles with the recycling endosome for cargo to reach the cell surface.
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Affiliation(s)
- Junsu Kang
- Research Center for Functional Cellulomics, School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
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50
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Yu S, Driscoll M. EGF signaling comes of age: promotion of healthy aging in C. elegans. Exp Gerontol 2011; 46:129-34. [PMID: 21074601 PMCID: PMC4841623 DOI: 10.1016/j.exger.2010.10.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 10/24/2010] [Accepted: 10/26/2010] [Indexed: 01/23/2023]
Abstract
More than 400 genes have been noted to modulate Caenorhabditis elegans longevity. Recent studies testing the role of proposed secreted insulin-binding proteins unexpectedly revealed a potent role for the EGF signaling pathway in promoting healthy aging and longevity in C. elegans. Activation of EGF receptor LET-23 is associated with increased mean and maximum lifespan, maintained pharyngeal pumping, extended locomotory function, and low lipofuscin and advanced glycation end product accumulation. Conversely, reducing the activity of the EGF pathway is associated with system-wide evidence of progeria. The EGF pathway appears to work in a manner largely independent of the insulin/IGF-like pathway, in that effects are additive with reduction of DAF-2/InsR activity and are not affected by DAF-16/FOXO transcription factor deficiency. Two novel regulators of EGF signaling, called HPA-1 and HPA-2 (for the high performance in advanced age locomotory phenotypes that their disruption confers), negatively regulate EGF action, possibly by binding and sequestering EGF. Interestingly, whereas HPA-1 appears to control aging of the animal overall, HPA-2 exerts an effect primarily on locomotory aging. As such, HPA-2 is an example of a protein with an effect on healthspan but not lifespan, a gene class that may have been missed in screens focused on longevity endpoint. To date, roles for EGF signaling in adult maintenance (particularly in non-dividing tissues) have not been addressed in other organisms-should EGF signaling exert a conserved impact on healthy aging, testing this hypothesis could hold implications for anti-aging therapies.
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Affiliation(s)
- Simon Yu
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08855, USA
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