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Chavez DR, Snow AK, Smith JR, Stanfield GM. Soma-germ line interactions and a role for muscle in the regulation of C. elegans sperm motility. Development 2018; 145:dev.167734. [PMID: 30470702 DOI: 10.1242/dev.167734] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 11/12/2018] [Indexed: 12/13/2022]
Abstract
The development of highly differentiated sperm cells that are specialized for navigating to and fusing with an oocyte is essential for sexual reproduction. As a major part of differentiation, sperm undergo extensive post-meiotic maturation en route to the oocyte. This is regulated largely by soma-derived cues. In Caenorhabditis elegans, this process is called sperm activation, and it transforms immotile spermatids into migratory fertilization-competent cells. Here, we show that the negative regulator of sperm activation, SWM-1, is produced in an unexpected cell type: body wall muscle. SWM-1 is secreted into the body cavity and enters the gonad; there, it is present with its likely target, TRY-5, a spermiogenesis activator. We show that, in addition to SWM-1, the somatic gonad and body fluid can exchange other factors, suggesting that soma-germ line transfer could affect other reproductive processes. In addition, we show that SWM-1 may have a separate role in the sperm migratory environment, to which it is contributed by both males and hermaphrodites. These findings reveal that late stages in gamete differentiation can be regulated at the whole-organism level by broadly secreted factors.This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- Daniela R Chavez
- Department of Human Genetics, University of Utah, 15 North 2030 East, Salt Lake City, UT 84112, USA.,Smithsonian Conservation Biology Institute, National Zoological Park, 3001 Connecticut Ave. NW, Washington, DC 20008, USA
| | - Angela K Snow
- Department of Human Genetics, University of Utah, 15 North 2030 East, Salt Lake City, UT 84112, USA
| | - Joseph R Smith
- Department of Human Genetics, University of Utah, 15 North 2030 East, Salt Lake City, UT 84112, USA
| | - Gillian M Stanfield
- Department of Human Genetics, University of Utah, 15 North 2030 East, Salt Lake City, UT 84112, USA
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52
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Narayanaswamy N, Chakraborty K, Saminathan A, Zeichner E, Leung K, Devany J, Krishnan Y. A pH-correctable, DNA-based fluorescent reporter for organellar calcium. Nat Methods 2018; 16:95-102. [PMID: 30532082 DOI: 10.1038/s41592-018-0232-7] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 10/30/2018] [Indexed: 01/01/2023]
Abstract
It is extremely challenging to quantitate lumenal Ca2+ in acidic Ca2+ stores of the cell because all Ca2+ indicators are pH sensitive, and Ca2+ transport is coupled to pH in acidic organelles. We have developed a fluorescent DNA-based reporter, CalipHluor, that is targetable to specific organelles. By ratiometrically reporting lumenal pH and Ca2+ simultaneously, CalipHluor functions as a pH-correctable Ca2+ reporter. By targeting CalipHluor to the endolysosomal pathway, we mapped lumenal Ca2+ changes during endosomal maturation and found a surge in lumenal Ca2+ specifically in lysosomes. Using lysosomal proteomics and genetic analysis, we found that catp-6, a Caenorhabditis elegans homolog of ATP13A2, was responsible for lysosomal Ca2+ accumulation-an example of a lysosome-specific Ca2+ importer in animals. By enabling the facile quantification of compartmentalized Ca2+, CalipHluor can expand the understanding of subcellular Ca2+ importers.
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Affiliation(s)
- Nagarjun Narayanaswamy
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, USA
| | - Kasturi Chakraborty
- Department of Chemistry, The University of Chicago, Chicago, IL, USA. .,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, USA.
| | - Anand Saminathan
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, USA
| | | | - KaHo Leung
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, USA
| | - John Devany
- Department of Physics, The University of Chicago, Chicago, IL, USA
| | - Yamuna Krishnan
- Department of Chemistry, The University of Chicago, Chicago, IL, USA. .,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, USA.
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53
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Scimone ML, Wurtzel O, Malecek K, Fincher CT, Oderberg IM, Kravarik KM, Reddien PW. foxF-1 Controls Specification of Non-body Wall Muscle and Phagocytic Cells in Planarians. Curr Biol 2018; 28:3787-3801.e6. [PMID: 30471994 DOI: 10.1016/j.cub.2018.10.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/17/2018] [Accepted: 10/10/2018] [Indexed: 12/31/2022]
Abstract
Planarians are flatworms capable of regenerating any missing body part in a process requiring stem cells and positional information. Muscle is a major source of planarian positional information and consists of several types of fibers with distinct regulatory roles in regeneration. The transcriptional regulatory programs used to specify different muscle fibers are poorly characterized. Using single-cell RNA sequencing, we define the transcriptomes of planarian dorsal-ventral muscle (DVM), intestinal muscle (IM), and pharynx muscle. This analysis identifies foxF-1, which encodes a broadly conserved Fox-family transcription factor, as a master transcriptional regulator of all non-body wall muscle. The transcription factors encoded by nk4 and gata4/5/6-2 specify two different subsets of DVM, lateral and medial, respectively, whereas gata4/5/6-3 specifies IM. These muscle types all express planarian patterning genes. Both lateral and medial DVM are required for medial-lateral patterning in regeneration, whereas medial DVM and IM have a role in maintaining and regenerating intestine morphology. In addition to the role in muscle, foxF-1 is required for the specification of multiple cell types with transcriptome similarities, including high expression levels of cathepsin genes. These cells include pigment cells, glia, and several other cells with unknown function. cathepsin+ cells phagocytose E. coli, suggesting these are phagocytic cells. In conclusion, we describe a regulatory program for planarian muscle cell subsets and phagocytic cells, both driven by foxF-1. FoxF proteins specify different mesoderm-derived tissues in other organisms, suggesting that FoxF regulates formation of an ancient and broadly conserved subset of mesoderm derivatives in the Bilateria.
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Affiliation(s)
- M Lucila Scimone
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Omri Wurtzel
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Kathryn Malecek
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Christopher T Fincher
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Isaac M Oderberg
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Kellie M Kravarik
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Peter W Reddien
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA.
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54
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Tikiyani V, Li L, Sharma P, Liu H, Hu Z, Babu K. Wnt Secretion Is Regulated by the Tetraspan Protein HIC-1 through Its Interaction with Neurabin/NAB-1. Cell Rep 2018; 25:1856-1871.e6. [PMID: 30428353 PMCID: PMC6258899 DOI: 10.1016/j.celrep.2018.10.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 08/25/2018] [Accepted: 10/11/2018] [Indexed: 12/22/2022] Open
Abstract
The aberrant regulation of Wnt secretion is implicated in various neurological diseases. However, the mechanisms of Wnt release are still largely unknown. Here we describe the role of a C. elegans tetraspan protein, HIC-1, in maintaining normal Wnt release. We show that HIC-1 is expressed in cholinergic synapses and that mutants in hic-1 show increased levels of the acetylcholine receptor AChR/ACR-16. Our results suggest that HIC-1 maintains normal AChR/ACR-16 levels by regulating normal Wnt release from presynaptic neurons, as hic-1 mutants show an increase in secreted Wnt from cholinergic neurons. We further show that HIC-1 affects Wnt secretion by modulating the actin cytoskeleton through its interaction with the actin-binding protein NAB-1. In summary, we describe a protein, HIC-1, that functions as a neuromodulator by affecting postsynaptic AChR/ACR-16 levels by regulating presynaptic Wnt release from cholinergic motor neurons.
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Affiliation(s)
- Vina Tikiyani
- Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Manauli PO 140306, Punjab, India
| | - Lei Li
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), University of Queensland, Upland Road 79, St. Lucia, QLD 4072, Australia
| | - Pallavi Sharma
- Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Manauli PO 140306, Punjab, India
| | - Haowen Liu
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), University of Queensland, Upland Road 79, St. Lucia, QLD 4072, Australia
| | - Zhitao Hu
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), University of Queensland, Upland Road 79, St. Lucia, QLD 4072, Australia
| | - Kavita Babu
- Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Manauli PO 140306, Punjab, India.
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Madhivanan K, Greiner ER, Alves-Ferreira M, Soriano-Castell D, Rouzbeh N, Aguirre CA, Paulsson JF, Chapman J, Jiang X, Ooi FK, Lemos C, Dillin A, Prahlad V, Kelly JW, Encalada SE. Cellular clearance of circulating transthyretin decreases cell-nonautonomous proteotoxicity in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2018; 115:E7710-E7719. [PMID: 30061394 PMCID: PMC6099907 DOI: 10.1073/pnas.1801117115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cell-autonomous and cell-nonautonomous mechanisms of neurodegeneration appear to occur in the proteinopathies, including Alzheimer's and Parkinson's diseases. However, how neuronal toxicity is generated from misfolding-prone proteins secreted by nonneuronal tissues and whether modulating protein aggregate levels at distal locales affects the degeneration of postmitotic neurons remains unknown. We generated and characterized animal models of the transthyretin (TTR) amyloidoses that faithfully recapitulate cell-nonautonomous neuronal proteotoxicity by expressing human TTR in the Caenorhabditis elegans muscle. We identified sensory neurons with affected morphological and behavioral nociception-sensing impairments. Nonnative TTR oligomer load and neurotoxicity increased following inhibition of TTR degradation in distal macrophage-like nonaffected cells. Moreover, reducing TTR levels by RNAi or by kinetically stabilizing natively folded TTR pharmacologically decreased TTR aggregate load and attenuated neuronal dysfunction. These findings reveal a critical role for in trans modulation of aggregation-prone degradation that directly affects postmitotic tissue degeneration observed in the proteinopathies.
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Affiliation(s)
- Kayalvizhi Madhivanan
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037
| | - Erin R Greiner
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037
| | - Miguel Alves-Ferreira
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-171 Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4150-171 Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4150-171 Porto, Portugal
| | - David Soriano-Castell
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037
| | - Nirvan Rouzbeh
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037
| | - Carlos A Aguirre
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037
| | - Johan F Paulsson
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
| | | | - Xin Jiang
- Misfolding Diagnostics, San Diego, CA 92121
| | - Felicia K Ooi
- Department of Biology, Aging Mind and Brain Initiative, University of Iowa, Iowa City, IA 52242
| | - Carolina Lemos
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-171 Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4150-171 Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4150-171 Porto, Portugal
| | - Andrew Dillin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720
| | - Veena Prahlad
- Department of Biology, Aging Mind and Brain Initiative, University of Iowa, Iowa City, IA 52242
| | - Jeffery W Kelly
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Sandra E Encalada
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037;
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037
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56
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Axonal Mitochondria Modulate Neuropeptide Secretion Through the Hypoxic Stress Response in Caenorhabditis elegans. Genetics 2018; 210:275-285. [PMID: 30049781 DOI: 10.1534/genetics.118.301014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 07/25/2018] [Indexed: 12/13/2022] Open
Abstract
Neurons are highly dependent on mitochondrial function, and mitochondrial damage has been implicated in many neurological and neurodegenerative diseases. Here we show that axonal mitochondria are necessary for neuropeptide secretion in Caenorhabditis elegans and that oxidative phosphorylation, but not mitochondrial calcium uptake, is required for secretion. Oxidative phosphorylation produces cellular ATP, reactive oxygen species, and consumes oxygen. Disrupting any of these functions could inhibit neuropeptide secretion. We show that blocking mitochondria transport into axons or decreasing mitochondrial function inhibits neuropeptide secretion through activation of the hypoxia inducible factor HIF-1 Our results suggest that axonal mitochondria modulate neuropeptide secretion by regulating transcriptional responses induced by metabolic stress.
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57
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Ren M, Zhao L, Ding X, Krasteva N, Rui Q, Wang D. Developmental basis for intestinal barrier against the toxicity of graphene oxide. Part Fibre Toxicol 2018; 15:26. [PMID: 29929559 PMCID: PMC6013870 DOI: 10.1186/s12989-018-0262-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 05/21/2018] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Intestinal barrier is crucial for animals against translocation of engineered nanomaterials (ENMs) into secondary targeted organs. However, the molecular mechanisms for the role of intestinal barrier against ENMs toxicity are still largely unclear. The intestine of Caenorhabditis elegans is a powerful in vivo experimental system for the study on intestinal function. In this study, we investigated the molecular basis for intestinal barrier against toxicity and translocation of graphene oxide (GO) using C. elegans as a model animal. RESULTS Based on the genetic screen of genes required for the control of intestinal development at different aspects using intestine-specific RNA interference (RNAi) technique, we identified four genes (erm-1, pkc-3, hmp-2 and act-5) required for the function of intestinal barrier against GO toxicity. Under normal conditions, mutation of any of these genes altered the intestinal permeability. With the focus on PKC-3, an atypical protein kinase C, we identified an intestinal signaling cascade of PKC-3-SEC-8-WTS-1, which implies that PKC-3 might regulate intestinal permeability and GO toxicity by affecting the function of SEC-8-mediated exocyst complex and the role of WTS-1 in maintaining integrity of apical intestinal membrane. ISP-1 and SOD-3, two proteins required for the control of oxidative stress, were also identified as downstream targets for PKC-3, and functioned in parallel with WTS-1 in the regulation of GO toxicity. CONCLUSIONS Using C. elegans as an in vivo assay system, we found that several developmental genes required for the control of intestinal development regulated both the intestinal permeability and the GO toxicity. With the focus on PKC-3, we raised two intestinal signaling cascades, PKC-3-SEC-8-WTS-1 and PKC-3-ISP-1/SOD-3. Our results will strengthen our understanding the molecular basis for developmental machinery of intestinal barrier against GO toxicity and translocation in animals.
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Affiliation(s)
- Mingxia Ren
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing, 210009 China
| | - Li Zhao
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing, 210009 China
| | - Xuecheng Ding
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 China
| | - Natalia Krasteva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Science, 1113 Sofia, Bulgaria
| | - Qi Rui
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 China
| | - Dayong Wang
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing, 210009 China
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58
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Ryu L, Cheon Y, Huh YH, Pyo S, Chinta S, Choi H, Butcher RA, Kim K. Feeding state regulates pheromone-mediated avoidance behavior via the insulin signaling pathway in Caenorhabditis elegans. EMBO J 2018; 37:embj.201798402. [PMID: 29925517 DOI: 10.15252/embj.201798402] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 05/10/2018] [Accepted: 05/15/2018] [Indexed: 12/21/2022] Open
Abstract
Animals change sensory responses and their eventual behaviors, depending on their internal metabolic status and external food availability. However, the mechanisms underlying feeding state-dependent behavioral changes remain undefined. Previous studies have shown that Caenorhabditis elegans hermaphrodite exhibits avoidance behaviors to acute exposure of a pheromone, ascr#3 (asc-ΔC9, C9). Here, we show that the ascr#3 avoidance behavior is modulated by feeding state via the insulin signaling pathway. Starvation increases ascr#3 avoidance behavior, and loss-of-function mutations in daf-2 insulin-like receptor gene dampen this starvation-induced ascr#3 avoidance behavior. DAF-2 and its downstream signaling molecules, including the DAF-16 FOXO transcription factor, act in the ascr#3-sensing ADL neurons to regulate synaptic transmission to downstream target neurons, including the AVA command interneurons. Moreover, we found that starvation decreases the secretion of INS-18 insulin-like peptides from the intestine, which antagonizes DAF-2 function in the ADL neurons. Altogether, this study provides insights about the molecular communication between intestine and sensory neurons delivering hunger message to sensory neurons, which regulates avoidance behavior from pheromones to facilitate survival chance.
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Affiliation(s)
- Leesun Ryu
- Department of Brain and Cognitive Sciences, DGIST, Daegu, Korea
| | - YongJin Cheon
- Department of Brain and Cognitive Sciences, DGIST, Daegu, Korea
| | - Yang Hoon Huh
- Electron Microscopy Research Center, Korea Basic Science Institute, Cheongju-si, Chungcheongbuk-do, Korea
| | - Seondong Pyo
- Department of Brain and Cognitive Sciences, DGIST, Daegu, Korea
| | - Satya Chinta
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Hongsoo Choi
- Robotics Engineering Department, DGIST, Daegu, Korea
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Kyuhyung Kim
- Department of Brain and Cognitive Sciences, DGIST, Daegu, Korea
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59
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Li Y, Zhang Y, Gan Q, Xu M, Ding X, Tang G, Liang J, Liu K, Liu X, Wang X, Guo L, Gao Z, Hao X, Yang C. C. elegans-based screen identifies lysosome-damaging alkaloids that induce STAT3-dependent lysosomal cell death. Protein Cell 2018; 9:1013-1026. [PMID: 29611115 PMCID: PMC6251801 DOI: 10.1007/s13238-018-0520-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/16/2018] [Indexed: 01/13/2023] Open
Abstract
Lysosomes are degradation and signaling centers within the cell, and their dysfunction impairs a wide variety of cellular processes. To understand the cellular effect of lysosome damage, we screened natural small-molecule compounds that induce lysosomal abnormality using Caenorhabditis elegans (C. elegans) as a model system. A group of vobasinyl-ibogan type bisindole alkaloids (ervachinines A-D) were identified that caused lysosome enlargement in C. elegans macrophage-like cells. Intriguingly, these compounds triggered cell death in the germ line independently of the canonical apoptosis pathway. In mammalian cells, ervachinines A-D induced lysosomal enlargement and damage, leading to leakage of cathepsin proteases, inhibition of autophagosome degradation and necrotic cell death. Further analysis revealed that this ervachinine-induced lysosome damage and lysosomal cell death depended on STAT3 signaling, but not RIP1 or RIP3 signaling. These findings suggest that lysosome-damaging compounds are promising reagents for dissecting signaling mechanisms underlying lysosome homeostasis and lysosome-related human disorders.
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Affiliation(s)
- Yang Li
- Department of Pharmacology, Key Laboratory of Metabolism and Molecular Medicine (The Ministry of Education), School of Basic Medical Science, Fudan University, Shanghai, 200032, China. .,State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Yu Zhang
- State Key Laboratory of Phytochemistry and Plant Resources in Western China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650021, China
| | - Qiwen Gan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Meng Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiao Ding
- State Key Laboratory of Phytochemistry and Plant Resources in Western China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650021, China
| | - Guihua Tang
- State Key Laboratory of Phytochemistry and Plant Resources in Western China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650021, China
| | - Jingjing Liang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Kai Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xuezhao Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xin Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Center for Life Sciences, School of Life Sciences, Yunnan University, Kunming, 650091, China
| | - Lingli Guo
- State Key Laboratory of Phytochemistry and Plant Resources in Western China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650021, China
| | - Zhiyang Gao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaojiang Hao
- State Key Laboratory of Phytochemistry and Plant Resources in Western China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650021, China. .,The Key Laboratory of Chemistry for Natural Product of Guizhou Province, Chinese Academy of Science, Guiyang, 550002, China.
| | - Chonglin Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. .,State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Center for Life Sciences, School of Life Sciences, Yunnan University, Kunming, 650091, China.
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60
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Williams TD, Kay RR. The physiological regulation of macropinocytosis during Dictyostelium growth and development. J Cell Sci 2018; 131:jcs213736. [PMID: 29440238 PMCID: PMC5897714 DOI: 10.1242/jcs.213736] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/05/2018] [Indexed: 01/02/2023] Open
Abstract
Macropinocytosis is a conserved endocytic process used by Dictyostelium amoebae for feeding on liquid medium. To further Dictyostelium as a model for macropinocytosis, we developed a high-throughput flow cytometry assay to measure macropinocytosis, and used it to identify inhibitors and investigate the physiological regulation of macropinocytosis. Dictyostelium has two feeding states: phagocytic and macropinocytic. When cells are switched from phagocytic growth on bacteria to liquid media, the rate of macropinocytosis slowly increases, due to increased size and frequency of macropinosomes. Upregulation is triggered by a minimal medium containing three amino acids plus glucose and likely depends on macropinocytosis itself. The presence of bacteria suppresses macropinocytosis while their product, folate, partially suppresses upregulation of macropinocytosis. Starvation, which initiates development, does not of itself suppress macropinocytosis: this can continue in isolated cells, but is shut down by a conditioned-medium factor or activation of PKA signalling. Thus macropinocytosis is a facultative ability of Dictyostelium cells, regulated by environmental conditions that are identified here.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Thomas D Williams
- MRC-Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Robert R Kay
- MRC-Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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Ghose P, Rashid A, Insley P, Trivedi M, Shah P, Singhal A, Lu Y, Bao Z, Shaham S. EFF-1 fusogen promotes phagosome sealing during cell process clearance in Caenorhabditis elegans. Nat Cell Biol 2018; 20:393-399. [PMID: 29556089 PMCID: PMC5876135 DOI: 10.1038/s41556-018-0068-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 02/16/2018] [Indexed: 12/21/2022]
Abstract
Phagocytosis of dying cells is critical in development and immunity1–3. While proteins for recognition and engulfment of cellular debris following cell death are known4,5, proteins that directly mediate phagosome sealing are uncharacterized. Furthermore, whether all phagocytic targets are cleared using the same machinery is unclear. Degeneration of morphologically-complex cells, such as neurons, glia, and melanocytes, produces phagocytic targets of various shapes and sizes located in different microenvironments6,7. Such cells, therefore, offer unique settings to explore engulfment program mechanisms and specificity. Here we report that dismantling and clearance of a morphologically-complex C. elegans epithelial cell requires separate cell-soma, proximal-, and distal-process programs. Similar compartment-specific events govern elimination of a C. elegans neuron. While canonical engulfment proteins drive cell-soma clearance, these are not required for process removal. We find that EFF-1, a protein previously implicated in cell-cell fusion8, specifically promotes distal-process phagocytosis. EFF-1 localizes to phagocyte pseudopod tips, and acts exoplasmically to drive phagosome sealing. eff-1 mutations result in phagocytosis arrest with unsealed phagosomes. Our studies suggest universal mechanisms for dismantling morphologically-complex cells, and uncover a phagosome sealing component promoting cell-process clearance.
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Affiliation(s)
- Piya Ghose
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY, USA
| | - Alina Rashid
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY, USA
| | - Peter Insley
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY, USA
| | - Meera Trivedi
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY, USA
| | - Pavak Shah
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Anupriya Singhal
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY, USA
| | - Yun Lu
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY, USA.
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62
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Huynh JM, Dang H, Fares H. Measurement of Lysosomal Size and Lysosomal Marker Intensities in Adult Caenorhabditis elegans. Bio Protoc 2018; 8:e2724. [PMID: 34179259 DOI: 10.21769/bioprotoc.2724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 01/19/2018] [Accepted: 01/29/2018] [Indexed: 11/02/2022] Open
Abstract
Assays have been developed to study trafficking in various tissues of Caenorhabditis elegans. Adult C. elegans intestinal cells are large and have extensive endocytic networks, thus making them a good system for deciphering the endocytic pathway using live imaging techniques. However, the presence of auto-fluorescent gut granules in adult intestine can interfere with the signals of endocytic compartment reporters, like GFP. Here we demonstrate a protocol adapted from the original method developed by the Grant laboratory to identify signals from reporters in adult intestinal cells. The goal of this protocol is to identify endocytic compartments tagged with fluorescent markers without any confounding effects of background autofluorescent gut granules in adult intestinal cells of Caenorhabditis elegans.
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Affiliation(s)
- Julie M Huynh
- College of Medicine-Tucson, University of Arizona, Tucson, USA
| | - Hope Dang
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, USA
| | - Hanna Fares
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, USA
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63
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Lei N, Mellem JE, Brockie PJ, Madsen DM, Maricq AV. NRAP-1 Is a Presynaptically Released NMDA Receptor Auxiliary Protein that Modifies Synaptic Strength. Neuron 2017; 96:1303-1316.e6. [DOI: 10.1016/j.neuron.2017.11.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/20/2017] [Accepted: 11/14/2017] [Indexed: 12/19/2022]
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64
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Yin JA, Gao G, Liu XJ, Hao ZQ, Li K, Kang XL, Li H, Shan YH, Hu WL, Li HP, Cai SQ. Genetic variation in glia-neuron signalling modulates ageing rate. Nature 2017; 551:198-203. [PMID: 29120414 DOI: 10.1038/nature24463] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 10/02/2017] [Indexed: 12/25/2022]
Abstract
The rate of behavioural decline in the ageing population is remarkably variable among individuals. Despite the considerable interest in studying natural variation in ageing rate to identify factors that control healthy ageing, no such factor has yet been found. Here we report a genetic basis for variation in ageing rates in Caenorhabditis elegans. We find that C. elegans isolates show diverse lifespan and age-related declines in virility, pharyngeal pumping, and locomotion. DNA polymorphisms in a novel peptide-coding gene, named regulatory-gene-for-behavioural-ageing-1 (rgba-1), and the neuropeptide receptor gene npr-28 influence the rate of age-related decline of worm mating behaviour; these two genes might have been subjected to recent selective sweeps. Glia-derived RGBA-1 activates NPR-28 signalling, which acts in serotonergic and dopaminergic neurons to accelerate behavioural deterioration. This signalling involves the SIR-2.1-dependent activation of the mitochondrial unfolded protein response, a pathway that modulates ageing. Thus, natural variation in neuropeptide-mediated glia-neuron signalling modulates the rate of ageing in C. elegans.
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Affiliation(s)
- Jiang-An Yin
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ge Gao
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xi-Juan Liu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Zi-Qian Hao
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Kai Li
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xin-Lei Kang
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Hong Li
- Core Facility of Molecular Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yuan-Hong Shan
- Core Facility Center of the Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Wen-Li Hu
- Core Facility Center of the Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Hai-Peng Li
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Shi-Qing Cai
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
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65
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Ohno H, Yoshida M, Sato T, Kato J, Miyazato M, Kojima M, Ida T, Iino Y. Luqin-like RYamide peptides regulate food-evoked responses in C. elegans. eLife 2017; 6. [PMID: 28847365 PMCID: PMC5576490 DOI: 10.7554/elife.28877] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/08/2017] [Indexed: 12/25/2022] Open
Abstract
Peptide signaling controls many processes involving coordinated actions of multiple organs, such as hormone-mediated appetite regulation. However, the extent to which the mode of action of peptide signaling is conserved in different animals is largely unknown, because many peptides and receptors remain orphan and many undiscovered peptides still exist. Here, we identify two novel Caenorhabditis elegans neuropeptides, LURY-1-1 and LURY-1-2, as endogenous ligands for the neuropeptide receptor-22 (NPR-22). Both peptides derive from the same precursor that is orthologous to invertebrate luqin/arginine-tyrosine-NH2 (RYamide) proneuropeptides. LURY-1 peptides are secreted from two classes of pharyngeal neurons and control food-related processes: feeding, lifespan, egg-laying, and locomotory behavior. We propose that LURY-1 peptides transmit food signals to NPR-22 expressed in feeding pacemaker neurons and a serotonergic neuron. Our results identified a critical role for luqin-like RYamides in feeding-related processes and suggested that peptide-mediated negative feedback is important for satiety regulation in C. elegans.
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Affiliation(s)
- Hayao Ohno
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Morikatsu Yoshida
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Takahiro Sato
- Molecular Genetics, Institute of Life Sciences, Kurume University, Fukuoka, Japan
| | - Johji Kato
- Department of Bioactive Peptides, Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| | - Mikiya Miyazato
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Masayasu Kojima
- Molecular Genetics, Institute of Life Sciences, Kurume University, Fukuoka, Japan
| | - Takanori Ida
- Department of Bioactive Peptides, Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan.,Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan
| | - Yuichi Iino
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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66
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Chakraborty K, Leung K, Krishnan Y. High lumenal chloride in the lysosome is critical for lysosome function. eLife 2017; 6. [PMID: 28742019 PMCID: PMC5526669 DOI: 10.7554/elife.28862] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 06/23/2017] [Indexed: 12/31/2022] Open
Abstract
Lysosomes are organelles responsible for the breakdown and recycling of cellular machinery. Dysfunctional lysosomes give rise to lysosomal storage disorders as well as common neurodegenerative diseases. Here, we use a DNA-based, fluorescent chloride reporter to measure lysosomal chloride in Caenorhabditis elegans as well as murine and human cell culture models of lysosomal diseases. We find that the lysosome is highly enriched in chloride, and that chloride reduction correlates directly with a loss in the degradative function of the lysosome. In nematodes and mammalian cell culture models of diverse lysosomal disorders, where previously only lysosomal pH dysregulation has been described, massive reduction of lumenal chloride is observed that is ~103 fold greater than the accompanying pH change. Reducing chloride within the lysosome impacts Ca2+ release from the lysosome and impedes the activity of specific lysosomal enzymes indicating a broader role for chloride in lysosomal function. DOI:http://dx.doi.org/10.7554/eLife.28862.001 In cells, worn out proteins and other unnecessary materials are sent to small compartments called lysosomes to be broken down and recycled. Lysosomes contain many different proteins including some that break down waste material into recyclable fragments and others that transport the fragments out of the lysosome. If any of these proteins do not work, waste products build up and cause disease. There are around 70 such lysosomal storage diseases, each arising from a different lysosomal protein not working correctly. A recently developed “nanodevice” called Clensor can measure the levels of chloride ions inside cells. Clensor is constructed from DNA, and its fluorescence changes when it detects chloride ions. Although chloride ions have many biological roles, chloride ion levels had not been measured inside a living organism. Now, Chakraborty et al. – including some of the researchers who developed Clensor – have used this nanodevice to examine chloride ion levels in the lysosomes of the roundworm Caenorhabditis elegans. This revealed that the lysosomes contain high levels of chloride ions. Furthermore, reducing the amount of chloride in the lysosomes made them worse at breaking down waste. Do lysosomes affected by lysosome storage diseases also contain low levels of chloride ions? To find out, Chakraborty et al. used Clensor to study C. elegans worms and mouse and human cells whose lysosomes accumulate waste products. In all these cases, the levels of chloride in the diseased lysosomes were much lower than normal. This had a number of effects on how the lysosomes worked, such as reducing the activity of key lysosomal proteins. Chakraborty et al. also found that Clensor can be used to distinguish between different lysosomal storage diseases. This means that in the future, Clensor (or similar methods that directly measure chloride ion levels in lysosomes) may be useful not just for research purposes. They may also be valuable for diagnosing lysosomal storage diseases early in infancy that, if left undiagnosed, are fatal. DOI:http://dx.doi.org/10.7554/eLife.28862.002
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Affiliation(s)
- Kasturi Chakraborty
- Department of Chemistry, University of Chicago, Chicago, United States.,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, United States
| | - KaHo Leung
- Department of Chemistry, University of Chicago, Chicago, United States.,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, United States
| | - Yamuna Krishnan
- Department of Chemistry, University of Chicago, Chicago, United States.,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, United States
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67
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Tong XJ, López-Soto EJ, Li L, Liu H, Nedelcu D, Lipscombe D, Hu Z, Kaplan JM. Retrograde Synaptic Inhibition Is Mediated by α-Neurexin Binding to the α2δ Subunits of N-Type Calcium Channels. Neuron 2017; 95:326-340.e5. [PMID: 28669545 DOI: 10.1016/j.neuron.2017.06.018] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 04/20/2017] [Accepted: 06/08/2017] [Indexed: 12/31/2022]
Abstract
The synaptic adhesion molecules Neurexin and Neuroligin alter the development and function of synapses and are linked to autism in humans. In C. elegans, post-synaptic Neurexin (NRX-1) and pre-synaptic Neuroligin (NLG-1) mediate a retrograde synaptic signal that inhibits acetylcholine (ACh) release at neuromuscular junctions. Here, we show that the retrograde signal decreases ACh release by inhibiting the function of pre-synaptic UNC-2/CaV2 calcium channels. Post-synaptic NRX-1 binds to an auxiliary subunit of pre-synaptic UNC-2/CaV2 channels (UNC-36/α2δ), decreasing UNC-36 abundance at pre-synaptic elements. Retrograde inhibition is mediated by a soluble form of NRX-1's ectodomain, which is released from the post-synaptic membrane by the SUP-17/ADAM10 protease. Mammalian Neurexin-1α binds α2δ-3 and decreases CaV2.2 current in transfected cells, whereas Neurexin-1α has no effect on CaV2.2 reconstituted with α2δ-1 and α2δ-2. Collectively, these results suggest that α-Neurexin binding to α2δ is a conserved mechanism for regulating synaptic transmission.
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Affiliation(s)
- Xia-Jing Tong
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Eduardo Javier López-Soto
- Department of Neuroscience and Brown Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Lei Li
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Haowen Liu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Daniel Nedelcu
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Diane Lipscombe
- Department of Neuroscience and Brown Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Zhitao Hu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Joshua M Kaplan
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA.
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68
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Midha A, Schlosser J, Hartmann S. Reciprocal Interactions between Nematodes and Their Microbial Environments. Front Cell Infect Microbiol 2017; 7:144. [PMID: 28497029 PMCID: PMC5406411 DOI: 10.3389/fcimb.2017.00144] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/07/2017] [Indexed: 01/07/2023] Open
Abstract
Parasitic nematode infections are widespread in nature, affecting humans as well as wild, companion, and livestock animals. Most parasitic nematodes inhabit the intestines of their hosts living in close contact with the intestinal microbiota. Many species also have tissue migratory life stages in the absence of severe systemic inflammation of the host. Despite the close coexistence of helminths with numerous microbes, little is known concerning these interactions. While the environmental niche is considerably different, the free-living nematode Caenorhabditis elegans (C. elegans) is also found amongst a diverse microbiota, albeit on decaying organic matter. As a very well characterized model organism that has been intensively studied for several decades, C. elegans interactions with bacteria are much more deeply understood than those of their parasitic counterparts. The enormous breadth of understanding achieved by the C. elegans research community continues to inform many aspects of nematode parasitology. Here, we summarize what is known regarding parasitic nematode-bacterial interactions while comparing and contrasting this with information from work in C. elegans. This review highlights findings concerning responses to bacterial stimuli, antimicrobial peptides, and the reciprocal influences between nematodes and their environmental bacteria. Furthermore, the microbiota of nematodes as well as alterations in the intestinal microbiota of mammalian hosts by helminth infections are discussed.
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Affiliation(s)
- Ankur Midha
- Department of Veterinary Medicine, Institute of Immunology, Freie Universität BerlinBerlin, Germany
| | - Josephine Schlosser
- Department of Veterinary Medicine, Institute of Immunology, Freie Universität BerlinBerlin, Germany
| | - Susanne Hartmann
- Department of Veterinary Medicine, Institute of Immunology, Freie Universität BerlinBerlin, Germany
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69
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Jeong DE, Lee D, Hwang SY, Lee Y, Lee JE, Seo M, Hwang W, Seo K, Hwang AB, Artan M, Son HG, Jo JH, Baek H, Oh YM, Ryu Y, Kim HJ, Ha CM, Yoo JY, Lee SJV. Mitochondrial chaperone HSP-60 regulates anti-bacterial immunity via p38 MAP kinase signaling. EMBO J 2017; 36:1046-1065. [PMID: 28283579 DOI: 10.15252/embj.201694781] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 02/08/2017] [Accepted: 02/10/2017] [Indexed: 12/13/2022] Open
Abstract
Mitochondria play key roles in cellular immunity. How mitochondria contribute to organismal immunity remains poorly understood. Here, we show that HSP-60/HSPD1, a major mitochondrial chaperone, boosts anti-bacterial immunity through the up-regulation of p38 MAP kinase signaling. We first identify 16 evolutionarily conserved mitochondrial components that affect the immunity of Caenorhabditis elegans against pathogenic Pseudomonas aeruginosa (PA14). Among them, the mitochondrial chaperone HSP-60 is necessary and sufficient to increase resistance to PA14. We show that HSP-60 in the intestine and neurons is crucial for the resistance to PA14. We then find that p38 MAP kinase signaling, an evolutionarily conserved anti-bacterial immune pathway, is down-regulated by genetic inhibition of hsp-60, and up-regulated by increased expression of hsp-60 Overexpression of HSPD1, the mammalian ortholog of hsp-60, increases p38 MAP kinase activity in human cells, suggesting an evolutionarily conserved mechanism. Further, cytosol-localized HSP-60 physically binds and stabilizes SEK-1/MAP kinase kinase 3, which in turn up-regulates p38 MAP kinase and increases immunity. Our study suggests that mitochondrial chaperones protect host eukaryotes from pathogenic bacteria by up-regulating cytosolic p38 MAPK signaling.
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Affiliation(s)
- Dae-Eun Jeong
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Dongyeop Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Sun-Young Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Yujin Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Jee-Eun Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Mihwa Seo
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Wooseon Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Keunhee Seo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Ara B Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Murat Artan
- Information Technology Convergence Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Heehwa G Son
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Jay-Hyun Jo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Haeshim Baek
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Young Min Oh
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Youngjae Ryu
- Research Division, Korea Brain Research Institute, Daegu, Korea
| | - Hyung-Jun Kim
- Research Division, Korea Brain Research Institute, Daegu, Korea
| | - Chang Man Ha
- Research Division, Korea Brain Research Institute, Daegu, Korea
| | - Joo-Yeon Yoo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
| | - Seung-Jae V Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea .,School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea.,Information Technology Convergence Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Korea
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70
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Abstract
Lysosomes, the major membrane-bound degradative organelles, have a multitude of functions in eukaryotic cells. Lysosomes are the terminal compartments in the endocytic pathway, though they display highly dynamic behaviors, fusing with each other and with late endosomes in the endocytic pathway, and with the plasma membrane during regulated exocytosis and for wound repair. After fusing with late endosomes, lysosomes are reformed from the resulting hybrid organelles through a process that involves budding of a nascent lysosome, extension of the nascent lysosome from the hybrid organelle, while remaining connected by a membrane bridge, and scission of the membrane bridge to release the newly formed lysosome. The newly formed lysosomes undergo cycles of homotypic fusion and fission reactions to form mature lysosomes. In this study, we used a forward genetic screen in Caenorhabditis elegans to identify six regulators of lysosome biology. We show that these proteins function in different steps of lysosome biology, regulating lysosome formation, lysosome fusion, and lysosome degradation.
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71
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Pu P, Stone CE, Burdick JT, Murray JI, Sundaram MV. The Lipocalin LPR-1 Cooperates with LIN-3/EGF Signaling To Maintain Narrow Tube Integrity in Caenorhabditis elegans. Genetics 2017; 205:1247-1260. [PMID: 28040739 PMCID: PMC5340336 DOI: 10.1534/genetics.116.195156] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 12/21/2016] [Indexed: 11/18/2022] Open
Abstract
Lipocalins are secreted cup-shaped glycoproteins that bind sterols, fatty acids, and other lipophilic molecules. Lipocalins have been implicated in a wide array of processes related to lipophilic cargo transport, sequestration, and signaling, and several are used as biomarkers for human disease, but the functions of most lipocalins remain poorly understood. Here we show that the Caenorhabditis elegans lipocalin LPR-1 is required to maintain apical membrane integrity and a continuous lumen in two narrow unicellular tubes, the excretory duct and pore, during a period of rapid lumen elongation. LPR-1 fusion protein is expressed by the duct and pore and accumulates both intracellularly and in apical extracellular compartments, but it can also function cell nonautonomously when provided from outside of the excretory system. lpr-1 mutant defects can be rescued by increased signaling through the epidermal growth factor (EGF)-Ras-extracellular signal regulated kinase (ERK) pathway, which promotes the more elongated duct vs. less elongated pore tube fate. Spatial and temporal rescue experiments indicate that Ras signaling acts within the duct and pore tubes during or prior to cell fate determination to bypass the requirement for LPR-1 lpr-1 mutations did not disrupt LIN-3/EGF-dependent duct-fate specification, prevent functioning of any specific LIN-3/EGF isoform, or alter LET-23/EGFR localization, and reduced signaling did not phenocopy or enhance lpr-1 mutant defects. These data suggest that LPR-1 protects lumen integrity through a LIN-3/EGF-independent mechanism, but that increased signaling upregulates some target(s) that can compensate for lpr-1 absence.
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Affiliation(s)
- Pu Pu
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Craig E Stone
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Joshua T Burdick
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - John I Murray
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Meera V Sundaram
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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72
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Chen C, Itakura E, Nelson GM, Sheng M, Laurent P, Fenk LA, Butcher RA, Hegde RS, de Bono M. IL-17 is a neuromodulator of Caenorhabditis elegans sensory responses. Nature 2017; 542:43-48. [PMID: 28099418 DOI: 10.1038/nature20818] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 11/23/2016] [Indexed: 01/08/2023]
Abstract
Interleukin-17 (IL-17) is a major pro-inflammatory cytokine: it mediates responses to pathogens or tissue damage, and drives autoimmune diseases. Little is known about its role in the nervous system. Here we show that IL-17 has neuromodulator-like properties in Caenorhabditis elegans. IL-17 can act directly on neurons to alter their response properties and contribution to behaviour. Using unbiased genetic screens, we delineate an IL-17 signalling pathway and show that it acts in the RMG hub interneurons. Disrupting IL-17 signalling reduces RMG responsiveness to input from oxygen sensors, and renders sustained escape from 21% oxygen transient and contingent on additional stimuli. Over-activating IL-17 receptors abnormally heightens responses to 21% oxygen in RMG neurons and whole animals. IL-17 deficiency can be bypassed by optogenetic stimulation of RMG. Inducing IL-17 expression in adults can rescue mutant defects within 6 h. These findings reveal a non-immunological role of IL-17 modulating circuit function and behaviour.
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Affiliation(s)
- Changchun Chen
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Eisuke Itakura
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Geoffrey M Nelson
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Ming Sheng
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Patrick Laurent
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Lorenz A Fenk
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
| | - Ramanujan S Hegde
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Mario de Bono
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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73
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SNX-1 and RME-8 oppose the assembly of HGRS-1/ESCRT-0 degradative microdomains on endosomes. Proc Natl Acad Sci U S A 2017; 114:E307-E316. [PMID: 28053230 DOI: 10.1073/pnas.1612730114] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
After endocytosis, transmembrane cargo reaches endosomes, where it encounters complexes dedicated to opposing functions: recycling and degradation. Microdomains containing endosomal sorting complexes required for transport (ESCRT)-0 component Hrs [hepatocyte growth factor-regulated tyrosine kinase substrate (HGRS-1) in Caenorhabditis elegans] mediate cargo degradation, concentrating ubiquitinated cargo and organizing the activities of ESCRT. At the same time, retromer associated sorting nexin one (SNX-1) and its binding partner, J-domain protein RME-8, sort cargo away from degradation, promoting cargo recycling to the Golgi. Thus, we hypothesized that there could be important regulatory interactions between retromer and ESCRT that balance degradative and recycling functions. Taking advantage of the naturally large endosomes of the C. elegans coelomocyte, we visualized complementary ESCRT-0 and RME-8/SNX-1 microdomains in vivo and assayed the ability of retromer and ESCRT microdomains to regulate one another. We found in snx-1(0) and rme-8(ts) mutants increased endosomal coverage and intensity of HGRS-1-labeled microdomains, as well as increased total levels of HGRS-1 bound to membranes. These effects are specific to SNX-1 and RME-8, as loss of other retromer components SNX-3 and vacuolar protein sorting-associated protein 35 (VPS-35) did not affect HGRS-1 microdomains. Additionally, knockdown of hgrs-1 had little to no effect on SNX-1 and RME-8 microdomains, suggesting directionality to the interaction. Separation of the functionally distinct ESCRT-0 and SNX-1/RME-8 microdomains was also compromised in the absence of RME-8 and SNX-1, a phenomenon we observed to be conserved, as depletion of Snx1 and Snx2 in HeLa cells also led to greater overlap of Rme-8 and Hrs on endosomes.
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74
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A Bystander Mechanism Explains the Specific Phenotype of a Broadly Expressed Misfolded Protein. PLoS Genet 2016; 12:e1006450. [PMID: 27926939 PMCID: PMC5142776 DOI: 10.1371/journal.pgen.1006450] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 10/31/2016] [Indexed: 12/18/2022] Open
Abstract
Misfolded proteins in transgenic models of conformational diseases interfere with proteostasis machinery and compromise the function of many structurally and functionally unrelated metastable proteins. This collateral damage to cellular proteins has been termed 'bystander' mechanism. How a single misfolded protein overwhelms the proteostasis, and how broadly-expressed mutant proteins cause cell type-selective phenotypes in disease are open questions. We tested the gain-of-function mechanism of a R37C folding mutation in an endogenous IGF-like C.elegans protein DAF-28. DAF-28(R37C) is broadly expressed, but only causes dysfunction in one specific neuron, ASI, leading to a distinct developmental phenotype. We find that this phenotype is caused by selective disruption of normal biogenesis of an unrelated endogenous protein, DAF-7/TGF-β. The combined deficiency of DAF-28 and DAF-7 biogenesis, but not of DAF-28 alone, explains the gain-of-function phenotype—deficient pro-growth signaling by the ASI neuron. Using functional, fluorescently-tagged protein, we find that, in animals with mutant DAF-28/IGF, the wild-type DAF-7/TGF-β is mislocalized to and accumulates in the proximal axon of the ASI neuron. Activation of two different branches of the unfolded protein response can modulate both the developmental phenotype and DAF-7 mislocalization in DAF-28(R37C) animals, but appear to act through divergent mechanisms. Our finding that bystander targeting of TGF-β explains the phenotype caused by a folding mutation in an IGF-like protein suggests that, in conformational diseases, bystander misfolding may specify the distinct phenotypes caused by different folding mutations. Correct protein folding and localization ensures cellular health. Dedicated proteostasis machinery assists in protein folding and protects against misfolding. Yet, folding mutations cause many conformational diseases, including neurodegenerative diseases and certain types of diabetes and cancer. Misfolded disease-related proteins interfere with proteostasis machinery, causing global misfolding in the cell. How this global mechanism leads to the specific phenotypes in different conformational diseases is unknown. Moreover, mutant misfolded proteins that only damage specific cell-types in disease often lose this cell-selectivity when overexpressed in genetic models. Here we use an endogenous folding mutation in a C. elegans secreted IGF-like protein, DAF-28, that causes dysfunction in one neuron and a specific developmental phenotype, despite expression in many cells. We find that misfolding of mutant DAF-28 causes mislocalization and defective function of another, wild-type growth factor that is expressed in the affected neuron, the TGF-β protein DAF-7. Decrease in DAF-7 function explains the observed developmental phenotype. This targeting of the bystander protein DAF-7 by the misfolded mutant DAF-28 is specific and is not caused by the global stress. Our data suggest that rather than global effects, it is the selective targeting of specific susceptible bystander proteins that defines the specific phenotypes in conformational diseases.
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75
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Battisti JM, Watson LA, Naung MT, Drobish AM, Voronina E, Minnick MF. Analysis of the Caenorhabditis elegans innate immune response to Coxiella burnetii. Innate Immun 2016; 23:111-127. [PMID: 27884946 DOI: 10.1177/1753425916679255] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The nematode Caenorhabditis elegans is well established as a system for characterization and discovery of molecular mechanisms mediating microbe-specific inducible innate immune responses to human pathogens. Coxiella burnetii is an obligate intracellular bacterium that causes a flu-like syndrome in humans (Q fever), as well as abortions in domesticated livestock, worldwide. Initially, when wild type C. elegans (N2 strain) was exposed to mCherry-expressing C. burnetii (CCB) a number of overt pathological manifestations resulted, including intestinal distension, deformed anal region and a decreased lifespan. However, nematodes fed autoclave-killed CCB did not exhibit these symptoms. Although vertebrates detect C. burnetii via TLRs, pathologies in tol-1(-) mutant nematodes were indistinguishable from N2, and indicate nematodes do not employ this orthologue for detection of C. burnetii. sek-1(-) MAP kinase mutant nematodes succumbed to infection faster, suggesting that this signaling pathway plays a role in immune activation, as previously shown for orthologues in vertebrates during a C. burnetii infection. C. elegans daf-2(-) mutants are hyper-immune and exhibited significantly reduced pathological consequences during challenge. Collectively, these results demonstrate the utility of C. elegans for studying the innate immune response against C. burnetii and could lead to discovery of novel methods for prevention and treatment of disease in humans and livestock.
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Affiliation(s)
- James M Battisti
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Lance A Watson
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Myo T Naung
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Adam M Drobish
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Ekaterina Voronina
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Michael F Minnick
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
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76
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Zou W, Shen A, Dong X, Tugizova M, Xiang YK, Shen K. A multi-protein receptor-ligand complex underlies combinatorial dendrite guidance choices in C. elegans. eLife 2016; 5. [PMID: 27705746 PMCID: PMC5079751 DOI: 10.7554/elife.18345] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 10/03/2016] [Indexed: 11/24/2022] Open
Abstract
Ligand receptor interactions instruct axon guidance during development. How dendrites are guided to specific targets is less understood. The C. elegans PVD sensory neuron innervates muscle-skin interface with its elaborate dendritic branches. Here, we found that LECT-2, the ortholog of leukocyte cell-derived chemotaxin-2 (LECT2), is secreted from the muscles and required for muscle innervation by PVD. Mosaic analyses showed that LECT-2 acted locally to guide the growth of terminal branches. Ectopic expression of LECT-2 from seam cells is sufficient to redirect the PVD dendrites onto seam cells. LECT-2 functions in a multi-protein receptor-ligand complex that also contains two transmembrane ligands on the skin, SAX-7/L1CAM and MNR-1, and the neuronal transmembrane receptor DMA-1. LECT-2 greatly enhances the binding between SAX-7, MNR-1 and DMA-1. The activation of DMA-1 strictly requires all three ligands, which establishes a combinatorial code to precisely target and pattern dendritic arbors. DOI:http://dx.doi.org/10.7554/eLife.18345.001
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Affiliation(s)
- Wei Zou
- Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, United States
| | - Ao Shen
- Department of Pharmacology, University of California, Davis, Davis, United States
| | - Xintong Dong
- Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, United States
| | - Madina Tugizova
- Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, United States
| | - Yang K Xiang
- Department of Pharmacology, University of California, Davis, Davis, United States
| | - Kang Shen
- Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, United States
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77
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Gengyo-Ando K, Kage-Nakadai E, Yoshina S, Otori M, Kagawa-Nagamura Y, Nakai J, Mitani S. Distinct roles of the two VPS33 proteins in the endolysosomal system in Caenorhabditis elegans. Traffic 2016; 17:1197-1213. [PMID: 27558849 DOI: 10.1111/tra.12430] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 08/18/2016] [Accepted: 08/18/2016] [Indexed: 02/02/2023]
Abstract
Sec1/Munc-18 (SM) family proteins are essential regulators in intracellular transport in eukaryotic cells. The SM protein Vps33 functions as a core subunit of two tethering complexes, class C core vacuole/endosome tethering (CORVET) and homotypic fusion and vacuole protein sorting (HOPS) in the endocytic pathway in yeast. Metazoan cells possess two Vps33 proteins, VPS33A and VPS33B, but their precise roles remain unknown. Here, we present a comparative analysis of Caenorhabditis elegans null mutants for these proteins. We found that the vps-33.1 (VPS33A) mutants exhibited severe defects in both endocytic function and endolysosomal biogenesis in scavenger cells. Furthermore, vps-33.1 mutations caused endocytosis defects in other tissues, and the loss of maternal and zygotic VPS-33.1 resulted in embryonic lethality. By contrast, vps-33.2 mutants were viable but sterile, with terminally arrested spermatocytes. The spermatogenesis phenotype suggests that VPS33.2 is involved in the formation of a sperm-specific organelle. The endocytosis defect in the vps-33.1 mutant was not restored by the expression of VPS-33.2, which indicates that these proteins have nonredundant functions. Together, our data suggest that VPS-33.1 shares most of the general functions of yeast Vps33 in terms of tethering complexes in the endolysosomal system, whereas VPS-33.2 has tissue/organelle specific functions in C. elegans.
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Affiliation(s)
- Keiko Gengyo-Ando
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan. .,Brain and Body System Science Institute, Saitama University, Saitama, Japan. .,Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
| | - Eriko Kage-Nakadai
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan.,The OCU Advanced Research Institute for Natural Science and Technology, Osaka City University, Osaka, Japan
| | - Sawako Yoshina
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
| | - Muneyoshi Otori
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
| | - Yuko Kagawa-Nagamura
- Brain and Body System Science Institute, Saitama University, Saitama, Japan.,Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Junichi Nakai
- Brain and Body System Science Institute, Saitama University, Saitama, Japan.,Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan.
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78
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The Neuropeptides FLP-2 and PDF-1 Act in Concert To Arouse Caenorhabditis elegans Locomotion. Genetics 2016; 204:1151-1159. [PMID: 27585848 DOI: 10.1534/genetics.116.192898] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/24/2016] [Indexed: 01/24/2023] Open
Abstract
During larval molts, Caenorhabditis elegans exhibits a sleep-like state (termed lethargus) that is characterized by the absence of feeding and profound locomotion quiescence. The rhythmic pattern of locomotion quiescence and arousal linked to the molting cycle is mediated by reciprocal changes in sensory responsiveness, whereby arousal is associated with increased responsiveness. Sensory neurons arouse locomotion via release of a neuropeptide (PDF-1) and glutamate. Here we identify a second arousing neuropeptide (FLP-2). We show that FLP-2 acts via an orexin-like receptor (FRPR-18), and that FLP-2 and PDF-1 secretion are regulated by reciprocal positive feedback. These results suggest that the aroused behavioral state is stabilized by positive feedback between two neuropeptides.
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79
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Gravato-Nobre MJ, Vaz F, Filipe S, Chalmers R, Hodgkin J. The Invertebrate Lysozyme Effector ILYS-3 Is Systemically Activated in Response to Danger Signals and Confers Antimicrobial Protection in C. elegans. PLoS Pathog 2016; 12:e1005826. [PMID: 27525822 PMCID: PMC4985157 DOI: 10.1371/journal.ppat.1005826] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 07/25/2016] [Indexed: 12/17/2022] Open
Abstract
Little is known about the relative contributions and importance of antibacterial effectors in the nematode C. elegans, despite extensive work on the innate immune responses in this organism. We report an investigation of the expression, function and regulation of the six ilys (invertebrate-type lysozyme) genes of C. elegans. These genes exhibited a surprising variety of tissue-specific expression patterns and responses to starvation or bacterial infection. The most strongly expressed, ilys-3, was investigated in detail. ILYS-3 protein was expressed constitutively in the pharynx and coelomocytes, and dynamically in the intestine. Analysis of mutants showed that ILYS-3 was required for pharyngeal grinding (disruption of bacterial cells) during normal growth and consequently it contributes to longevity, as well as being protective against bacterial pathogens. Both starvation and challenge with Gram-positive pathogens resulted in ERK-MAPK-dependent up-regulation of ilys-3 in the intestine. The intestinal induction by pathogens, but not starvation, was found to be dependent on MPK-1 activity in the pharynx rather than in the intestine, demonstrating unexpected communication between these two tissues. The coelomocyte expression appeared to contribute little to normal growth or immunity. Recombinant ILYS-3 protein was found to exhibit appropriate lytic activity against Gram-positive cell wall material. Innate immune defenses against bacterial pathogenesis depend on the activation of antibacterial factors. We examined the expression and relative importance of a gene family encoding six invertebrate-type lysozymes in the much-studied nematode C. elegans. The ilys genes exhibit distinct patterns of tissue-specific expression and response to pathogenic challenge and/or starvation. The most abundantly expressed, ilys-3, exhibits constitutive pharyngeal expression, which we show is essential for efficient disruption of bacteria under non-pathogenic growth conditions, and consequently it contributes to normal longevity. ilys-3 is also strongly up-regulated in intestinal cells after starvation or exposure to Gram-positive pathogens such as Microbacterium nematophilum and acts as a ‘slow-effector’ in limiting pathogenic damage from intestinal infections. We show that this induction by pathogens depends on the action of an ERK-MAPK cascade, which acts in pharyngeal rather than intestinal cells; this implies communication between pharynx and intestine. Tagged ILYS-3 protein was detected mainly in recycling endosomes of intestinal cells and in the intestinal lumen after starvation. ILYS-3 was also expressed in coelomocytes (scavenger cells) but we found that these cells make little or no contribution to defense. We examined the enzymatic properties of recombinant ILYS-3 protein, finding that it has lytic activity against M. nematophilum cell-walls.
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Affiliation(s)
| | - Filipa Vaz
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Sergio Filipe
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Ronald Chalmers
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica and Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Jonathan Hodgkin
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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80
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Liu K, Jian Y, Sun X, Yang C, Gao Z, Zhang Z, Liu X, Li Y, Xu J, Jing Y, Mitani S, He S, Yang C. Negative regulation of phosphatidylinositol 3-phosphate levels in early-to-late endosome conversion. J Cell Biol 2016; 212:181-98. [PMID: 26783301 PMCID: PMC4738380 DOI: 10.1083/jcb.201506081] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
C. elegans SORF-1 and SORF-2 and their mammalian homologs WDR91 and WDR81 maintain appropriate PtdIns3P levels in early-to-late endosome conversion by forming a complex with the Beclin1 subunit of the PI3K complex. Phosphatidylinositol 3-phosphate (PtdIns3P) plays a central role in endosome fusion, recycling, sorting, and early-to-late endosome conversion, but the mechanisms that determine how the correct endosomal PtdIns3P level is achieved remain largely elusive. Here we identify two new factors, SORF-1 and SORF-2, as essential PtdIns3P regulators in Caenorhabditis elegans. Loss of sorf-1 or sorf-2 leads to greatly elevated endosomal PtdIns3P, which drives excessive fusion of early endosomes. sorf-1 and sorf-2 function coordinately with Rab switching genes to inhibit synthesis of PtdIns3P, allowing its turnover for endosome conversion. SORF-1 and SORF-2 act in a complex with BEC-1/Beclin1, and their loss causes elevated activity of the phosphatidylinositol 3-kinase (PI3K) complex. In mammalian cells, inactivation of WDR91 and WDR81, the homologs of SORF-1 and SORF-2, induces Beclin1-dependent enlargement of PtdIns3P-enriched endosomes and defective degradation of epidermal growth factor receptor. WDR91 and WDR81 interact with Beclin1 and inhibit PI3K complex activity. These findings reveal a conserved mechanism that controls appropriate PtdIns3P levels in early-to-late endosome conversion.
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Affiliation(s)
- Kai Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences. Beijing 100101, China Graduate University of Chinese Academy of Sciences, Beijing 100109, China
| | - Youli Jian
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences. Beijing 100101, China
| | - Xiaojuan Sun
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences. Beijing 100101, China
| | - Chengkui Yang
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Suzhou 215123, China
| | - Zhiyang Gao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences. Beijing 100101, China
| | - Zhili Zhang
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Suzhou 215123, China
| | - Xuezhao Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences. Beijing 100101, China Graduate University of Chinese Academy of Sciences, Beijing 100109, China
| | - Yang Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences. Beijing 100101, China
| | - Jing Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences. Beijing 100101, China
| | - Yudong Jing
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences. Beijing 100101, China
| | - Shohei Mitani
- Department of Physiology, School of Medicine and Institute for Integrated Medical Sciences, Tokyo Women's Medical University, Shinjuku-ku, Tokyo 162-0054, Japan
| | - Sudan He
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Suzhou 215123, China
| | - Chonglin Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences. Beijing 100101, China
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81
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Dimitriadi M, Derdowski A, Kalloo G, Maginnis MS, O'Hern P, Bliska B, Sorkaç A, Nguyen KCQ, Cook SJ, Poulogiannis G, Atwood WJ, Hall DH, Hart AC. Decreased function of survival motor neuron protein impairs endocytic pathways. Proc Natl Acad Sci U S A 2016; 113:E4377-86. [PMID: 27402754 PMCID: PMC4968725 DOI: 10.1073/pnas.1600015113] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spinal muscular atrophy (SMA) is caused by depletion of the ubiquitously expressed survival motor neuron (SMN) protein, with 1 in 40 Caucasians being heterozygous for a disease allele. SMN is critical for the assembly of numerous ribonucleoprotein complexes, yet it is still unclear how reduced SMN levels affect motor neuron function. Here, we examined the impact of SMN depletion in Caenorhabditis elegans and found that decreased function of the SMN ortholog SMN-1 perturbed endocytic pathways at motor neuron synapses and in other tissues. Diminished SMN-1 levels caused defects in C. elegans neuromuscular function, and smn-1 genetic interactions were consistent with an endocytic defect. Changes were observed in synaptic endocytic proteins when SMN-1 levels decreased. At the ultrastructural level, defects were observed in endosomal compartments, including significantly fewer docked synaptic vesicles. Finally, endocytosis-dependent infection by JC polyomavirus (JCPyV) was reduced in human cells with decreased SMN levels. Collectively, these results demonstrate for the first time, to our knowledge, that SMN depletion causes defects in endosomal trafficking that impair synaptic function, even in the absence of motor neuron cell death.
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Affiliation(s)
- Maria Dimitriadi
- Department of Neuroscience, Brown University, Providence, RI 02912; Department of Biological and Environmental Sciences, University of Hertfordshire, Hatfield AL10 9AB, United Kingdom
| | - Aaron Derdowski
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912
| | - Geetika Kalloo
- Department of Neuroscience, Brown University, Providence, RI 02912
| | - Melissa S Maginnis
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912; Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469
| | - Patrick O'Hern
- Department of Neuroscience, Brown University, Providence, RI 02912
| | - Bryn Bliska
- Department of Neuroscience, Brown University, Providence, RI 02912
| | - Altar Sorkaç
- Department of Neuroscience, Brown University, Providence, RI 02912
| | - Ken C Q Nguyen
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Steven J Cook
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - George Poulogiannis
- Chester Beatty Labs, The Institute of Cancer Research, London SW3 6JB, United Kingdom
| | - Walter J Atwood
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912
| | - David H Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Anne C Hart
- Department of Neuroscience, Brown University, Providence, RI 02912;
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82
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Dembska A. The analytical and biomedical potential of cytosine-rich oligonucleotides: A review. Anal Chim Acta 2016; 930:1-12. [PMID: 27265899 DOI: 10.1016/j.aca.2016.05.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 04/30/2016] [Accepted: 05/04/2016] [Indexed: 02/04/2023]
Abstract
Polycytosine DNA strands are often found among natural sequences, including the ends of telomeres, centromeres, and introns or in the regulatory regions of genes. A characteristic feature of oligonucleotides that are rich in cytosine (C-rich) is their ability to associate under acidic conditions to form a tetraplex i-motif consisting of two parallel stranded cytosine-hemiprotonated cytosine (C·C+) base-paired duplexes that are mutually intercalated in an antiparallel orientation. Nanotechnology has been exploiting the advantages of i-motif pH-dependent formation to fabricate nanomachines, nanoswitches, electrodes and intelligent nanosurfaces or nanomaterials. Although a few reviews regarding the structure, properties and applications of i-motifs have been published, this review focuses on recently developed biosensors (e.g., to detect pH, glucose or silver ions) and drug-delivery biomaterials. Furthermore, we have included examples of sensors based on parallel C-rich triplexes and silver nanoclusters (AgNCs) fabricated on cytosine-rich DNA strands. The potential diagnostic and therapeutic applications of this type of material are discussed.
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Affiliation(s)
- Anna Dembska
- Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznan, Poland.
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83
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Morrissey MA, Jayadev R, Miley GR, Blebea CA, Chi Q, Ihara S, Sherwood DR. SPARC Promotes Cell Invasion In Vivo by Decreasing Type IV Collagen Levels in the Basement Membrane. PLoS Genet 2016; 12:e1005905. [PMID: 26926673 PMCID: PMC4771172 DOI: 10.1371/journal.pgen.1005905] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 02/07/2016] [Indexed: 02/04/2023] Open
Abstract
Overexpression of SPARC, a collagen-binding glycoprotein, is strongly associated with tumor invasion through extracellular matrix in many aggressive cancers. SPARC regulates numerous cellular processes including integrin-mediated cell adhesion, cell signaling pathways, and extracellular matrix assembly; however, the mechanism by which SPARC promotes cell invasion in vivo remains unclear. A main obstacle in understanding SPARC function has been the difficulty of visualizing and experimentally examining the dynamic interactions between invasive cells, extracellular matrix and SPARC in native tissue environments. Using the model of anchor cell invasion through the basement membrane (BM) extracellular matrix in Caenorhabditis elegans, we find that SPARC overexpression is highly pro-invasive and rescues BM transmigration in mutants with defects in diverse aspects of invasion, including cell polarity, invadopodia formation, and matrix metalloproteinase expression. By examining BM assembly, we find that overexpression of SPARC specifically decreases levels of BM type IV collagen, a crucial structural BM component. Reduction of type IV collagen mimicked SPARC overexpression and was sufficient to promote invasion. Tissue-specific overexpression and photobleaching experiments revealed that SPARC acts extracellularly to inhibit collagen incorporation into BM. By reducing endogenous SPARC, we also found that SPARC functions normally to traffic collagen from its site of synthesis to tissues that do not express collagen. We propose that a surplus of SPARC disrupts extracellular collagen trafficking and reduces BM collagen incorporation, thus weakening the BM barrier and dramatically enhancing its ability to be breached by invasive cells.
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Affiliation(s)
- Meghan A Morrissey
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Ranjay Jayadev
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Ginger R Miley
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Catherine A Blebea
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Qiuyi Chi
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Shinji Ihara
- Multicellular Organization Laboratory, National Institute of Genetics,Yata, Mishima, Japan
| | - David R Sherwood
- Department of Biology, Duke University, Durham, North Carolina, United States of America
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84
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Galbadage T, Shepherd TF, Cirillo SLG, Gumienny TL, Cirillo JD. The Caenorhabditis elegans p38 MAPK Gene plays a key role in protection from mycobacteria. Microbiologyopen 2016; 5:436-52. [PMID: 26919641 PMCID: PMC4905996 DOI: 10.1002/mbo3.341] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/13/2016] [Accepted: 01/19/2016] [Indexed: 12/17/2022] Open
Abstract
Mitogen-activated protein kinases (MAPK) are critical mediators of cellular responses to pathogens and are activated in response to infection, but investigation is difficult in multi-cell hosts due to developmental lethality of mutations. Mycobacterium marinum (Mm) is an established model for tuberculosis, a disease afflicting nearly one-third of the world's population. We found that Mm-infected Caenorhabditis elegans display >80% mortality, but nonpathogenic M. smegmatis cause <15% mortality. C. elegans display pathological changes when infected with Mm, whereas Mm mutants produce lower mortality, suggesting that C. elegans is a promising virulence model for detailed genetic analysis. C. elegans MAPK mutants are hypersusceptible to mycobacterial infection; however, the C. elegans TOL-like, TGF-β and insulin-like pathway genes do not play important roles in susceptibility. We show that pathogenic mycobacteria inhibit MAPK-mediated protection through the MAPK phosphatase gene and demonstrate that C. elegans provide a genetically tractable pathogenicity model of both the host and pathogen.
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Affiliation(s)
- Thushara Galbadage
- Departments of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, 77807-3260
| | - Tonya F Shepherd
- Departments of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, 77807-3260
| | - Suat L G Cirillo
- Departments of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, 77807-3260
| | - Tina L Gumienny
- Department of Biology, Texas Woman's University, Denton, Texas, 76204-5799
| | - Jeffrey D Cirillo
- Departments of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, 77807-3260
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85
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Smurova K, Podbilewicz B. RAB-5- and DYNAMIN-1-Mediated Endocytosis of EFF-1 Fusogen Controls Cell-Cell Fusion. Cell Rep 2016; 14:1517-1527. [PMID: 26854231 PMCID: PMC4761113 DOI: 10.1016/j.celrep.2016.01.027] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 11/30/2015] [Accepted: 01/04/2016] [Indexed: 01/15/2023] Open
Abstract
Cell-cell fusion plays essential roles during fertilization and organogenesis. Previous studies in C. elegans led to the identification of the eukaryotic fusion protein (EFF-1 fusogen), which has structural homology to class II viral fusogens. Transcriptional repression of EFF-1 ensures correct fusion fates, and overexpression of EFF-1 results in embryonic lethality. EFF-1 must be expressed on the surface of both fusing cells; however, little is known regarding how cells regulate EFF-1 surface exposure. Here, we report that EFF-1 is actively removed from the plasma membrane of epidermal cells by dynamin- and RAB-5-dependent endocytosis and accumulates in early endosomes. EFF-1 was transiently localized to apical domains of fusion-competent cells. Effective cell-cell fusion occurred only between pairs of cell membranes in which EFF-1 localized. Downregulation of dynamin or RAB-5 caused EFF-1 mislocalization to all apical membrane domains and excessive fusion. Thus, internalization of EFF-1 is a safety mechanism preventing excessive cell fusion. The fusion protein EFF-1 is targeted to early endosomes Dynamin and RAB-5 downregulate EFF-1 in C. elegans embryos Transient and dynamic localization of EFF-1 to apical cell membranes mediates fusion Prevention of EFF-1 endocytosis induces excessive cell fusion
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Affiliation(s)
- Ksenia Smurova
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Benjamin Podbilewicz
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.
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86
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Diapause is associated with a change in the polarity of secretion of insulin-like peptides. Nat Commun 2016; 7:10573. [PMID: 26838180 PMCID: PMC4742890 DOI: 10.1038/ncomms10573] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 12/30/2015] [Indexed: 12/19/2022] Open
Abstract
The insulin/IGF-1 signalling (IIS) pathway plays an important role in the regulation of larval diapause, the long-lived growth arrest state called dauer arrest, in Caenorhabditis elegans. In this nematode, 40 insulin-like peptides (ILPs) have been identified as putative ligands of the IIS pathway; however, it remains unknown how ILPs modulate larval diapause. Here we show that the secretory polarity of INS-35 and INS-7, which suppress larval diapause, is changed in the intestinal epithelial cells at larval diapause. These ILPs are secreted from the intestine into the body cavity during larval stages. In contrast, they are secreted into the intestinal lumen and degraded during dauer arrest, only to be secreted into the body cavity again when the worms return to developmental growth. The process that determines the secretory polarity of INS-35 and INS-7, thus, has an important role in the modulation of larval diapause. Insulin-like peptides INS-7 and INS-35 suppress larval diapause in Caenorhabditis elegans via unknown mechanism. Here, Matsunaga et al. show that the secretory polarity of both peptides changes in diapause, when these peptides are secreted into the intestinal lumen instead of the body cavity like in other larval stages.
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87
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ESCRT-Dependent Cell Death in a Caenorhabditis elegans Model of the Lysosomal Storage Disorder Mucolipidosis Type IV. Genetics 2015; 202:619-38. [PMID: 26596346 DOI: 10.1534/genetics.115.182485] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/14/2015] [Indexed: 01/08/2023] Open
Abstract
Mutations in MCOLN1, which encodes the cation channel protein TRPML1, result in the neurodegenerative lysosomal storage disorder Mucolipidosis type IV. Mucolipidosis type IV patients show lysosomal dysfunction in many tissues and neuronal cell death. The ortholog of TRPML1 in Caenorhabditis elegans is CUP-5; loss of CUP-5 results in lysosomal dysfunction in many tissues and death of developing intestinal cells that results in embryonic lethality. We previously showed that a null mutation in the ATP-Binding Cassette transporter MRP-4 rescues the lysosomal defect and embryonic lethality of cup-5(null) worms. Here we show that reducing levels of the Endosomal Sorting Complex Required for Transport (ESCRT)-associated proteins DID-2, USP-50, and ALX-1/EGO-2, which mediate the final de-ubiquitination step of integral membrane proteins being sequestered into late endosomes, also almost fully suppresses cup-5(null) mutant lysosomal defects and embryonic lethality. Indeed, we show that MRP-4 protein is hypo-ubiquitinated in the absence of CUP-5 and that reducing levels of ESCRT-associated proteins suppresses this hypo-ubiquitination. Thus, increased ESCRT-associated de-ubiquitinating activity mediates the lysosomal defects and corresponding cell death phenotypes in the absence of CUP-5.
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88
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Oláhová M, Veal EA. A peroxiredoxin, PRDX-2, is required for insulin secretion and insulin/IIS-dependent regulation of stress resistance and longevity. Aging Cell 2015; 14:558-68. [PMID: 25808059 PMCID: PMC4531070 DOI: 10.1111/acel.12321] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2014] [Indexed: 12/22/2022] Open
Abstract
Peroxiredoxins (Prx) are abundant thiol peroxidases with a conserved anti-ageing role. In contrast to most animals, the nematode worm, Caenorhabditis elegans, encodes a single cytosolic 2-Cys Prx, PRDX-2, rendering it an excellent model for examining how peroxiredoxins affect animal physiology and ageing. Our previous work revealed that, although PRDX-2 protects against the toxicity of peroxides, enigmatically, prdx-2-mutant animals are hyper-resistant to other forms of oxidative stress. Here, we have investigated the basis for this increased resistance. Mammalian FOXO and Nrf2 transcription factors directly promote the expression of a range of detoxification enzymes. We show that the FOXO orthologue, DAF-16, and the Nrf2 orthologue, SKN-1, are required for the increased stress resistance of prdx-2-mutant worms. Our data suggest that PRDX-2 is required for normal levels of insulin secretion and hence the inhibition of DAF-16 and SKN-1 by insulin/IGF-1-like signalling (IIS) under nutrient-rich conditions. Intriguingly, loss of PRDX-2 increases DAF-16 and SKN-1 activities sufficiently to increase arsenite resistance without initiating other IIS-inhibited processes. Together, these data suggest that loss of peroxiredoxin function may increase stress resistance by reducing insulin secretion, but that further changes in insulin signalling are required for the reprogramming of development and fat metabolism. In addition, we reveal that the temperature-dependent prolongevity function of PRDX-2 is required for the extended lifespan associated with several pathways, including further reductions in IIS.
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Affiliation(s)
- Monika Oláhová
- Institute for Cell and Molecular Biosciences Newcastle University Framlington Place Newcastle upon Tyne NE2 4HH UK
| | - Elizabeth A. Veal
- Institute for Cell and Molecular Biosciences Newcastle University Framlington Place Newcastle upon Tyne NE2 4HH UK
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89
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Yoshina S, Mitani S. Loss of C. elegans GON-1, an ADAMTS9 Homolog, Decreases Secretion Resulting in Altered Lifespan and Dauer Formation. PLoS One 2015. [PMID: 26218657 PMCID: PMC4517882 DOI: 10.1371/journal.pone.0133966] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
ADAMTS9 is a metalloprotease that cleaves components of the extracellular matrix and is also implicated in transport from the endoplasmic reticulum (ER) to the Golgi. It has been reported that an ADAMTS9 gene variant is associated with type 2 diabetes. The underlying pathology of type 2 diabetes is insulin resistance and beta-cell dysfunction. However, the molecular mechanisms underlying ADAMTS9 function in beta cells and peripheral tissues are unknown. We show that loss of C. elegans GON-1, an ADAMTS9 homolog, alters lifespan and dauer formation. GON-1 loss impairs secretion of proteins such as insulin orthologs and TGF-beta, and additionally impacts insulin/IGF-1 signaling in peripheral tissues. The function of the GON domain, but not the protease domain, is essential for normal lifespan and dauer formation in these scenarios. We conclude that the GON domain is critical for ADAMTS9/GON-1 function across species, which should help the understanding of type 2 diabetes in humans.
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Affiliation(s)
- Sawako Yoshina
- Department of Physiology, Tokyo Women’s Medical University School of Medicine, Tokyo, 162–8666, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women’s Medical University School of Medicine, Tokyo, 162–8666, Japan
- Tokyo Women’s Medical University Institute for Integrated Medical Sciences (TIIMS), Tokyo Women’s Medical University, Tokyo, 162–8666, Japan
- * E-mail:
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90
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Valdivieso E, Perteguer MJ, Hurtado C, Campioli P, Rodríguez E, Saborido A, Martínez-Sernández V, Gómez-Puertas P, Ubeira FM, Gárate T. ANISERP: a new serpin from the parasite Anisakis simplex. Parasit Vectors 2015; 8:399. [PMID: 26215984 PMCID: PMC4517634 DOI: 10.1186/s13071-015-1006-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 07/11/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Serine proteinase inhibitors (serpins) finely regulate serine proteinase activity via a suicide substrate-like inhibitory mechanism. In parasitic nematodes, some serpins interact with host physiological processes; however, little is known about these essential molecules in Anisakis. This article reports the gene sequencing, cloning, expression and preliminary biochemical and bioinformatically-based structural characterization of a new Anisakis serpin (ANISERP). METHODS The full AniSerp gene was cloned by specific RACE-PCR after screening an Anisakis simplex (L3) cDNA library. For biochemical assays, the AniSerp gene was subcloned into both prokaryotic and eukaryotic vectors, and the recombinant proteins were purified. The inhibitory properties of the proteins were tested in classical biochemical assays using human serine peptidases and AMC substrates. Immunolocalization of ANISERP, theoretical structural analysis and bioinformatically-based structural modelling of the ANISERP protein were also conducted. RESULTS The AniSerp gene was found to have 1194 nucleotides, coding for a protein of 397 amino acid residues plus a putative N-terminal signal peptide. It showed significant similarity to other nematode, arthropod and mammalian serpins. The recombinant ANISERP expressed in the prokaryotic and eukaryotic systems inhibited the human serine proteases thrombin, trypsin and cathepsin G in a concentration-dependent manner. No inhibitory activity against Factor Xa, Factor XIa, Factor XIIa, elastase, plasmin or chymotrypsin was observed. ANISERP also acted on the cysteine protease cathepsin L. ANISERP was mainly localized in the nematode pseudocoelomic fluid, somatic muscle cell bodies and intestinal cells. The findings of molecular dynamics studies suggest that ANISERP inhibits thrombin via a suicide substrate-like inhibitory mechanism, similar to the mechanism of action of mammalian coagulation inhibitors. In contrast to findings concerning human antithrombin III, heparin had no effect on ANISERP anticoagulant inhibitory activity. CONCLUSIONS Our findings suggest that ANISERP is an internal Anisakis regulatory serpin and that the inhibitory activity against thrombin depends on a suicide substrate-like inhibitory mechanism, similar to that described for human antithrombin (AT)-III. The fact that heparin does not modulate the anticoagulant activity of ANISERP might be explained by the absence in the latter of five of the six positively charged residues usually seen at the AT-III-heparin binding site.
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Affiliation(s)
- Elizabeth Valdivieso
- Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220, Majadahonda, Madrid, Spain.
- Laboratorio de Biología Celular de Parásitos, Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela, 47069, Caracas, 1041-A, Venezuela.
| | - Maria J Perteguer
- Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220, Majadahonda, Madrid, Spain.
- Parasitology Department, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220, Majadahonda, Madrid, Spain.
| | - Carolina Hurtado
- Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220, Majadahonda, Madrid, Spain.
- Present Address: Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad San Pablo-CEU, Campus de Montepríncipe, Urb. Montepríncipe, 28668, Madrid, Spain.
| | - Pamela Campioli
- Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220, Majadahonda, Madrid, Spain.
| | - Esperanza Rodríguez
- Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220, Majadahonda, Madrid, Spain.
| | - Ana Saborido
- Departamento de Bioquímica y Biología Molecular I, Facultad de Químicas, Universidad Complutense, Madrid, Spain.
| | | | - Paulino Gómez-Puertas
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) Campus UAM. Cantoblanco, 28049, Madrid, Spain.
| | - Florencio M Ubeira
- Laboratorio de Parasitología, Facultad de Farmacia, Universidad de Santiago de Compostela, A Coruña, Spain.
| | - Teresa Gárate
- Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220, Majadahonda, Madrid, Spain.
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91
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Sensory Neurons Arouse C. elegans Locomotion via Both Glutamate and Neuropeptide Release. PLoS Genet 2015; 11:e1005359. [PMID: 26154367 PMCID: PMC4495980 DOI: 10.1371/journal.pgen.1005359] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/13/2015] [Indexed: 12/17/2022] Open
Abstract
C. elegans undergoes periods of behavioral quiescence during larval molts (termed lethargus) and as adults. Little is known about the circuit mechanisms that establish these quiescent states. Lethargus and adult locomotion quiescence is dramatically reduced in mutants lacking the neuropeptide receptor NPR-1. Here, we show that the aroused locomotion of npr-1 mutants results from the exaggerated activity in multiple classes of sensory neurons, including nociceptive (ASH), touch sensitive (ALM and PLM), and stretch sensing (DVA) neurons. These sensory neurons accelerate locomotion via both neuropeptide and glutamate release. The relative contribution of these sensory neurons to arousal differs between larval molts and adults. Our results suggest that a broad network of sensory neurons dictates transitions between aroused and quiescent behavioral states. Animals switch between periods of behavioral arousal and quiescence in response to environmental, developmental, and circadian cues. Little is known about the circuit mechanisms that produce these behavioral states. During larval molts, C. elegans exhibits a sleep-like state (termed lethargus) that is characterized by the absence of feeding and profound locomotion quiescence. We previously showed that mutants lacking the neuropeptide receptor NPR-1 exhibit increased arousal during larval molts, which is in part mediated by increased secretion of an arousal peptide (PDF-1). Here, we compare the circuits regulating arousal in larval molts and adults. We show that a broad network of sensory neurons arouses locomotion but that the impact of each neuron differs between lethargus and adults. We propose that this broad sensory network allows C. elegans to adapt its behavior across a broad range of developmental and physiological circumstances.
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92
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Baranczak A, Liu Y, Connelly S, Du WGH, Greiner ER, Genereux JC, Wiseman RL, Eisele YS, Bradbury NC, Dong J, Noodleman L, Sharpless KB, Wilson IA, Encalada SE, Kelly JW. A fluorogenic aryl fluorosulfate for intraorganellar transthyretin imaging in living cells and in Caenorhabditis elegans. J Am Chem Soc 2015; 137:7404-14. [PMID: 26051248 PMCID: PMC4472559 DOI: 10.1021/jacs.5b03042] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Fluorogenic probes, due to their often greater spatial and temporal sensitivity in comparison to permanently fluorescent small molecules, represent powerful tools to study protein localization and function in the context of living systems. Herein, we report fluorogenic probe 4, a 1,3,4-oxadiazole designed to bind selectively to transthyretin (TTR). Probe 4 comprises a fluorosulfate group not previously used in an environment-sensitive fluorophore. The fluorosulfate functional group does not react covalently with TTR on the time scale required for cellular imaging, but does red shift the emission maximum of probe 4 in comparison to its nonfluorosulfated analogue. We demonstrate that probe 4 is dark in aqueous buffers, whereas the TTR·4 complex exhibits a fluorescence emission maximum at 481 nm. The addition of probe 4 to living HEK293T cells allows efficient binding to and imaging of exogenous TTR within intracellular organelles, including the mitochondria and the endoplasmic reticulum. Furthermore, live Caenorhabditis elegans expressing human TTR transgenically and treated with probe 4 display TTR·4 fluorescence in macrophage-like coelomocytes. An analogue of fluorosulfate probe 4 does react selectively with TTR without labeling the remainder of the cellular proteome. Studies on this analogue suggest that certain aryl fluorosulfates, due to their cell and organelle permeability and activatable reactivity, could be considered for the development of protein-selective covalent probes.
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Affiliation(s)
- Aleksandra Baranczak
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Yu Liu
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Stephen Connelly
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Wen-Ge Han Du
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Erin R. Greiner
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Joseph C. Genereux
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - R. Luke Wiseman
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- Department of Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Yvonne S. Eisele
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Nadine C. Bradbury
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Jiajia Dong
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Louis Noodleman
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - K. Barry Sharpless
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Sandra E. Encalada
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- Dorris Neuroscience Center, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
| | - Jeffery W. Kelly
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, USA
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Necrotic Cells Actively Attract Phagocytes through the Collaborative Action of Two Distinct PS-Exposure Mechanisms. PLoS Genet 2015; 11:e1005285. [PMID: 26061275 PMCID: PMC4464654 DOI: 10.1371/journal.pgen.1005285] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 05/14/2015] [Indexed: 11/19/2022] Open
Abstract
Necrosis, a kind of cell death closely associated with pathogenesis and genetic programs, is distinct from apoptosis in both morphology and mechanism. Like apoptotic cells, necrotic cells are swiftly removed from animal bodies to prevent harmful inflammatory and autoimmune responses. In the nematode Caenorhabditis elegans, gain-of-function mutations in certain ion channel subunits result in the excitotoxic necrosis of six touch neurons and their subsequent engulfment and degradation inside engulfing cells. How necrotic cells are recognized by engulfing cells is unclear. Phosphatidylserine (PS) is an important apoptotic-cell surface signal that attracts engulfing cells. Here we observed PS exposure on the surface of necrotic touch neurons. In addition, the phagocytic receptor CED-1 clusters around necrotic cells and promotes their engulfment. The extracellular domain of CED-1 associates with PS in vitro. We further identified a necrotic cell-specific function of CED-7, a member of the ATP-binding cassette (ABC) transporter family, in promoting PS exposure. In addition to CED-7, anoctamin homolog-1 (ANOH-1), the C. elegans homolog of the mammalian Ca(2+)-dependent phospholipid scramblase TMEM16F, plays an independent role in promoting PS exposure on necrotic cells. The combined activities from CED-7 and ANOH-1 ensure efficient exposure of PS on necrotic cells to attract their phagocytes. In addition, CED-8, the C. elegans homolog of mammalian Xk-related protein 8 also makes a contribution to necrotic cell-removal at the first larval stage. Our work indicates that cells killed by different mechanisms (necrosis or apoptosis) expose a common "eat me" signal to attract their phagocytic receptor(s); furthermore, unlike what was previously believed, necrotic cells actively present PS on their outer surfaces through at least two distinct molecular mechanisms rather than leaking out PS passively.
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94
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Gonzalez-Moragas L, Roig A, Laromaine A. C. elegans as a tool for in vivo nanoparticle assessment. Adv Colloid Interface Sci 2015; 219:10-26. [PMID: 25772622 DOI: 10.1016/j.cis.2015.02.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 01/26/2015] [Accepted: 02/06/2015] [Indexed: 11/16/2022]
Abstract
Characterization of the in vivo behavior of nanomaterials aims to optimize their design, to determine their biological effects, and to validate their application. The characteristics of the model organism Caenorhabditis elegans (C. elegans) advocate this 1mm long nematode as an ideal living system for the primary screening of engineered nanoparticles in a standard synthetic laboratory. This review describes some practicalities and advantages of working with C. elegans that will be of interest for chemists and materials scientists who would like to enter the "worm" community, anticipates some drawbacks, and offers relevant examples of nanoparticle assessment by using C. elegans.
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Affiliation(s)
- L Gonzalez-Moragas
- Institut de Ciència de Materials de Barcelona, Campus UAB, 08193 Bellaterra, Spain
| | - A Roig
- Institut de Ciència de Materials de Barcelona, Campus UAB, 08193 Bellaterra, Spain
| | - A Laromaine
- Institut de Ciència de Materials de Barcelona, Campus UAB, 08193 Bellaterra, Spain.
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95
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Li L, Wan T, Wan M, Liu B, Cheng R, Zhang R. The effect of the size of fluorescent dextran on its endocytic pathway. Cell Biol Int 2015; 39:531-9. [DOI: 10.1002/cbin.10424] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 12/19/2014] [Indexed: 02/05/2023]
Affiliation(s)
- Lei Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Tao Wan
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Min Wan
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Bei Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Ran Cheng
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Rongying Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
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96
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97
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Abstract
Heparan sulfate (HS) glycosaminoglycan chains contain highly modified HS domains that are separated by sections of sparse or no modification. HS domains are central to the role of HS in protein binding and mediating protein-protein interactions in the extracellular matrix. Since HS domains are not genetically encoded, they are impossible to visualize and study with conventional methods in vivo. Here we describe a transgenic approach using previously described single chain variable fragment (scFv) antibodies that bind HS in vitro and on tissue sections with different specificities. By engineering a secretion signal and a fluorescent protein to the scFvs and transgenically expressing these fluorescently tagged antibodies in Caenorhabditis elegans, we are able to directly visualize specific HS domains in live animals (Attreed et al. Nat Methods 9(5):477-479, 2012). The approach allows concomitant colabeling of multiple epitopes, the study of HS dynamics and, could lend itself to a genetic analysis of HS domain biosynthesis or to visualize other nongenetically encoded or posttranslational modifications.
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98
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Abstract
Neuron manipulation in vivo by ablation, activation, or inactivation, and regulation of gene expression, is essential for dissecting nervous system function. Here we describe genetic means for neuron manipulation in the nematode C. elegans, and provide protocols for generating transgenic animals containing these genetic tools.
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Affiliation(s)
- Menachem Katz
- Laboratory of Developmental Genetics, The Rockefeller University, 810 Weiss Research Building, 1230 York Avenue, New York, NY, 10065, USA.
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99
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Solinger JA, Spang A. Loss of the Sec1/Munc18-family proteins VPS-33.2 and VPS-33.1 bypasses a block in endosome maturation in Caenorhabditis elegans. Mol Biol Cell 2014; 25:3909-25. [PMID: 25273556 PMCID: PMC4244200 DOI: 10.1091/mbc.e13-12-0710] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Evidence is presented for the existence of HOPS and CORVET tethering complexes in metazoans. A role is shown for the SM protein components of tethers in controlling the flux of material through the endosomal system. The end of the life of a transport vesicle requires a complex series of tethering, docking, and fusion events. Tethering complexes play a crucial role in the recognition of membrane entities and bringing them into close opposition, thereby coordinating and controlling cellular trafficking events. Here we provide a comprehensive RNA interference analysis of the CORVET and HOPS tethering complexes in metazoans. Knockdown of CORVET components promoted RAB-7 recruitment to subapical membranes, whereas in HOPS knockdowns, RAB-5 was found also on membrane structures close to the cell center, indicating the RAB conversion might be impaired in the absence of these tethering complexes. Unlike in yeast, metazoans have two VPS33 homologues, which are Sec1/Munc18 (SM)-family proteins involved in the regulation of membrane fusion. We assume that in wild type, each tethering complex contains a specific SM protein but that they may be able to substitute for each other in case of absence of the other. Of importance, knockdown of both SM proteins allowed bypass of the endosome maturation block in sand-1 mutants. We propose a model in which the SM proteins in tethering complexes are required for coordinated flux of material through the endosomal system.
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Affiliation(s)
- Jachen A Solinger
- Growth and Development, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Anne Spang
- Growth and Development, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
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100
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Egami Y, Taguchi T, Maekawa M, Arai H, Araki N. Small GTPases and phosphoinositides in the regulatory mechanisms of macropinosome formation and maturation. Front Physiol 2014; 5:374. [PMID: 25324782 PMCID: PMC4179697 DOI: 10.3389/fphys.2014.00374] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 09/10/2014] [Indexed: 12/26/2022] Open
Abstract
Macropinosome formation requires the sequential activation of numerous signaling pathways that coordinate the actin-driven formation of plasma membrane protrusions (ruffles) and circular ruffles (macropinocytic cups), followed by the closure of these macropinocytic cups into macropinosomes. In the process of macropinosome formation, localized productions of phosphoinositides such as PI(4,5)P2 and PI(3,4,5)P3 spatiotemporally orchestrate actin polymerization and rearrangement through recruiting and activating a variety of actin-associated proteins. In addition, the sequential activation of small GTPases, which are known to be master regulators of the actin cytoskeleton, plays a pivotal role in parallel with phosphoinositides. To complete macropinosome formation, phosphoinositide breakdown and Rho GTPase deactivation must occur in appropriate timings. After the nascent macropinosomes are formed, phosphoinositides and several Rab GTPases control macropinosome maturation by regulating vesicle trafficking and membrane fusion. In this review, we summarize recent advances in our understanding of the critical functions of phosphoinositide metabolism and small GTPases in association with their downstream effectors in macropinocytosis.
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Affiliation(s)
- Youhei Egami
- Department of Histology and Cell Biology, School of Medicine, Kagawa University Miki, Japan
| | - Tomohiko Taguchi
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan ; Pathological Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan
| | - Masashi Maekawa
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan ; Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital Toronto, ON, Canada
| | - Hiroyuki Arai
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan ; Pathological Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, University of Tokyo Tokyo, Japan
| | - Nobukazu Araki
- Department of Histology and Cell Biology, School of Medicine, Kagawa University Miki, Japan
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