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Bhar S, Yoon CS, Mai K, Han J, Prajapati DV, Wang Y, Steffen CL, Bailey LS, Basso KB, Butcher RA. An acyl-CoA thioesterase is essential for the biosynthesis of a key dauer pheromone in C. elegans. Cell Chem Biol 2024; 31:1011-1022.e6. [PMID: 38183989 PMCID: PMC11102344 DOI: 10.1016/j.chembiol.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 09/02/2023] [Accepted: 12/10/2023] [Indexed: 01/08/2024]
Abstract
Methyl ketone (MK)-ascarosides represent essential components of several pheromones in Caenorhabditis elegans, including the dauer pheromone, which triggers the stress-resistant dauer larval stage, and the male-attracting sex pheromone. Here, we identify an acyl-CoA thioesterase, ACOT-15, that is required for the biosynthesis of MK-ascarosides. We propose a model in which ACOT-15 hydrolyzes the β-keto acyl-CoA side chain of an ascaroside intermediate during β-oxidation, leading to decarboxylation and formation of the MK. Using comparative metabolomics, we identify additional ACOT-15-dependent metabolites, including an unusual piperidyl-modified ascaroside, reminiscent of the alkaloid pelletierine. The β-keto acid generated by ACOT-15 likely couples to 1-piperideine to produce the piperidyl ascaroside, which is much less dauer-inducing than the dauer pheromone, asc-C6-MK (ascr#2, 1). The bacterial food provided influences production of the piperidyl ascaroside by the worm. Our work shows how the biosynthesis of MK- and piperidyl ascarosides intersect and how bacterial food may impact chemical signaling in the worm.
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Affiliation(s)
- Subhradeep Bhar
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Chi-Su Yoon
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Kevin Mai
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Jungsoo Han
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Dilip V Prajapati
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Yuting Wang
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Candy L Steffen
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Laura S Bailey
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Kari B Basso
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
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2
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Wu T, Ge M, Wu M, Duan F, Liang J, Chen M, Gracida X, Liu H, Yang W, Dar AR, Li C, Butcher RA, Saltzman AL, Zhang Y. Pathogenic bacteria modulate pheromone response to promote mating. Nature 2023; 613:324-331. [PMID: 36599989 PMCID: PMC10732163 DOI: 10.1038/s41586-022-05561-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 11/11/2022] [Indexed: 01/05/2023]
Abstract
Pathogens generate ubiquitous selective pressures and host-pathogen interactions alter social behaviours in many animals1-4. However, very little is known about the neuronal mechanisms underlying pathogen-induced changes in social behaviour. Here we show that in adult Caenorhabditis elegans hermaphrodites, exposure to a bacterial pathogen (Pseudomonas aeruginosa) modulates sensory responses to pheromones by inducing the expression of the chemoreceptor STR-44 to promote mating. Under standard conditions, C. elegans hermaphrodites avoid a mixture of ascaroside pheromones to facilitate dispersal5-13. We find that exposure to the pathogenic Pseudomonas bacteria enables pheromone responses in AWA sensory neurons, which mediate attractive chemotaxis, to suppress the avoidance. Pathogen exposure induces str-44 expression in AWA neurons, a process regulated by a transcription factor zip-5 that also displays a pathogen-induced increase in expression in AWA. STR-44 acts as a pheromone receptor and its function in AWA neurons is required for pathogen-induced AWA pheromone response and suppression of pheromone avoidance. Furthermore, we show that C. elegans hermaphrodites, which reproduce mainly through self-fertilization, increase the rate of mating with males after pathogen exposure and that this increase requires str-44 in AWA neurons. Thus, our results uncover a causal mechanism for pathogen-induced social behaviour plasticity, which can promote genetic diversity and facilitate adaptation of the host animals.
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Affiliation(s)
- Taihong Wu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Minghai Ge
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Min Wu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Fengyun Duan
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Jingting Liang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Maoting Chen
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Xicotencatl Gracida
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - He Liu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Wenxing Yang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Abdul Rouf Dar
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Chengyin Li
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Arneet L Saltzman
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.
- Center for Brain Science, Harvard University, Cambridge, MA, USA.
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3
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Wasson JA, Harris G, Keppler-Ross S, Brock TJ, Dar AR, Butcher RA, Fischer SEJ, Kagias K, Clardy J, Zhang Y, Mango SE. Neuronal control of maternal provisioning in response to social cues. Sci Adv 2021; 7:7/34/eabf8782. [PMID: 34417172 PMCID: PMC8378817 DOI: 10.1126/sciadv.abf8782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 06/30/2021] [Indexed: 05/03/2023]
Abstract
Mothers contribute cytoplasmic components to their progeny in a process called maternal provisioning. Provisioning is influenced by the parental environment, but the molecular pathways that transmit environmental cues between generations are not well understood. Here, we show that, in Caenorhabditis elegans, social cues modulate maternal provisioning to regulate gene silencing in offspring. Intergenerational signal transmission depends on a pheromone-sensing neuron and neuronal FMRFamide (Phe-Met-Arg-Phe)-like peptides. Parental FMRFamide-like peptide signaling dampens oxidative stress resistance and promotes the deposition of mRNAs for translational components in progeny, which, in turn, reduces gene silencing. This study identifies a previously unknown pathway for intergenerational communication that links neuronal responses to maternal provisioning. We suggest that loss of social cues in the parental environment represents an adverse environment that stimulates stress responses across generations.
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Affiliation(s)
| | - Gareth Harris
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA
- Department of Biology, California State University Channel Islands, Camarillo, CA, USA
| | | | | | - Abdul R Dar
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Sylvia E J Fischer
- Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA
| | - Konstantinos Kagias
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Cambridge, MA, USA
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA.
| | - Susan E Mango
- Biozentrum, University of Basel, Basel, Switzerland.
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4
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Faghih N, Bhar S, Zhou Y, Dar AR, Mai K, Bailey LS, Basso KB, Butcher RA. A Large Family of Enzymes Responsible for the Modular Architecture of Nematode Pheromones. J Am Chem Soc 2020; 142:13645-13650. [PMID: 32702987 DOI: 10.1021/jacs.0c04223] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The nematode Caenorhabditis elegans produces a broad family of pheromones, known as the ascarosides, that are modified with a variety of groups derived from primary metabolism. These modifications are essential for the diverse activities of the ascarosides in development and various behaviors, including attraction, aggregation, avoidance, and foraging. The mechanism by which these different groups are added to the ascarosides is poorly understood. Here, we identify a family of over 30 enzymes, which are homologous to mammalian carboxylesterase (CES) enzymes, and show that a number of these enzymes are responsible for the selective addition of specific modifications to the ascarosides. Through stable isotope feeding experiments, we demonstrate the in vivo activity of the CES-like enzymes and provide direct evidence that the acyl-CoA synthetase ACS-7, which was previously implicated in the attachment of certain modifications to the ascarosides in C. elegans, instead activates the side chains of certain ascarosides for shortening through β-oxidation. Our data provide a key to the combinatorial logic that gives rise to different modified ascarosides, which should greatly facilitate the exploration of the specific biological functions of these pheromones in the worm.
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Affiliation(s)
- Nasser Faghih
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
| | - Subhradeep Bhar
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
| | - Yue Zhou
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
| | - Abdul Rouf Dar
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
| | - Kevin Mai
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
| | - Laura S Bailey
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
| | - Kari B Basso
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
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5
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Roder AC, Wang Y, Butcher RA, Stock SP. Influence of symbiotic and non-symbiotic bacteria on pheromone production in Steinernema nematodes (Nematoda, Steinernematidae). ACTA ACUST UNITED AC 2019; 222:jeb.212068. [PMID: 31511342 DOI: 10.1242/jeb.212068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 09/04/2019] [Indexed: 11/20/2022]
Abstract
In this study, we assessed the effect of symbiotic (cognate and non-cognate) and non-symbiotic bacteria on ascaroside production of first-generation adults in two Steinernema spp.: S. carpocapsae All strain and S. feltiae SN strain. Each nematode species was reared under three bacterial scenarios: (1) cognate symbiotic, (2) non-cognate symbiotic strain and (3) non-cognate symbiotic species. Our results showed S. carpocapsae produced four quantifiable ascaroside molecules: asc-C5, asc-C6, asc-C7 and asc-C11, whereas in S. feltiae only three molecules were detected: asc-C5, asc-C7 and asc-C11. Bacterial conditions did not significantly affect the quantity of the secreted ascarosides in first-generation adults of S. carpocapsae However, in S. feltiae, Xenorhabdus nematophila All strain influenced the production of two ascaroside molecules: asc-C5 and asc-C11.
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Affiliation(s)
- Alexandra C Roder
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Yuting Wang
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - S Patricia Stock
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ 85721, USA .,Department of Entomology, University of Arizona, Forbes Building Rm 410, 1140 E. South Campus Drive, Tucson, AZ 85721, USA
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6
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Butcher RA. Natural products as chemical tools to dissect complex biology in C. elegans. Curr Opin Chem Biol 2019; 50:138-144. [PMID: 31102973 DOI: 10.1016/j.cbpa.2019.03.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/22/2019] [Accepted: 03/05/2019] [Indexed: 12/18/2022]
Abstract
The search for novel pheromones, hormones, and other types of natural products in the nematode Caenorhabditis elegans has accelerated over the last 10-15 years. Many of these natural products perturb fundamental processes such as developmental progression, metabolism, reproductive and somatic aging, and various behaviors and have thus become essential tools for probing these processes, which are difficult to study in higher organisms. Furthermore, given the similarity between C. elegans and parasitic nematodes, these natural products could potentially be used to manipulate the development and behavior of parasitic nematodes and target the infections caused by them.
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Affiliation(s)
- Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, FL 32611, United States.
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7
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Park J, Choi W, Dar AR, Butcher RA, Kim K. Neuropeptide Signaling Regulates Pheromone-Mediated Gene Expression of a Chemoreceptor Gene in C. elegans. Mol Cells 2019; 42:28-35. [PMID: 30453729 PMCID: PMC6354054 DOI: 10.14348/molcells.2018.0380] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 10/16/2018] [Accepted: 10/17/2018] [Indexed: 11/27/2022] Open
Abstract
Animals need to be able to alter their developmental and behavioral programs in response to changing environmental conditions. This developmental and behavioral plasticity is mainly mediated by changes in gene expression. The knowledge of the mechanisms by which environmental signals are transduced and integrated to modulate changes in sensory gene expression is limited. Exposure to ascaroside pheromone has been reported to alter the expression of a subset of putative G protein-coupled chemosensory receptor genes in the ASI chemosensory neurons of C. elegans (Kim et al., 2009; Nolan et al., 2002; Peckol et al., 1999). Here we show that ascaroside pheromone reversibly represses expression of the str-3 chemoreceptor gene in the ASI neurons. Repression of str-3 expression can be initiated only at the L1 stage, but expression is restored upon removal of ascarosides at any developmental stage. Pheromone receptors including SRBC-64/66 and SRG-36/37 are required for str-3 repression. Moreover, pheromone-mediated str-3 repression is mediated by FLP-18 neuropeptide signaling via the NPR-1 neuropeptide receptor. These results suggest that environmental signals regulate chemosensory gene expression together with internal neuropeptide signals which, in turn, modulate behavior.
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Affiliation(s)
- Jisoo Park
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988,
Korea
| | - Woochan Choi
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988,
Korea
| | - Abdul Rouf Dar
- Department of Chemistry, University of Florida, Gainesville, FL 32611,
USA
| | - Rebecca A. Butcher
- Department of Chemistry, University of Florida, Gainesville, FL 32611,
USA
| | - Kyuhyung Kim
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988,
Korea
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8
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Abstract
Caenorhabditis elegans uses aggregation pheromones to communicate its nutritional status and recruit fellow members of its species to food sources. These aggregation pheromones include the IC-ascarosides, ascarosides modified with an indole-3-carbonyl (IC) group on the 4'-position of the ascarylose sugar. Nothing is known about the biosynthesis of the IC modification beyond the fact that it is derived from tryptophan. Here, we show that C. elegans produces endogenously several indole-containing metabolites, including indole-3-pyruvic acid (IPA), indole-3-acetic acid (IAA; auxin), and indole-3-carboxylic acid, and that these metabolites are intermediates in the biosynthetic pathway from tryptophan to the IC group. Stable isotope-labeled IPA and IAA are incorporated into the IC-ascarosides. Importantly, we show that flux through the biosynthetic pathway is affected by the activity of the pyruvate dehydrogenase complex (PDC). Knockdown of the PDC by RNA interference leads to an accumulation of upstream metabolites and a reduction in downstream metabolites in the pathway. Our results show that production of aggregation pheromones is linked to PDC activity and that aggregation behavior may reflect a favorable metabolic state in the worm. Lastly, we show that treatment of C. elegans with indole-containing metabolites in the pathway induces the biosynthesis of the IC-ascarosides. Because the natural environment of C. elegans is rotting plant material, indole-containing metabolites in this environment could potentially stimulate pheromone biosynthesis and aggregation behavior in the worm. Thus, there may be important links between tryptophan metabolism in C. elegans and in plants and bacteria that enable interkingdom signaling.
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Affiliation(s)
- Yue Zhou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Xinxing Zhang
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Rebecca A. Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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9
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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10
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Zhou Y, Wang Y, Zhang X, Bhar S, Jones Lipinski RA, Han J, Feng L, Butcher RA. Biosynthetic tailoring of existing ascaroside pheromones alters their biological function in C. elegans. eLife 2018; 7:33286. [PMID: 29863473 PMCID: PMC5986272 DOI: 10.7554/elife.33286] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 04/26/2018] [Indexed: 11/13/2022] Open
Abstract
Caenorhabditis elegans produces ascaroside pheromones to control its development and behavior. Even minor structural differences in the ascarosides have dramatic consequences for their biological activities. Here, we identify a mechanism that enables C. elegans to dynamically tailor the fatty-acid side chains of the indole-3-carbonyl (IC)-modified ascarosides it has produced. In response to starvation, C. elegans uses the peroxisomal acyl-CoA synthetase ACS-7 to activate the side chains of medium-chain IC-ascarosides for β-oxidation involving the acyl-CoA oxidases ACOX-1.1 and ACOX-3. This pathway rapidly converts a favorable ascaroside pheromone that induces aggregation to an unfavorable one that induces the stress-resistant dauer larval stage. Thus, the pathway allows the worm to respond to changing environmental conditions and alter its chemical message without having to synthesize new ascarosides de novo. We establish a new model for biosynthesis of the IC-ascarosides in which side-chain β-oxidation is critical for controlling the type of IC-ascarosides produced. Small roundworms such as Caenorhabditis elegans release chemical signals called ascarosides in order to communicate with other worms of the same species. Using the ascarosides, the worm can tell its friends, for example, how crowded the neighborhood is and whether there is enough food. The ascarosides thus help the worms in the population decide whether the neighborhood is good – meaning they should hang around, eat, and make babies – or whether the neighborhood is bad. If so, the worms should develop into a larval stage specialized for dispersal that will allow them to find a better neighborhood. Roundworms make the ascarosides by attaching a long chemical ‘side chain’ to an ascarylose sugar. Further chemical modifications allow the worms to produce different signals. In general, to signal a good neighborhood, worms attach a structure called an indole group to the ascarosides. To signal a bad neighborhood, worms make the side chain very short. But how does a worm control which ascarosides it makes? Zhou, Wang et al. now show that C. elegans can change the meaning of its chemical message by modifying the ascarosides that it has already produced instead of making new ones from scratch. Specifically, as their neighborhood runs out of food, C. elegans can use an enzyme called ACS-7 to initiate the shortening of the side chains of indole-ascarosides. The worm can thus change a favorable ascaroside signal that causes the worms to group together into an unfavorable ascaroside signal that causes the worms to enter their dispersal stage. Although Zhou, Wang et al. have focused on chemical communication in C. elegans, the findings could easily apply to the many other species of roundworm that produce ascarosides. Knowing how worms communicate will help us to understand how worms respond to their environment. This knowledge could potentially be used to interfere with the lifecycles and survival of parasitic worm species that harm health and crops.
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Affiliation(s)
- Yue Zhou
- Department of Chemistry, University of Florida, Gainesville, United States
| | - Yuting Wang
- Department of Chemistry, University of Florida, Gainesville, United States
| | - Xinxing Zhang
- Department of Chemistry, University of Florida, Gainesville, United States
| | - Subhradeep Bhar
- Department of Chemistry, University of Florida, Gainesville, United States
| | | | - Jungsoo Han
- Department of Chemistry, University of Florida, Gainesville, United States
| | - Likui Feng
- Department of Chemistry, University of Florida, Gainesville, United States
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, United States
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11
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Zhang X, Wang Y, Perez DH, Jones Lipinski RA, Butcher RA. Acyl-CoA Oxidases Fine-Tune the Production of Ascaroside Pheromones with Specific Side Chain Lengths. ACS Chem Biol 2018. [PMID: 29537254 DOI: 10.1021/acschembio.7b01021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Caenorhabditis elegans produces a complex mixture of ascaroside pheromones to control its development and behavior. Acyl-CoA oxidases, which participate in β-oxidation cycles that shorten the side chains of the ascarosides, regulate the mixture of pheromones produced. Here, we use CRISPR-Cas9 to make specific nonsense and missense mutations in acox genes and determine the effect of these mutations on ascaroside production in vivo. Ascaroside production in acox-1.1 deletion and nonsense strains, as well as a strain with a missense mutation in a catalytic residue, confirms the central importance of ACOX-1.1 in ascaroside biosynthesis and suggests that ACOX-1.1 functions in part by facilitating the activity of other acyl-CoA oxidases. Ascaroside production in an acox-1.1 strain with a missense mutation in an ATP-binding site at the ACOX-1.1 dimer interface suggests that ATP binding is important for the enzyme to function in ascaroside biosynthesis in vivo. Ascaroside production in strains with deletion, nonsense, and missense mutations in other acox genes demonstrates that ACOX-1.1 works with ACOX-1.3 in processing ascarosides with 7-carbon side chains, ACOX-1.4 in processing ascarosides with 9- and 11-carbon side chains, and ACOX-3 in processing ascarosides with 13- and 15-carbon side chains. It also shows that ACOX-1.2, but not ACOX-1.1, processes ascarosides with 5-carbon ω-side chains. By modeling the ACOX structures, we uncover characteristics of the enzyme active sites that govern substrate preferences. Our work demonstrates the role of specific acyl-CoA oxidases in controlling the length of ascaroside side chains and thus in determining the mixture of pheromones produced by C. elegans.
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Affiliation(s)
- Xinxing Zhang
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Yuting Wang
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - David H. Perez
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | | | - Rebecca A. Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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12
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Zhou Y, Loeza-Cabrera M, Liu Z, Aleman-Meza B, Nguyen JK, Jung SK, Choi Y, Shou Q, Butcher RA, Zhong W. Potential Nematode Alarm Pheromone Induces Acute Avoidance in Caenorhabditis elegans. Genetics 2017; 206:1469-1478. [PMID: 28495959 PMCID: PMC5500144 DOI: 10.1534/genetics.116.197293] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 05/04/2017] [Indexed: 01/16/2023] Open
Abstract
It is crucial for animal survival to detect dangers such as predators. A good indicator of dangers is injury of conspecifics. Here we show that fluids released from injured conspecifics invoke acute avoidance in both free-living and parasitic nematodes. Caenorhabditis elegans avoids extracts from closely related nematode species but not fruit fly larvae. The worm extracts have no impact on animal lifespan, suggesting that the worm extract may function as an alarm instead of inflicting physical harm. Avoidance of the worm extract requires the function of a cGMP signaling pathway that includes the cGMP-gated channel TAX-2/TAX-4 in the amphid sensory neurons ASI and ASK. Genetic evidence indicates that the avoidance behavior is modulated by the neurotransmitters GABA and serotonin, two common targets of anxiolytic drugs. Together, these data support a model that nematodes use a nematode-specific alarm pheromone to detect conspecific injury.
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Affiliation(s)
- Ying Zhou
- Department of BioSciences, Rice University, Houston, Texas 77005
| | | | - Zheng Liu
- Department of BioSciences, Rice University, Houston, Texas 77005
| | | | - Julie K Nguyen
- Department of BioSciences, Rice University, Houston, Texas 77005
| | - Sang-Kyu Jung
- Department of BioSciences, Rice University, Houston, Texas 77005
| | - Yuna Choi
- Department of BioSciences, Rice University, Houston, Texas 77005
| | - Qingyao Shou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida 32611
| | - Weiwei Zhong
- Department of BioSciences, Rice University, Houston, Texas 77005
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13
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Abstract
The nematode Caenorhabditis elegans produces tens, if not hundreds, of different ascarosides as pheromones to communicate with other members of its species. Overlapping mixtures of these pheromones affect the development of the worm and a variety of different behaviors. The ascarosides represent a unique tool for dissecting the neural circuitry that controls behavior and that connects to important signaling pathways, such as the insulin and TGFβ pathways, that lie at the nexus of development, metabolism, and lifespan in C. elegans. However, the exact physiological roles of many of the ascarosides are unclear, especially since many of these pheromones likely have multiple functions depending on their concentrations, the presence of other pheromones, and a variety of other factors. Determining these physiological roles will be facilitated by top-down approaches to characterize the pheromone receptors and their function, as well as bottom-up approaches to characterize the pheromone biosynthetic enzymes and their regulation.
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Affiliation(s)
- Rebecca A Butcher
- University of Florida, Department of Chemistry, Gainesville, FL 32611, USA.
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14
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Butcher RA, Feng L, Shou Q. Discovery and biosynthesis of hybrid polyketide‐nonribosomal peptides in nematodes. FASEB J 2017. [DOI: 10.1096/fasebj.31.1_supplement.121.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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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: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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16
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Greene JS, Dobosiewicz M, Butcher RA, McGrath PT, Bargmann CI. Regulatory changes in two chemoreceptor genes contribute to a Caenorhabditis elegans QTL for foraging behavior. eLife 2016; 5. [PMID: 27893361 PMCID: PMC5125752 DOI: 10.7554/elife.21454] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/14/2016] [Indexed: 12/22/2022] Open
Abstract
Natural isolates of C. elegans differ in their sensitivity to pheromones that inhibit exploratory behavior. Previous studies identified a QTL for pheromone sensitivity that includes alternative alleles of srx-43, a chemoreceptor that inhibits exploration through its activity in ASI sensory neurons. Here we show that the QTL is multigenic and includes alternative alleles of srx-44, a second chemoreceptor gene that modifies pheromone sensitivity. srx-44 either promotes or inhibits exploration depending on its expression in the ASJ or ADL sensory neurons, respectively. Naturally occurring pheromone insensitivity results in part from previously described changes in srx-43 expression levels, and in part from increased srx-44 expression in ASJ, which antagonizes ASI and ADL. Antagonism between the sensory neurons results in cellular epistasis that is reflected in their transcription of insulin genes that regulate exploration. These results and genome-wide evidence suggest that chemoreceptor genes may be preferred sites of adaptive variation in C. elegans. DOI:http://dx.doi.org/10.7554/eLife.21454.001
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Affiliation(s)
- Joshua S Greene
- Howard Hughes Medical Institute (HHMI), Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, United States
| | - May Dobosiewicz
- Howard Hughes Medical Institute (HHMI), Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, United States
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, United States
| | - Patrick T McGrath
- Department of Biology, Georgia Institute of Technology, Atlanta, United States
| | - Cornelia I Bargmann
- Howard Hughes Medical Institute (HHMI), Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, United States
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17
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Greene JS, Brown M, Dobosiewicz M, Ishida IG, Macosko EZ, Zhang X, Butcher RA, Cline DJ, McGrath PT, Bargmann CI. Balancing selection shapes density-dependent foraging behaviour. Nature 2016; 539:254-258. [PMID: 27799655 PMCID: PMC5161598 DOI: 10.1038/nature19848] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Accepted: 09/14/2016] [Indexed: 02/04/2023]
Abstract
The optimal foraging strategy in a given environment depends on the number of competing individuals and their behavioral strategies. Little is known about the genes and neural circuits that integrate social information into foraging decisions. Here we show that ascaroside pheromones that signal population density suppress exploratory foraging in Caenorhabditis elegans, and that heritable variation in this behavior generates alternative foraging strategies. Natural C. elegans isolates differ in their sensitivity to the potent ascaroside icas#9 (IC-asc-C5). A quantitative trait locus (QTL) for icas#9 sensitivity includes srx-43, a G protein-coupled icas#9 receptor; srx-43 acts in ASI sensory neurons to suppress exploration. Two ancient haplotypes associated with this QTL confer competitive growth advantages that depend on ascaroside secretion, its detection by srx-43, and the distribution of food. These results suggest that balancing selection at the srx-43 locus generates alternative density-dependent behaviors, fulfilling a prediction of foraging game theory.
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Affiliation(s)
- Joshua S Greene
- Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, New York 10065, USA
| | - Maximillian Brown
- Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, New York 10065, USA
| | - May Dobosiewicz
- Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, New York 10065, USA
| | - Itzel G Ishida
- Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, New York 10065, USA
| | - Evan Z Macosko
- Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, New York 10065, USA
| | - Xinxing Zhang
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
| | - Devin J Cline
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Patrick T McGrath
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Cornelia I Bargmann
- Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, New York 10065, USA
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18
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Shou Q, Feng L, Long Y, Han J, Nunnery JK, Powell DH, Butcher RA. A hybrid polyketide-nonribosomal peptide in nematodes that promotes larval survival. Nat Chem Biol 2016; 12:770-2. [PMID: 27501395 PMCID: PMC5030153 DOI: 10.1038/nchembio.2144] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 06/16/2016] [Indexed: 11/18/2022]
Abstract
Polyketides and nonribosomal peptides are two important classes of natural products that are produced by many species of bacteria and fungi, but are exceedingly rare in metazoans. Here, we elucidate the structure of a hybrid polyketide-nonribosomal peptide from Caenorhabditis elegans that is produced in the CAN neurons and promotes survival during starvation-induced larval arrest. Our results uncover a novel mechanism by which animals respond to nutrient fluctuations to extend survival.
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Affiliation(s)
- Qingyao Shou
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Likui Feng
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Yaoling Long
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Jungsoo Han
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Joshawna K Nunnery
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - David H Powell
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
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19
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Large EE, Xu W, Zhao Y, Brady SC, Long L, Butcher RA, Andersen EC, McGrath PT. Selection on a Subunit of the NURF Chromatin Remodeler Modifies Life History Traits in a Domesticated Strain of Caenorhabditis elegans. PLoS Genet 2016; 12:e1006219. [PMID: 27467070 PMCID: PMC4965130 DOI: 10.1371/journal.pgen.1006219] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/01/2016] [Indexed: 11/20/2022] Open
Abstract
Evolutionary life history theory seeks to explain how reproductive and survival traits are shaped by selection through allocations of an individual’s resources to competing life functions. Although life-history traits evolve rapidly, little is known about the genetic and cellular mechanisms that control and couple these tradeoffs. Here, we find that two laboratory-adapted strains of C. elegans descended from a single common ancestor that lived in the 1950s have differences in a number of life-history traits, including reproductive timing, lifespan, dauer formation, growth rate, and offspring number. We identified a quantitative trait locus (QTL) of large effect that controls 24%–75% of the total trait variance in reproductive timing at various timepoints. Using CRISPR/Cas9-induced genome editing, we show this QTL is due in part to a 60 bp deletion in the 3’ end of the nurf-1 gene, which is orthologous to the human gene encoding the BPTF component of the NURF chromatin remodeling complex. Besides reproduction, nurf-1 also regulates growth rate, lifespan, and dauer formation. The fitness consequences of this deletion are environment specific—it increases fitness in the growth conditions where it was fixed but decreases fitness in alternative laboratory growth conditions. We propose that chromatin remodeling, acting through nurf-1, is a pleiotropic regulator of life history trade-offs underlying the evolution of multiple traits across different species. Sex and death are two fundamental concerns of each organism. These traits evolve rapidly in natural populations as animals seek to maximize their fitness in a given environment. For example, in mammals, lifespan, size, and fecundity vary over two order of magnitude. A key observation of evolutionary life history theory is the recognition that there are limited amount of resources available, which creates tradeoffs between competing life functions. By studying a domesticated strain of C. elegans, we identify a beneficial mutation that regulates a number of life history tradeoffs. This mutation affects a subunit of the NURF chromatin remodeling complex. Our work suggests that NURF is a master regulator of life history tradeoffs through epigenetic regulation, and a target of evolution.
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Affiliation(s)
- Edward E. Large
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Wen Xu
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Yuehui Zhao
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Shannon C. Brady
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Lijiang Long
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Rebecca A. Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida, United States of America
| | - Erik C. Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Patrick T. McGrath
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- * E-mail:
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20
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Neal SJ, Park J, DiTirro D, Yoon J, Shibuya M, Choi W, Schroeder FC, Butcher RA, Kim K, Sengupta P. A Forward Genetic Screen for Molecules Involved in Pheromone-Induced Dauer Formation in Caenorhabditis elegans. G3 (Bethesda) 2016; 6:1475-87. [PMID: 26976437 PMCID: PMC4856098 DOI: 10.1534/g3.115.026450] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/07/2016] [Indexed: 01/09/2023]
Abstract
Animals must constantly assess their surroundings and integrate sensory cues to make appropriate behavioral and developmental decisions. Pheromones produced by conspecific individuals provide critical information regarding environmental conditions. Ascaroside pheromone concentration and composition are instructive in the decision of Caenorhabditis elegans to either develop into a reproductive adult or enter into the stress-resistant alternate dauer developmental stage. Pheromones are sensed by a small set of sensory neurons, and integrated with additional environmental cues, to regulate neuroendocrine signaling and dauer formation. To identify molecules required for pheromone-induced dauer formation, we performed an unbiased forward genetic screen and identified phd (pheromone response-defective dauer) mutants. Here, we describe new roles in dauer formation for previously identified neuronal molecules such as the WD40 domain protein QUI-1 and MACO-1 Macoilin, report new roles for nociceptive neurons in modulating pheromone-induced dauer formation, and identify tau tubulin kinases as new genes involved in dauer formation. Thus, phd mutants define loci required for the detection, transmission, or integration of pheromone signals in the regulation of dauer formation.
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Affiliation(s)
- Scott J Neal
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
| | - JiSoo Park
- Department of Brain and Cognitive Sciences, DGIST, Daegu 711-873, Republic of Korea
| | - Danielle DiTirro
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
| | - Jason Yoon
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
| | - Mayumi Shibuya
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
| | - Woochan Choi
- Department of Brain and Cognitive Sciences, DGIST, Daegu 711-873, Republic of Korea
| | - Frank C Schroeder
- Boyce Thompson Institute, Cornell University, Ithaca, New York 14853 Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida 32611
| | - Kyuhyung Kim
- Department of Brain and Cognitive Sciences, DGIST, Daegu 711-873, Republic of Korea
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454
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21
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Neal SJ, Takeishi A, O'Donnell MP, Park J, Hong M, Butcher RA, Kim K, Sengupta P. Correction: Feeding state-dependent regulation of developmental plasticity via CaMKI and neuroendocrine signaling. eLife 2015; 4:e11547. [PMID: 26394001 PMCID: PMC4576173 DOI: 10.7554/elife.11547] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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22
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Neal SJ, Takeishi A, O'Donnell MP, Park J, Hong M, Butcher RA, Kim K, Sengupta P. Feeding state-dependent regulation of developmental plasticity via CaMKI and neuroendocrine signaling. eLife 2015; 4. [PMID: 26335407 PMCID: PMC4558564 DOI: 10.7554/elife.10110] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 07/31/2015] [Indexed: 01/03/2023] Open
Abstract
Information about nutrient availability is assessed via largely unknown mechanisms to drive developmental decisions, including the choice of Caenorhabditis elegans larvae to enter into the reproductive cycle or the dauer stage. In this study, we show that CMK-1 CaMKI regulates the dauer decision as a function of feeding state. CMK-1 acts cell-autonomously in the ASI, and non cell-autonomously in the AWC, sensory neurons to regulate expression of the growth promoting daf-7 TGF-β and daf-28 insulin-like peptide (ILP) genes, respectively. Feeding state regulates dynamic subcellular localization of CMK-1, and CMK-1-dependent expression of anti-dauer ILP genes, in AWC. A food-regulated balance between anti-dauer ILP signals from AWC and pro-dauer signals regulates neuroendocrine signaling and dauer entry; disruption of this balance in cmk-1 mutants drives inappropriate dauer formation under well-fed conditions. These results identify mechanisms by which nutrient information is integrated in a small neuronal network to modulate neuroendocrine signaling and developmental plasticity. DOI:http://dx.doi.org/10.7554/eLife.10110.001 Living organisms have the remarkable ability to adapt to changes in their external environment. For example, when conditions are favorable, the larvae of the tiny roundworm C. elegans rapidly mature into adults and reproduce. However, when faced with starvation, over-crowding or other adverse conditions, they can stop growing and enter a type of stasis called the dauer stage, which enables them to survive in harsh conditions for extended periods of time. The worms enter the dauer stage if they detect high levels of a pheromone mixture that is produced by other worms—which indicates that the local population is over-crowded. However, temperature, food availability, and other environmental cues also influence this decision. A protein called TGF-β and other proteins called insulin-like peptides are produced by a group of sensory neurons in the worm's head. These proteins usually promote the growth of the worms by increasing the production of particular steroid hormones. However, high levels of the pheromone mixture, an inadequate supply of food and other adverse conditions decrease the expression of the genes that encode these proteins, which allows the worm to enter the dauer state. It is not clear how the worm senses food, nor how this is integrated with the information provided by the pheromones to influence this decision. To address these questions, Neal et al. studied a variety of mutant worms that lacked proteins involved in different aspects of food sensing. The experiments show that worms missing a protein called CaMKI enter the dauer state even under conditions in which food is plentiful and normal worms continue to grow. CaMKI inhibits entry into the dauer stage by increasing the expression of the genes that encode TGF-β and the insulin-like peptides in sensory neurons in response to food. Neal et al.'s findings reveal how CaMKI enables information about food availability to be integrated with other environmental cues to influence whether young worms enter the dauer state. Understanding how food sensing is linked to changes in hormone levels will help us appreciate why and how the availability of food has complex effects on animal biology and behavior. DOI:http://dx.doi.org/10.7554/eLife.10110.002
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Affiliation(s)
- Scott J Neal
- Department of Biology, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
| | - Asuka Takeishi
- Department of Biology, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
| | - Michael P O'Donnell
- Department of Biology, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
| | - JiSoo Park
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Myeongjin Hong
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, United States
| | - Kyuhyung Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Piali Sengupta
- Department of Biology, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
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23
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Zhao L, Mota M, Vieira P, Butcher RA, Sun J. Interspecific communication between pinewood nematode, its insect vector, and associated microbes. Trends Parasitol 2014; 30:299-308. [DOI: 10.1016/j.pt.2014.04.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 04/08/2014] [Accepted: 04/11/2014] [Indexed: 01/23/2023]
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Zhao L, Zhang S, Wei W, Hao H, Zhang B, Butcher RA, Sun J. Chemical signals synchronize the life cycles of a plant-parasitic nematode and its vector beetle. Curr Biol 2013; 23:2038-43. [PMID: 24120638 DOI: 10.1016/j.cub.2013.08.041] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 05/13/2013] [Accepted: 08/12/2013] [Indexed: 01/24/2023]
Abstract
The pinewood nematode Bursaphelenchus xylophilus has caused severe damage to pine forests in large parts of the world [1-4]. Dispersal of this plant-parasitic nematode occurs when the nematode develops into the dispersal fourth larval stage (LIV) upon encountering its insect vector, the Monochamus pine sawyer beetle, inside an infected pine tree [5-9]. Here, we show that LIV formation in B. xylophilus is induced by C16 and C18 fatty acid ethyl esters (FAEEs), which are produced abundantly on the body surface of the vector beetle specifically during the late development pupal, emerging adult, and newly eclosed adult stages. The LIV can then enter the tracheal system of the adult beetle for dispersal to a new pine tree. Treatment of B. xylophilus with long-chain FAEEs, or the PI3 kinase inhibitor LY294002, promotes LIV formation, while Δ7-dafachronic acid blocks the effects of these chemicals, suggesting a conserved role for the insulin/IGF-1 and DAF-12 pathways in LIV formation. Our work provides a mechanism by which LIV formation in B. xylophilus is specifically coordinated with the life cycle of its vector beetle. Knowledge of the chemical signals that control the LIV developmental decision could be used to interfere with the dispersal of this plant-parasitic nematode.
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Affiliation(s)
- Lilin Zhao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
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25
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Sakai N, Iwata R, Yokoi S, Butcher RA, Clardy J, Tomioka M, Iino Y. A sexually conditioned switch of chemosensory behavior in C. elegans. PLoS One 2013; 8:e68676. [PMID: 23861933 PMCID: PMC3701651 DOI: 10.1371/journal.pone.0068676] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 06/06/2013] [Indexed: 11/18/2022] Open
Abstract
In sexually reproducing animals, mating is essential for transmitting genetic information to the next generation and therefore animals have evolved mechanisms for optimizing the chance of successful mate location. In the soil nematode C. elegans, males approach hermaphrodites via the ascaroside pheromones, recognize hermaphrodites when their tails contact the hermaphrodites' body, and eventually mate with them. These processes are mediated by sensory signals specialized for sexual communication, but other mechanisms may also be used to optimize mate location. Here we describe associative learning whereby males use sodium chloride as a cue for hermaphrodite location. Both males and hermaphrodites normally avoid sodium chloride after associative conditioning with salt and starvation. However, we found that males become attracted to sodium chloride after conditioning with salt and starvation if hermaphrodites are present during conditioning. For this conditioning, which we call sexual conditioning, hermaphrodites are detected by males through pheromonal signaling and additional cue(s). Sex transformation experiments suggest that neuronal sex of males is essential for sexual conditioning. Altogether, these results suggest that C. elegans males integrate environmental, internal and social signals to determine the optimal strategy for mate location.
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Affiliation(s)
- Naoko Sakai
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Ryo Iwata
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Saori Yokoi
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Rebecca A. Butcher
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Masahiro Tomioka
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yuichi Iino
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail:
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Zhang X, Noguez JH, Zhou Y, Butcher RA. Analysis of ascarosides from Caenorhabditis elegans using mass spectrometry and NMR spectroscopy. Methods Mol Biol 2013; 1068:71-92. [PMID: 24014355 DOI: 10.1007/978-1-62703-619-1_6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The nematode Caenorhabditis elegans secretes a family of water-soluble small molecules, known as the ascarosides, into its environment and uses these ascarosides in chemical communication. The ascarosides are derivatives of the 3,6-dideoxysugar ascarylose, modified with different fatty acid-derived side chains. C. elegans uses specific ascarosides, which are together known as the dauer pheromone, to trigger entry into the stress-resistant dauer larval stage. In addition, C. elegans uses specific ascarosides to control certain behaviors, including mating attraction, aggregation, and avoidance. Although in general the concentration of the ascarosides in the environment increases with population density, C. elegans can vary the types and amounts of ascarosides that it secretes depending on the culture conditions under which it has been grown and its developmental history. Here, we describe how to grow high-density worm cultures and the bacterial food for those cultures, as well as how to extract the culture medium to generate a crude pheromone extract. Then, we discuss how to analyze the types and amounts of ascarosides in that extract using mass spectrometry and NMR spectroscopy.
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Affiliation(s)
- Xinxing Zhang
- Department of Chemistry, University of Florida, Gainesville, FL, USA
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27
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Jang H, Kim K, Neal SJ, Macosko E, Kim D, Butcher RA, Zeiger DM, Bargmann CI, Sengupta P. Neuromodulatory state and sex specify alternative behaviors through antagonistic synaptic pathways in C. elegans. Neuron 2012; 75:585-92. [PMID: 22920251 DOI: 10.1016/j.neuron.2012.06.034] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2012] [Indexed: 12/14/2022]
Abstract
Pheromone responses are highly context dependent. For example, the C. elegans pheromone ascaroside C9 (ascr#3) is repulsive to wild-type hermaphrodites, attractive to wild-type males, and usually neutral to "social" hermaphrodites with reduced activity of the npr-1 neuropeptide receptor gene. We show here that these distinct behavioral responses arise from overlapping push-pull circuits driven by two classes of pheromone-sensing neurons. The ADL sensory neurons detect C9 and, in wild-type hermaphrodites, drive C9 repulsion through their chemical synapses. In npr-1 mutant hermaphrodites, C9 repulsion is reduced by the recruitment of a gap junction circuit that antagonizes ADL chemical synapses. In males, ADL sensory responses are diminished; in addition, a second pheromone-sensing neuron, ASK, antagonizes C9 repulsion. The additive effects of these antagonistic circuit elements generate attractive, repulsive, or neutral pheromone responses. Neuronal modulation by circuit state and sex, and flexibility in synaptic output pathways, may permit small circuits to maximize their adaptive behavioral outputs.
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Affiliation(s)
- Heeun Jang
- Howard Hughes Medical Institute and Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA
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Noguez JH, Conner ES, Zhou Y, Ciche TA, Ragains JR, Butcher RA. A novel ascaroside controls the parasitic life cycle of the entomopathogenic nematode Heterorhabditis bacteriophora. ACS Chem Biol 2012; 7:961-6. [PMID: 22444073 DOI: 10.1021/cb300056q] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Entomopathogenic nematodes survive in the soil as stress-resistant infective juveniles that seek out and infect insect hosts. Upon sensing internal host cues, the infective juveniles regurgitate bacterial pathogens from their gut that ultimately kill the host. Inside the host, the nematode develops into a reproductive adult and multiplies until unknown cues trigger the accumulation of infective juveniles. Here, we show that the entomopathogenic nematode Heterorhabditis bacteriophora uses a small-molecule pheromone to control infective juvenile development. The pheromone is structurally related to the dauer pheromone ascarosides that the free-living nematode Caenorhabditis elegans uses to control its development. However, none of the C. elegans ascarosides are effective in H. bacteriophora, suggesting that there is a high degree of species specificity. Our report is the first to show that ascarosides are important regulators of development in a parasitic nematode species. An understanding of chemical signaling in parasitic nematodes may enable the development of chemical tools to control these species.
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Affiliation(s)
- Jaime H. Noguez
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
| | - Elizabeth S. Conner
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana, United States
| | - Yue Zhou
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
| | - Todd A. Ciche
- Department of Microbiology and
Molecular Genetics, Michigan State University, East Lansing, Michigan, United States
| | - Justin R. Ragains
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana, United States
| | - Rebecca A. Butcher
- Department of Chemistry, University of Florida, Gainesville, Florida, United States
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29
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McGrath PT, Xu Y, Ailion M, Garrison JL, Butcher RA, Bargmann CI. Parallel evolution of domesticated Caenorhabditis species targets pheromone receptor genes. Nature 2011; 477:321-5. [PMID: 21849976 PMCID: PMC3257054 DOI: 10.1038/nature10378] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 07/20/2011] [Indexed: 11/15/2022]
Abstract
Evolution can follow predictable genetic trajectories1, indicating that discrete environmental shifts can select for reproducible genetic changes2-4. Conspecific individuals are an important feature of an animal's environment, and a potential source of selective pressures. We show here that adaptation of two Caenorhabditis species to growth at high density, a feature common to domestic environments, occurs by reproducible genetic changes to pheromone receptor genes. Chemical communication through pheromones that accumulate during high-density growth causes young nematode larvae to enter the long-lived but non-reproductive dauer stage. Two strains of Caenorhabditis elegans grown at high density have independently acquired multigenic resistance to pheromone-induced dauer formation. In each strain, resistance to the pheromone ascaroside C3 results from a deletion that disrupts the adjacent chemoreceptor genes serpentine receptor class g (srg)-36 and -37. Through misexpression experiments, we show that these genes encode redundant G protein-coupled receptors for ascaroside C3. Multigenic resistance to dauer formation has also arisen in high-density cultures of a different nematode species, Caenorhabditis briggsae, resulting in part from deletion of an srg gene paralogous to srg-36 and srg-37. These results demonstrate rapid remodeling of the chemoreceptor repertoire as an adaptation to specific environments, and indicate that parallel changes to a common genetic substrate can affect life history traits across species.
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Affiliation(s)
- Patrick T McGrath
- Howard Hughes Medical Institute, Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, New York 10065, USA
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30
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Yamada K, Hirotsu T, Matsuki M, Butcher RA, Tomioka M, Ishihara T, Clardy J, Kunitomo H, Iino Y. Olfactory plasticity is regulated by pheromonal signaling in Caenorhabditis elegans. Science 2010; 329:1647-50. [PMID: 20929849 PMCID: PMC3021133 DOI: 10.1126/science.1192020] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Population density-dependent dispersal is a well-characterized strategy of animal behavior in which dispersal rate increases when population density is higher. Caenorhabditis elegans shows positive chemotaxis to a set of odorants, but the chemotaxis switches from attraction to dispersal after prolonged exposure to the odorants. We show here that this plasticity of olfactory behavior is dependent on population density and that this regulation is mediated by pheromonal signaling. We show that a peptide, suppressor of NEP-2 (SNET-1), negatively regulates olfactory plasticity and that its expression is down-regulated by the pheromone. NEP-2, a homolog of the extracellular peptidase neprilysin, antagonizes SNET-1, and this function is essential for olfactory plasticity. These results suggest that population density information is transmitted through the external pheromone and endogenous peptide signaling to modulate chemotactic behavior.
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Affiliation(s)
- Koji Yamada
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Takaaki Hirotsu
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Department of Biology, Graduate School of Science, Kyushu University, Fukuoka, Japan
| | - Masahiro Matsuki
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Rebecca A Butcher
- Department of Biological Chemistry and Molecular Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Masahiro Tomioka
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Takeshi Ishihara
- Department of Biology, Graduate School of Science, Kyushu University, Fukuoka, Japan
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Hirofumi Kunitomo
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yuichi Iino
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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31
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Kim K, Sato K, Shibuya M, Zeiger DM, Butcher RA, Ragains JR, Clardy J, Touhara K, Sengupta P. Two chemoreceptors mediate developmental effects of dauer pheromone in C. elegans. Science 2009; 326:994-8. [PMID: 19797623 PMCID: PMC4448937 DOI: 10.1126/science.1176331] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Intraspecific chemical communication is mediated by signals called pheromones. Caenorhabditis elegans secretes a mixture of small molecules (collectively termed dauer pheromone) that regulates entry into the alternate dauer larval stage and also modulates adult behavior via as yet unknown receptors. Here, we identify two heterotrimeric GTP-binding protein (G protein)-coupled receptors (GPCRs) that mediate dauer formation in response to a subset of dauer pheromone components. The SRBC-64 and SRBC-66 GPCRs are members of the large Caenorhabditis-specific SRBC subfamily and are expressed in the ASK chemosensory neurons, which are required for pheromone-induced dauer formation. Expression of both, but not each receptor alone, confers pheromone-mediated effects on heterologous cells. Identification of dauer pheromone receptors will allow a better understanding of the signaling cascades that transduce the context-dependent effects of ecologically important chemical signals.
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Affiliation(s)
- Kyuhyung Kim
- Department of Biology and National Center for Behavioral Genomics Brandeis University, Waltham, MA 02454
| | - Koji Sato
- Department of Integrated Biosciences, University of Tokyo Chiba, Japan
| | - Mayumi Shibuya
- Department of Biology and National Center for Behavioral Genomics Brandeis University, Waltham, MA 02454
| | - Danna M. Zeiger
- Department of Biology and National Center for Behavioral Genomics Brandeis University, Waltham, MA 02454
| | - Rebecca A. Butcher
- Department of Biological Chemistry and Molecular Pharmacology Harvard Medical School, Boston, MA 02115
| | - Justin R. Ragains
- Department of Biological Chemistry and Molecular Pharmacology Harvard Medical School, Boston, MA 02115
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology Harvard Medical School, Boston, MA 02115
| | - Kazushige Touhara
- Department of Integrated Biosciences, University of Tokyo Chiba, Japan
| | - Piali Sengupta
- Department of Biology and National Center for Behavioral Genomics Brandeis University, Waltham, MA 02454
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Butcher RA, Ragains JR, Clardy J. An indole-containing dauer pheromone component with unusual dauer inhibitory activity at higher concentrations. Org Lett 2009; 11:3100-3. [PMID: 19545143 DOI: 10.1021/ol901011c] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In Caenorhabditis elegans, the dauer pheromone, which consists of a number of derivatives of the 3,6-dideoxysugar ascarylose, is the primary cue for entry into the stress-resistant, "nonaging" dauer larval stage. Here, using activity-guided fractionation and NMR-based structure elucidation, a structurally novel, indole-3-carboxyl-modified ascaroside is identified that promotes dauer formation at low nanomolar concentrations but inhibits dauer formation at higher concentrations.
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Affiliation(s)
- Rebecca A Butcher
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA
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33
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Macosko EZ, Pokala N, Feinberg EH, Chalasani SH, Butcher RA, Clardy J, Bargmann CI. A hub-and-spoke circuit drives pheromone attraction and social behaviour in C. elegans. Nature 2009; 458:1171-5. [PMID: 19349961 PMCID: PMC2760495 DOI: 10.1038/nature07886] [Citation(s) in RCA: 337] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2008] [Accepted: 02/11/2009] [Indexed: 11/29/2022]
Abstract
Innate social behaviors emerge from neuronal circuits that interpret sensory information based on an individual's own genotype, sex, and experience. The regulated aggregation behavior of C. elegans, a simple animal with only 302 neurons, is an attractive system to analyze these circuits. Wild social strains of the nematode Caenorhabditis elegans aggregate in the presence of specific sensory cues, but solitary strains do not1,2,3,4. Here we identify the RMG inter/motor neuron as the hub of a regulated circuit that controls aggregation and related behaviors. RMG is the central site of action of the neuropeptide receptor gene npr-1, which distinguishes solitary strains (high npr-1 activity) from wild social strains (low npr-1 activity); high RMG activity is essential for all aspects of social behavior. Anatomical gap junctions connect RMG to multiple classes of sensory neurons known to promote aggregation, and to ASK sensory neurons, which are implicated in male attraction to hermaphrodite pheromones5. We find that ASK neurons respond directly to pheromones, and that high RMG activity enhances ASK responses in social strains, causing hermaphrodite attraction to pheromones at concentrations that repel solitary hermaphrodites. The coordination of social behaviors by RMG suggests an anatomical hub-and-spoke model for sensory integration in aggregation, and points to functions for related circuit motifs in the C. elegans wiring diagram.
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Affiliation(s)
- Evan Z Macosko
- Howard Hughes Medical Institute, Laboratory of Neural Circuits and Behavior, The Rockefeller University, 1230 York Avenue, New York, New York 10065, USA
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34
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Abstract
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Sporulene, a C35-terpenoid hydrocarbon with an unusual pentacyclic structure, is produced by Bacillus subtilis during sporulation.
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Affiliation(s)
- Renee Kontnik
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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35
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Abstract
Gene overexpression can be used to investigate the biological pathways that are important in the response to a small molecule or other perturbation. To facilitate the use of gene overexpression in the study of small-molecule mechanisms, we developed a microarray-based protocol for monitoring the growth of a pool of yeast strains, each overexpressing a different protein. In this protocol, yeast harboring a set of approximately 3,900 galactose-inducible overexpression plasmids are grown in the absence or presence of a small molecule for multiple generations. The plasmids are then extracted from the two populations, processed and labeled in such a manner that their relative concentrations can be determined by competitive hybridization to a microarray. Although this protocol was developed for monitoring a specific set of overexpression plasmids, it could presumably be adapted to monitor yeast that have been transformed with any set of plasmids for which the gene inserts have been spotted, or otherwise arrayed, in a microarray format. This protocol can be completed in approximately 15 hours of hands-on time over the course of several days.
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Affiliation(s)
- Rebecca A Butcher
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
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36
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Butcher RA, Fujita M, Schroeder FC, Clardy J. Small-molecule pheromones that control dauer development in Caenorhabditis elegans. Nat Chem Biol 2007; 3:420-2. [PMID: 17558398 DOI: 10.1038/nchembio.2007.3] [Citation(s) in RCA: 250] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Accepted: 05/14/2007] [Indexed: 01/24/2023]
Abstract
In response to high population density or low food supply, the nematode Caenorhabditis elegans enters an alternative larval stage, known as the dauer, that can withstand adverse conditions for prolonged periods. C. elegans senses its population density through a small-molecule signal, traditionally called the dauer pheromone, that it secretes into its surroundings. Here we show that the dauer pheromone consists of several structurally related ascarosides-derivatives of the dideoxysugar ascarylose-and that two of these ascarosides (1 and 2) are roughly two orders of magnitude more potent at inducing dauer formation than a previously reported dauer pheromone component (3) and constitute a physiologically relevant signal. The identification of dauer pheromone components 1 and 2 will facilitate the identification of target receptors and downstream signaling proteins.
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Affiliation(s)
- Rebecca A Butcher
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Ave., Boston, Massachusetts 02115, USA
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37
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Butcher RA, Schroeder FC, Fischbach MA, Straight PD, Kolter R, Walsh CT, Clardy J. The identification of bacillaene, the product of the PksX megacomplex in Bacillus subtilis. Proc Natl Acad Sci U S A 2007; 104:1506-9. [PMID: 17234808 PMCID: PMC1785240 DOI: 10.1073/pnas.0610503104] [Citation(s) in RCA: 211] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The approximately 80-kb pksX gene cluster in Bacillus subtilis encodes an unusual hybrid polyketide/nonribosomal peptide synthase that has been linked to the production of the uncharacterized antibiotic bacillaene. Multiple copies of this synthase, each similar in size to the ribosome, assemble into a single organelle-like complex with a mass of tens to hundreds of megadaltons. The resource requirements of the assembled megacomplex suggest that bacillaene has an important biological role. By coupling a differential NMR spectroscopic technique with genetically manipulated strains of B. subtilis, we were able to characterize the structure of this unusual secondary metabolite, which could not be predicted by using bioinformatic analysis. We report that bacillaene is a linear molecule with two amide bonds: the first links an alpha-hydroxy carboxylic acid to a omega-amino carboxylic acid containing a conjugated hexaene, and the second links the hexaene-containing carboxylic acid to an (omega-1) amino carboxylic acid containing a conjugated triene. Knowledge of bacillaene's structure has enabled us to annotate the pksX gene cluster and should facilitate the study of bacillaene's biosynthesis as well as its biological role in B. subtilis.
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Affiliation(s)
| | | | | | - Paul D. Straight
- Microbiology and Molecular Genetics, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115
| | - Roberto Kolter
- Microbiology and Molecular Genetics, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115
| | - Christopher T. Walsh
- Departments of *Biological Chemistry and Molecular Pharmacology and
- To whom correspondence may be addressed. E-mail:
or
| | - Jon Clardy
- Departments of *Biological Chemistry and Molecular Pharmacology and
- To whom correspondence may be addressed. E-mail:
or
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38
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Butcher RA, Bhullar BS, Perlstein EO, Marsischky G, LaBaer J, Schreiber SL. Microarray-based method for monitoring yeast overexpression strains reveals small-molecule targets in TOR pathway. Nat Chem Biol 2006; 2:103-9. [PMID: 16415861 DOI: 10.1038/nchembio762] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Accepted: 12/20/2005] [Indexed: 01/16/2023]
Abstract
Identification of the cellular targets of small-molecule hits in phenotypic screens is a central challenge in the development of small molecules as biological tools and potential therapeutics. To facilitate the process of small-molecule target identification, we developed a global, microarray-based method for monitoring the growth of pools of yeast strains, each overexpressing a different protein, in the presence of small molecules. Specifically, the growth of Saccharomyces cerevisiae strains harboring approximately 3,900 different overexpression plasmids was monitored in the presence of rapamycin, which inhibits the target of rapamycin (TOR) proteins. TOR was successfully identified as a candidate rapamycin target, and many additional gene products were implicated in the TOR signaling pathway. We also characterized the mechanism of LY-83583, a small-molecule suppressor of rapamycin-induced growth inhibition. These data enabled functional links to be drawn between groups of genes implicated in the TOR pathway, identified several candidate targets for LY-83583, and suggested a role for mitochondrial respiration in mediating rapamycin sensitivity.
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Affiliation(s)
- Rebecca A Butcher
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
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Abstract
Transcriptional profiling with DNA microarrays can be used to measure the genome-wide transcriptional response to small molecules. Recent progress in the analysis of gene-expression data has relied on the generation of databases of profiles documenting the transcriptional effects of various compound treatments and genetic perturbations. A positive correlation between the transcriptional response induced by a novel small molecule and a database profile can provide insight into the molecule's mechanism. Transcriptional profiling can also be used to assess a small molecule's specificity for its target and to facilitate analysis of pathways downstream of the target.
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Affiliation(s)
- Rebecca A Butcher
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA
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40
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Butcher RA, Schreiber SL. Identification of Ald6p as the target of a class of small-molecule suppressors of FK506 and their use in network dissection. Proc Natl Acad Sci U S A 2004; 101:7868-73. [PMID: 15146068 PMCID: PMC419523 DOI: 10.1073/pnas.0402317101] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
FK506 inhibits the Ca2+/calmodulin-dependent protein phosphatase calcineurin, which plays a critical role in yeast subjected to salt stress. A chemical genetic screen for small molecules that suppress growth inhibition by high NaCl plus FK506 identified a structurally related class of suppressors of FK506 (SFKs) named SFKs 2-4. To identify possible protein targets for these small molecules, a genome-wide screen of approximately 4,700 haploid yeast deletion strains was undertaken for strains showing resistance to high NaCl plus FK506. This screen yielded a number of genes not previously implicated in salt stress, including ALD6, which encodes an NADP(+)-dependent aldehyde dehydrogenase, and UTR1, which encodes an NAD+ kinase. Transcriptional profiling of yeast treated with SFK2 indicated that the SFKs target the Ald6p pathway. In addition, screening of the deletion strains for hypersensitivity to SFK2 yielded ZWF1, encoding glucose-6-phosphate dehydrogenase, which has been shown to play an overlapping role with Ald6p in NADPH production. Furthermore, the SFKs inhibited the activity of Ald6p in vitro. Having established that the SFKs target Ald6p, they were used as tools to implicate systematically other gene products in the Ald6p pathway, including Utr1p, which may function by supplying Ald6p with its NADP+ cofactor. Furthermore, growth improvement by the SFKs on high NaCl plus FK506 was shown to require GPD1, which encodes an NADH-dependent glycerol-3-phosphate dehydrogenase that is important for the production of glycerol in response to osmotic stress.
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Affiliation(s)
- Rebecca A Butcher
- Department of Chemistry and Chemical Biology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
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41
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Butcher RA, Schreiber SL. A small molecule suppressor of FK506 that targets the mitochondria and modulates ionic balance in Saccharomyces cerevisiae. Chem Biol 2003; 10:521-31. [PMID: 12837385 DOI: 10.1016/s1074-5521(03)00108-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
FK506 inhibits the evolutionarily conserved, Ca(2+)-dependent phosphatase calcineurin, which in yeast is essential for growth during sodium stress. We undertook a chemical genetic modifier screen to identify small molecules that suppress the ability of FK506 to inhibit yeast growth in high NaCl. One of these small molecule suppressors, SFK1 (suppressor of FK506 1), causes a mitochondrially induced death in low salt, concomitant with the release of reactive oxygen species. Biochemically, SFK1 interacts with Por1p, a channel protein in the outer mitochondrial membrane, suggesting that SFK1 interacts with the mitochondria directly. A genome-wide screen of yeast deletion strains for hypersensitivity to SFK1 yielded several strains with impaired mitochondrial function, as well as several with reduced sodium tolerance. Our data link ionic balance to mitochondrial function and suggest a role for calcineurin in mediating this signaling network.
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Affiliation(s)
- Rebecca A Butcher
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
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Haggarty SJ, Koeller KM, Wong JC, Butcher RA, Schreiber SL. Multidimensional chemical genetic analysis of diversity-oriented synthesis-derived deacetylase inhibitors using cell-based assays. Chem Biol 2003; 10:383-96. [PMID: 12770821 DOI: 10.1016/s1074-5521(03)00095-4] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Systematic chemical genetics aims to explore the space representing interactions between small molecules and biological systems. Beyond measuring binding interactions and enzyme inhibition, measuring changes in the activity of proteins in intact signaling networks is necessary. Toward this end, we are partitioning chemical space into regions with different biological activities using a panel of cell-based assays and small molecule "chemical genetic modifiers." Herein, we report on the use of this methodology for the discovery of 617 small molecule inhibitors of histone deacetylases from a multidimensional screen of an encoded, diversity-oriented synthesis library. Following decoding of chemical tags and resynthesis, we demonstrate the selectivity of one inhibitory molecule (tubacin) toward alpha-tubulin deacetylation and another (histacin) toward histone deacetylation. These small molecules will facilitate dissecting the role of acetylation in a variety of cell biological processes.
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Affiliation(s)
- Stephen J Haggarty
- Departments of Molecular and Cellular Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
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