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Salem H, Bauer E, Kirsch R, Berasategui A, Cripps M, Weiss B, Koga R, Fukumori K, Vogel H, Fukatsu T, Kaltenpoth M. Drastic Genome Reduction in an Herbivore's Pectinolytic Symbiont. Cell 2017; 171:1520-1531.e13. [PMID: 29153832 DOI: 10.1016/j.cell.2017.10.029] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 10/10/2017] [Accepted: 10/17/2017] [Indexed: 02/07/2023]
Abstract
Pectin, an integral component of the plant cell wall, is a recalcitrant substrate against enzymatic challenges by most animals. In characterizing the source of a leaf beetle's (Cassida rubiginosa) pectin-degrading phenotype, we demonstrate its dependency on an extracellular bacterium housed in specialized organs connected to the foregut. Despite possessing the smallest genome (0.27 Mb) of any organism not subsisting within a host cell, the symbiont nonetheless retained a functional pectinolytic metabolism targeting the polysaccharide's two most abundant classes: homogalacturonan and rhamnogalacturonan I. Comparative transcriptomics revealed pectinase expression to be enriched in the symbiotic organs, consistent with enzymatic buildup in these structures following immunostaining with pectinase-targeting antibodies. Symbiont elimination results in a drastically reduced host survivorship and a diminished capacity to degrade pectin. Collectively, our findings highlight symbiosis as a strategy for an herbivore to metabolize one of nature's most complex polysaccharides and a universal component of plant tissues.
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Affiliation(s)
- Hassan Salem
- Insect Symbiosis Research Group, Max Planck Institute for Chemical Ecology, Jena 07745, Germany; Department of Biology, Emory University, Atlanta, GA 30320, USA.
| | - Eugen Bauer
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette 4365, Luxembourg
| | - Roy Kirsch
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany
| | - Aileen Berasategui
- Insect Symbiosis Research Group, Max Planck Institute for Chemical Ecology, Jena 07745, Germany; Department of Biology, Emory University, Atlanta, GA 30320, USA; Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena 07745, Germany
| | - Michael Cripps
- AgResearch, Lincoln Research Centre, Lincoln 7608, New Zealand
| | - Benjamin Weiss
- Insect Symbiosis Research Group, Max Planck Institute for Chemical Ecology, Jena 07745, Germany; Department of Evolutionary Ecology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Ryuichi Koga
- National Institute for Advanced Industrial Science and Technology, Tsukuba 305-8566, Japan
| | - Kayoko Fukumori
- National Institute for Advanced Industrial Science and Technology, Tsukuba 305-8566, Japan
| | - Heiko Vogel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany
| | - Takema Fukatsu
- National Institute for Advanced Industrial Science and Technology, Tsukuba 305-8566, Japan
| | - Martin Kaltenpoth
- Insect Symbiosis Research Group, Max Planck Institute for Chemical Ecology, Jena 07745, Germany; Department of Evolutionary Ecology, Johannes Gutenberg University, Mainz 55128, Germany
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Owen J, Kent L, Ralet MC, Cameron R, Williams M. A tale of two pectins: Diverse fine structures can result from identical processive PME treatments on similar high DM substrates. Carbohydr Polym 2017; 168:365-373. [DOI: 10.1016/j.carbpol.2017.03.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/06/2017] [Accepted: 03/11/2017] [Indexed: 10/20/2022]
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Wybouw N, Pauchet Y, Heckel DG, Van Leeuwen T. Horizontal Gene Transfer Contributes to the Evolution of Arthropod Herbivory. Genome Biol Evol 2016; 8:1785-801. [PMID: 27307274 PMCID: PMC4943190 DOI: 10.1093/gbe/evw119] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2016] [Indexed: 01/07/2023] Open
Abstract
Within animals, evolutionary transition toward herbivory is severely limited by the hostile characteristics of plants. Arthropods have nonetheless counteracted many nutritional and defensive barriers imposed by plants and are currently considered as the most successful animal herbivores in terrestrial ecosystems. We gather a body of evidence showing that genomes of various plant feeding insects and mites possess genes whose presence can only be explained by horizontal gene transfer (HGT). HGT is the asexual transmission of genetic information between reproductively isolated species. Although HGT is known to have great adaptive significance in prokaryotes, its impact on eukaryotic evolution remains obscure. Here, we show that laterally transferred genes into arthropods underpin many adaptations to phytophagy, including efficient assimilation and detoxification of plant produced metabolites. Horizontally acquired genes and the traits they encode often functionally diversify within arthropod recipients, enabling the colonization of more host plant species and organs. We demonstrate that HGT can drive metazoan evolution by uncovering its prominent role in the adaptations of arthropods to exploit plants.
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Affiliation(s)
- Nicky Wybouw
- Department of Evolutionary Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
| | - Yannick Pauchet
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - David G Heckel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Thomas Van Leeuwen
- Department of Evolutionary Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
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Kirsch R, Heckel DG, Pauchet Y. How the rice weevil breaks down the pectin network: Enzymatic synergism and sub-functionalization. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 71:72-82. [PMID: 26899322 DOI: 10.1016/j.ibmb.2016.02.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/12/2016] [Accepted: 02/14/2016] [Indexed: 05/19/2023]
Abstract
Pectin is the most complex polysaccharide in nature and highly abundant in plant cell walls and middle lamellae, where it functions in plant growth and development. Phytopathogens utilize plant pectin as an energy source through enzyme-mediated degradation. These pectolytic enzymes include polygalacturonases (PGs) of the GH28 family and pectin methylesterases (PMEs) of the CE8 family. Recently, PGs were also identified in herbivorous insects of the distantly related plant bug, stick insect and Phytophaga beetle lineages. Unlike all other insects, weevils possess PMEs in addition to PGs. To investigate pectin digestion in insects and the role of PMEs in weevils, all PME and PG family members of the rice weevil Sitophilus oryzae were heterologously expressed and functionally characterized. Enzymatically active and inactive PG and PME family members were identified. The loss of activity can be explained by a lack of substrate binding correlating with substitutions of functionally important amino acid residues. We found subfunctionalization in both enzyme families, supported by expression pattern and substrate specificities as well as evidence for synergistic pectin breakdown. Our data suggest that the rice weevil might be able to use pectin as an energy source, and illustrates the potential of both PG and PME enzyme families to functionally diversify after horizontal gene transfer.
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Affiliation(s)
- Roy Kirsch
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, Jena, 07745, Germany.
| | - David G Heckel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, Jena, 07745, Germany
| | - Yannick Pauchet
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, Jena, 07745, Germany.
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5
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Kent LM, Loo TS, Melton LD, Mercadante D, Williams MAK, Jameson GB. Structure and Properties of a Non-processive, Salt-requiring, and Acidophilic Pectin Methylesterase from Aspergillus niger Provide Insights into the Key Determinants of Processivity Control. J Biol Chem 2015; 291:1289-306. [PMID: 26567911 DOI: 10.1074/jbc.m115.673152] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Indexed: 12/17/2022] Open
Abstract
Many pectin methylesterases (PMEs) are expressed in plants to modify plant cell-wall pectins for various physiological roles. These pectins are also attacked by PMEs from phytopathogens and phytophagous insects. The de-methylesterification by PMEs of the O6-methyl ester groups of the homogalacturonan component of pectin, exposing galacturonic acids, can occur processively or non-processively, respectively, describing sequential versus single de-methylesterification events occurring before enzyme-substrate dissociation. The high resolution x-ray structures of a PME from Aspergillus niger in deglycosylated and Asn-linked N-acetylglucosamine-stub forms reveal a 10⅔-turn parallel β-helix (similar to but with less extensive loops than bacterial, plant, and insect PMEs). Capillary electrophoresis shows that this PME is non-processive, halophilic, and acidophilic. Molecular dynamics simulations and electrostatic potential calculations reveal very different behavior and properties compared with processive PMEs. Specifically, uncorrelated rotations are observed about the glycosidic bonds of a partially de-methyl-esterified decasaccharide model substrate, in sharp contrast to the correlated rotations of processive PMEs, and the substrate-binding groove is negatively not positively charged.
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Affiliation(s)
- Lisa M Kent
- From Riddet Institute and Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Trevor S Loo
- From Riddet Institute and Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Laurence D Melton
- From Riddet Institute and School of Chemical Sciences, University of Auckland, Auckland 1142, New Zealand
| | - Davide Mercadante
- From Riddet Institute and Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg, 69118 Heidelberg, Germany, and
| | - Martin A K Williams
- From Riddet Institute and Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand, MacDiarmid Institute for Advanced Materials and Nanotechnology, Palmerston North 4442, New Zealand
| | - Geoffrey B Jameson
- From Riddet Institute and Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand, MacDiarmid Institute for Advanced Materials and Nanotechnology, Palmerston North 4442, New Zealand
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Evangelista DE, de Paula FFP, Rodrigues A, Henrique-Silva F. Pectinases from Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae): putative accessory digestive enzymes. JOURNAL OF INSECT SCIENCE (ONLINE) 2015; 15:168. [PMID: 25673050 PMCID: PMC4535137 DOI: 10.1093/jisesa/ieu168] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 11/24/2014] [Indexed: 05/29/2023]
Abstract
The cell wall in plants offers protection against invading organisms and is mainly composed of the polysaccharides pectin, cellulose, and hemicellulose, which can be degraded by plant cell wall degrading enzymes (PCWDEs). Such enzymes are often synthesized by free living microorganisms or endosymbionts that live in the gut of some animals, including certain phytophagous insects. Thus, the ability of an insect to degrade the cell wall was once thought to be related to endosymbiont enzyme activity. However, recent studies have revealed that some phytophagous insects are able to synthesize their own PCWDEs by endogenous genes, although questions regarding the origin of these genes remain unclear. This study describes two pectinases from the sugarcane weevil, Sphenophorus levis Vaurie, 1978 (Sl-pectinases), which is considered one of the most serious agricultural pests in Brazil. Two cDNA sequences identified in a cDNA library of the insect larvae coding for a pectin methylesterase (PME) and an endo-polygalacturonase (endo-PG)-denominated Sl-PME and Sl-endoPG, respectively-were isolated and characterized. The quantitative real-time reverse transcriptase polymerase chain reaction expression profile for both Sl-pectinases showed mRNA production mainly in the insect feeding stages and exclusively in midgut tissue of the larvae. This analysis, together Western blotting data, suggests that Sl-pectinases have a digestive role. Phylogenetic analyses indicate that Sl-PME and Sl-endoPG sequences are closely related to bacteria and fungi, respectively. Moreover, the partial genomic sequences of the pectinases were amplified from insect fat body DNA, which was certified to be free of endosymbiotic DNA. The analysis of genomic sequences revealed the existence of two small introns with 53 and 166 bp in Sl-endoPG, which is similar to the common pattern in fungal introns. In contrast, no intron was identified in the Sl-PME genomic sequence, as generally observed in bacteria. These data support the theory of horizontal gene transfer proposed for the origin of insect pectinases, reinforcing the acquisition of PME genes from bacteria and endo-PG genes from fungi.
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Affiliation(s)
- Danilo Elton Evangelista
- Laboratory of Molecular Biology, Department of Genetics and Evolution, Federal University of São Carlos, Road Washington Luis Km 235, São Carlos, 13565-905 São Paulo, Brazil
| | - Fernando Fonseca Pereira de Paula
- Laboratory of Molecular Biology, Department of Genetics and Evolution, Federal University of São Carlos, Road Washington Luis Km 235, São Carlos, 13565-905 São Paulo, Brazil
| | - André Rodrigues
- Department of Biochemistry and Microbiology, UNESP-São Paulo State University, Av. 24A, n. 1515-Bela Vista, Rio Claro, São Paulo 13506-900, Brazil
| | - Flávio Henrique-Silva
- Laboratory of Molecular Biology, Department of Genetics and Evolution, Federal University of São Carlos, Road Washington Luis Km 235, São Carlos, 13565-905 São Paulo, Brazil
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7
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Teller DC, Behnke CA, Pappan K, Shen Z, Reese JC, Reeck GR, Stenkamp RE. The structure of rice weevil pectin methylesterase. Acta Crystallogr F Struct Biol Commun 2014; 70:1480-4. [PMID: 25372813 PMCID: PMC4231848 DOI: 10.1107/s2053230x14020433] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 09/11/2014] [Indexed: 11/10/2022] Open
Abstract
Rice weevils (Sitophilus oryzae) use a pectin methylesterase (EC 3.1.1.11), along with other enzymes, to digest cell walls in cereal grains. The enzyme is a right-handed β-helix protein, but is circularly permuted relative to plant and bacterial pectin methylesterases, as shown by the crystal structure determination reported here. This is the first structure of an animal pectin methylesterase. Diffraction data were collected to 1.8 Å resolution some time ago for this crystal form, but structure solution required the use of molecular-replacement techniques that have been developed and similar structures that have been deposited in the last 15 years. Comparison of the structure of the rice weevil pectin methylesterase with that from Dickeya dandantii (formerly Erwinia chrysanthemi) indicates that the reaction mechanisms are the same for the insect, plant and bacterial pectin methylesterases. The similarity of the structure of the rice weevil enzyme to the Escherichia coli lipoprotein YbhC suggests that the evolutionary origin of the rice weevil enzyme was a bacterial lipoprotein, the gene for which was transferred to a primitive ancestor of modern weevils and other Curculionidae. Structural comparison of the rice weevil pectin methylesterase with plant and bacterial enzymes demonstrates that the rice weevil protein is circularly permuted relative to the plant and bacterial molecules.
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Affiliation(s)
- David C. Teller
- Department of Biochemistry, University of Washington, Box 357430, Seattle, WA 98195-7430, USA
- Biomolecular Structure Center, University of Washington, Box 357742, Seattle, WA 98195-7742, USA
| | - Craig A. Behnke
- Department of Biochemistry, University of Washington, Box 357430, Seattle, WA 98195-7430, USA
| | - Kirk Pappan
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Zicheng Shen
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - John C. Reese
- Department of Entomology, Kansas State University, Manhattan, KS 66506, USA
| | - Gerald R. Reeck
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Ronald E. Stenkamp
- Department of Biochemistry, University of Washington, Box 357430, Seattle, WA 98195-7430, USA
- Biomolecular Structure Center, University of Washington, Box 357742, Seattle, WA 98195-7742, USA
- Department of Biological Structure, University of Washington, Box 357420, Seattle, WA 98195-7420, USA
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8
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Sénéchal F, Wattier C, Rustérucci C, Pelloux J. Homogalacturonan-modifying enzymes: structure, expression, and roles in plants. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:5125-60. [PMID: 25056773 PMCID: PMC4400535 DOI: 10.1093/jxb/eru272] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 05/20/2014] [Accepted: 05/22/2014] [Indexed: 05/18/2023]
Abstract
Understanding the changes affecting the plant cell wall is a key element in addressing its functional role in plant growth and in the response to stress. Pectins, which are the main constituents of the primary cell wall in dicot species, play a central role in the control of cellular adhesion and thereby of the rheological properties of the wall. This is likely to be a major determinant of plant growth. How the discrete changes in pectin structure are mediated is thus a key issue in our understanding of plant development and plant responses to changes in the environment. In particular, understanding the remodelling of homogalacturonan (HG), the most abundant pectic polymer, by specific enzymes is a current challenge in addressing its fundamental role. HG, a polymer that can be methylesterified or acetylated, can be modified by HGMEs (HG-modifying enzymes) which all belong to large multigenic families in all species sequenced to date. In particular, both the degrees of substitution (methylesterification and/or acetylation) and polymerization can be controlled by specific enzymes such as pectin methylesterases (PMEs), pectin acetylesterases (PAEs), polygalacturonases (PGs), or pectate lyases-like (PLLs). Major advances in the biochemical and functional characterization of these enzymes have been made over the last 10 years. This review aims to provide a comprehensive, up to date summary of the recent data concerning the structure, regulation, and function of these fascinating enzymes in plant development and in response to biotic stresses.
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Affiliation(s)
- Fabien Sénéchal
- EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France
| | - Christopher Wattier
- EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France
| | - Christine Rustérucci
- EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France
| | - Jérôme Pelloux
- EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France
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Insect-derived enzymes: a treasure for industrial biotechnology and food biotechnology. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2014. [PMID: 23881056 DOI: 10.1007/10_2013_204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2023]
Abstract
Insects are the most diverse group of organisms on earth, colonizing almost every ecological niche of the planet. To survive in various and sometimes extreme habitats, insects have established diverse biological and chemical systems. Core components of these systems are enzymes that enable the insects to feed on diverse nutrient sources. The enzymes are produced by either the insects themselves (homologous) or by symbiotic organisms located in the insects' bodies or in their nests (heterologous). The use of these insect-associated enzymes for applications in the fields of food biotechnology and industrial (white) biotechnology is gaining more and more interest. Prominent examples of insect-derived enzymes include peptidases, amylases, lipases, and β-D-glucosidases. Highly potent peptidases for the degradation of gluten, a storage protein that can cause intestinal disorders, may be received from grain pests. Several insects, such as bark and ambrosia beetles and termites, are able to feed on wood. In the field of white biotechnology, their cellulolytic enzyme systems of mainly endo-1,4-β-D-glucanases and β-D-glucosidases can be employed for saccharification of the most prominent polymer on earth-cellulose.
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Pauchet Y, Saski CA, Feltus FA, Luyten I, Quesneville H, Heckel DG. Studying the organization of genes encoding plant cell wall degrading enzymes in Chrysomela tremula provides insights into a leaf beetle genome. INSECT MOLECULAR BIOLOGY 2014; 23:286-300. [PMID: 24456018 DOI: 10.1111/imb.12081] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The ability of herbivorous beetles from the superfamilies Chrysomeloidea and Curculionoidea to degrade plant cell wall polysaccharides has only recently begun to be appreciated. The presence of plant cell wall degrading enzymes (PCWDEs) in the beetle's digestive tract makes this degradation possible. Sequences encoding these beetle-derived PCWDEs were originally identified from transcriptomes and strikingly resemble those of saprophytic and phytopathogenic microorganisms, raising questions about their origin; e.g. are they insect- or microorganism-derived? To demonstrate unambiguously that the genes encoding PCWDEs found in beetle transcriptomes are indeed of insect origin, we generated a bacterial artificial chromosome library from the genome of the leaf beetle Chrysomela tremula, containing 18 432 clones with an average size of 143 kb. After hybridizing this library with probes derived from 12 C. tremula PCWDE-encoding genes and sequencing the positive clones, we demonstrated that the latter genes are encoded by the insect's genome and are surrounded by genes possessing orthologues in the genome of Tribolium castaneum as well as in three other beetle genomes. Our analyses showed that although the level of overall synteny between C. tremula and T. castaneum seems high, the degree of microsynteny between both species is relatively low, in contrast to the more closely related Colorado potato beetle.
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Affiliation(s)
- Y Pauchet
- Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
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11
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Jiang X, Chen P, Yin M, Yang Q. Constitutive expression, purification and characterisation of pectin methylesterase from Aspergillus niger in Pichia pastoris for potential application in the fruit juice industry. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2013; 93:375-381. [PMID: 22806239 DOI: 10.1002/jsfa.5771] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Revised: 03/15/2012] [Accepted: 05/17/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Pectin methylesterase (PME) catalyses the hydrolysis of the methyl ester of pectin, yielding free carboxyl groups and methanol. PME is widely used in the food, cosmetic and pharmaceutical industries. RESULTS PME from Aspergillus niger was constitutively expressed to a high level in the yeast Pichia pastoris. The recombinant PME was purified by a combination of ammonium sulfate fractionation and ion exchange chromatography, giving an overall yield of 28.0%. It appeared as a single band in sodium dodecyl sulfate polyacrylamide gel electrophoresis, with a molecular mass of about 45 kDa. Optimal activity of the enzyme occurred at a temperature of 50 °C and a pH of 4.7. The K(m), V(max) and k(cat) values of the enzyme with respect to pectin were 8.6 mmol L⁻¹ [Formula: See Text], 1.376 mmol min⁻¹ mg⁻¹ and 8.26 × 10² s⁻¹ respectively. Cations such as K⁺, Mg²⁺, Ni²⁺, Mn²⁺ and Co²⁺ slightly inhibited its activity, whereas Na⁺ had no effect. CONCLUSION PME from A. niger was constitutively expressed to a high level in P. pastoris without methanol induction. The recombinant PME was purified and characterised and shown to be a good candidate for potential application in the fruit juice industry.
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Affiliation(s)
- Xiuping Jiang
- Department of Bioscience and Biotechnology, Dalian University of Technology, No. 2 Linggong Road, Dalian 116024, China
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12
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Kirsch R, Wielsch N, Vogel H, Svatoš A, Heckel DG, Pauchet Y. Combining proteomics and transcriptome sequencing to identify active plant-cell-wall-degrading enzymes in a leaf beetle. BMC Genomics 2012; 13:587. [PMID: 23116131 PMCID: PMC3505185 DOI: 10.1186/1471-2164-13-587] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/29/2012] [Indexed: 11/24/2022] Open
Abstract
Background The primary plant cell wall is a complex mixture of polysaccharides and proteins encasing living plant cells. Among these polysaccharides, cellulose is the most abundant and useful biopolymer present on earth. These polysaccharides also represent a rich source of energy for organisms which have evolved the ability to degrade them. A growing body of evidence suggests that phytophagous beetles, mainly species from the superfamilies Chrysomeloidea and Curculionoidea, possess endogenous genes encoding complex and diverse families of so-called plant cell wall degrading enzymes (PCWDEs). The presence of these genes in phytophagous beetles may have been a key element in their success as herbivores. Here, we combined a proteomics approach and transcriptome sequencing to identify PCWDEs present in larval gut contents of the mustard leaf beetle, Phaedon cochleariae. Results Using a two-dimensional proteomics approach, we recovered 11 protein bands, isolated using activity assays targeting cellulose-, pectin- and xylan-degrading enzymes. After mass spectrometry analyses, a total of 13 proteins putatively responsible for degrading plant cell wall polysaccharides were identified; these proteins belong to three glycoside hydrolase (GH) families: GH11 (xylanases), GH28 (polygalacturonases or pectinases), and GH45 (β-1,4-glucanases or cellulases). Additionally, highly stable and proteolysis-resistant host plant-derived proteins from various pathogenesis-related protein (PRs) families as well as polygalacturonase-inhibiting proteins (PGIPs) were also identified from the gut contents proteome. In parallel, transcriptome sequencing revealed the presence of at least 19 putative PCWDE transcripts encoded by the P. cochleariae genome. All of these were specifically expressed in the insect gut rather than the rest of the body, and in adults as well as larvae. The discrepancy observed in the number of putative PCWDEs between transcriptome and proteome analyses could be partially explained by differences in transcriptional level. Conclusions Combining proteome and transcriptome sequencing analyses proved to be a powerful tool for the discovery of active PCWDEs in a non-model species. Our data represent the starting point of an in-depth functional and evolutionary characterization of PCWDE gene families in phytophagous beetles and their contribution to the adaptation of these highly successful herbivores to their host plants.
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Affiliation(s)
- Roy Kirsch
- Entomology Department, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745 Jena, Germany
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13
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Chen SJ, Lu F, Cheng JA, Jiang MX, Way MO. Identification and biological role of the endosymbionts Wolbachia in rice water weevil (Coleoptera: Curculionidae). ENVIRONMENTAL ENTOMOLOGY 2012; 41:469-477. [PMID: 22732604 DOI: 10.1603/en11195] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Wolbachia spp. are obligate intracellular bacteria present in reproductive tissues of many arthropod species. Wolbachia infection status and roles in host reproduction were studied in the rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera, Curculionidae), an introduced species in China. We examined Wolbachia infection status in five populations in China where it reproduces parthenogenetically, and one native population in Southeast Texas, where it reproduces bisexually. All populations were infected by Wolbachia, and all specimens in each population were infected by Wolbachia of a single strain. Phylogenetic analyses based on multilocus sequence typing system indicated that Wolbachia in non-native L. oryzophilus weevils diverges evidently from those in native weevils. After treatments with tetracycline, parthenogenetic weevils reduced the fecundity significantly and eggs were not viable. Our results suggest that Wolbachia are necessary for oocyte production in L oryzophilus.
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Affiliation(s)
- Shu-Juan Chen
- Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, 310058 Hangzhou, China
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Salavatifar M, Amin S, Jahromi ZM, Rasgoo N, Rastgoo N, Arbabi M. Green fluorescent-conjugated anti-CEA single chain antibody for the detection of CEA-positive cancer cells. Hybridoma (Larchmt) 2011; 30:229-38. [PMID: 21707357 DOI: 10.1089/hyb.2011.0009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
According to World Health Organization (WHO), cancer is a leading cause of death worldwide, accounting for 7.4 million deaths (around 13% of all deaths) in 2004. Monoclonal/recombinant antibodies, which specifically target clinical biomarkers of disease, have increasingly been applied as powerful tools in cancer imaging and therapy, a fact that is highlighted by some nine FDA-approved monoclonal antibodies (MAbs) or their immunoconjugates (as of December 2008) for use in cancer treatment. In this study, five monoclonal antibodies (MAbs) were generated and characterized against carcinoembryonic antigen (CEA), which is widely used clinically as both a blood and tissue tumor marker of epithelial malignancy. Variable domains (VH and VL) of one the stable MAbs with highest affinity were PCR-amplified and assembled as single-chain antibody fragment (scFv). Following the cloning and expression of scFv antibody fragments in Escherichia coli, the functional binding and specificity of the recombinant antibody were confirmed by ELISA. To develop a direct in vitro detection of CEA-positive cancer cells, scFv DNA was genetically fused to enhanced green fluorescent protein (EGFP) gene and expressed in bacteria. The chimeric fluorescent protein is able to specifically detect CEA-positive cell lines; no cross-reactivity was observed with a negative control cell line. This strategy will likely allow the establishment of a rapid, single-step detection assay of CEA, which is considered to be one of the best predictors of malignancy among all other tumor markers.
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Leaf-cutting ant fungi produce cell wall degrading pectinase complexes reminiscent of phytopathogenic fungi. BMC Biol 2010; 8:156. [PMID: 21194476 PMCID: PMC3022778 DOI: 10.1186/1741-7007-8-156] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 12/31/2010] [Indexed: 11/21/2022] Open
Abstract
Background Leaf-cutting (attine) ants use their own fecal material to manure fungus gardens, which consist of leaf material overgrown by hyphal threads of the basidiomycete fungus Leucocoprinus gongylophorus that lives in symbiosis with the ants. Previous studies have suggested that the fecal droplets contain proteins that are produced by the fungal symbiont to pass unharmed through the digestive system of the ants, so they can enhance new fungus garden growth. Results We tested this hypothesis by using proteomics methods to determine the gene sequences of fecal proteins in Acromyrmex echinatior leaf-cutting ants. Seven (21%) of the 33 identified proteins were pectinolytic enzymes that originated from the fungal symbiont and which were still active in the fecal droplets produced by the ants. We show that these enzymes are found in the fecal material only when the ants had access to fungus garden food, and we used quantitative polymerase chain reaction analysis to show that the expression of six of these enzyme genes was substantially upregulated in the fungal gongylidia. These unique structures serve as food for the ants and are produced only by the evolutionarily advanced garden symbionts of higher attine ants, but not by the fungi reared by the basal lineages of this ant clade. Conclusions Pectinolytic enzymes produced in the gongylidia of the fungal symbiont are ingested but not digested by Acromyrmex leaf-cutting ants so that they end up in the fecal fluid and become mixed with new garden substrate. Substantial quantities of pectinolytic enzymes are typically found in pathogenic fungi that attack live plant tissue, where they are known to breach the cell walls to allow the fungal mycelium access to the cell contents. As the leaf-cutting ant symbionts are derived from fungal clades that decompose dead plant material, our results suggest that their pectinolytic enzymes represent secondarily evolved adaptations that are convergent to those normally found in phytopathogens.
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Diversity of beetle genes encoding novel plant cell wall degrading enzymes. PLoS One 2010; 5:e15635. [PMID: 21179425 PMCID: PMC3003705 DOI: 10.1371/journal.pone.0015635] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2010] [Accepted: 11/18/2010] [Indexed: 11/19/2022] Open
Abstract
Plant cell walls are a heterogeneous mixture of polysaccharides and proteins that require a range of different enzymes to degrade them. Plant cell walls are also the primary source of cellulose, the most abundant and useful biopolymer on the planet. Plant cell wall degrading enzymes (PCWDEs) are therefore important in a wide range of biotechnological processes from the production of biofuels and food to waste processing. However, despite the fact that the last common ancestor of all deuterostomes was inferred to be able to digest, or even synthesize, cellulose using endogenous genes, all model insects whose complete genomes have been sequenced lack genes encoding such enzymes. To establish if the apparent "disappearance" of PCWDEs from insects is simply a sampling problem, we used 454 mediated pyrosequencing to scan the gut transcriptomes of beetles that feed on a variety of plant derived diets. By sequencing the transcriptome of five beetles, and surveying publicly available ESTs, we describe 167 new beetle PCWDEs belonging to eight different enzyme families. This survey proves that these enzymes are not only present in non-model insects but that the multigene families that encode them are apparently undergoing complex birth-death dynamics. This reinforces the observation that insects themselves, and not just their microbial symbionts, are a rich source of PCWDEs. Further it emphasises that the apparent absence of genes encoding PCWDEs from model organisms is indeed simply a sampling artefact. Given the huge diversity of beetles alive today, and the diversity of their lifestyles and diets, we predict that beetle guts will emerge as an important new source of enzymes for use in biotechnology.
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