scholarly journals Spatial separation of the cyanogenic β-glucosidase ZfBGD2 and cyanogenic glucosides in the haemolymph of Zygaena larvae facilitates cyanide release

2017 ◽  
Vol 4 (6) ◽  
pp. 170262 ◽  
Author(s):  
Stefan Pentzold ◽  
Mikael Kryger Jensen ◽  
Annemarie Matthes ◽  
Carl Erik Olsen ◽  
Bent Larsen Petersen ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Insect Cells ◽  
Phylogenetic Analyses ◽  
Spatial Separation ◽  
Low Molecular Weight ◽  
Proteomic Profiling ◽  
Cyanogenic Glucosides ◽  
Two Component System ◽  
Cyanogenic Plants ◽  
Two Kingdoms

Low molecular weight compounds are typically used by insects and plants for defence against predators. They are often stored as inactive β-glucosides and kept separate from activating β-glucosidases. When the two components are mixed, the β-glucosides are hydrolysed releasing toxic aglucones. Cyanogenic plants contain cyanogenic glucosides and release hydrogen cyanide due to such a well-characterized two-component system. Some arthropods are also cyanogenic, but comparatively little is known about their system. Here, we identify a specific β-glucosidase ( ZfBGD2) involved in cyanogenesis from larvae of Zygaena filipendulae (Lepidoptera, Zygaenidae), and analyse the spatial organization of cyanide release in this specialized insect. High levels of ZfBGD2 mRNA and protein were found in haemocytes by transcriptomic and proteomic profiling. Heterologous expression in insect cells showed that ZfBGD2 hydrolyses linamarin and lotaustralin, the two cyanogenic glucosides present in Z. filipendulae . Linamarin and lotaustralin as well as cyanide release were found exclusively in the haemoplasma. Phylogenetic analyses revealed that ZfBGD2 clusters with other insect β-glucosidases, and correspondingly, the ability to hydrolyse cyanogenic glucosides catalysed by a specific β-glucosidase evolved convergently in insects and plants. The spatial separation of the β-glucosidase ZfBGD2 and its cyanogenic substrates within the haemolymph provides the basis for cyanide release in Z. filipendulae . This spatial separation is similar to the compartmentalization of the two components found in cyanogenic plant species, and illustrates one similarity in cyanide-based defence in these two kingdoms of life.

scholarly journals Computational analysis of 1,3-propanediol operon transcriptional regulators: Insights into Clostridium sp. glycerol metabolism regulation

2014 ◽  
Vol 20 (1) ◽  
pp. 129 ◽  
Author(s):  
Carlos Eduardo Barragan ◽  
Andrés Julián Gutiérrez-Escobar ◽  
Dolly Montoya Castaño
Keyword(s):  
Transcriptional Activity ◽  
Phylogenetic Analyses ◽  
Glycerol Metabolism ◽  
Two Component System ◽  
Native Strain ◽  
Conserved Residues ◽  
Metabolism Regulation ◽  
Regulator Genes ◽  
Signal Transduction Systems

We designed a strategy for the sequencing and bioinformatical characterization of the 1,3-propanediol operon regulator genes from the Colombian Clostridium sp. strain IBUN13A, which is taxonomically related to Clostridium butyricum;. Three genes are proposed to be involved in the operon’s transcriptional activity, the S and A genes through a two-component system and the third gene named Y, which encodes a putative transcriptional regulator similar to the domains of the S/A system. Phylogenetic analyses indicated that the predicted proteins had a modular structure consisting of domains homologous to different signal transduction systems, but had significant differences concerning their conserved residues, pointing to the possibility that they constitute ancestral domains. In accordance with the prediction of functions, we propose a mechanism of regulation of the proteins studied of the 1,3-propanediol operon of the native strain, as a response to the presence of glycerol in the medium, which provides valuable information on the overall regulation of the glycerol metabolism in Clostridium</em> sp.</p>

scholarly journals The Evanescent GacS Signal

2020 ◽  
Vol 8 (11) ◽  
pp. 1746
Author(s):  
Xavier Latour
Keyword(s):  
Biofilm Formation ◽  
Plant Protection ◽  
Signal Transduction Pathway ◽  
Low Molecular Weight ◽  
Transduction Pathway ◽  
Significant Progress ◽  
Two Component System ◽  
Wide Range ◽  
Two Component ◽  
Bacterial Fitness

The GacS histidine kinase is the membrane sensor of the major upstream two-component system of the regulatory Gac/Rsm signal transduction pathway. This pathway governs the expression of a wide range of genes in pseudomonads and controls bacterial fitness and motility, tolerance to stress, biofilm formation, and virulence or plant protection. Despite the importance of these roles, the ligands binding to the sensor domain of GacS remain unknown, and their identification is an exciting challenge in this domain. At high population densities, the GacS signal triggers a switch from primary to secondary metabolism and a change in bacterial lifestyle. It has been suggested, based on these observations, that the GacS signal is a marker of the emergence of nutritional stress and competition. Biochemical investigations have yet to characterize the GacS signal fully. However, they portray this cue as a low-molecular weight, relatively simple and moderately apolar metabolite possibly resembling, but nevertheless different, from the aliphatic organic acids acting as quorum-sensing signaling molecules in other Proteobacteria. Significant progress in the development of metabolomic tools and new databases dedicated to Pseudomonas metabolism should help to unlock some of the last remaining secrets of GacS induction, making it possible to control the Gac/Rsm pathway.

scholarly journals Genetic and antigenic diversity among noroviruses

2006 ◽  
Vol 87 (4) ◽  
pp. 909-919 ◽  
Author(s):  
Grant S. Hansman ◽  
Katsuro Natori ◽  
Haruko Shirato-Horikoshi ◽  
Satoko Ogawa ◽  
Tomoichiro Oka ◽  
...  
Keyword(s):  
Amino Acid ◽  
Insect Cells ◽  
Phylogenetic Analyses ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Cell Culture Systems ◽  
Antibody Elisa ◽  
Polyclonal Antisera ◽  
Antigenic Relationships

Human norovirus (NoV) strains cause a considerable number of outbreaks of gastroenteritis worldwide. Based on their capsid gene (VP1) sequence, human NoV strains can be grouped into two genogroups (GI and GII) and at least 14 GI and 17 GII genotypes (GI/1–14 and GII/1–17). Human NoV strains cannot be propagated in cell-culture systems, but expression of recombinant VP1 in insect cells results in the formation of virus-like particles (VLPs). In order to understand NoV antigenic relationships better, cross-reactivity among 26 different NoV VLPs was analysed. Phylogenetic analyses grouped these NoV strains into six GI and 12 GII genotypes. An antibody ELISA using polyclonal antisera raised against these VLPs was used to determine cross-reactivity. Antisera reacted strongly with homologous VLPs; however, a number of novel cross-reactivities among different genotypes was observed. For example, GI/11 antiserum showed a broad-range cross-reactivity, detecting two GI and 10 GII genotypes. Likewise, GII/1, GII/10 and GII/12 antisera showed a broad-range cross-reactivity, detecting several other distinct GII genotypes. Alignment of VP1 amino acid sequences suggested that these broad-range cross-reactivities were due to conserved amino acid residues located within the shell and/or P1-1 domains. However, unusual cross-reactivities among different GII/3 antisera were found, with the results indicating that both conserved amino acid residues and VP1 secondary structures influence antigenicity.

scholarly journals Sustainability of spatially distributed bacteria-phage systems

2018 ◽  
Author(s):  
Rasmus Skytte Eriksen ◽  
Namiko Mitarai ◽  
Kim Sneppen
Keyword(s):  
Spatial Organization ◽  
Spatial Separation ◽  
The Self ◽  
Transient Dynamics ◽  
Large Reduction ◽  
Spatial Structures ◽  
Bacterial Survival ◽  
Spatially Distributed ◽  
Final Survival ◽  
Self Protection

AbstractVirulent phages can expose their bacterial hosts to devastating epidemics, in principle opening for a complete elimination of their hosts. Although experiments indeed confirm large reduction of susceptible bacteria, there is no reports of complete extinctions. We here address this phenomenon from the perspective of spatial organization of bacteria and how this can influence the final survival of them. By modeling the transient dynamics of bacteria and phages when they are introduced into an environment with finite resources, we quantify how the spatial separation of initial bacterial positions and the self-protection of bacteria growing in spherical colonies favor bacterial survival. This suggest that spatial structures on the millimeter scale plays an important role in maintaining microbial diversity.

scholarly journals Investigating the dynamics of microbial consortia in spatially structured environments

2020 ◽  
Author(s):  
Sonali Gupta ◽  
Tyler D. Ross ◽  
Marcella M. Gomez ◽  
Job L. Grant ◽  
Philip A. Romero ◽  
...  
Keyword(s):  
Gene Expression ◽  
Spatial Organization ◽  
Expression Patterns ◽  
Interaction Network ◽  
Spatial Separation ◽  
Microbial Consortia ◽  
Ecosystem Functions ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Microfluidic Platform

ABSTRACTThe spatial organization of microbial communities arises from a complex interplay of biotic and abiotic interactions and is a major determinant of ecosystem functions. We design a microfluidic platform to investigate how the spatial arrangement of microbes impacts gene expression and growth. We elucidate key biochemical parameters that dictate the mapping between spatial positioning and gene expression patterns. We show that distance can establish a low-pass filter to periodic inputs, and can enhance the fidelity of information processing. Positive and negative feedback can play disparate roles in the synchronization and robustness of a genetic oscillator distributed between two strains to spatial separation. Quantification of growth and metabolite release in an amino-acid auxotroph community demonstrates that the interaction network and stability of the community are highly sensitive to temporal perturbations and spatial arrangements. In sum, our microfluidic platform can quantify spatiotemporal parameters influencing diffusion-mediated interactions in microbial consortia.

scholarly journals The spatial separation of processing and transport functions to the interior and periphery of the Golgi stack

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Hieng Chiong Tie ◽  
Alexander Ludwig ◽  
Sara Sandin ◽  
Lei Lu
Keyword(s):  
Optical Imaging ◽  
Golgi Complex ◽  
Spatial Organization ◽  
Super Resolution ◽  
Spatial Separation ◽  
Dense Packing ◽  
Golgi Stack ◽  
Central Disk ◽  
En Face ◽  
Super Resolution Microscopy

It is unclear how the two principal functions of the Golgi complex, processing and transport, are spatially organized. Studying such spatial organization by optical imaging is challenging, partially due to the dense packing of stochastically oriented Golgi stacks. Using super-resolution microscopy and markers such as Giantin, we developed a method to identify en face and side views of individual nocodazole-induced Golgi mini-stacks. Our imaging uncovered that Golgi enzymes preferentially localize to the cisternal interior, appearing as a central disk or inner-ring, whereas components of the trafficking machinery reside at the periphery of the stack, including the cisternal rim. Interestingly, conventional secretory cargos appeared at the cisternal interior during their intra-Golgi trafficking and transiently localized to the cisternal rim before exiting the Golgi. In contrast, bulky cargos were found only at the rim. Our study therefore directly demonstrates the spatial separation of processing and transport functions within the Golgi complex.

The Bakerian Lecture, 1981 Natural Selection of the Chemical elements

1981 ◽  
Vol 213 (1193) ◽  
pp. 361-397 ◽  
Keyword(s):  
Spatial Organization ◽  
Chemical Elements ◽  
Spatial Separation ◽  
Electronic Charge ◽  
Biological Chemistry ◽  
Protein Ligands ◽  
Atomic Properties ◽  
Functional Specification ◽  
Chemical Combination ◽  
Selection Of

Biochemistry is the study of an intricate interwoven ‘designed’ use of many elements in cells. It can only be fully appreciated in terms of the patterns of flow of chemicals, of ionic and electronic charge, and of energy directed in space. This requires a knowledge of the selection of the elements not only in analytical terms of uptake and chemical combination but also in terms of their spatial separation and functional specification. Starting from the abundance and availability of the elements an attempt is made here to analyse the roles of the elements, showing that much of the ‘chosen’ chemistry is an inevitable consequence of atomic properties. Selection has played upon this chemistry, extracting the utmost value from it, as seen in the refinement of functions of individual elements so that each element plays a quite separate and distinct role. Unique qualities dominate comparative similarities through the use of evolved specific small molecule and protein ligands. Proteins provide the evolu­tionary media for the development of function. It was the recognition and separation of each element in their specific sites (proteins) that allowed elements to be positioned in space. In turn the spatial organization generates, through feedback, the flow of other elements. Biological chemistry is only understandable in terms of the symbiotic use of some 25 elements and should not be related to so-called organic rather than to so-called inorganic chemistry.

scholarly journals Spatial organization of FcγR and TLR2/1 on phagosome membranes differentially regulates their synergistic and inhibitory receptor crosstalk

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wenqian Li ◽  
Miao Li ◽  
Stephen M. Anthony ◽  
Yan Yu
Keyword(s):  
Spatial Organization ◽  
Spatial Separation ◽  
Inhibitory Effect ◽  
Spatial Proximity ◽  
Signaling Crosstalk ◽  
Quantitative Evidence ◽  
Physical Mechanisms ◽  
Cell Responses ◽  
Gamma Receptor ◽  
Receptor Crosstalk

AbstractMany innate immune receptors function collaboratively to detect and elicit immune responses to pathogens, but the physical mechanisms that govern the interaction and signaling crosstalk between the receptors are unclear. In this study, we report that the signaling crosstalk between Fc gamma receptor (FcγR) and Toll-like receptor (TLR)2/1 can be overall synergistic or inhibitory depending on the spatial proximity between the receptor pair on phagosome membranes. Using a geometric manipulation strategy, we physically altered the spatial distribution of FcγR and TLR2 on single phagosomes. We demonstrate that the signaling synergy between FcγR and TLR2/1 depends on the proximity of the receptors and decreases as spatial separation between them increases. However, the inhibitory effect from FcγRIIb on TLR2-dependent signaling is always present and independent of receptor proximity. The overall cell responses are an integration from these two mechanisms. This study presents quantitative evidence that the nanoscale proximity between FcγR and TLR2 functions as a key regulatory mechanism in their signaling crosstalk.

scholarly journals Recombinant human hyaluronidase Hyal-1: insect cells versus Escherichia coli as expression system and identification of low molecular weight inhibitors +

Glycobiology ◽  
2007 ◽  
Vol 17 (4) ◽  
pp. 444-453 ◽  
Author(s):  
Edith S.A. Hofinger ◽  
Martin Spickenreither ◽  
Jan Oschmann ◽  
Günther Bernhardt ◽  
Rainer Rudolph ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Insect Cells ◽  
Expression System ◽  
Low Molecular Weight ◽  
Recombinant Human Hyaluronidase
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