scholarly journals The Drosophila Baramicin polypeptide gene protects against fungal infection

2021 ◽  
Vol 17 (8) ◽  
pp. e1009846
Author(s):  
Mark Austin Hanson ◽  
Lianne B. Cohen ◽  
Alice Marra ◽  
Igor Iatsenko ◽  
Steven A. Wasserman ◽  
...  
Keyword(s):  
Fat Body ◽  
Fruit Fly ◽  
Cleavage Sites ◽  
Microbial Infection ◽  
Furin Cleavage ◽  
Immune Effector ◽  
Effector Genes ◽  
Peptide Gene ◽  
Growth Of Fungi

The fruit fly Drosophila melanogaster combats microbial infection by producing a battery of effector peptides that are secreted into the haemolymph. Technical difficulties prevented the investigation of these short effector genes until the recent advent of the CRISPR/CAS era. As a consequence, many putative immune effectors remain to be formally described, and exactly how each of these effectors contribute to survival is not well characterized. Here we describe a novel Drosophila antifungal peptide gene that we name Baramicin A. We show that BaraA encodes a precursor protein cleaved into multiple peptides via furin cleavage sites. BaraA is strongly immune-induced in the fat body downstream of the Toll pathway, but also exhibits expression in other tissues. Importantly, we show that flies lacking BaraA are viable but susceptible to the entomopathogenic fungus Beauveria bassiana. Consistent with BaraA being directly antimicrobial, overexpression of BaraA promotes resistance to fungi and the IM10-like peptides produced by BaraA synergistically inhibit growth of fungi in vitro when combined with a membrane-disrupting antifungal. Surprisingly, BaraA mutant males but not females display an erect wing phenotype upon infection. Here, we characterize a new antifungal immune effector downstream of Toll signalling, and show it is a key contributor to the Drosophila antimicrobial response.

scholarly journals The Drosophila Baramicin polypeptide gene protects against fungal infection

2020 ◽  
Author(s):  
M.A. Hanson ◽  
L.B. Cohen ◽  
A. Marra ◽  
I. Iatsenko ◽  
S.A. Wasserman ◽  
...  
Keyword(s):  
Nervous System ◽  
Fungal Infection ◽  
Fat Body ◽  
Functional Characterization ◽  
Fruit Fly ◽  
Microbial Infection ◽  
Furin Cleavage ◽  
Polypeptide Structure

AbstractThe fruit fly Drososphila melanogaster combats microbial infection by producing a battery of effector peptides that are secreted into the haemolymph. The existence of many effectors that redundantly contribute to host defense has hampered their functional characterization. As a consequence, the logic underlying the role of immune effectors is only poorly defined, and exactly how each gene contributes to survival is not well characterized. Here we describe a novel Drosophila antifungal peptide gene that we name Baramicin A. We show that BaraA encodes a precursor protein cleaved into multiple peptides via furin cleavage sites. BaraA is strongly immune-induced in the fat body downstream of the Toll pathway, but also exhibits expression in the nervous system. Importantly, we show that flies lacking BaraA are viable but susceptible to a subset of filamentous fungi. Consistent with BaraA being directly antimicrobial, overexpression of BaraA promotes resistance to fungi and the IM10-like peptides produced by BaraA synergistically inhibit growth of fungi in vitro when combined with a membrane-disrupting antifungal. Surprisingly, BaraA males but not females display an erect wing phenotype upon infection, pointing to an adaptive role for BaraA on the wing muscle or the nervous system. Collectively, we identify a new antifungal immune effector downstream of Toll signalling, improving our knowledge of the Drosophila antimicrobial response.Significance statementAntimicrobial peptides (AMPs) of the innate immune system provide a front line of defence against infection. Recently AMPs have been implicated in physiological processes including inflammation, aging, and neurodegeneration. Drosophila melanogaster has been a useful model for understanding AMP functions and specificities in vivo. Here we describe a new Drosophila AMP family, Baramicin, which protects flies against fungal infection. The Baramicin polypeptide structure is also unique amongst animal AMPs, encoding multiple peptides on a single protein precursor cleaved by furin. Furthermore Baramicin mutants display a behavioural response to infection, suggesting Baramicin AMPs interact with more than just pathogens. Baramicin adds to our knowledge of the potent Drosophila antifungal response, and to growing observations of AMPs acting in seemingly non-canonical roles.

scholarly journals Targeting furin activity through in silico and in vitro drug repurposing strategy for SARS-CoV-2 spike glycoprotein cleavage repression

2020 ◽  
Author(s):  
Bruno O. Villoutreix ◽  
John Creemers ◽  
Yannick Léger ◽  
Geraldine Siegfried ◽  
Etienne Decroly ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Drug Repurposing ◽  
Protein S ◽  
Central China ◽  
Host Cells ◽  
Spike Protein ◽  
Cleavage Sites ◽  
Furin Cleavage ◽  
High Death

Abstract In December 2019, a new coronavirus was identified in the Hubei province of central china and named SRAS-CoV-2. This new virus induces COVID-19, a severe respiratory disease with high death rate. The spike protein (S) of SARS-CoV-2 contains furin-like cleavage sites absent the other SARS-like viruses. The viral infection requires the priming or cleavage of the S protein and such processing seems essential for virus entry into the host cells. Furin is highly expressed in the lung tissue and the expression is further increased in lung cancer, suggesting the exploitation of this mechanism by the virus to mediate enhanced virulence as shown by the higher risk of COVID-19 in these patients. In this study, we used structure- based virtual screening and a collection of about 8,000 unique approved and investigational drugs suitable for docking to search for molecules that could inhibits furin activity. Sulconazole, a broad-spectrum anti-fungal agent, was found to be of potential interest. Using Western blot analysis, Sulconazole was found to inhibit the cleavage of the cell surface furin substrate MT1-MMP that contains two furin cleavage sites similar to those of the SARS- CoV-2 spike protein. Sulconazole and analogs could be interesting for repurposing studies and to probe the yet not fully understood molecular mechanisms involved in cell entry.

scholarly journals A hybrid model based on general regression neural network and fruit fly optimization algorithm for forecasting and optimizing paclitaxel biosynthesis in Corylus avellana cell culture

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Mina Salehi ◽  
Siamak Farhadi ◽  
Ahmad Moieni ◽  
Naser Safaie ◽  
Mohsen Hesami
Keyword(s):  
Neural Network ◽  
Fruit Fly ◽  
Corylus Avellana ◽  
General Regression Neural Network ◽  
Fruit Fly Optimization Algorithm ◽  
Harvesting Time ◽  
Fruit Fly Optimization ◽  
General Regression ◽  
Concentration Levels

Abstract Background Paclitaxel is a well-known chemotherapeutic agent widely applied as a therapy for various types of cancers. In vitro culture of Corylus avellana has been named as a promising and low-cost strategy for paclitaxel production. Fungal elicitors have been reported as an impressive strategy for improving paclitaxel biosynthesis in cell suspension culture (CSC) of C. avellana. The objectives of this research were to forecast and optimize growth and paclitaxel biosynthesis based on four input variables including cell extract (CE) and culture filtrate (CF) concentration levels, elicitor adding day and CSC harvesting time in C. avellana cell culture, as a case study, using general regression neural network-fruit fly optimization algorithm (GRNN-FOA) via data mining approach for the first time. Results GRNN-FOA models (0.88–0.97) showed the superior prediction performances as compared to regression models (0.57–0.86). Comparative analysis of multilayer perceptron-genetic algorithm (MLP-GA) and GRNN-FOA showed very slight difference between two models for dry weight (DW), intracellular and extracellular paclitaxel in testing subset, the unseen data. However, MLP-GA was slightly more accurate as compared to GRNN-FOA for total paclitaxel and extracellular paclitaxel portion in testing subset. The slight difference was observed in maximum growth and paclitaxel biosynthesis optimized by FOA and GA. The optimization analysis using FOA on developed GRNN-FOA models showed that optimal CE [4.29% (v/v)] and CF [5.38% (v/v)] concentration levels, elicitor adding day (17) and harvesting time (88 h and 19 min) can lead to highest paclitaxel biosynthesis (372.89 µg l−1). Conclusions Great accordance between the predicted and observed values of DW, intracellular, extracellular and total yield of paclitaxel, and also extracellular paclitaxel portion support excellent performance of developed GRNN-FOA models. Overall, GRNN-FOA as new mathematical tool may pave the way for forecasting and optimizing secondary metabolite production in plant in vitro culture.

scholarly journals Identification and Functional Analysis of a Lysozyme Gene from Coridius Chinensis (Hemiptera: Dinidoridae)

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 330
Author(s):  
Hai Huang ◽  
Juan Du ◽  
Shang-Wei Li ◽  
Tao Gong
Keyword(s):  
Innate Immunity ◽  
Fat Body ◽  
Expression Patterns ◽  
Evolutionary Relationship ◽  
Immune Defense ◽  
Amino Acid Residues ◽  
Immune Effector ◽  
Medicinal Value ◽  
Muramidase Activity ◽  
Insect Innate Immunity

Coridius chinensis is a valuable medicinal insect resource in China. Previous studies have indicated that the antibacterial and anticancer effects of the C. chinensis extract mainly come from the active polypeptides. Lysozyme is an effective immune effector in insect innate immunity and usually has excellent bactericidal effects. There are two kinds of lysozymes in insects, c-type and i-type, which play an important role in innate immunity and intestinal digestion. Studying lysozyme in C. chinensis will be helpful to further explore the evolutionary relationship and functional differences among lysozymes of various species and to determine whether they have biological activity and medicinal value. In this study, a lysozyme CcLys2 was identified from C. chinensis. CcLys2 contains 223 amino acid residues, and possesses a typical domain of the c-type lysozyme and a putative catalytic site formed by two conserved residues Glu32 and Asp50. Phylogenetic analysis showed that CcLys2 belongs to the H-branch of the c-type lysozyme. The analysis of spatiotemporal expression patterns indicated that CcLys2 was mainly expressed in the fat body of C. chinensis adults and was highly expressed in the second- and fifth-instar nymphs. In addition, CcLys2 was significantly up-regulated after injecting and feeding bacteria. In the bacterial inhibition assay, it was found that CcLys2 had antibacterial activity against Gram-positive bacteria at a low pH. These results indicate that CcLys2 has muramidase activity, involves in the innate immunity of C. chinensis, and is also closely related to the bacterial immune defense or digestive function of the intestine.

scholarly journals Furin cleavage sites naturally occur in coronaviruses

2021 ◽  
Vol 50 ◽  
pp. 102115
Author(s):  
Yiran Wu ◽  
Suwen Zhao
Keyword(s):  
Cleavage Sites ◽  
Furin Cleavage

scholarly journals Tick Importin-α Is Implicated in the Interactome and Regulome of the Cofactor Subolesin

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 457
Author(s):  
Sara Artigas-Jerónimo ◽  
Margarita Villar ◽  
Alejandro Cabezas-Cruz ◽  
Grégory Caignard ◽  
Damien Vitour ◽  
...  
Keyword(s):  
Rational Design ◽  
Fat Body ◽  
Animal Health ◽  
Direct Interaction ◽  
Vaccine Antigen ◽  
Tick Feeding ◽  
Interacting Protein ◽  
Expression Levels ◽  
Importin Α

Ticks and tick-borne diseases (TBDs) represent a burden for human and animal health worldwide. Currently, vaccines constitute the safest and most effective approach to control ticks and TBDs. Subolesin (SUB) has been identified as a vaccine antigen for the control of tick infestations and pathogen infection and transmission. The characterization of the molecular function of SUB and the identification of tick proteins interacting with SUB may provide the basis for the discovery of novel antigens and for the rational design of novel anti-tick vaccines. In the present study, we used the yeast two-hybrid system (Y2H) as an unbiased approach to identify tick SUB-interacting proteins in an Ixodes ricinus cDNA library, and studied the possible role of SUB as a chromatin remodeler through direct interaction with histones. The Y2H screening identified Importin-α as a potential SUB-interacting protein, which was confirmed in vitro in a protein pull-down assay. The sub gene expression levels in tick midgut and fat body were significantly higher in unfed than fed female ticks, however, the importin-α expression levels did not vary between unfed and fed ticks but tended to be higher in the ovary when compared to those in other organs. The effect of importin-α RNAi was characterized in I. ricinus under artificial feeding conditions. Both sub and importin-α gene knockdown was observed in all tick tissues and, while tick weight was significantly lower in sub RNAi-treated ticks than in controls, importin-α RNAi did not affect tick feeding or oviposition, suggesting that SUB is able to exert its function in the absence of Importin-α. Furthermore, SUB was shown to physically interact with histone 4, which was corroborated by protein pull-down and western blot analysis. These results confirm that by interacting with numerous tick proteins, SUB is a key cofactor of the tick interactome and regulome. Further studies are needed to elucidate the nature of the SUB-Importin-α interaction and the biological processes and functional implications that this interaction may have.

scholarly journals Direct repeats bind the EcR/USP receptor and mediate ecdysteroid responses in Drosophila melanogaster.

1996 ◽  
Vol 16 (6) ◽  
pp. 2977-2986 ◽  
Author(s):  
C Antoniewski ◽  
B Mugat ◽  
F Delbac ◽  
J A Lepesant
Keyword(s):  
Fat Body ◽  
Cell Transformation ◽  
Direct Repeat ◽  
Transgenic Animals ◽  
Transcriptional Level ◽  
Regulatory Sequences ◽  
Direct Repeats ◽  
Fbp1 Gene

The steroid hormone 20-hydroxyecdysone plays a key role in the induction and modulation of morphogenetic events throughout Drosophila development. Previous studies have shown that a heterodimeric nuclear receptor composed of the EcR and USP proteins mediates the action of the hormone at the transcriptional through binding to palindromic ecdysteroid mediates the action of the hormone at the transcriptional level through binding to palindromic ecdysteroid response elements (EcREs) such as those present in the promoter of the hsp27 gene or the fat body-specific enhancer of the Fbp1 gene. We show that in addition to palindromic EcREs, the EcR/USP heterodimer can bind in vitro with various affinities to direct repetitions of the motif AGGTCA separated by 1 to 5 nucleotides (DR1 to DR5), which are known to be target sites for vertebrate nuclear receptors. At variance with the receptors, EcR/USP was also found to bind to a DR0 direct repeat with no intervening nucleotide. In cell transformation assays, direct repeats DR0 to DR5 alone can render the minimum viral tk or Drosophila Fbp1 promoter responsive to 20-hydroxyecdysone, as does the palindromic hsp27 EcRE. In a transgenic assay, however, neither the palindromic hsp27 element nor direct repeat DR3 alone can make the Fbp1 minimal promoter responsive to premetamorphic ecdysteroid peaks. In contrast, DR0 and DR3 elements, when substituted for the natural palindromic EcRE in the context of the Fbp1 enhancer, can drive a strong fat body-specific ecdysteroid response in transgenic animals. These results demonstrate that directly repeated EcR/USP binding sites are as effective as palindromic EcREs in vivo. They also provide evidence that additional flanking regulatory sequences are crucially required to potentiate the hormonal response mediated by both types of elements and specify its spatial and temporal pattern.

scholarly journals The trithorax Group Genemoira Encodes a Brahma-Associated Putative Chromatin-Remodeling Factor in Drosophila melanogaster

1999 ◽  
Vol 19 (2) ◽  
pp. 1159-1170 ◽  
Author(s):  
Madeline A. Crosby ◽  
Chaya Miller ◽  
, Tamar Alon ◽  
Kellie L. Watson ◽  
C. Peter Verrijzer ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Chromatin Remodeling ◽  
Leucine Zipper ◽  
Genetic Relationships ◽  
Fruit Fly ◽  
Protein Product ◽  
Homeotic Genes ◽  
Trithorax Group ◽  
Functional Relationships

ABSTRACT The genes of the trithorax group (trxG) inDrosophila melanogaster are required to maintain the pattern of homeotic gene expression that is established early in embryogenesis by the transient expression of the segmentation genes. The precise role of each of the diverse trxG members and the functional relationships among them are not well understood. Here, we report on the isolation of the trxG gene moira(mor) and its molecular characterization. morencodes a fruit fly homolog of the human and yeast chromatin-remodeling factors BAF170, BAF155, and SWI3. mor is widely expressed throughout development, and its 170-kDa protein product is present in many embryonic tissues. In vitro, MOR can bind to itself and it interacts with Brahma (BRM), an SWI2-SNF2 homolog, with which it is associated in embryonic nuclear extracts. The leucine zipper motif of MOR is likely to participate in self-oligomerization; the equally conserved SANT domain, for which no function is known, may be required for optimal binding to BRM. MOR thus joins BRM and Snf5-related 1 (SNR1), two known Drosophila SWI-SNF subunits that act as positive regulators of the homeotic genes. These observations provide a molecular explanation for the phenotypic and genetic relationships among several of the trxG genes by suggesting that they encode evolutionarily conserved components of a chromatin-remodeling complex.

scholarly journals Neutrophil Extracellular Traps Serve as Key Effector Molecules in the Protection Against Phialophora verrucosa

2021 ◽  
Vol 186 (3) ◽  
pp. 367-375
Author(s):  
Qin Liu ◽  
Wenjuan Yi ◽  
Si Jiang ◽  
Jiquan Song ◽  
Pin Liang
Keyword(s):  
Neutrophil Extracellular Traps ◽  
Innate Immune ◽  
Immune Effector ◽  
Phialophora Verrucosa ◽  
Extracellular Traps ◽  
Sytox Green ◽  
Innate Immune Effector ◽  
Pathogen Control ◽  
Extracellular Structures

AbstractPhialophora verrucosa (P. verrucosa) is a pathogen that can cause chromoblastomycosis and phaeohyphomycosis. Recent evidence suggests that neutrophils can produce neutrophil extracellular traps (NETs) that can protect against invasive pathogens. As such, we herein explored the in vitro functional importance of P. verrucosa-induced NET formation. By assessing the co-localization of neutrophil elastase and DNA, we were able to confirm the formation of classical NETs entrapping P. verrucosa specimens. Sytox Green was then used to stain these NETs following neutrophil infection with P. verrucosa in order to quantify the formation of these extracellular structures. NET formation was induced upon neutrophil exposure to both live, UV-inactivated, and dead P. verrucosa fungi. The ability of these NETs to kill fungal hyphae and conidia was demonstrated through MTT and pouring plate assays, respectively. Overall, our results confirmed that P. verrucosa was able to trigger the production of NETs, suggesting that these extracellular structures may represent an important innate immune effector mechanism controlling physiological responses to P. verrucosa infection, thereby aiding in pathogen control during the acute phases of infection.

scholarly journals Advances in bacterial specific imaging

2005 ◽  
Vol 48 (spe2) ◽  
pp. 145-152 ◽  
Author(s):  
David Wareham ◽  
J. Michael ◽  
Satya Das
Keyword(s):  
Nuclear Medicine ◽  
Clinical Studies ◽  
Human Disease ◽  
Diagnostic Technique ◽  
Sterile Inflammation ◽  
Microbial Infection ◽  
Course Of Disease ◽  
Wide Range ◽  
Diagnosis Of Infection

Nuclear medicine is a powerful diagnostic technique able to detect inflammatory foci in human disease. A wide range of agents have been evaluated for their ability to distinguish lesions due to microbial infection from those due to sterile inflammation. Advances continue to be made on the use of radiolabelled antibiotics which as well as being highly specific in the diagnosis of infection may be useful in monitoring the treatment and course of disease. Here we provide an update on in-vitro and clinical studies with a number of established and novel radiopharmaceuticals

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