scholarly journals Identification and functional characterization of the first molluscan neuromedin U receptor in the slug, Deroceras reticulatum

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Seung-Joon Ahn ◽  
Rory J. Mc Donnell ◽  
Jacob A. Corcoran ◽  
Ruth C. Martin ◽  
Man-Yeon Choi
Keyword(s):  
Receptor Gene ◽  
Functional Characterization ◽  
Binding Activity ◽  
Deroceras Reticulatum ◽  
Structural Modifications ◽  
Active Peptides ◽  
Physiological Processes ◽  
Splicing Variants ◽  
Encoding Genes

AbstractNeuromedin U (NmU) is a neuropeptide regulating diverse physiological processes. The insect homologs of vertebrate NmU are categorized as PRXamide family peptides due to their conserved C-terminal end. However, NmU homologs have been elusive in Mollusca, the second largest phylum in the animal kingdom. Here we report the first molluscan NmU/PRXamide receptor from the slug, Deroceras reticulatum. Two splicing variants of the receptor gene were functionally expressed and tested for binding with ten endogenous peptides from the slug and some insect PRXamide and vertebrate NmU peptides. Three heptapeptides (QPPLPRYa, QPPVPRYa and AVPRPRIa) triggered significant activation of the receptors, suggesting that they are true ligands for the NmU/PRXamide receptor in the slug. Synthetic peptides with structural modifications at different amino acid positions provided important insights on the core moiety of the active peptides. One receptor variant always exhibited higher binding activity than the other variant. The NmU-encoding genes were highly expressed in the slug brain, while the receptor gene was expressed at lower levels in general with relatively higher expression levels in both the brain and foot. Injection of the bioactive peptides into slugs triggered defensive behavior such as copious mucus secretion and a range of other anomalous behaviors including immobilization, suggesting their role in important physiological functions.

scholarly journals Functional Characterization of a Novel Promoter Element Required for an Innate Immune Response in Drosophila

2003 ◽  
Vol 23 (22) ◽  
pp. 8272-8281 ◽  
Author(s):  
Hanna Uvell ◽  
Ylva Engström
Keyword(s):  
Gene Expression ◽  
Antimicrobial Peptide ◽  
Functional Characterization ◽  
Binding Activity ◽  
Innate Immune ◽  
Site Directed Mutagenesis ◽  
Promoter Element ◽  
Peptide Gene ◽  
Inducible Genes

ABSTRACT Innate immune reactions are crucial processes of metazoans to protect the organism against overgrowth of faster replicating microorganisms. Drosophila melanogaster is a precious model for genetic and molecular studies of the innate immune system. In response to infection, the concerted action of a battery of antimicrobial peptides ensures efficient killing of the microbes. The induced gene expression relies on translocation of the Drosophila Rel transcription factors Relish, Dif, and Dorsal to the nucleus where they bind to κB-like motifs in the promoters of the inducible genes. We have identified another putative promoter element, called region 1 (R1), in a number of antimicrobial peptide genes. Site-directed mutagenesis of the R1 site diminished Cecropin A1 (CecA1) expression in transgenic Drosophila larvae and flies. Infection of flies induced a nuclear R1-binding activity that was unrelated to the κB-binding activity in the same extracts. Although the R1 motif was required for Rel protein-mediated CecA1 expression in cotransfection experiments, our data argue against it being a direct target for the Drosophila Rel proteins. We propose that the R1 and κB motifs are targets for distinct regulatory complexes that act in concert to promote high levels of antimicrobial peptide gene expression in response to infection.

scholarly journals Molecular and functional characterization of somatostatin-type signalling in a deuterostome invertebrate

Open Biology ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 200172
Author(s):  
Ya Zhang ◽  
Luis Alfonso Yañez Guerra ◽  
Michaela Egertová ◽  
Cleidiane G. Zampronio ◽  
Alexandra M. Jones ◽  
...  
Keyword(s):  
Functional Characterization ◽  
The Body ◽  
Pharmacological Characterization ◽  
Cardiac Stomach ◽  
Physiological Processes ◽  
Pharmacological Tests ◽  
The Central Nervous System

Somatostatin (SS) and allatostatin-C (ASTC) are structurally and evolutionarily related neuropeptides that act as inhibitory regulators of physiological processes in mammals and insects, respectively. Here, we report the first molecular and functional characterization of SS/ASTC-type signalling in a deuterostome invertebrate—the starfish Asterias rubens (phylum Echinodermata). Two SS/ASTC-type precursors were identified in A. rubens (ArSSP1 and ArSSP2) and the structures of neuropeptides derived from these proteins (ArSS1 and ArSS2) were analysed using mass spectrometry. Pharmacological characterization of three cloned A. rubens SS/ASTC-type receptors (ArSSR1–3) revealed that ArSS2, but not ArSS1, acts as a ligand for all three receptors. Analysis of ArSS2 expression in A. rubens using mRNA in situ hybridization and immunohistochemistry revealed stained cells/fibres in the central nervous system, the digestive system (e.g. cardiac stomach) and the body wall and its appendages (e.g. tube feet). Furthermore, in vitro pharmacological tests revealed that ArSS2 causes dose-dependent relaxation of tube foot and cardiac stomach preparations, while injection of ArSS2 in vivo causes partial eversion of the cardiac stomach. Our findings provide new insights into the molecular evolution of SS/ASTC-type signalling in the animal kingdom and reveal an ancient role of SS-type neuropeptides as inhibitory regulators of muscle contractility.

scholarly journals Functional characterization of naturally occurring NR3C2 gene mutations in Italian patients suffering from pseudohypoaldosteronism type 1

2007 ◽  
Vol 156 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Antonio Balsamo ◽  
Alessandro Cicognani ◽  
Monia Gennari ◽  
Wolfgang G Sippell ◽  
Soara Menabò ◽  
...  
Keyword(s):  
Receptor Gene ◽  
Functional Characterization ◽  
Clinical Signs ◽  
Gene Mutations ◽  
Ethnic Origin ◽  
Snp Markers ◽  
Italian Population ◽  
Pseudohypoaldosteronism Type

Objective: The renal form of pseudohypoaldosteronism type 1 (PHA1) is a rare disease caused by mutations in the human mineralocorticoid receptor gene (NR3C2). Design: Aim of the study was to analyze the NR3C2 gene in three Italian patients with clinical signs of renal PHA1 and to evaluate the distribution of the -2G > C, c.538A > G, and c.722C > T single nucleotide polymorphism (SNP) pattern in the PHA1 patients and in 90 controls of the same ethnic origin. Methods: Analysis of the NR3C2 gene sequence and of the polymorphic SNP markers. Functional characterization of the detected novel NR3C2 mutations utilizing aldosterone-binding assays and reporter gene transactivation assays. Results: One novel nonsense (Y134X) and one novel frameshift (2125delA) mutation were detected. They exhibited no aldosterone binding and no transactivation abilities. No mutation was detected in the third patient. Haploinsufficiency of NR3C2 was ruled out by microsatellite analysis in this patient. The c.722T SNP was detected in 97% of alleles in the Italian population which is significantly different from the general German or US population. Conclusions: Molecular analysis of the NR3C2 gene in PHA1 patients is warranted to detect novel mutations in order to clarify the underlying genetic cause, which may extend the insight into relevant functional regions of the hMR protein. The effect the different distribution of the c.722T SNP is not clear to date. Further studies are necessary to provide evidence as to a possible advantage of a less sensitive hMR in southern countries.

Signalling pathways in schistosomes: novel targets for control interventions against schistosomiasis

2017 ◽  
Vol 1 (6) ◽  
pp. 633-639 ◽  
Author(s):  
Pengfei Cai ◽  
Donald P. McManus ◽  
Hong You
Keyword(s):  
Functional Characterization ◽  
Cell Signalling ◽  
Signalling Pathways ◽  
Signal Transduction Pathways ◽  
Future Perspectives ◽  
Self Renewal ◽  
Physiological Processes ◽  
Growth Development ◽  
Novel Targets

Over the last decade, there has been accumulating evidence showing that signalling pathways are involved in extensive biological and physiological processes in the human blood fluke schistosomes, playing essential roles in environmental sensing, host penetration, growth, development, maturation, embryogenesis, tissue self-renewal and survival. Owing to the likelihood of resistance developing against praziquantel, the only drug currently available that is effective against all the human schistosome species, there is an urgent requirement for an alternative treatment, arguing for continuing research into novel or repurposed anti-schistosomal drugs. An increasing number of anticancer drugs are being developed which block abnormal signalling pathways, a feature that has stimulated interest in developing novel interventions against human schistosomiasis by targeting key cell signalling components. In this review, we discuss the functional characterization of signal transduction pathways in schistosomes and consider current challenges and future perspectives in this important area of research.

Cloning and functional characterization of the mouse C3a anaphylatoxin receptor gene

1997 ◽  
Vol 47 (1) ◽  
pp. 64-72 ◽  
Author(s):  
Matthew H. Hsu ◽  
Julia A. Ember ◽  
Meiying Wang ◽  
Eric R. Prossnitz ◽  
Tony E. Hugli ◽  
...  
Keyword(s):  
Receptor Gene ◽  
Functional Characterization

scholarly journals Functional Characterization of Burkholderia pseudomallei Trimeric Autotransporters

2013 ◽  
Vol 81 (8) ◽  
pp. 2788-2799 ◽  
Author(s):  
Cristine G. Campos ◽  
Matthew S. Byrd ◽  
Peggy A. Cotter
Keyword(s):  
Burkholderia Pseudomallei ◽  
Functional Characterization ◽  
A549 Cells ◽  
Content Type ◽  
Tier 1 ◽  
Type V ◽  
Mouse Model Of Infection ◽  
Encoding Genes

ABSTRACTBurkholderia pseudomalleiis a tier 1 select agent and the causative agent of melioidosis, a severe and often fatal disease with symptoms ranging from acute pneumonia and septic shock to a chronic infection characterized by abscess formation in the lungs, liver, and spleen. Autotransporters (ATs) are exoproteins belonging to the type V secretion system family, with many playing roles in pathogenesis. The genome ofB. pseudomalleistrain 1026b encodes nine putative trimeric AT proteins, of which only four have been described. Using a bioinformatic approach, we annotated putative domains within each trimeric AT protein, excluding the well-studied BimA protein, and found short repeated sequences unique toBurkholderiaspecies, as well as an unexpectedly large proportion of ATs with extended signal peptide regions (ESPRs). To characterize the role of trimeric ATs in pathogenesis, we constructed disruption or deletion mutations in each of eight AT-encoding genes and evaluated the resulting strains for adherence to, invasion of, and plaque formation in A549 cells. The majority of the ATs (and/or the proteins encoded downstream) contributed to adherence to and efficient invasion of A549 cells. Using a BALB/c mouse model of infection, we determined the contributions of each AT to bacterial burdens in the lungs, liver, and spleen. At 48 h postinoculation, only one strain, Bp340::pDbpaC, demonstrated a defect in dissemination and/or survival in the liver, indicating that BpaC is required for wild-type virulence in this model.

scholarly journals Functional characterization of ecdysone receptor gene switches in mammalian cells

FEBS Journal ◽  
2006 ◽  
Vol 273 (24) ◽  
pp. 5550-5563 ◽  
Author(s):  
Siva K. Panguluri ◽  
Prasanna Kumar ◽  
Subba R. Palli
Keyword(s):  
Mammalian Cells ◽  
Receptor Gene ◽  
Functional Characterization ◽  
Ecdysone Receptor ◽  
Gene Switches
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