scholarly journals MOLECULAR EVOLUTION OF GPCRS: CRH/CRH receptors

2014 ◽  
Vol 52 (3) ◽  
pp. T43-T60 ◽  
Author(s):  
David A Lovejoy ◽  
Belinda S W Chang ◽  
Nathan R Lovejoy ◽  
Jon del Castillo
Keyword(s):  
Stress Response ◽  
Molecular System ◽  
Peptide Hormone ◽  
Nutrient Acquisition ◽  
Energy Usage ◽  
Receptor System ◽  
Genome Duplications ◽  
Complex Forms ◽  
Multicellular Organisms ◽  
Crh Receptors

Corticotrophin-releasing hormone (CRH) is the pivotal neuroendocrine peptide hormone associated with the regulation of the stress response in vertebrates. However, CRH-like peptides are also found in a number of invertebrate species. The origin of this peptide can be traced to a common ancestor of lineages leading to chordates and to arthropods, postulated to occur some 500 million years ago. Evidence indicates the presence of a single CRH-like receptor and a soluble binding protein system that acted to transduce and regulate the actions of the early CRH peptide. In vertebrates, genome duplications led to the divergence of CRH receptors into CRH1 and CRH2 forms in tandem with the development of four paralogous ligand lineages that included CRH; urotensin I/urocortin (Ucn), Ucn2 and Ucn3. In addition, taxon-specific genome duplications led to further local divergences in CRH ligands and receptors. Functionally, the CRH ligand–receptor system evolved initially as a molecular system to integrate early diuresis and nutrient acquisition. As multicellular organisms evolved into more complex forms, this ligand–receptor system became integrated with the organismal stress response to coordinate homoeostatic challenges with internal energy usage. In vertebrates, CRH and the CRH1 receptor became associated with the hypothalamo-pituitary–adrenal/interrenal axis and the initial stress response, whereas the CRH2 receptor was selected to play a greater role in diuresis, nutrient acquisition and the latter aspects of the stress response.

Plant peptide hormone signalling

2015 ◽  
Vol 58 ◽  
pp. 115-131 ◽  
Author(s):  
Ayane Motomitsu ◽  
Shinichiro Sawa ◽  
Takashi Ishida
Keyword(s):  
Communication Systems ◽  
Cell Communication ◽  
Peptide Hormone ◽  
Peptide Hormones ◽  
Target Cells ◽  
Signalling Molecules ◽  
Receptor Complexes ◽  
Environmental Responses ◽  
Plant Life Cycle ◽  
Multicellular Organisms

The ligand–receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone–receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions.

Optimal ligand discrimination by asymmetric dimerization and turnover of interferon receptors

2021 ◽  
Vol 118 (37) ◽  
pp. e2103939118
Author(s):  
Patrick Binder ◽  
Nikolas D. Schnellbächer ◽  
Thomas Höfer ◽  
Nils B. Becker ◽  
Ulrich S. Schwarz
Keyword(s):  
Defense Mechanisms ◽  
Antiviral Defense ◽  
Discrimination Power ◽  
Receptor System ◽  
Information Theoretic ◽  
Single Receptor ◽  
Ligand Type ◽  
Theoretic Problem ◽  
Multicellular Organisms ◽  
Receptor Turnover

In multicellular organisms, antiviral defense mechanisms evoke a reliable collective immune response despite the noisy nature of biochemical communication between tissue cells. A molecular hub of this response, the interferon I receptor (IFNAR), discriminates between ligand types by their affinity regardless of concentration. To understand how ligand type can be decoded robustly by a single receptor, we frame ligand discrimination as an information-theoretic problem and systematically compare the major classes of receptor architectures: allosteric, homodimerizing, and heterodimerizing. We demonstrate that asymmetric heterodimers achieve the best discrimination power over the entire physiological range of local ligand concentrations. This design enables sensing of ligand presence and type, and it buffers against moderate concentration fluctuations. In addition, receptor turnover, which drives the receptor system out of thermodynamic equilibrium, allows alignment of activation points for ligands of different affinities and thereby makes ligand discrimination practically independent of concentration. IFNAR exhibits this optimal architecture, and our findings thus suggest that this specialized receptor can robustly decode digital messages carried by its different ligands.

scholarly journals Leptin/leptin receptor system in the regulation of reproductive functions and stress response in the European beaver

2018 ◽  
Vol 65 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Katarzyna Chojnowska ◽  
Joanna Czerwinska ◽  
Tadeusz Kaminski ◽  
Barbara Kaminska ◽  
Aleksandra Kurzynska ◽  
...  
Keyword(s):  
Stress Response ◽  
Leptin Receptor ◽  
Receptor System ◽  
European Beaver

scholarly journals GOAT: the master switch for the ghrelin system?

2010 ◽  
Vol 163 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Amparo Romero ◽  
Henriette Kirchner ◽  
Kristy Heppner ◽  
Paul T Pfluger ◽  
Matthias H Tschöp ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Peptide Hormone ◽  
Complete Understanding ◽  
Receptor System ◽  
Ghrelin Receptor ◽  
The Metabolic Syndrome ◽  
Carbon Fatty Acid ◽  
Biological Actions ◽  
Made In

AbstractThe ghrelin–ghrelin receptor system is one of the most important mechanisms regulating energy balance and metabolism. Among other actions, central and peripheral administration of ghrelin increases food intake and adiposity. During the last years, many efforts have been made in the investigation of the cellular and molecular mechanisms modulating the effects of ghrelin. One particularity of this peptide hormone is its acylation at serine-3 with an eight-carbon fatty acid (octanoate), which confers its biological activity. Recent reports have demonstrated that the ghrelin O-acyltransferase (GOAT) is the enzyme that catalyzes ghrelin octanoylation. Therefore, all questions concerning the posttranslational acylation of ghrelin are of great interest for the complete understanding of this system. In this review, we summarize the discovery and characterization of GOAT, and remark the importance of GOAT as a novel and potential target that regulates the biological actions of ghrelin, revealing several therapeutical possibilities for the treatment of the metabolic syndrome.

scholarly journals Genome-Wide Identification of H-NS-Controlled, Temperature-Regulated Genes in Escherichiacoli K-12

2008 ◽  
Vol 191 (3) ◽  
pp. 1106-1110 ◽  
Author(s):  
Christine A. White-Ziegler ◽  
Talya R. Davis
Keyword(s):  
Stress Response ◽  
Biofilm Formation ◽  
Dna Microarrays ◽  
Cold Shock ◽  
Nutrient Acquisition ◽  
General Stress Response ◽  
General Stress ◽  
Genome Wide ◽  
K 12 ◽  
Common Regulator

ABSTRACT DNA microarrays demonstrate that H-NS controls 69% of the temperature regulated genes in Escherichia coli K-12. H-NS is shown to be a common regulator of multiple iron and other nutrient acquisition systems preferentially expressed at 37°C and of general stress response, biofilm formation, and cold shock genes highly expressed at 23°C.

scholarly journals Cancer Metabolism and the Evasion of Apoptotic Cell Death

Cancers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1144 ◽  
Author(s):  
Aditi Sharma ◽  
Lawrence H. Boise ◽  
Mala Shanmugam
Keyword(s):  
Cell Death ◽  
Cancer Metabolism ◽  
Apoptotic Cell ◽  
Therapy Resistance ◽  
Nutrient Acquisition ◽  
Cellular Growth ◽  
Cancer Hallmarks ◽  
Primary Focus ◽  
Multicellular Organisms ◽  
Energy Dependent

Cellular growth and proliferation depend upon the acquisition and synthesis of specific metabolites. These metabolites fuel the bioenergy, biosynthesis, and redox potential required for duplication of cellular biomass. Multicellular organisms maintain tissue homeostasis by balancing signals promoting proliferation and removal of cells via apoptosis. While apoptosis is in itself an energy dependent process activated by intrinsic and extrinsic signals, whether specific nutrient acquisition (elevated or suppressed) and their metabolism regulates apoptosis is less well investigated. Normal cellular metabolism is regulated by lineage specific intrinsic features and microenvironment driven extrinsic features. In the context of cancer, genetic abnormalities, unconventional microenvironments and/or therapy engage constitutive pro-survival signaling to re-program and rewire metabolism to maintain survival, growth, and proliferation. It thus becomes particularly relevant to understand whether altered nutrient acquisition and metabolism in cancer can also contribute to the evasion of apoptosis and consequently therapy resistance. Our review attempts to dissect a causal relationship between two cancer hallmarks, i.e., deregulated cellular energetics and the evasion of programmed cell death with primary focus on the intrinsic pathway of apoptosis.

scholarly journals Nutrient acquisition, rather than stress response over diel cycles, drives microbial transcription in a dessicated Namib Desert soil

2018 ◽  
Author(s):  
Carlos León-Sobrino ◽  
Jean-Baptiste Ramond ◽  
Gillian Maggs-Kölling ◽  
Don A Cowan
Keyword(s):  
Stress Response ◽  
Carbon Fixation ◽  
Nutrient Acquisition ◽  
Desert Soil ◽  
Namib Desert ◽  
Community Function ◽  
Network Analyses ◽  
Diel Cycles ◽  
Functional Profiling ◽  
Acquisition Processes

AbstractHot desert surface soils are characterised by extremely low water activities for large parts of any annual cycle. It is widely assumed that microbial processes in such soils are very limited. Here we present the first metatranscriptomic survey of microbial community function in a low water activity hyperarid desert soil. Sequencing of total mRNA revealed a diverse and active community, dominated byActinobacteria. Metatranscriptomic analysis of samples taken at different times over three days indicated that most functions did not fluctuate on a diel basis, except for a eukaryotic subpopulation which was induced during the cooler night hours. High levels of transcription of chemoautotrophic carbon fixation genes contrasted with limited expression of photosynthetic genes, indicating that chemoautotrophy is an important alternative to photosynthesis for carbon cycling in desiccated desert soils. Analysis of the transcriptional levels of key N-cycling genes provided strong evidence that soil nitrate was the dominant nitrogen input source. Transcriptional network analyses and taxon-resolved functional profiling suggested that nutrient acquisition processes, and not diurnal environmental variation, were the main drivers of community activity in hyperarid Namib Desert soil. While we also observed significant levels of expression of common stress response genes, these genes were not dominant hubs in the co-occurrence network.

Organization of the Pellicle and the Muciferous Glands in Euglena Gracilis

1970 ◽  
Vol 28 ◽  
pp. 104-105
Author(s):  
Hilton H. Mollenhauer ◽  
W. Evans
Keyword(s):  
Plasma Membrane ◽  
Euglena Gracilis ◽  
Complex Forms ◽  
Secondary Periodicity

The pellicular structure of Euglena gracilis consists of a series of relatively rigid strips (Fig. 1) composed of ridges and grooves which are helically oriented along the cell and which fuse together into a common junction at either end of the cell. The strips are predominantly protein and consist in part of a series of fibers about 50 Å in diameter spaced about 85 Å apart and with a secondary periodicity of about 450 Å. Microtubules are also present below each strip (Fig. 1) and are often considered as part of the pellicular complex. In addition, there may be another fibrous component near the base of the pellicle which has not yet been very well defined.The pellicular complex lies underneath the plasma membrane and entirely within the cell (Fig. 1). Each strip of the complex forms an overlapping junction with the adjacent strip along one side of each groove (Fig. 1), in such a way that a certain amount of sideways movement is possible between one strip and the next.

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