scholarly journals Melatonin

2002 ◽  
Vol 4 (1) ◽  
pp. 57-72 ◽  
Keyword(s):  
Seasonal Affective Disorder ◽  
Physiological Role ◽  
G Protein Coupled Receptors ◽  
The Body ◽  
Receptor Subtypes ◽  
Seasonal Breeding ◽  
Livestock Management ◽  
G Protein Coupled ◽  
The Brain ◽  
Melatonin Production

Melatonin (MEL) is a hormone synthesized and secreted by the pineal gland deep within the brain in response to photoperiodic cues relayed from the retina via an endogenous circadian oscillator within the suprachiasmatic nucleus in the hypothalamus. The circadian rhythm of melatonin production and release, characterized by nocturnal activity and daytime quiescence, is an important temporal signal to the body structures that can read it. Melatonin acts through high-affinity receptors located centrally and in numerous peripheral organs. Different receptor subtypes have been cloned and characterized: MT(1) and MT(2) (transmembrane G-protein-coupled receptors), and MT(3). However, their physiological role remains unelucidated, although livestock management applications already include the control of seasonal breeding and milk production. As for potential therapeutic applications, exogenous melatonin or a melatonin agonist and selective 5-hydroxytrypiamine receptor (5-HT(2c)) antagonist, eg, S 20098, can be used to manipulate circadian processes such as the sleep-vake cycle, which are frequently disrupted in many conditions, most notably seasonal affective disorder.

scholarly journals The Galanin and Galanin Receptor Subtypes, its Regulatory Role in the Biological and Pathological Functions

2017 ◽  
pp. 729-740 ◽  
Author(s):  
J. ŠÍPKOVÁ ◽  
I. KRAMÁRIKOVÁ ◽  
S. HYNIE ◽  
V. KLENEROVÁ
Keyword(s):  
G Protein Coupled Receptors ◽  
Receptor Subtypes ◽  
Galanin Receptor ◽  
Peripheral Tissues ◽  
Important Target ◽  
Galanin Receptors ◽  
The Relationship ◽  
G Protein Coupled ◽  
The Brain ◽  
Stimulation Of

The multitalented neuropeptide galanin was first discovered 30 years ago but initially no biologic activity was found. Further research studies discovered the presence of galanin in the brain and some peripheral tissues, and galanin was identified as a modulator of neurotransmission in the central and peripheral nervous system. Over the last decade there were performed very intensive studies of the neuronal actions and also of nonneuronal actions of galanin. Other galanin family peptides have been described, namely galanin, galanin-like peptide, galanin-message associated peptide and alarin. The effect of these peptides is mediated through three galanin receptors subtypes, GalR1, GalR2 and GalR3 belonging to G protein coupled receptors, and signaling via multiple transduction pathways, including inhibition of cyclic AMP/protein kinase A (GalR1, GalR3) and stimulation of phospholipase C (GalR2). This also explains why one specific molecule of galanin can be responsible for different roles in different tissues. The present review summarizes the information currently available on the relationship between the galaninergic system and known pathological states. The research of novel galanin receptor specific agonists and antagonists is also very promising for its future role in pharmacological treatment. The galaninergic system is important target for current and future biomedical research.

scholarly journals Dysregulation of dopamine-dependent mechanisms as a determinant of hypertension: studies in dopamine receptor knockout mice

2008 ◽  
Vol 294 (2) ◽  
pp. H551-H569 ◽  
Author(s):  
Chunyu Zeng ◽  
Ines Armando ◽  
Yingjin Luo ◽  
Gilbert M. Eisner ◽  
Robin A. Felder ◽  
...  
Keyword(s):  
Dopamine Receptor ◽  
Physiological Role ◽  
G Protein Coupled Receptors ◽  
Receptor Subtypes ◽  
Humoral Factors ◽  
Dopamine Receptor Subtypes ◽  
Receptor Mutant ◽  
G Protein Coupled ◽  
Regulation Of Blood Pressure

Dopamine plays an important role in the pathogenesis of hypertension by regulating epithelial sodium transport and by interacting with vasoactive hormones/humoral factors, such as aldosterone, angiotensin, catecholamines, endothelin, oxytocin, prolactin pro-opiomelancortin, reactive oxygen species, renin, and vasopressin. Dopamine receptors are classified into D1-like (D1 and D5) and D2-like (D2, D3, and D4) subtypes based on their structure and pharmacology. In recent years, mice deficient in one or more of the five dopamine receptor subtypes have been generated, leading to a better understanding of the physiological role of each of the dopamine receptor subtypes. This review summarizes the results from studies of various dopamine receptor mutant mice on the role of individual dopamine receptor subtypes and their interactions with other G protein-coupled receptors in the regulation of blood pressure.

Mapping the Heart

2010 ◽  
Vol 18 (4) ◽  
pp. 6-8
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
G Protein Coupled Receptors ◽  
Receptor Subtypes ◽  
Cardiac Muscle Cells ◽  
Guanine Nucleotide Binding Protein ◽  
The Common ◽  
Guanine Nucleotide Binding ◽  
First Time ◽  
G Protein Coupled

Some of the receptors on the surface of cardiac muscle cells (cardiomyocytes) mediate the response of these cells to catecholamines by causing the production of the common second messenger cyclic adenosine monophosphate (cAMP). An example of such receptors are the β1- and β2-adrenergic receptors (βARs) that are heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors. Selective stimulation of these two receptor subtypes leads to distinct physiological and pathophysiological responses, but their precise location on the surface of cardiomyocytes has not been correlated with these responses. In an ingenious combination of techniques, Viacheslav Nikolaev, Alexey Moshkov, Alexander Lyon, Michele Miragoli, Pavel Novak, Helen Paur, Martin Lohse, Yuri Korchev, Sian Harding, and Julia Gorelik have mapped the function of these receptors for the first time.

scholarly journals GRKs as Modulators of Neurotransmitter Receptors

Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 52
Author(s):  
Eugenia V. Gurevich ◽  
Vsevolod V. Gurevich
Keyword(s):  
G Protein ◽  
General Model ◽  
G Protein Coupled Receptors ◽  
Receptor Internalization ◽  
Neurotransmitter Receptors ◽  
Receptor Subtype ◽  
Receptor Subtypes ◽  
Receptor Kinase ◽  
G Protein Coupled ◽  
Homologous Desensitization

Many receptors for neurotransmitters, such as dopamine, norepinephrine, acetylcholine, and neuropeptides, belong to the superfamily of G protein-coupled receptors (GPCRs). A general model posits that GPCRs undergo two-step homologous desensitization: the active receptor is phosphorylated by kinases of the G protein-coupled receptor kinase (GRK) family, whereupon arrestin proteins specifically bind active phosphorylated receptors, shutting down G protein-mediated signaling, facilitating receptor internalization, and initiating distinct signaling pathways via arrestin-based scaffolding. Here, we review the mechanisms of GRK-dependent regulation of neurotransmitter receptors, focusing on the diverse modes of GRK-mediated phosphorylation of receptor subtypes. The immediate signaling consequences of GRK-mediated receptor phosphorylation, such as arrestin recruitment, desensitization, and internalization/resensitization, are equally diverse, depending not only on the receptor subtype but also on phosphorylation by GRKs of select receptor residues. We discuss the signaling outcome as well as the biological and behavioral consequences of the GRK-dependent phosphorylation of neurotransmitter receptors where known.

scholarly journals The cell biology of smell

2010 ◽  
Vol 191 (3) ◽  
pp. 443-452 ◽  
Author(s):  
Shannon DeMaria ◽  
John Ngai
Keyword(s):  
Olfactory System ◽  
Cell Biology ◽  
Odorant Receptor ◽  
Large Family ◽  
G Protein Coupled Receptors ◽  
Odorant Receptors ◽  
Chemical Structures ◽  
Wide Range ◽  
G Protein Coupled ◽  
The Brain

The olfactory system detects and discriminates myriad chemical structures across a wide range of concentrations. To meet this task, the system utilizes a large family of G protein–coupled receptors—the odorant receptors—which are the chemical sensors underlying the perception of smell. Interestingly, the odorant receptors are also involved in a number of developmental decisions, including the regulation of their own expression and the patterning of the olfactory sensory neurons' synaptic connections in the brain. This review will focus on the diverse roles of the odorant receptor in the function and development of the olfactory system.

scholarly journals Beyond the Flavour: The Potential Druggability of Chemosensory G Protein-Coupled Receptors

2019 ◽  
Vol 20 (6) ◽  
pp. 1402 ◽  
Author(s):  
Antonella Di Pizio ◽  
Maik Behrens ◽  
Dietmar Krautwurst
Keyword(s):  
G Protein ◽  
Drug Targets ◽  
Current Knowledge ◽  
Chemical Space ◽  
G Protein Coupled Receptors ◽  
The Body ◽  
Odorant Receptors ◽  
Taste Receptors ◽  
Umami Taste ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) belong to the largest class of drug targets. Approximately half of the members of the human GPCR superfamily are chemosensory receptors, including odorant receptors (ORs), trace amine-associated receptors (TAARs), bitter taste receptors (TAS2Rs), sweet and umami taste receptors (TAS1Rs). Interestingly, these chemosensory GPCRs (csGPCRs) are expressed in several tissues of the body where they are supposed to play a role in biological functions other than chemosensation. Despite their abundance and physiological/pathological relevance, the druggability of csGPCRs has been suggested but not fully characterized. Here, we aim to explore the potential of targeting csGPCRs to treat diseases by reviewing the current knowledge of csGPCRs expressed throughout the body and by analysing the chemical space and the drug-likeness of flavour molecules.

scholarly journals Homo- and hetero-oligomeric interactions between G-protein-coupled receptors in living cells monitored by two variants of bioluminescence resonance energy transfer (BRET): hetero-oligomers between receptor subtypes form more efficiently than between less closely related sequences

2002 ◽  
Vol 365 (2) ◽  
pp. 429-440 ◽  
Author(s):  
Douglas RAMSAY ◽  
Elaine KELLETT ◽  
Mary McVEY ◽  
Stephen REES ◽  
Graeme MILLIGAN
Keyword(s):  
Opioid Receptor ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Living Cells ◽  
G Protein Coupled Receptors ◽  
Receptor Subtypes ◽  
Bioluminescence Resonance Energy Transfer ◽  
Oligomer Formation ◽  
G Protein Coupled ◽  
Energy Acceptor

Homo- and hetero-oligomerization of G-protein-coupled receptors (GPCRs) were examined in HEK-293 cells using two variants of bioluminescence resonance energy transfer (BRET). BRET2 (a variant of BRET) offers greatly improved separation of the emission spectra of the donor and acceptor moieties compared with traditional BRET. Previously recorded homo-oligomerization of the human δ-opioid receptor was confirmed using BRET2. Homo-oligomerization of the κ-opioid receptor was observed using both BRET techniques. Both homo- and hetero-oligomers, containing both δ- and κ-opioid receptors, were unaffected by the presence of receptor ligands. BRET detection of opioid receptor homo- and hetero-oligomers required expression of 50000–100000 copies of the receptor energy acceptor construct per cell. The effectiveness of δ—κ-opioid receptor hetero-oligomer formation was as great as for homomeric interactions. The capacity of the two opioid receptors to form oligomeric complexes with the β2-adrenoceptor was also assessed. Although such interactions were detected, at least 250000 copies per cell of the energy acceptor were required. Requirement for high levels of receptor expression was equally pronounced in attempts to measure hetero-oligomer formation between the κ-opioid receptor and the thyrotropin-releasing hormone receptor-1. These studies indicate that constitutively formed homo- and hetero-oligomers of opioid receptor subtypes can be detected in living cells containing less than 100000 copies of the receptors. However, although hetero-oligomeric interactions between certain less closely related GPCRs can be detected, they appear to be of lower affinity than homo- or hetero-oligomers containing closely related sequences. Interactions recorded between certain GPCR family members in heterologous expression systems are likely to be artefacts of extreme levels of overexpression.

scholarly journals Loss of neurogenesis in Hydra leads to compensatory regulation of neurogenic and neurotransmission genes in epithelial cells

2016 ◽  
Vol 371 (1685) ◽  
pp. 20150040 ◽  
Author(s):  
Y. Wenger ◽  
W. Buzgariu ◽  
B. Galliot
Keyword(s):  
Stem Cells ◽  
Nervous System ◽  
G Protein Coupled Receptors ◽  
The Body ◽  
Neurogenic Genes ◽  
Cell Type Specific ◽  
The Impact ◽  
G Protein Coupled ◽  
Body Column ◽  
Compensatory Regulation

Hydra continuously differentiates a sophisticated nervous system made of mechanosensory cells (nematocytes) and sensory–motor and ganglionic neurons from interstitial stem cells. However, this dynamic adult neurogenesis is dispensable for morphogenesis. Indeed animals depleted of their interstitial stem cells and interstitial progenitors lose their active behaviours but maintain their developmental fitness, and regenerate and bud when force-fed. To characterize the impact of the loss of neurogenesis in Hydra , we first performed transcriptomic profiling at five positions along the body axis. We found neurogenic genes predominantly expressed along the central body column, which contains stem cells and progenitors, and neurotransmission genes predominantly expressed at the extremities, where the nervous system is dense. Next, we performed transcriptomics on animals depleted of their interstitial cells by hydroxyurea, colchicine or heat-shock treatment. By crossing these results with cell-type-specific transcriptomics, we identified epithelial genes up-regulated upon loss of neurogenesis: transcription factors ( Dlx , Dlx1 , DMBX1/Manacle , Ets1 , Gli3 , KLF11 , LMX1A , ZNF436 , Shox1 ), epitheliopeptides ( Arminins , PW peptide ), neurosignalling components ( CAMK1D , DDCl2 , Inx1 ), ligand-ion channel receptors ( CHRNA1 , NaC7 ), G-Protein Coupled Receptors and FMRFRL. Hence epitheliomuscular cells seemingly enhance their sensing ability when neurogenesis is compromised. This unsuspected plasticity might reflect the extended multifunctionality of epithelial-like cells in early eumetazoan evolution.

Transmembrane Signaling in the Brain by Serotonin, A Key Regulator of Physiology and Emotion

2005 ◽  
Vol 25 (5-6) ◽  
pp. 363-385 ◽  
Author(s):  
Tatyana Adayev ◽  
Buddima Ranasinghe ◽  
Probal Banerjee
Keyword(s):  
Gene Expression ◽  
Immune Cells ◽  
Functional Role ◽  
Living Organism ◽  
Covalent Modification ◽  
G Protein Coupled Receptors ◽  
And Behavior ◽  
G Protein Coupled ◽  
Compare And Contrast ◽  
The Brain

Serotonin (5-HT) is an ancient chemical that plays a crucial functional role in almost every living organism. It regulates platelet aggregation, activation of immune cells, and contraction of stomach and intestinal muscles. In addition, serotonin acts as a neurotransmitter in the brain and the peripheral nervous system. These activities are initiated by the binding of serotonin to 15 or more receptors that are pharmacologically classified into seven groups, 5-HT1 through 5-HT7. Each group is further divided into subgroups of receptors that are homologous but are encoded by discrete genes. With the exception of the 5-HT3 receptor-a cation channel—all of the others are G protein-coupled receptors that potentially activate or inhibit a large number of biochemical cascades. This review will endeavor to compare and contrast such signaling pathways with special attention to their tissue-specific occurrence, their possible role in immediate effects on covalent modification of other proteins, and relatively slower effects on gene expression, physiology and behavior.

scholarly journals Effect of 5-hydroxytryptamine Receptor in the Lower Esophageal Sphincter Regulation Mechanism

2020 ◽  
Vol 3 (6) ◽  
Author(s):  
Hefei Li ◽  
Junfeng Liu ◽  
Xixuan Zhang ◽  
Zhiwei Lai ◽  
Zhen Gao ◽  
...  
Keyword(s):  
G Protein ◽  
G Protein Coupled Receptors ◽  
Regulation Mechanism ◽  
Visceral Sensitivity ◽  
Gastrointestinal Dysfunction ◽  
Secretion Regulation ◽  
The Central Nervous System ◽  
Esophageal Sphincter ◽  
G Protein Coupled ◽  
The Brain

As a neurotransmitter and avascular active substance, the 5-hydroxytryptamine (5-HT, serotonin) is widely distributed in the central nervous system and surrounding tissues. The 5-HT can play its role by acting on its corresponding 5-HT receptor. Nowadays, the 5-HT receptor can be classified into seven, according to different signal transduction method of receptors, the 5-HT3 receptor belongs to the ligand-gated ion channels, while other six 5-HT receptors are involved into the G protein-coupled receptors and play the biological role by binding to specific G protein-coupled receptors (GPCRs) on the surface of the cell membrane. The 5-HT plays an important role in the brain-gut information transmission and studies showed that the physiological stimulations like having meals, and pathological stimulations like ischemia and stress could promote the release of the 5-HT. In the gastrointestinal tract, the 5-HT is closely related to gastrointestinal sensitivity, gastrointestinal movement and secretion regulation, as well as many gastrointestinal dysfunction disorders, such as gastrointestinal power and visceral sensitivity abnormality and abnormalities of brain-gut axis.

Sign in / Sign up

Export Citation Format

Share Document