scholarly journals Visualization of the binding between gintonin, a Panax ginseng-derived LPA receptor ligand, and the LPA receptor subtypes and transactivation of the EGF receptor

2021 ◽  
Author(s):  
Sun-Hye Choi ◽  
Ra Mi Lee ◽  
Han-Sung Cho ◽  
Sung Hee Hwang ◽  
Hong-Ik Hwang ◽  
...  
Keyword(s):  
Panax Ginseng ◽  
Egf Receptor ◽  
Receptor Subtypes ◽  
Receptor Ligand ◽  
Lpa Receptor

scholarly journals Galanin-receptor ligand M40 peptide distinguishes between putative galanin-receptor subtypes

1993 ◽  
Vol 90 (23) ◽  
pp. 11287-11291 ◽  
Author(s):  
T Bartfai ◽  
U Langel ◽  
K Bedecs ◽  
S Andell ◽  
T Land ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Binding Sites ◽  
Receptor Subtype ◽  
Receptor Subtypes ◽  
Galanin Receptor ◽  
Flexor Reflex ◽  
Receptor Ligand ◽  
Insulinoma Cells ◽  
Galanin Receptors

The galanin-receptor ligand M40 [galanin-(1-12)-Pro3-(Ala-Leu)2-Ala amide] binds with high affinity to [mono[125I]iodo-Tyr26]galanin-binding sites in hippocampal, hypothalamic, and spinal cord membranes and in membranes from Rin m5F rat insulinoma cells (IC50 = 3-15 nM). Receptor autoradiographic studies show that M40 (1 microM) displaces [mono[125I]iodo-Tyr26]galanin from binding sites in the hippocampus, hypothalamus, and spinal cord. In the brain, M40 acts as a potent galanin-receptor antagonist: M40, in doses comparable to that of galanin, antagonizes the stimulatory effects of galanin on feeding, and it blocks the galaninergic inhibition of the scopolamine-induced acetylcholine release in the ventral hippocampus in vivo. In contrast, M40 completely fails to antagonize both the galanin-mediated inhibition of the glucose-induced insulin release in isolated mouse pancreatic islets and the inhibitory effects of galanin on the forskolin-stimulated accumulation of 3',5'-cAMP in Rin m5F cells; instead M40 is a weak agonist at the galanin receptors in these two systems. M40 acts as a weak antagonist of galanin in the spinal flexor reflex model. These results suggest that at least two subtypes of the galanin receptor may exist. Hypothalamic and hippocampal galanin receptors represent a putative central galanin-receptor subtype (GL-1-receptor) that is blocked by M40. The pancreatic galanin receptor may represent another subtype (GL-2-receptor) that recognizes M40, but as a weak agonist. The galanin receptors in the spinal cord occupy an intermediate position between these two putative subtypes.

scholarly journals A Complete Assessment of Dopamine Receptor-Ligand Interactions through Computational Methods

2019 ◽  
Author(s):  
Beatriz Bueschbell ◽  
Carlos A.V. Barreto ◽  
Antonio J. Preto ◽  
Anke C. Schiedel ◽  
Irina S. Moreira
Keyword(s):  
Dopamine Receptor ◽  
Electrostatic Interactions ◽  
Specific Binding ◽  
Binding Pocket ◽  
Binding Mode ◽  
Receptor Subtypes ◽  
Receptor Ligand ◽  
Pi Stacking ◽  
Ligand Interactions ◽  
New Treatments

Background: Selectively targeting dopamine receptors has been a persistent challenge in the last years for the development of new treatments to combat the large variety of diseases evolving these receptors. Although, several drugs have been successfully brought to market, the subtype-specific binding mode on a molecular basis has not been fully elucidated. Methods: Homology modeling and molecular dynamics were applied to construct robust conformational models of all dopamine receptor subtypes (D1-like and D2-like receptors). Fifteen structurally diverse ligands were docked to these models. Contacts at the binding pocket were fully described in order to reveal new structural findings responsible for DR sub-type specificity. Results: We showed that the number of conformations for a receptor:ligand complex was associated to unspecific interactions > 2.5 Å and hydrophobic contacts, while the decoys binding energy was influenced by specific electrostatic interactions. Known residues such as 3.32Asp, the serine microdomain and the aromatic microdomain were found interacting in a variety of modes (HB, SB, π-stacking). Purposed TM2-TM3-TM7 microdomain was found to form a hydrophobic network involving Orthosteric Binding Pocket (OBP) and Secondary Binding Pocket (SBP). T-stacking interactions revealed as especially relevant for some large ligands such as apomorphine, risperidone or aripiprazole. Conclusions: This in silico approach was successful in showing known receptor-ligand interactions as well as in determining unique combinations of interactions, key for the design of more specific ligands.

Effect of the anti-receptor ligand-blocking 225 monoclonal antibody on EGF receptor endocytosis and sorting

2006 ◽  
Vol 312 (15) ◽  
pp. 2778-2790 ◽  
Author(s):  
Maria L. Jaramillo ◽  
Zully Leon ◽  
Suzanne Grothe ◽  
Beatrice Paul-Roc ◽  
Abedelnasser Abulrob ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Egf Receptor ◽  
Receptor Ligand ◽  
Receptor Endocytosis

scholarly journals Characterization of U-97775 as a GABAA receptor ligand of dual functionality in cloned rat GABAA receptor subtypes

1995 ◽  
Vol 115 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Haesook K. Im ◽  
Wha Bin Im ◽  
Jeff F. Pregenzer ◽  
Donald B. Carter ◽  
E. Jon Jacobsen ◽  
...  
Keyword(s):  
Gabaa Receptor ◽  
Receptor Subtypes ◽  
Receptor Ligand ◽  
Gabaa Receptor Subtypes

scholarly journals Effect of the Gintonin-Enriched Fraction on Glucagon-Like-Protein-1 Release

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6298
Author(s):  
Rami Lee ◽  
Sun-Hye Choi ◽  
Han-Sung Cho ◽  
Hongik Hwang ◽  
Hyewhon Rhim ◽  
...  
Keyword(s):  
Western Blotting ◽  
Receptor Activation ◽  
Receptor Subtype ◽  
Receptor Subtypes ◽  
Dependent Manner ◽  
Receptor Ligands ◽  
Lpa Receptor ◽  
Beneficial Effects

Ginseng-derived gintonin reportedly contains functional lysophosphatidic acids (LPAs) as LPA receptor ligands. The effect of the gintonin-enriched fraction (GEF) on in vitro and in vivo glucagon-like protein-1 (GLP-1) secretion, which is known to stimulate insulin secretion, via LPA receptor(s) remains unclear. Accordingly, we examined the effects of GEF on GLP-1 secretion using human enteroendocrine NCI-H716 cells. The expression of several of LPA receptor subtypes in NCI-H716 cells using qPCR and Western blotting was examined. LPA receptor subtype expression was in the following order: LPA6 > LPA2 > LPA4 > LPA5 > LPA1 (qPCR), and LPA6 > LPA4 > LPA2 > LPA1 > LPA3 > LPA5 (Western blotting). GEF-stimulated GLP-1 secretion occurred in a dose- and time-dependent manner, which was suppressed by cAMP-Rp, a cAMP antagonist, but not by U73122, a phospholipase C inhibitor. Furthermore, silencing the human LPA6 receptor attenuated GEF-mediated GLP-1 secretion. In mice, low-dose GEF (50 mg/kg, peroral) increased serum GLP-1 levels; this effect was not blocked by Ki16425 co-treatment. Our findings indicate that GEF-induced GLP-1 secretion could be achieved via LPA6 receptor activation through the cAMP pathway. Hence, GEF-induced GLP secretion via LPA6 receptor regulation might be responsible for its beneficial effects on human endocrine physiology.

Transcriptional regulation of lysophosphatidic acid receptors 2 and 3 regulates myeloid commitment of hematopoietic stem cells

2021 ◽  
Author(s):  
Kuan-Hung Lin ◽  
Jui-Chung Chiang ◽  
Wei-Min Chen ◽  
Ya-Hsuan Ho ◽  
Chao-Ling Yao ◽  
...  
Keyword(s):  
Lysophosphatidic Acid ◽  
Stem Cell Differentiation ◽  
Receptor Subtypes ◽  
Physical Interaction ◽  
Hematopoietic Stem ◽  
Lpa Receptor ◽  
Gata Factors ◽  
Lpa Receptors ◽  
Myeloid Progenitors

Lysophosphatidic acid (LPA) is one of the lipids identified to be involved in stem cell differentiation. It exerts various functions through activation of G protein-coupled LPA receptors (LPARs). In previous studies, we have demonstrated that activation of LPA receptor 3 (LPA3) promotes erythropoiesis in human HSCs and zebrafish using molecular andpharmacological approaches. Our results show that treatment of LPA2 agonist suppressed erythropoiesis, whereas activation of LPA3 by 2S-OMPT promoted it, both in vitro and in vivo. Furthermore, we have demonstrated the inhibitory role of LPA3 during megakaryopoiesis. However, the mechanism underlying these observation remains elusive. In the present study, we suggest that the expression pattern of LPARs may be correlated with the transcriptional factors GATA-1 and GATA-2 at different stages of myeloid progenitors. We determined that manipulation of GATA factors affected the expression levels of LPA2 and LPA3. Using luciferase assays, we demonstrate that the promoter regions of LPAR2 and LPAR3 were regulated by these GATA factors. Mutation of GATA binding sites in these regions abrogated luciferase activity, suggesting that LPA2 and LPA3 are regulated by GATA factors. Moreover, physical interaction between GATA factors and the promoter region of LPA receptors was verified using chromatin immunoprecipitation (ChIP) studies. Taken together, our results suggest that balance between LPA2 and LPA3, which may be determined by GATA factors, is a regulatory switch for lineage commitment in myeloid progenitors. The expression-level balance of LPA receptor subtypes represents a novel mechanism regulating erythropoiesis and megakaryopoiesis.

Abstract 273: Exosome targeted receptor activation (ExTRAcrine) signaling: A new mode of EGF receptor ligand signaling

2010 ◽  
Author(s):  
Michelle Demory Beckler ◽  
James N. Higginbotham ◽  
Jonathan Gephart ◽  
Robert J. Coffey
Keyword(s):  
Egf Receptor ◽  
Receptor Activation ◽  
Receptor Ligand
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