scholarly journals Hemorphins Targeting G Protein-Coupled Receptors

2021 ◽  
Vol 14 (3) ◽  
pp. 225
Author(s):  
Mohammed Akli Ayoub ◽  
Ranjit Vijayan
Keyword(s):  
Angiotensin Ii ◽  
G Protein ◽  
Molecular Basis ◽  
Allosteric Modulation ◽  
G Protein Coupled Receptors ◽  
Beta Subunit ◽  
Short Peptides ◽  
Physiological Effects ◽  
Diverse Range ◽  
G Protein Coupled

Hemorphins are short peptides produced by the proteolysis of the beta subunit of hemoglobin. These peptides have diverse physiological effects especially in the nervous and the renin-angiotensin systems. Such effects occur through the modulation of a diverse range of proteins including enzymes and receptors. In this review, we focus on pharmacological and functional targeting of G protein-coupled receptors (GPCRs) by hemorphins and their implication in physiology and pathophysiology. Among GPCRs, the opioid receptors constitute the first set of targets of hemorphins with implication in analgesia. Subsequently, several other GPCRs have been reported to be directly or indirectly involved in hemorphins’ action. This includes the receptors for angiotensin II, oxytocin, bombesin, and bradykinin, as well as the human MAS-related G protein-coupled receptor X1. Interestingly, both orthosteric activation and allosteric modulation of GPCRs by hemorphins have been reported. This review links hemorphins with GPCR pharmacology and signaling, supporting the implication of GPCRs in hemorphins’ effects. Thus, this aids a better understanding of the molecular basis of the action of hemorphins and further demonstrates that hemorphin-GPCR axis constitutes a valid target for therapeutic intervention in different systems.

scholarly journals The molecular basis of subtype selectivity of human kinin G-protein-coupled receptors

2018 ◽  
Vol 14 (3) ◽  
pp. 284-290 ◽  
Author(s):  
Lisa Joedicke ◽  
Jiafei Mao ◽  
Georg Kuenze ◽  
Christoph Reinhart ◽  
Tejaswi Kalavacherla ◽  
...  
Keyword(s):  
G Protein ◽  
Molecular Basis ◽  
G Protein Coupled Receptors ◽  
Subtype Selectivity ◽  
G Protein Coupled

ChemInform Abstract: Allosteric Modulation of G Protein-Coupled Receptors

ChemInform ◽  
2010 ◽  
Vol 32 (28) ◽  
pp. no-no
Author(s):  
Ad Ijzerman ◽  
Angeliki Kourounakis ◽  
Pieter van der Klein
Keyword(s):  
G Protein ◽  
Allosteric Modulation ◽  
G Protein Coupled Receptors ◽  
G Protein Coupled

scholarly journals Molecular Basis of Secretin Docking to Its Intact Receptor Using Multiple Photolabile Probes Distributed throughout the Pharmacophore

2011 ◽  
Vol 286 (27) ◽  
pp. 23888-23899 ◽  
Author(s):  
Maoqing Dong ◽  
Polo C.-H. Lam ◽  
Delia I. Pinon ◽  
Keiko Hosohata ◽  
Andrew Orry ◽  
...  
Keyword(s):  
G Protein ◽  
Molecular Basis ◽  
Peptide Mapping ◽  
G Protein Coupled Receptors ◽  
Peptide Ligands ◽  
Amino Terminus ◽  
Amino Terminal ◽  
Binding Cleft ◽  
Mutant Receptors ◽  
G Protein Coupled

The molecular basis of ligand binding and activation of family B G protein-coupled receptors is not yet clear due to the lack of insight into the structure of intact receptors. Although NMR and crystal structures of amino-terminal domains of several family members support consistency in general structural motifs that include a peptide-binding cleft, there are variations in the details of docking of the carboxyl terminus of peptide ligands within this cleft, and there is no information about siting of the amino terminus of these peptides. There are also no empirical data to orient the receptor amino terminus relative to the core helical bundle domain. Here, we prepared a series of five new probes, incorporating photolabile moieties into positions 2, 15, 20, 24, and 25 of full agonist secretin analogues. Each bound specifically to the receptor and covalently labeled single distinct receptor residues. Peptide mapping of labeled wild-type and mutant receptors identified that the position 15, 20, and 25 probes labeled residues within the distal amino terminus of the receptor, whereas the position 24 probe labeled the amino terminus adjacent to TM1. Of note, the position 2 probe labeled a residue within the first extracellular loop of the receptor, a region not previously labeled, providing an important new constraint for docking the amino-terminal region of secretin to its receptor core. These additional experimentally derived constraints help to refine our understanding of the structure of the secretin-intact receptor complex and provide new insights into understanding the molecular mechanism for activation of family B G protein-coupled receptors.

scholarly journals Roles of G Protein-Coupled Receptors (GPCRs) in Gastrointestinal Cancers: Focus on Sphingosine 1-Shosphate Receptors, Angiotensin II Receptors, and Estrogen-Related GPCRs

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2988
Author(s):  
Zhen Zeng ◽  
Chunxiang Ma ◽  
Kexin Chen ◽  
Mingshan Jiang ◽  
Reshma Vasu ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
G Protein ◽  
G Protein Coupled Receptors ◽  
Angiotensin Ii Receptors ◽  
Biological Processes ◽  
Substantial Evidence ◽  
Sphingosine 1 Phosphate ◽  
Gi Cancers ◽  
G Protein Coupled ◽  
Made In

It is well established that gastrointestinal (GI) cancers are common and devastating diseases around the world. Despite the significant progress that has been made in the treatment of GI cancers, the mortality rates remain high, indicating a real need to explore the complex pathogenesis and develop more effective therapeutics for GI cancers. G protein-coupled receptors (GPCRs) are critical signaling molecules involved in various biological processes including cell growth, proliferation, and death, as well as immune responses and inflammation regulation. Substantial evidence has demonstrated crucial roles of GPCRs in the development of GI cancers, which provided an impetus for further research regarding the pathophysiological mechanisms and drug discovery of GI cancers. In this review, we mainly discuss the roles of sphingosine 1-phosphate receptors (S1PRs), angiotensin II receptors, estrogen-related GPCRs, and some other important GPCRs in the development of colorectal, gastric, and esophageal cancer, and explore the potential of GPCRs as therapeutic targets.

scholarly journals Unique Features of Different Classes of G-Protein-Coupled Receptors Revealed from Sequence Coevolutionary and Structural Analysis

2021 ◽  
Author(s):  
Hung Do ◽  
Allan Haldane ◽  
Ronald Levy ◽  
Yinglong Miao
Keyword(s):  
Structural Analysis ◽  
G Protein ◽  
Allosteric Modulation ◽  
G Protein Coupled Receptors ◽  
Class A ◽  
Gpcr Activation ◽  
Residue Contacts ◽  
Critical Residue ◽  
Contact Frequency ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs) are the largest family of human membrane proteins and serve as the primary targets of about one third of currently marketed drugs. Despite the critical importance, experimental structures have been determined for only a limited portion of GPCRs. Functional mechanisms of GPCRs remain poorly understood. Here, we have constructed sequence coevolutionary models of the A, B and C classes of GPCRs and compared them with residue contact frequency maps generated with available experimental structures. Significant portions of structural residue contacts have been successfully detected in the sequence-based covariational models. "Exception" residue contacts predicted from sequence coevolutionary models but not available structures added missing links that were important for GPCR activation and allosteric modulation. Our combined coevolutionary and structural analysis revealed unique features of the different classes of GPCRs. First, we provided evidence from coevolutionary couplings that dimerization is required for activation of class C GPCRs, but not for activation of class A and B GPCRs. Second, we identified distinct residue contacts involving different sets of functional motifs for activation of the class A and B GPCRs. Finally, we uncovered critical residue contacts tuned by allosteric modulation in the three classes of GPCRs. These findings provide a promising framework for designing selective therapeutics of GPCRs.

scholarly journals Unique Features of Different Classes of G-Protein-Coupled Receptors Revealed from Sequence Coevolutionary and Structural Analysis

2021 ◽  
Author(s):  
Hung Do ◽  
Allan Haldane ◽  
Ronald M. Levy ◽  
Yinglong Miao
Keyword(s):  
G Protein ◽  
Rational Design ◽  
Allosteric Modulation ◽  
G Protein Coupled Receptors ◽  
Class A ◽  
Gpcr Activation ◽  
Residue Contacts ◽  
Critical Residue ◽  
Contact Frequency ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs) are the largest family of human membrane proteins and represent the primary targets of about one third of currently marketed drugs. Despite the critical importance, experimental structures have been determined for only a limited portion of GPCRs and functional mechanisms of GPCRs remain poorly understood. Here, we have constructed novel sequence coevolutionary models of the A and B classes of GPCRs and compared them with residue contact frequency maps generated with available experimental structures. Significant portions of structural residue contacts were successfully detected in the sequence-based covariational models. “Exception” residue contacts predicted from sequence coevolutionary models but not available structures added missing links that were important for GPCR activation and allosteric modulation. Moreover, we identified distinct residue contacts involving different sets of functional motifs for GPCR activation, such as the Na+ pocket, CWxP, DRY, PIF and NPxxY motifs in the class A and the HETx and PxxG motifs in the class B. Finally, we systematically uncovered critical residue contacts tuned by allosteric modulation in the two classes of GPCRs, including those from the activation motifs and particularly the extracellular and intracellular loops in class A GPCRs. These findings provide a promising framework for rational design of ligands to regulate GPCR activation and allosteric modulation.

scholarly journals Structural Basis for Allosteric Modulation of Class B G Protein–Coupled Receptors

2020 ◽  
Vol 60 (1) ◽  
pp. 89-107 ◽  
Author(s):  
Denise Wootten ◽  
Laurence J. Miller
Keyword(s):  
G Protein ◽  
Allosteric Modulation ◽  
G Protein Coupled Receptors ◽  
Structural Basis ◽  
Allosteric Modulators ◽  
Class B ◽  
Endogenous Proteins ◽  
And Function ◽  
Agonist Ligands ◽  
G Protein Coupled

Recent advances in our understanding of the structure and function of class B G protein–coupled receptors (GPCRs) provide multiple opportunities for targeted development of allosteric modulators. Given the pleiotropic signaling patterns emanating from these receptors in response to a variety of natural agonist ligands, modulators have the potential to sculpt the responses to meet distinct needs of different groups of patients. In this review, we provide insights into how this family of GPCRs differs from the rest of the superfamily, how orthosteric agonists bind and activate these receptors, the potential for allosteric modulators to interact with various regions of these targets, and the allosteric influence of endogenous proteins on the pharmacology of these receptors, all of which are important considerations when developing new therapies.

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