scholarly journals Gq-Coupled Receptors in Autoimmunity

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lu Zhang ◽  
Guixiu Shi
Keyword(s):  
G Proteins ◽  
Immune Regulation ◽  
Vital Role ◽  
G Protein Coupled Receptors ◽  
Main Function ◽  
Heterotrimeric G Proteins ◽  
Transmembrane Receptors ◽  
Downstream Signaling ◽  
G Protein Coupled

Heterotrimeric G proteins can be divided into Gi, Gs, Gq/11, and G12/13 subfamilies according to theirαsubunits. The main function of G proteins is transducing signals from G protein coupled receptors (GPCRs), a family of seven transmembrane receptors. In recent years, studies have demonstrated that GPCRs interact with Gq, a member of the Gq/11 subfamily of G proteins. This interaction facilitates the vital role of this family of proteins in immune regulation and autoimmunity, particularly for Gαq, which is considered the functionalαsubunit of Gq protein. Therefore, understanding the mechanisms through which Gq-coupled receptors control autoreactive lymphocytes is critical and may provide insights into the treatment of autoimmune disorders. In this review, we summarize recent advances in studies of the role of Gq-coupled receptors in autoimmunity, with a focus on their pathologic role and downstream signaling.

scholarly journals Signaling from G Protein-coupled Receptors to ERK5/Big MAPK 1 Involves Gαqand Gα12/13Families of Heterotrimeric G Proteins

2000 ◽  
Vol 275 (28) ◽  
pp. 21730-21736 ◽  
Author(s):  
Shigetomo Fukuhara ◽  
Maria Julia Marinissen ◽  
Mario Chiariello ◽  
J. Silvio Gutkind
Keyword(s):  
G Protein ◽  
G Proteins ◽  
G Protein Coupled Receptors ◽  
Heterotrimeric G Proteins ◽  
G Protein Coupled

scholarly journals Physiology of the orexinergic/hypocretinergic system: a revisit in 2012

2013 ◽  
Vol 304 (1) ◽  
pp. C2-C32 ◽  
Author(s):  
Jyrki P. Kukkonen
Keyword(s):  
Central Nervous System ◽  
G Proteins ◽  
Cellular Responses ◽  
G Protein Coupled Receptors ◽  
Heterotrimeric G Proteins ◽  
Neuronal Excitation ◽  
System A ◽  
The Central Nervous System ◽  
G Protein Coupled ◽  
Systemic Responses

The neuropeptides orexins and their G protein-coupled receptors, OX1and OX2, were discovered in 1998, and since then, their role has been investigated in many functions mediated by the central nervous system, including sleep and wakefulness, appetite/metabolism, stress response, reward/addiction, and analgesia. Orexins also have peripheral actions of less clear physiological significance still. Cellular responses to the orexin receptor activity are highly diverse. The receptors couple to at least three families of heterotrimeric G proteins and other proteins that ultimately regulate entities such as phospholipases and kinases, which impact on neuronal excitation, synaptic plasticity, and cell death. This article is a 10-year update of my previous review on the physiology of the orexinergic/hypocretinergic system. I seek to provide a comprehensive update of orexin physiology that spans from the molecular players in orexin receptor signaling to the systemic responses yet emphasizing the cellular physiological aspects of this system.

scholarly journals A2B Adenosine Receptor and Cancer

2019 ◽  
Vol 20 (20) ◽  
pp. 5139 ◽  
Author(s):  
Zhan-Guo Gao ◽  
Kenneth A. Jacobson
Keyword(s):  
G Proteins ◽  
Anticancer Agents ◽  
Immune Suppression ◽  
Adenosine Receptors ◽  
Immune Surveillance ◽  
G Protein Coupled Receptors ◽  
Normal Tissues ◽  
Cancer Tissues ◽  
G Protein Coupled

There are four subtypes of adenosine receptors (ARs), named A1, A2A, A2B and A3, all of which are G protein-coupled receptors (GPCRs). Locally produced adenosine is a suppressant in anti-tumor immune surveillance. The A2BAR, coupled to both Gαs and Gαi G proteins, is one of the several GPCRs that are expressed in a significantly higher level in certain cancer tissues, in comparison to adjacent normal tissues. There is growing evidence that the A2BAR plays an important role in tumor cell proliferation, angiogenesis, metastasis, and immune suppression. Thus, A2BAR antagonists are novel, potentially attractive anticancer agents. Several antagonists targeting A2BAR are currently in clinical trials for various types of cancers. In this review, we first describe the signaling, agonists, and antagonists of the A2BAR. We further discuss the role of the A2BAR in the progression of various cancers, and the rationale of using A2BAR antagonists in cancer therapy.

New thoughts on the role of the βγ subunit in G protein signal transduction

2000 ◽  
Vol 78 (5) ◽  
pp. 537-550 ◽  
Author(s):  
Barbara Vanderbeld ◽  
Gregory M Kelly
Keyword(s):  
Signal Transduction ◽  
G Protein ◽  
G Proteins ◽  
G Protein Coupled Receptors ◽  
Limited Information ◽  
Α Subunit ◽  
Downstream Effectors ◽  
Receptor Signal ◽  
G Protein Coupled

Heterotrimeric G proteins are involved in numerous biological processes, where they mediate signal transduction from agonist-bound G-protein-coupled receptors to a variety of intracellular effector molecules and ion channels. G proteins consist of two signaling moieties: a GTP-bound α subunit and a βγ heterodimer. The βγ dimer, recently credited as a significant modulator of G-protein-mediated cellular responses, is postulated to be a major determinant of signaling fidelity between G-protein-coupled receptors and downstream effectors. In this review we have focused on the role of βγ signaling and have included examples to demonstrate the heterogeneity in the heterodimer composition and its implications in signaling fidelity. We also present an overview of some of the effectors regulated by βγ and draw attention to the fact that, although G proteins and their associated receptors play an instrumental role in development, there is rather limited information on βγ signaling in embryogenesis.Key words: G protein, βγ subunit, G-protein-coupled receptor, signal transduction, adenylyl cyclase.

scholarly journals II. Regulation of neuropeptide receptors in enteric neurons

1998 ◽  
Vol 274 (5) ◽  
pp. G792-G796
Author(s):  
Karen McConalogue ◽  
Nigel W. Bunnett
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Target Cell ◽  
Biological Effects ◽  
G Protein Coupled Receptors ◽  
Enteric Neurons ◽  
Heterotrimeric G Proteins ◽  
High Affinity ◽  
Neuropeptide Receptors ◽  
G Protein Coupled

Neuropeptides exert their diverse biological effects by interacting with G protein-coupled receptors (GPCRs). In this review we address the question, What regulates the ability of a target cell, in particular a neuron, to respond to a neuropeptide? Available evidence from studies of many GPCRs in reconstituted systems and transfected cell lines indicates that much of this regulation occurs at the level of the receptor and serves to alter the capacity of the receptor to bind ligands with high affinity and to couple to heterotrimeric G proteins. Although some of the knowledge gained from these studies is applicable to the regulation of neuropeptide receptors on neurons, at present there are far more questions than answers.

scholarly journals Research Advances in Heterotrimeric G-Protein α Subunits and Uncanonical G-Protein Coupled Receptors in Plants

2021 ◽  
Vol 22 (16) ◽  
pp. 8678
Author(s):  
Ying Liu ◽  
Xiaoyun Wang ◽  
Danhui Dong ◽  
Luqin Guo ◽  
Xiaonan Dong ◽  
...  
Keyword(s):  
Signal Transduction ◽  
G Protein ◽  
G Proteins ◽  
Mode Of Action ◽  
Plant Stress ◽  
G Protein Coupled Receptors ◽  
Signal Transducers ◽  
New Perspective ◽  
G Protein Coupled

As crucial signal transducers, G-proteins and G-protein-coupled receptors (GPCRs) have attracted increasing attention in the field of signal transduction. Research on G-proteins and GPCRs has mainly focused on animals, while research on plants is relatively rare. The mode of action of G-proteins is quite different from that in animals. The G-protein α (Gα) subunit is the most essential member of the G-protein signal cycle in animals and plants. The G-protein is activated when Gα releases GDP and binds to GTP, and the relationships with the GPCR and the downstream signal are also achieved by Gα coupling. It is important to study the role of Gα in the signaling pathway to explore the regulatory mechanism of G-proteins. The existence of a self-activated Gα in plants makes it unnecessary for the canonical GPCR to activate the G-protein by exchanging GDP with GTP. However, putative GPCRs have been found and proven to play important roles in G-protein signal transduction. The unique mode of action of G-proteins and the function of putative GPCRs in plants suggest that the same definition used in animal research cannot be used to study uncanonical GPCRs in plants. This review focuses on the different functions of the Gα and the mode of action between plants and animals as well as the functions of the uncanonical GPCR. This review employs a new perspective to define uncanonical GPCRs in plants and emphasizes the role of uncanonical GPCRs and Gα subunits in plant stress resistance and agricultural production.

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