The Opsins: Lies Between Image Forming and Non-image Forming Process

Light, the most abundant and important stimuli, can be sensed by a single photon by the photoreceptors. These photoreceptors are usually a group of protein of GPCR (G protein-coupled receptor) family. Opsins, a group of this family absorb these photons and processes both image forming and non-image forming phototransduction. Initially, their role was only limited to image formation, but recent studies reveal their importance in non -image forming functions also. In this review, we discussed various roles of opsins other than image formation, such as in photorelaxation of blood vessels, mechanoreception of skin, temperature regulation, hearing, immune system, thermotaxis of sperms, photosensation as well as in reproduction. These various functions of opsins show their immense importance in non-image forming functions as well as their evolutionary importance.

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Adhesion GPCRs in Glioblastoma

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab046 ◽

2021 ◽

Author(s):

Gabriele Stephan ◽

Niklas Ravn-Boess ◽

Dimitris G Placantonakis

Keyword(s):

G Protein ◽

G Protein Coupled Receptors ◽

The Past ◽

Novel Treatment ◽

The Family ◽

Health And Disease ◽

Basic Biology ◽

G Protein Coupled ◽

Potential Use ◽

Receptor Family

Abstract Members of the adhesion family of G protein-coupled receptors (GPCRs) have received attention for their roles in health and disease, including cancer. Over the past decade, several members of the family have been implicated in the pathogenesis of glioblastoma. Here, we discuss the basic biology of adhesion GPCRs and review in detail specific members of the receptor family with known functions in glioblastoma. Finally, we discuss the potential use of adhesion GPCRs as novel treatment targets in neuro-oncology.

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Characterization of the G protein-coupled receptor family SREB across fish evolution

Scientific Reports ◽

10.1038/s41598-021-91590-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Timothy S. Breton ◽

William G. B. Sampson ◽

Benjamin Clifford ◽

Anyssa M. Phaneuf ◽

Ilze Smidt ◽

...

Keyword(s):

G Protein ◽

Genomic Structure ◽

Integrated Approach ◽

Orphan Receptor ◽

Specific Gene ◽

Testicular Development ◽

Brain Expression ◽

And Function ◽

G Protein Coupled ◽

Receptor Family

AbstractThe SREB (Super-conserved Receptors Expressed in Brain) family of G protein-coupled receptors is highly conserved across vertebrates and consists of three members: SREB1 (orphan receptor GPR27), SREB2 (GPR85), and SREB3 (GPR173). Ligands for these receptors are largely unknown or only recently identified, and functions for all three are still beginning to be understood, including roles in glucose homeostasis, neurogenesis, and hypothalamic control of reproduction. In addition to the brain, all three are expressed in gonads, but relatively few studies have focused on this, especially in non-mammalian models or in an integrated approach across the entire receptor family. The purpose of this study was to more fully characterize sreb genes in fish, using comparative genomics and gonadal expression analyses in five diverse ray-finned (Actinopterygii) species across evolution. Several unique characteristics were identified in fish, including: (1) a novel, fourth euteleost-specific gene (sreb3b or gpr173b) that likely emerged from a copy of sreb3 in a separate event after the teleost whole genome duplication, (2) sreb3a gene loss in Order Cyprinodontiformes, and (3) expression differences between a gar species and teleosts. Overall, gonadal patterns suggested an important role for all sreb genes in teleost testicular development, while gar were characterized by greater ovarian expression that may reflect similar roles to mammals. The novel sreb3b gene was also characterized by several unique features, including divergent but highly conserved amino acid positions, and elevated brain expression in puffer (Dichotomyctere nigroviridis) that more closely matched sreb2, not sreb3a. These results demonstrate that SREBs may differ among vertebrates in genomic structure and function, and more research is needed to better understand these roles in fish.

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Possible Relevance of Receptor-Receptor Interactions between Viral- and Host-Coded Receptors for Viral-Induced Disease

The Scientific World JOURNAL ◽

10.1100/tsw.2007.166 ◽

2007 ◽

Vol 7 ◽

pp. 1073-1081 ◽

Cited By ~ 1

Author(s):

Luigi F. Agnati ◽

Giuseppina Leo ◽

Susanna Genedani ◽

Diego Guidolin ◽

Nicola Andreoli ◽

...

Keyword(s):

Immune System ◽

G Protein ◽

Cell Metabolism ◽

G Protein Coupled Receptors ◽

Host Cells ◽

Receptor Function ◽

Viral Receptor ◽

Receptor Interactions ◽

Induced Changes ◽

G Protein Coupled

It has been demonstrated that some viruses, such as the cytomegalovirus, code for G-protein coupled receptors not only to elude the immune system, but also to redirect cellular signaling in the receptor networks of the host cells. In view of the existence of receptor-receptor interactions, the hypothesis is introduced that these viral-coded receptors not only operate as constitutively active monomers, but also can affect other receptor function by interacting with receptors of the host cell. Furthermore, it is suggested that viruses could also insert not single receptors (monomers), but clusters of receptors (receptor mosaics), altering the cell metabolism in a profound way. The prevention of viral receptor-induced changes in host receptor networks may give rise to novel antiviral drugs that counteract viral-induced disease.

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G protein–coupled receptor family C group 5 member B (GPRC5B)

Science-Business eXchange ◽

10.1038/scibx.2012.1283 ◽

2012 ◽

Vol 5 (49) ◽

pp. 1283-1283

Keyword(s):

G Protein ◽

G Protein Coupled Receptor ◽

Group 5 ◽

G Protein Coupled ◽

Receptor Family

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Adjuvant Arthritis Induces Down-Regulation of G Protein-Coupled Receptor Kinases in the Immune System

The Journal of Immunology ◽

10.4049/jimmunol.166.3.1635 ◽

2001 ◽

Vol 166 (3) ◽

pp. 1635-1640 ◽

Cited By ~ 82

Author(s):

Maria Stella Lombardi ◽

Annemieke Kavelaars ◽

Pieter M. Cobelens ◽

Reinhold E. Schmidt ◽

Manfred Schedlowski ◽

...

Keyword(s):

Immune System ◽

G Protein ◽

Adjuvant Arthritis ◽

G Protein Coupled Receptor ◽

Down Regulation ◽

Receptor Kinases ◽

G Protein Coupled

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The secretin G-protein-coupled receptor family: teleost receptors

Journal of Molecular Endocrinology ◽

10.1677/jme.1.01730 ◽

2005 ◽

Vol 34 (3) ◽

pp. 753-765 ◽

Cited By ~ 24

Author(s):

J C R Cardoso ◽

M S Clark ◽

F A Viera ◽

P D Bridge ◽

A Gilles ◽

...

Keyword(s):

Vasoactive Intestinal Peptide ◽

G Protein ◽

Strong Support ◽

Duplicated Genes ◽

Related Peptide ◽

Fugu Genome ◽

The Family ◽

Genome Consortium ◽

G Protein Coupled ◽

Receptor Family

Twenty-one members of the secretin family (family 2) of G-protein-coupled receptors (GPCRs) were identified via directed cloning and data-mining of the Fugu Genome Consortium database, representing the most comprehensive description of secretin GPCRs in a teleost fish to date. Duplicated genes were identified for many of the family members, namely the receptors for pituitary adenylate cyclase-activating polypeptide (PACAP)/vasoactive intestinal peptide (VIP), calcitonin, calcitonin gene-related peptide (CGRP), growth hormone releasing hormone (GHRH), glucagon receptor/glucagon-like peptide (GLP) and parathyroid hormone-related peptide (PTHrP)/PTH. Mining of other teleost genomes (zebrafish and Tetraodon) revealed that the duplicated genes identified in the Takifugu genome were also present in these fish. Additional database searching of the Escherichia coli, yeast, Drosophila, Caenorhabditis elegans and Ciona genomes revealed that the family 2 of GPCRs were only present in the multicellular organisms. Orthologues of all the human secretin receptors were identified with the exception of secretin itself. Additional database searches in the Fugu Genome Consortium database also failed to reveal a secretin ligand and so it is hypothesised that both the receptor and the ligand evolved after the divergence of teleost/tetrapod lineages. Phylogenetic analysis at both the protein and the DNA level provided strong support for each of the individual receptor family groupings, but weak support between groups, making evolutionary inferences difficult. A more critical analysis of the PACAP/VIP receptor family confirmed previous hypotheses that the vasoactive intestinal peptide receptor (VPAC1R) gene is the ancestral form of the receptor.

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