scholarly journals Adenosine turnover (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

2019 ◽  
Vol 2019 (4) ◽  
Author(s):  
Detlev Boison
Keyword(s):  
Cell Surface ◽  
Adenosine Deaminase ◽  
Inorganic Phosphate ◽  
G Protein Coupled Receptors ◽  
Adenosine Kinase ◽  
Nucleoside Transporters ◽  
Nucleotidase Activity ◽  
Extracellular Adenosine ◽  
Adenosylhomocysteine Hydrolase ◽  
G Protein Coupled

A multifunctional, ubiquitous molecule, adenosine acts at cell-surface G protein-coupled receptors, as well as numerous enzymes, including protein kinases and adenylyl cyclase. Extracellular adenosine is thought to be produced either by export or by metabolism, predominantly through ecto-5’-nucleotidase activity (also producing inorganic phosphate). It is inactivated either by extracellular metabolism via adenosine deaminase (also producing ammonia) or, following uptake by nucleoside transporters, via adenosine deaminase or adenosine kinase (requiring ATP as co-substrate). Intracellular adenosine may be produced by cytosolic 5’-nucleotidases or through S-adenosylhomocysteine hydrolase (also producing L-homocysteine).

scholarly journals Adenosine turnover in GtoPdb v.2021.3

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Detlev Boison
Keyword(s):  
Cell Surface ◽  
Adenosine Deaminase ◽  
Inorganic Phosphate ◽  
G Protein Coupled Receptors ◽  
Adenosine Kinase ◽  
Nucleoside Transporters ◽  
Nucleotidase Activity ◽  
Extracellular Adenosine ◽  
Adenosylhomocysteine Hydrolase ◽  
G Protein Coupled

A multifunctional, ubiquitous molecule, adenosine acts at cell-surface G protein-coupled receptors, as well as numerous enzymes, including protein kinases and adenylyl cyclase. Extracellular adenosine is thought to be produced either by export or by metabolism, predominantly through ecto-5’-nucleotidase activity (also producing inorganic phosphate). It is inactivated either by extracellular metabolism via adenosine deaminase (also producing ammonia) or, following uptake by nucleoside transporters, via adenosine deaminase or adenosine kinase (requiring ATP as co-substrate). Intracellular adenosine may be produced by cytosolic 5’-nucleotidases or through S-adenosylhomocysteine hydrolase (also producing L-homocysteine).

PET Imaging of Adenosine Receptors in Diseases

2019 ◽  
Vol 19 (16) ◽  
pp. 1445-1463 ◽  
Author(s):  
Jindian Li ◽  
Xingfang Hong ◽  
Guoquan Li ◽  
Peter S. Conti ◽  
Xianzhong Zhang ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Adenosine Receptors ◽  
Neurological Diseases ◽  
G Protein Coupled Receptors ◽  
Extracellular Adenosine ◽  
Positron Emission ◽  
Imaging Probes ◽  
Pet Probes ◽  
Cancer And Inflammation ◽  
G Protein Coupled

Adenosine receptors (ARs) are a class of purinergic G-protein-coupled receptors (GPCRs). Extracellular adenosine is a pivotal regulation molecule that adjusts physiological function through the interaction with four ARs: A1R, A2AR, A2BR, and A3R. Alterations of ARs function and expression have been studied in neurological diseases (epilepsy, Alzheimer’s disease, and Parkinson’s disease), cardiovascular diseases, cancer, and inflammation and autoimmune diseases. A series of Positron Emission Tomography (PET) probes for imaging ARs have been developed. The PET imaging probes have provided valuable information for diagnosis and therapy of diseases related to alterations of ARs expression. This review presents a concise overview of various ARs-targeted radioligands for PET imaging in diseases. The most recent advances in PET imaging studies by using ARs-targeted probes are briefly summarized.

scholarly journals Understudied G Protein-Coupled Receptors in the Kidney

Nephron ◽  
2021 ◽  
pp. 1-4
Author(s):  
Nathan A. Zaidman ◽  
Jennifer L. Pluznick
Keyword(s):  
Renal Function ◽  
Cell Surface ◽  
Gene Family ◽  
G Protein ◽  
External Environment ◽  
G Protein Coupled Receptors ◽  
Surface Proteins ◽  
Cell Surface Proteins ◽  
Large Subset ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) are cell surface proteins which play a key role in allowing cells, tissues, and organs to respond to changes in the external environment in order to maintain homeostasis. Despite the fact that GPCRs are known to play key roles in a variety of tissues, there are a large subset of GPCRs that remain poorly studied. In this minireview, we will summarize what is known regarding the “understudied” GPCRs with respect to renal function, and in so doing will highlight the promise represented by studying this gene family.

scholarly journals ADP-Ribosylation Factors Modulate the Cell Surface Transport of G Protein-Coupled Receptors

2010 ◽  
Vol 333 (1) ◽  
pp. 174-183 ◽  
Author(s):  
Chunmin Dong ◽  
Xiaoping Zhang ◽  
Fuguo Zhou ◽  
Huijuan Dou ◽  
Matthew T. Duvernay ◽  
...  
Keyword(s):  
Cell Surface ◽  
G Protein ◽  
G Protein Coupled Receptors ◽  
Surface Transport ◽  
Adp Ribosylation ◽  
G Protein Coupled

The Endoplasmic Reticulum Ca2+-pump SERCA2b Interacts with G Protein-coupled Receptors and Enhances their Expression at the Cell Surface

2007 ◽  
Vol 371 (3) ◽  
pp. 622-638 ◽  
Author(s):  
Jussi T. Tuusa ◽  
Piia M.H. Markkanen ◽  
Pirjo M. Apaja ◽  
Anna E. Hakalahti ◽  
Ulla E. Petäjä-Repo
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Surface ◽  
G Protein ◽  
G Protein Coupled Receptors ◽  
G Protein Coupled

scholarly journals Individual cells traffic the Vasopressin 2 Receptor to their cell surface with different success

2021 ◽  
Author(s):  
Eline J Koers ◽  
Bradley A Morgan ◽  
Iain B Styles ◽  
Dmitry J Veprintsev
Keyword(s):  
Cell Surface ◽  
Receptor Cell ◽  
Surface Expression ◽  
G Protein Coupled Receptors ◽  
Cell Surface Expression ◽  
Subcellular Localisation ◽  
Equal Distribution ◽  
Mutant Receptors ◽  
G Protein Coupled ◽  
Correct Expression

G protein coupled receptors (GPCRs) translate the actions of hormones and neurotransmitters into intracellular signalling events. Mutations in GPCRs can prevent their correct expression and trafficking to the cell surface and cause disease. Single cell subcellular localisation measurements reveal that while some cells appear to traffic the majority of the vasopressin 2 receptor (V2R) molecules to the cell surface, others retain a greater number of receptors in the ER or have approximately equal distribution. Mutations in the V2R affect the proportion of cells able to send this GPCR to their cell surface but surprisingly they do not prevent all cells from correctly trafficking the mutant receptors. These findings reveal the potential for rescue of mutant receptor cell surface expression by pharmacological manipulation of the GPCR folding and trafficking machinery.

scholarly journals Modulation of bladder function by luminal adenosine turnover and A1 receptor activation

2012 ◽  
Vol 303 (2) ◽  
pp. F279-F292 ◽  
Author(s):  
H. Sandeep Prakasam ◽  
Heather Herrington ◽  
James R. Roppolo ◽  
Edwin K. Jackson ◽  
Gerard Apodaca
Keyword(s):  
Receptor Activation ◽  
Adenosine Kinase ◽  
Nucleoside Transporters ◽  
Bladder Function ◽  
Extracellular Adenosine ◽  
Equilibrative Nucleoside Transporters ◽  
Lack Of Information ◽  
Bladder Activity ◽  
A1 Receptor ◽  
A Site

The bladder uroepithelium transmits information to the underlying nervous and musculature systems, is under constant cyclical strain, expresses all four adenosine receptors (A1, A2A, A2B, and A3), and is a site of adenosine production. Although adenosine has a well-described protective effect in several organs, there is a lack of information about adenosine turnover in the uroepithelium or whether altering luminal adenosine concentrations impacts bladder function or overactivity. We observed that the concentration of extracellular adenosine at the mucosal surface of the uroepithelium was regulated by ecto-adenosine deaminase and by equilibrative nucleoside transporters, whereas adenosine kinase and equilibrative nucleoside transporters modulated serosal levels. We further observed that enriching endogenous adenosine by blocking its routes of metabolism or direct activation of mucosal A1 receptors with 2-chloro- N6-cyclopentyladenosine (CCPA), a selective agonist, stimulated bladder activity by lowering the threshold pressure for voiding. Finally, CCPA did not quell bladder hyperactivity in animals with acute cyclophosphamide-induced cystitis but instead exacerbated their irritated bladder phenotype. In conclusion, we find that adenosine levels at both surfaces of the uroepithelium are modulated by turnover, that blocking these pathways or stimulating A1 receptors directly at the luminal surface promotes bladder contractions, and that adenosine further stimulates voiding in animals with cyclophosphamide-induced cystitis.

Oligomerisation of G-protein-coupled receptors

2001 ◽  
Vol 114 (7) ◽  
pp. 1265-1271 ◽  
Author(s):  
G. Milligan
Keyword(s):  
Energy Transfer ◽  
Cell Surface ◽  
G Protein ◽  
Living Cells ◽  
G Protein Coupled Receptors ◽  
Intact Cells ◽  
Effective Delivery ◽  
Multiple Copies ◽  
Agonist Ligands ◽  
G Protein Coupled

A range of approaches have recently provided evidence that G-protein-coupled receptors can exist as oligomeric complexes. Both homo-oligomers, comprising multiple copies of the same gene product, and hetero-oligomers containing more than one receptor have been detected. In several, but not all, examples, the extent of oligomerisation is regulated by the presence of agonist ligands, and emerging evidence indicates that receptor hetero-oligomers can display distinct pharmacological characteristics. A chaperonin-like role for receptor oligomerisation in effective delivery of newly synthesised receptors to the cell surface is a developing concept, and recent studies have employed a series of energy-transfer techniques to explore the presence and regulation of receptor oligomerisation in living cells. However, the majority of studies have relied largely on co-immunoprecipitation techniques, and there is still little direct information on the fraction of receptors existing as oligomers in intact cells.

Sign in / Sign up

Export Citation Format

Share Document