scholarly journals Ubiquitin-Mediated Regulation of Endocytosis by Proteins of the Arrestin Family

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Michel Becuwe ◽  
Antonio Herrador ◽  
Rosine Haguenauer-Tsapis ◽  
Olivier Vincent ◽  
Sébastien Léon

In metazoans, proteins of the arrestin family are key players of G-protein-coupled receptors (GPCRS) signaling and trafficking. Following stimulation, activated receptors are phosphorylated, thus allowing the binding of arrestins and hence an “arrest” of receptor signaling. Arrestins act by uncoupling receptors from G proteins and contribute to the recruitment of endocytic proteins, such as clathrin, to direct receptor trafficking into the endocytic pathway. Arrestins also serve as adaptor proteins by promoting the recruitment of ubiquitin ligases and participate in the agonist-induced ubiquitylation of receptors, known to have impact on their subcellular localization and stability. Recently, the arrestin family has expanded following the discovery of arrestin-related proteins in other eukaryotes such as yeasts or fungi. Surprisingly, most of these proteins are also involved in the ubiquitylation and endocytosis of plasma membrane proteins, thus suggesting that the role of arrestins as ubiquitin ligase adaptors is at the core of these proteins' functions. Importantly, arrestins are themselves ubiquitylated, and this modification is crucial for their function. In this paper, we discuss recent data on the intricate connections between arrestins and the ubiquitin pathway in the control of endocytosis.

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Frederic Delom ◽  
Delphine Fessart

The process by which G protein-coupled receptors (GPCRs) are internalized through the clathrin-coated vesicles involves interactions of multifunctional adaptor proteins. These interactions are tightly controlled by phosphorylation and dephosphorylation mechanisms resulting in the regulation of receptor endocytosis. However, the identities of the kinases involved in this process remained largely unknown until recently. This paper discusses advances in our knowledge of the important role played by protein phosphorylation in the regulation of the endocytic machinery and how phosphorylation controls the coated vesicle cycle.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Neil N. Patel ◽  
Alan D. Workman ◽  
Noam A. Cohen

Evidence is emerging that shows taste receptors serve functions outside of taste sensation of the tongue. Taste receptors have been found in tissue across the human body, including the gastrointestinal tract, bladder, brain, and airway. These extraoral taste receptors appear to be important in modulating the innate immune response through detection of pathogens. This review discusses taste receptor signaling, focusing on the G-protein–coupled receptors that detect bitter and sweet compounds in the upper airway epithelium. Emphasis is given to recent studies which link the physiology of sinonasal taste receptors to clinical manifestation of upper airway disease.


Author(s):  
Gayathri Viswanathan ◽  
Argen Mamazhakypov ◽  
Ralph T. Schermuly ◽  
Sudarshan Rajagopal

2021 ◽  
Author(s):  
Matthias Schlichting ◽  
Shlesha Richhariya ◽  
Nicholas Herndon ◽  
Dingbang Ma ◽  
Jason Xin ◽  
...  

The metronome-like circadian regulation of sleep timing must still adapt to an uncertain environment. Recent studies in Drosophila indicate that neuromodulation not only plays a key role in clock neuron synchronization but also affects interactions between the clock network and brain sleep centers. We show here that the targets of neuromodulators, G-Protein Coupled Receptors (GPCRs), are highly enriched in the fly brain circadian clock network. Single cell sequencing indicates that they are not only differentially expressed but also define clock neuron identity. We generated a comprehensive guide library to mutagenize individual GPCRs in specific neurons and verified the strategy with a targeted sequencing approach. Combined with a behavioral screen, the mutagenesis strategy revealed a novel role of dopamine in sleep regulation by identifying two dopamine receptors and a clock neuron subpopulation that gate the timing of sleep.


2021 ◽  
Vol 12 ◽  
Author(s):  
Roberta Lattanzi ◽  
Cinzia Severini ◽  
Daniela Maftei ◽  
Luciano Saso ◽  
Aldo Badiani

The prokineticin (PK) family, prokineticin 1 and Bv8/prokineticin 2 (PROK2), initially discovered as regulators of gastrointestinal motility, interacts with two G protein-coupled receptors, PKR1 and PKR2, regulating important biological functions such as circadian rhythms, metabolism, angiogenesis, neurogenesis, muscle contractility, hematopoiesis, immune response, reproduction and pain perception. PROK2 and PK receptors, in particular PKR2, are widespread distributed in the central nervous system, in both neurons and glial cells. The PROK2 expression levels can be increased by a series of pathological insults, such as hypoxia, reactive oxygen species, beta amyloid and excitotoxic glutamate. This suggests that the PK system, participating in different cellular processes that cause neuronal death, can be a key mediator in neurological/neurodegenerative diseases. While many PROK2/PKRs effects in physiological processes have been documented, their role in neuropathological conditions is not fully clarified, since PROK2 can have a double function in the mechanisms underlying to neurodegeneration or neuroprotection. Here, we briefly outline the latest findings on the modulation of PROK2 and its cognate receptors following different pathological insults, providing information about their opposite neurotoxic and neuroprotective role in different pathological conditions.


Biochimie ◽  
2014 ◽  
Vol 107 ◽  
pp. 28-32 ◽  
Author(s):  
Olivier Soubias ◽  
Walter E. Teague ◽  
Kirk G. Hines ◽  
Klaus Gawrisch

2021 ◽  
Vol 220 (11) ◽  
Author(s):  
James L. Shen ◽  
Tina M. Fortier ◽  
Ruoxi Wang ◽  
Eric H. Baehrecke

Defects in autophagy cause problems in metabolism, development, and disease. The autophagic clearance of mitochondria, mitophagy, is impaired by the loss of Vps13D. Here, we discover that Vps13D regulates mitophagy in a pathway that depends on the core autophagy machinery by regulating Atg8a and ubiquitin localization. This process is Pink1 dependent, with loss of pink1 having similar autophagy and mitochondrial defects as loss of vps13d. The role of Pink1 has largely been studied in tandem with Park/Parkin, an E3 ubiquitin ligase that is widely considered to be crucial in Pink1-dependent mitophagy. Surprisingly, we find that loss of park does not exhibit the same autophagy and mitochondrial deficiencies as vps13d and pink1 mutant cells and contributes to mitochondrial clearance through a pathway that is parallel to vps13d. These findings provide a Park-independent pathway for Pink1-regulated mitophagy and help to explain how Vps13D regulates autophagy and mitochondrial morphology and contributes to neurodegenerative diseases.


2019 ◽  
Vol 20 (20) ◽  
pp. 5139 ◽  
Author(s):  
Zhan-Guo Gao ◽  
Kenneth A. Jacobson

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.


2019 ◽  
Vol 119 (04) ◽  
pp. 534-541 ◽  
Author(s):  
Selin Gencer ◽  
Emiel van der Vorst ◽  
Maria Aslani ◽  
Christian Weber ◽  
Yvonne Döring ◽  
...  

AbstractInflammation has been well recognized as one of the main drivers of atherosclerosis development and therefore cardiovascular diseases (CVDs). It has been shown that several chemokines, small 8 to 12 kDa cytokines with chemotactic properties, play a crucial role in the pathophysiology of atherosclerosis. Chemokines classically mediate their effects by binding to G-protein-coupled receptors called chemokine receptors. In addition, chemokines can also bind to atypical chemokine receptors (ACKRs). ACKRs fail to induce G-protein-dependent signalling pathways and thus subsequent cellular response, but instead are able to internalize, scavenge or transport chemokines. In this review, we will give an overview of the current knowledge about the involvement of ACKR1–4 in CVDs and especially in atherosclerosis development. In the recent years, several studies have highlighted the importance of ACKRs in CVDs, although there are still several controversies and unexplored aspects that have to be further elucidated. A better understanding of the precise role of these atypical receptors may pave the way towards novel and improved therapeutic strategies.


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