scholarly journals Structural mechanisms of transient receptor potential ion channels

2020 ◽  
Vol 152 (3) ◽  
Author(s):  
Erhu Cao

Transient receptor potential (TRP) ion channels are evolutionarily ancient sensory proteins that detect and integrate a wide range of physical and chemical stimuli. TRP channels are fundamental for numerous biological processes and are therefore associated with a multitude of inherited and acquired human disorders. In contrast to many other major ion channel families, high-resolution structures of TRP channels were not available before 2013. Remarkably, however, the subsequent “resolution revolution” in cryo-EM has led to an explosion of TRP structures in the last few years. These structures have confirmed that TRP channels assemble as tetramers and resemble voltage-gated ion channels in their overall architecture. But beyond the relatively conserved transmembrane core embedded within the lipid bilayer, each TRP subtype appears to be endowed with a unique set of soluble domains that may confer diverse regulatory mechanisms. Importantly, TRP channel TR structures have revealed sites and mechanisms of action of numerous synthetic and natural compounds, as well as those for endogenous ligands such as lipids, Ca2+, and calmodulin. Here, I discuss these recent findings with a particular focus on the conserved transmembrane region and how these structures may help to rationally target this important class of ion channels for the treatment of numerous human conditions.

2019 ◽  
Vol 116 (31) ◽  
pp. 15540-15549 ◽  
Author(s):  
Leo C. T. Ng ◽  
Thuy N. Vien ◽  
Vladimir Yarov-Yarovoy ◽  
Paul G. DeCaen

The opening of voltage-gated ion channels is initiated by transfer of gating charges that sense the electric field across the membrane. Although transient receptor potential ion channels (TRP) are members of this family, their opening is not intrinsically linked to membrane potential, and they are generally not considered voltage gated. Here we demonstrate that TRPP2, a member of the polycystin subfamily of TRP channels encoded by the PKD2L1 gene, is an exception to this rule. TRPP2 borrows a biophysical riff from canonical voltage-gated ion channels, using 2 gating charges found in its fourth transmembrane segment (S4) to control its conductive state. Rosetta structural prediction demonstrates that the S4 undergoes ∼3- to 5-Å transitional and lateral movements during depolarization, which are coupled to opening of the channel pore. Here both gating charges form state-dependent cation–π interactions within the voltage sensor domain (VSD) during membrane depolarization. Our data demonstrate that the transfer of a single gating charge per channel subunit is requisite for voltage, temperature, and osmotic swell polymodal gating of TRPP2. Taken together, we find that irrespective of stimuli, TRPP2 channel opening is dependent on activation of its VSDs.


Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 816
Author(s):  
Oxana Yu. Kytikova ◽  
Tatyana P. Novgorodtseva ◽  
Yulia K. Denisenko ◽  
Denis E. Naumov ◽  
Tatyana A. Gvozdenko ◽  
...  

Asthma is a widespread chronic disease of the bronchopulmonary system with a heterogeneous course due to the complex etiopathogenesis. Natural-climatic and anthropogenic factors play an important role in the development and progression of this pathology. The reception of physical and chemical environmental stimuli and the regulation of body temperature are mediated by thermosensory channels, members of a subfamily of transient receptor potential (TRP) ion channels. It has been found that genes encoding vanilloid, ankyrin, and melastatin TRP channels are involved in the development of some asthma phenotypes and in the formation of exacerbations of this pathology. The review summarizes modern views on the role of high and low temperatures in airway inflammation in asthma. The participation of thermosensory TRP channels (vanilloid, ankyrin, and melastatin TRP channels) in the reaction to high and low temperatures and air humidity as well as in the formation of bronchial hyperreactivity and respiratory symptoms accompanying asthma is described. The genetic aspects of the functioning of thermosensory TRP channels are discussed. It is shown that new methods of treatment of asthma exacerbations caused by the influence of temperature and humidity should be based on the regulation of channel activity.


2007 ◽  
Vol 292 (1) ◽  
pp. R64-R76 ◽  
Author(s):  
Michael J. Caterina

Living organisms must evaluate changes in environmental and internal temperatures to mount appropriate physiological and behavioral responses conducive to survival. Classical physiology has provided a wealth of information regarding the specialization of thermosensory functions among subclasses of peripheral sensory neurons and intrinsically thermosensitive neurons within the hypothalamus. However, until recently, the molecular mechanisms by which these cells carry out thermometry have remained poorly understood. The demonstration that certain ion channels of the transient receptor potential (TRP) family can be activated by increases or decreases in ambient temperature, along with the recognition of their heterogeneous expression patterns and heterogeneous temperature sensitivities, has led investigators to evaluate these proteins as candidate endogenous thermosensors. Much of this work has involved one specific channel, TRP vanilloid 1 (TRPV1), which is both a receptor for capsaicin and related pungent vanilloid compounds and a “heat receptor,” capable of directly depolarizing neurons in response to temperatures >42°C. Evidence for a contribution of TRPV1 to peripheral thermosensation has come from pharmacological, physiological, and genetic approaches. In contrast, although capsaicin-sensitive mechanisms clearly influence core body temperature regulation, the specific contribution of TRPV1 to this process remains a matter of debate. Besides TRPV1, at least six additional thermally sensitive TRP channels have been identified in mammals, and many of these also appear to participate in thermosensation. Moreover, the identification of invertebrate TRP channels, whose genetic ablation alters thermally driven behaviors, makes it clear that thermosensation represents an evolutionarily conserved role of this ion channel family.


2013 ◽  
Vol 6 (1) ◽  
pp. 50-61 ◽  
Author(s):  
E.S. Fernandes ◽  
S. Awal ◽  
R. Karadaghi ◽  
S.D. Brain

Arthritis is a condition characterised by mainly pain, reduced joint movement and signs of inflammation, such as swelling. The disorder has many different types, of which osteoarthritis (a degenerative joint disease) and rheumatoid arthritis (a chronic autoimmune disease) are the two most common forms. There are >6 million sufferers in the UK and both conditions have a huge potential to impair capabilities and contribute to social and economic burdens. Whilst there are a wide range of arthritic therapies available, many patients under treatment complain of poor pain relief. Thus there is a need for novel therapeutic approaches, and the transient receptor potential (TRP) family of receptor channels has been investigated. One particular area of recent research has been the ligand-gated transient receptor potential vanilloid 1 (TRPV1) channel. Findings from numerous pre-clinical models and scientific studies have shown that TRPV1 desensitisation, or the use of TRPV1 antagonists alleviates pain and some inflammatory aspects. New findings have started to unveil the potential of other TRP channels in mediating arthritic pain and inflammation. With the understanding that the currently available treatments for arthritis are limited, researchers have looked into the exciting prospect that TRP receptor antagonists may be developed into effective, specific drugs, which would potentially protect against the complications of arthritis. These antagonists are still under development, although only data from studies from pre-clinical models are currently available. This review acts to summarize knowledge of the potential influence of TRP receptors in arthritis to date.


2021 ◽  
Author(s):  
Nupur S. Munjal ◽  
Dikscha Sapra ◽  
Abhishek Goyal ◽  
K.T. Shreya Parthasarathi ◽  
Akhilesh Pandey ◽  
...  

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the worldwide COVID-19 pandemic which began in 2019. It has a high transmission rate and pathogenicity leading to health emergencies and economic crisis. Recent studies pertaining to the understanding of the molecular pathogenesis of SARS-CoV-2 infection exhibited the indispensable role of ion channels in viral infection inside the host. Moreover, machine learning (ML)-based algorithms are providing higher accuracy for host-SARS-CoV-2 protein-protein interactions (PPIs). In this study, predictions of PPIs of SARS-CoV-2 proteins with human ion channels (HICs) were performed using PPI-MetaGO algorithm. The PPIs were predicted with 82.71% accuracy, 84.09% precision, 84.09% sensitivity, 0.89 AUC-ROC, 65.17% Matthews correlation coefficient (MCC) score and 84.09% F1 score. Thereafter, PPI networks of SARSCoV-2 proteins with HICs were generated. Furthermore, biological pathway analysis of HICs interacting with SARS-CoV-2 proteins showed the involvement of six pathways, namely inflammatory mediator regulation of transient receptor potential (TRP) channels, insulin secretion, renin secretion, gap junction, taste transduction and apelin signaling pathway. Our analysis suggests that transient receptor potential cation channel subfamily M member 4 (TRPM4), transient receptor potential cation channel subfamily A member 1 (TRPA1), gap junction protein alpha 1 (GJA1), potassium calcium-activated channel subfamily N member 4 (KCNN4), acid sensing ion channel subunit 1 (ASIC1) and inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) could serve as an initial set to the experimentalists for further validation. Additionally, various US food and drug administration (FDA) approved drugs interacting with the potential HICs were also identified. The study also reinforcesthe drug repurposing approach for the development of host directed antiviral drugs.


Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 478 ◽  
Author(s):  
Nicholas J. Sisco ◽  
Dustin D. Luu ◽  
Minjoo Kim ◽  
Wade D. Van Horn

Transient receptor potential (TRP) ion channels are polymodal receptors that have been implicated in a variety of pathophysiologies, including pain, obesity, and cancer. The capsaicin and heat sensor TRPV1, and the menthol and cold sensor TRPM8, have been shown to be modulated by the membrane protein PIRT (Phosphoinositide-interacting regulator of TRP). The emerging mechanism of PIRT-dependent TRPM8 regulation involves a competitive interaction between PIRT and TRPM8 for the activating phosphatidylinositol 4,5-bisphosphate (PIP2) lipid. As many PIP2 modulated ion channels also interact with calmodulin, we investigated the possible interaction between PIRT and calmodulin. Using microscale thermophoresis (MST), we show that calmodulin binds to the PIRT C-terminal α-helix, which we corroborate with a pull-down experiment, nuclear magnetic resonance-detected binding study, and Rosetta-based computational studies. Furthermore, we identify a cholesterol-recognition amino acid consensus (CRAC) domain in the outer leaflet of the first transmembrane helix of PIRT, and with MST, show that PIRT specifically binds to a number of cholesterol-derivatives. Additional studies identified that PIRT binds to cholecalciferol and oxytocin, which has mechanistic implications for the role of PIRT regulation of additional ion channels. This is the first study to show that PIRT specifically binds to a variety of ligands beyond TRP channels and PIP2.


Scientifica ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Nelson S. Yee ◽  
Ada S. Chan ◽  
Julian D. Yee ◽  
Rosemary K. Yee

Transient receptor potential (TRP) ion channels are essential for normal functions and health by acting as molecular sensors and transducing various stimuli into cellular and physiological responses. Growing evidence has revealed that TRP ion channels play important roles in a wide range of human diseases, including malignancies. In light of recent discoveries, it has been found that TRP melastatin-subfamily members, TRPM7 and TRPM8, are required for normal and cancerous development of exocrine pancreas. We are currently investigating the mechanisms which mediate the functional roles of TRPM7 and TRPM8 and attempting to develop these ion channels as clinical biomarkers and therapeutic targets for achieving the goal of personalized therapy in pancreatic cancer.


2012 ◽  
Vol 20 (3) ◽  
pp. 343-355 ◽  
Author(s):  
Bernd Nilius

The ‘transient receptor potential’ (TRP) multigene family encodes sixspan membrane proteins that function as ion channels in mostly tetrameric structures. Members of this family are conserved from yeast, worm, fly to invertebrate, vertebrate and man. These channels have been stigmatized to function only as cell sensors occupied by sensory function. It turns out that TRP channels fulfil a plethora of cellular functions, including non-sensory functions in our brain. This short paper will highlight the advent of novel ion channels in the brain serving different functions and being significantly involved in the genesis of multiple diseases. We will certainly witness a plethora of the novel roles of this protein family in physiological and pathophysiological functions in our central nervous system.


2021 ◽  
Vol 134 (13) ◽  
Author(s):  
Lixia Yue ◽  
Haoxing Xu

ABSTRACT The transient receptor potential (TRP) channel superfamily consists of a large group of non-selective cation channels that serve as cellular sensors for a wide spectrum of physical and environmental stimuli. The 28 mammalian TRPs, categorized into six subfamilies, including TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPA (ankyrin), TRPML (mucolipin) and TRPP (polycystin), are widely expressed in different cells and tissues. TRPs exhibit a variety of unique features that not only distinguish them from other superfamilies of ion channels, but also confer diverse physiological functions. Located at the plasma membrane or in the membranes of intracellular organelles, TRPs are the cellular safeguards that sense various cell stresses and environmental stimuli and translate this information into responses at the organismal level. Loss- or gain-of-function mutations of TRPs cause inherited diseases and pathologies in different physiological systems, whereas up- or down-regulation of TRPs is associated with acquired human disorders. In this Cell Science at a Glance article and the accompanying poster, we briefly summarize the history of the discovery of TRPs, their unique features, recent advances in the understanding of TRP activation mechanisms, the structural basis of TRP Ca2+ selectivity and ligand binding, as well as potential roles in mammalian physiology and pathology.


Sign in / Sign up

Export Citation Format

Share Document