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1
Johnkennedy, Nnodim, Bako Hauwa e Ezekwesiri Cletus. "Perspective of Ion Channels in Prostate Cancer". Sumerianz Journal of Medical and Healthcare, n. 42 (6 aprile 2021): 69–72. http://dx.doi.org/10.47752/sjmh.42.69.72.
Testo completoAbstract (sommario):
Ion channels are membrane proteins, which play a great role in regulating cellular excitability. Alteration of ion channel may contribute to prostate cancer. This could be linked to inherited mutations of ion channel genes which alter channel’s biophysical properties, in a prostate cancer. It is an observed fact that genomic instability is the main cause as well as the major characteristics of prostate cancer. Prostate cancer cell genotypes are mainly characterized by uncontrolled metastasis, resistance to programmed cell death, sustained angiogenesis as well as tissue invasion and metastasis. It is known that genes encoding ion channels are affected in prostate cancer. The Membrane proteins which is involved in signaling in cell and among cells, for coupling of extracellular events with intracellular responses, and for maintaining intracellular ionic homeostasis ion channels which contribute to some extents to pathophysiological features of each prostate cancer.
2
Johnkennedy, Nnodim, Bako Hauwa e Ezekwesiri Cletus. "Perspective of Ion Channels in Prostate Cancer". Sumerianz Journal of Medical and Healthcare, n. 42 (6 aprile 2021): 72–75. http://dx.doi.org/10.47752/sjmh.42.72.75.
Testo completoAbstract (sommario):
Ion channels are membrane proteins, which play a great role in regulating cellular excitability. Alteration of ion channel may contribute to prostate cancer. This could be linked to inherited mutations of ion channel genes which alter channel’s biophysical properties, in a prostate cancer. It is an observed fact that genomic instability is the main cause as well as the major characteristics of prostate cancer. Prostate cancer cell genotypes are mainly characterized by uncontrolled metastasis, resistance to programmed cell death, sustained angiogenesis as well as tissue invasion and metastasis. It is known that genes encoding ion channels are affected in prostate cancer. The Membrane proteins which is involved in signaling in cell and among cells, for coupling of extracellular events with intracellular responses, and for maintaining intracellular ionic homeostasis ion channels which contribute to some extents to pathophysiological features of each prostate cancer.
3
Hedrich, Rainer. "Ion Channels in Plants". Physiological Reviews 92, n. 4 (ottobre 2012): 1777–811. http://dx.doi.org/10.1152/physrev.00038.2011.
Testo completoAbstract (sommario):
Since the first recordings of single potassium channel activities in the plasma membrane of guard cells more than 25 years ago, patch-clamp studies discovered a variety of ion channels in all cell types and plant species under inspection. Their properties differed in a cell type- and cell membrane-dependent manner. Guard cells, for which the existence of plant potassium channels was initially documented, advanced to a versatile model system for studying plant ion channel structure, function, and physiology. Interestingly, one of the first identified potassium-channel genes encoding the Shaker-type channel KAT1 was shown to be highly expressed in guard cells. KAT1-type channels from Arabidopsis thaliana and its homologs from other species were found to encode the K+-selective inward rectifiers that had already been recorded in early patch-clamp studies with guard cells. Within the genome era, additional Arabidopsis Shaker-type channels appeared. All nine members of the Arabidopsis Shaker family are localized at the plasma membrane, where they either operate as inward rectifiers, outward rectifiers, weak voltage-dependent channels, or electrically silent, but modulatory subunits. The vacuole membrane, in contrast, harbors a set of two-pore K+ channels. Just very recently, two plant anion channel families of the SLAC/SLAH and ALMT/QUAC type were identified. SLAC1/SLAH3 and QUAC1 are expressed in guard cells and mediate Slow- and Rapid-type anion currents, respectively, that are involved in volume and turgor regulation. Anion channels in guard cells and other plant cells are key targets within often complex signaling networks. Here, the present knowledge is reviewed for the plant ion channel biology. Special emphasis is drawn to the molecular mechanisms of channel regulation, in the context of model systems and in the light of evolution.
4
Roux, Benoît. "Ion channels and ion selectivity". Essays in Biochemistry 61, n. 2 (9 maggio 2017): 201–9. http://dx.doi.org/10.1042/ebc20160074.
Testo completoAbstract (sommario):
Specific macromolecular transport systems, ion channels and pumps, provide the pathways to facilitate and control the passage of ions across the lipid membrane. Ion channels provide energetically favourable passage for ions to diffuse rapidly and passively according to their electrochemical potential. Selective ion channels are essential for the excitability of biological membranes: the action potential is a transient phenomenon that reflects the rapid opening and closing of voltage-dependent Na+-selective and K+-selective channels. One of the most critical functional aspects of K+ channels is their ability to remain highly selective for K+ over Na+ while allowing high-throughput ion conduction at a rate close to the diffusion limit. Permeation through the K+ channel selectivity filter is believed to proceed as a ‘knockon’ mechanism, in which 2–3 K+ ions interspersed by water molecules move in a single file. Permeation through the comparatively wider and less selective Na+ channels also proceeds via a loosely coupled knockon mechanism, although the ions do not need to be fully dehydrated. While simple structural concepts are often invoked to rationalize the mechanism of ion selectivity, a deeper analysis shows that subtle effects play an important role in these flexible dynamical structures.
5
Johnkennedy, Nnodim. "Disorders associated with Ion Channels". Journal of Clinical and Medical Reviews 1, n. 2 (29 dicembre 2022): 01–03. http://dx.doi.org/10.58489/2836-2330/007.
Testo completoAbstract (sommario):
Muscular wasting, a lack of muscle tone, or sporadic muscle paralysis are the most common symptoms of ion channel diseases, which are linked to defects in the proteins known as ion channels. Ion channels are diverse and differ with respect to how they open and close (gating) and their ionic conductance and selectivity (permeation). The development of novel molecules to modulate their activity, fundamental understanding of ion channel structure-function mechanisms, their physiological functions, how their dysfunction results in disease, their use as biosensors, and their utility as biosensors are important and active research frontiers. With a particular emphasis on voltage-gated ion channels, ion-channel engineering methods that have been used to investigate these facets of ion channel function are x-rayed.
6
Ślęczkowska, Milena, Kaalindi Misra, Silvia Santoro, Monique M. Gerrits e Janneke G. J. Hoeijmakers. "Ion Channel Genes in Painful Neuropathies". Biomedicines 11, n. 10 (29 settembre 2023): 2680. http://dx.doi.org/10.3390/biomedicines11102680.
Testo completoAbstract (sommario):
Neuropathic pain (NP) is a typical symptom of peripheral nerve disorders, including painful neuropathy. The biological mechanisms that control ion channels are important for many cell activities and are also therapeutic targets. Disruption of the cellular mechanisms that govern ion channel activity can contribute to pain pathophysiology. The voltage-gated sodium channel (VGSC) is the most researched ion channel in terms of NP; however, VGSC impairment is detected in only <20% of painful neuropathy patients. Here, we discuss the potential role of the other peripheral ion channels involved in sensory signaling (transient receptor potential cation channels), neuronal excitation regulation (potassium channels), involuntary action potential generation (hyperpolarization-activated cyclic nucleotide-gated channels), thermal pain (anoctamins), pH modulation (acid sensing ion channels), and neurotransmitter release (calcium channels) related to pain and their prospective role as therapeutic targets for painful neuropathy.
7
Pozdnyakov, Ilya, Olga Matantseva e Sergei Skarlato. "Consensus channelome of dinoflagellates revealed by transcriptomic analysis sheds light on their physiology". Algae 36, n. 4 (15 dicembre 2021): 315–26. http://dx.doi.org/10.4490/algae.2021.36.12.2.
Testo completoAbstract (sommario):
Ion channels are membrane protein complexes mediating passive ion flux across the cell membranes. Every organism has a certain set of ion channels that define its physiology. Dinoflagellates are ecologically important microorganisms characterized by effective physiological adaptability, which backs up their massive proliferations that often result in harmful blooms (red tides). In this study, we used a bioinformatics approach to identify homologs of known ion channels that belong to 36 ion channel families. We demonstrated that the versatility of the dinoflagellate physiology is underpinned by a high diversity of ion channels including homologs of animal and plant proteins, as well as channels unique to protists. The analysis of 27 transcriptomes allowed reconstructing a consensus ion channel repertoire (channelome) of dinoflagellates including the members of 31 ion channel families: inwardly-rectifying potassium channels, two-pore domain potassium channels, voltage-gated potassium channels (Kv), tandem Kv, cyclic nucleotide-binding domain-containing channels (CNBD), tandem CNBD, eukaryotic ionotropic glutamate receptors, large-conductance calcium-activated potassium channels, intermediate/small-conductance calcium-activated potassium channels, eukaryotic single-domain voltage-gated cation channels, transient receptor potential channels, two-pore domain calcium channels, four-domain voltage-gated cation channels, cation and anion Cys-loop receptors, small-conductivity mechanosensitive channels, large-conductivity mechanosensitive channels, voltage-gated proton channels, inositole-1,4,5- trisphosphate receptors, slow anion channels, aluminum-activated malate transporters and quick anion channels, mitochondrial calcium uniporters, voltage-dependent anion channels, vesicular chloride channels, ionotropic purinergic receptors, animal volage-insensitive cation channels, channelrhodopsins, bestrophins, voltage-gated chloride channels H+/Cl- exchangers, plant calcium-permeable mechanosensitive channels, and trimeric intracellular cation channels. Overall, dinoflagellates represent cells able to respond to physical and chemical stimuli utilizing a wide range of Gprotein coupled receptors- and Ca2+-dependent signaling pathways. The applied approach not only shed light on the ion channel set in dinoflagellates, but also provided the information on possible molecular mechanisms underlying vital cellular processes dependent on the ion transport.
8
Prevarskaya, Natalia, Roman Skryma e Yaroslav Shuba. "Ion Channels in Cancer: Are Cancer Hallmarks Oncochannelopathies?" Physiological Reviews 98, n. 2 (1 aprile 2018): 559–621. http://dx.doi.org/10.1152/physrev.00044.2016.
Testo completoAbstract (sommario):
Genomic instability is a primary cause and fundamental feature of human cancer. However, all cancer cell genotypes generally translate into several common pathophysiological features, often referred to as cancer hallmarks. Although nowadays the catalog of cancer hallmarks is quite broad, the most common and obvious of them are 1) uncontrolled proliferation, 2) resistance to programmed cell death (apoptosis), 3) tissue invasion and metastasis, and 4) sustained angiogenesis. Among the genes affected by cancer, those encoding ion channels are present. Membrane proteins responsible for signaling within cell and among cells, for coupling of extracellular events with intracellular responses, and for maintaining intracellular ionic homeostasis ion channels contribute to various extents to pathophysiological features of each cancer hallmark. Moreover, tight association of these hallmarks with ion channel dysfunction gives a good reason to classify them as special type of channelopathies, namely oncochannelopathies. Although the relation of cancer hallmarks to ion channel dysfunction differs from classical definition of channelopathies, as disease states causally linked with inherited mutations of ion channel genes that alter channel's biophysical properties, in a broader context of the disease state, to which pathogenesis ion channels essentially contribute, such classification seems absolutely appropriate. In this review the authors provide arguments to substantiate such point of view.
9
Vierra, Nicholas C., e James S. Trimmer. "Ion Channel Partnerships: Odd and Not-So-Odd Couples Controlling Neuronal Ion Channel Function". International Journal of Molecular Sciences 23, n. 4 (10 febbraio 2022): 1953. http://dx.doi.org/10.3390/ijms23041953.
Testo completoAbstract (sommario):
The concerted function of the large number of ion channels expressed in excitable cells, including brain neurons, shapes diverse signaling events by controlling the electrical properties of membranes. It has long been recognized that specific groups of ion channels are functionally coupled in mediating ionic fluxes that impact membrane potential, and that these changes in membrane potential impact ion channel gating. Recent studies have identified distinct sets of ion channels that can also physically and functionally associate to regulate the function of either ion channel partner beyond that afforded by changes in membrane potential alone. Here, we review canonical examples of such ion channel partnerships, in which a Ca2+ channel is partnered with a Ca2+-activated K+ channel to provide a dedicated route for efficient coupling of Ca2+ influx to K+ channel activation. We also highlight examples of non-canonical ion channel partnerships between Ca2+ channels and voltage-gated K+ channels that are not intrinsically Ca2+ sensitive, but whose partnership nonetheless yields enhanced regulation of one or the other ion channel partner. We also discuss how these ion channel partnerships can be shaped by the subcellular compartments in which they are found and provide perspectives on how recent advances in techniques to identify proteins in close proximity to one another in native cells may lead to an expanded knowledge of other ion channel partnerships.
10
Kaupp, U. Benjamin, e Reinhard Seifert. "Cyclic Nucleotide-Gated Ion Channels". Physiological Reviews 82, n. 3 (7 gennaio 2002): 769–824. http://dx.doi.org/10.1152/physrev.00008.2002.
Testo completoAbstract (sommario):
Cyclic nucleotide-gated (CNG) channels are nonselective cation channels first identified in retinal photoreceptors and olfactory sensory neurons (OSNs). They are opened by the direct binding of cyclic nucleotides, cAMP and cGMP. Although their activity shows very little voltage dependence, CNG channels belong to the superfamily of voltage-gated ion channels. Like their cousins the voltage-gated K+ channels, CNG channels form heterotetrameric complexes consisting of two or three different types of subunits. Six different genes encoding CNG channels, four A subunits (A1 to A4) and two B subunits (B1 and B3), give rise to three different channels in rod and cone photoreceptors and in OSNs. Important functional features of these channels, i.e., ligand sensitivity and selectivity, ion permeation, and gating, are determined by the subunit composition of the respective channel complex. The function of CNG channels has been firmly established in retinal photoreceptors and in OSNs. Studies on their presence in other sensory and nonsensory cells have produced mixed results, and their purported roles in neuronal pathfinding or synaptic plasticity are not as well understood as their role in sensory neurons. Similarly, the function of invertebrate homologs found in Caenorhabditis elegans, Drosophila,and Limulus is largely unknown, except for two subunits of C. elegans that play a role in chemosensation. CNG channels are nonselective cation channels that do not discriminate well between alkali ions and even pass divalent cations, in particular Ca2+. Ca2+ entry through CNG channels is important for both excitation and adaptation of sensory cells. CNG channel activity is modulated by Ca2+/calmodulin and by phosphorylation. Other factors may also be involved in channel regulation. Mutations in CNG channel genes give rise to retinal degeneration and color blindness. In particular, mutations in the A and B subunits of the CNG channel expressed in human cones cause various forms of complete and incomplete achromatopsia.
11
Islas, Leon D., e William N. Zagotta. "Short-range Molecular Rearrangements in Ion Channels Detected by Tryptophan Quenching of Bimane Fluorescence". Journal of General Physiology 128, n. 3 (28 agosto 2006): 337–46. http://dx.doi.org/10.1085/jgp.200609556.
Testo completoAbstract (sommario):
Ion channels are allosteric membrane proteins that open and close an ion-permeable pore in response to various stimuli. This gating process provides the regulation that underlies electrical signaling events such as action potentials, postsynaptic potentials, and sensory receptor potentials. Recently, the molecular structures of a number of ion channels and channel domains have been solved by x-ray crystallography. These structures have highlighted a gap in our understanding of the relationship between a channel's function and its structure. Here we introduce a new technique to fill this gap by simultaneously measuring the channel function with the inside-out patch-clamp technique and the channel structure with fluorescence spectroscopy. The structure and dynamics of short-range interactions in the channel can be measured by the presence of quenching of a covalently attached bimane fluorophore by a nearby tryptophan residue in the channel. This approach was applied to study the gating rearrangements in the bovine rod cyclic nucleotide-gated ion channel CNGA1 where it was found that C481 moves towards A461 during the opening allosteric transition induced by cyclic nucleotide. The approach offers new hope for elucidating the gating rearrangements in channels of known structure.
12
Meir, Alon, Simona Ginsburg, Alexander Butkevich, Sylvia G. Kachalsky, Igor Kaiserman, Ronit Ahdut, Serdar Demirgoren e Rami Rahamimoff. "Ion Channels in Presynaptic Nerve Terminals and Control of Transmitter Release". Physiological Reviews 79, n. 3 (1 luglio 1999): 1019–88. http://dx.doi.org/10.1152/physrev.1999.79.3.1019.
Testo completoAbstract (sommario):
The primary function of the presynaptic nerve terminal is to release transmitter quanta and thus activate the postsynaptic target cell. In almost every step leading to the release of transmitter quanta, there is a substantial involvement of ion channels. In this review, the multitude of ion channels in the presynaptic terminal are surveyed. There are at least 12 different major categories of ion channels representing several tens of different ion channel types; the number of different ion channel molecules at presynaptic nerve terminals is many hundreds. We describe the different ion channel molecules at the surface membrane and inside the nerve terminal in the context of their possible role in the process of transmitter release. Frequently, a number of different ion channel molecules, with the same basic function, are present at the same nerve terminal. This is especially evident in the cases of calcium channels and potassium channels. This abundance of ion channels allows for a physiological and pharmacological fine tuning of the process of transmitter release and thus of synaptic transmission.
13
Nowicka-Bauer, Karolina, e Monika Szymczak-Cendlak. "Structure and Function of Ion Channels Regulating Sperm Motility—An Overview". International Journal of Molecular Sciences 22, n. 6 (23 marzo 2021): 3259. http://dx.doi.org/10.3390/ijms22063259.
Testo completoAbstract (sommario):
Sperm motility is linked to the activation of signaling pathways that trigger movement. These pathways are mainly dependent on Ca2+, which acts as a secondary messenger. The maintenance of adequate Ca2+ concentrations is possible thanks to proper concentrations of other ions, such as K+ and Na+, among others, that modulate plasma membrane potential and the intracellular pH. Like in every cell, ion homeostasis in spermatozoa is ensured by a vast spectrum of ion channels supported by the work of ion pumps and transporters. To achieve success in fertilization, sperm ion channels have to be sensitive to various external and internal factors. This sensitivity is provided by specific channel structures. In addition, novel sperm-specific channels or isoforms have been found with compositions that increase the chance of fertilization. Notably, the most significant sperm ion channel is the cation channel of sperm (CatSper), which is a sperm-specific Ca2+ channel required for the hyperactivation of sperm motility. The role of other ion channels in the spermatozoa, such as voltage-gated Ca2+ channels (VGCCs), Ca2+-activated Cl-channels (CaCCs), SLO K+ channels or voltage-gated H+ channels (VGHCs), is to ensure the activation and modulation of CatSper. As the activation of sperm motility differs among metazoa, different ion channels may participate; however, knowledge regarding these channels is still scarce. In the present review, the roles and structures of the most important known ion channels are described in regard to regulation of sperm motility in animals.
14
McGeoch, J. E. M. "Development of Ion Channel Analysor Employing Pores of Subunit C of ATP Synthase". Microscopy and Microanalysis 6, S2 (agosto 2000): 978–79. http://dx.doi.org/10.1017/s1431927600037387.
Testo completoAbstract (sommario):
Many pathological states are related to aberrant functioning of ion channels. Cures for these conditions involve the design of chemicals that will interact with the ion channels or a channel regulator to return their function to the normal level. A notable example of a pathological state associated with ion channel malfunction is the abnormal conductance of inward rectifying potassium channels associated with irregular heart beat. The development of drugs targeting ion channels requires efficient screening of thousands of potential channel ligands. Classically the function of ion channels are assayed by patch clamping which is a fairly elaborate technique and not efficient from the point of screening thousands of ligands. Here is described the development of a compact sensor device where an ion channel is made to function in a lipid bilayer in 50nm holes in silicon or polymer hardware.
15
Marx, Steven O., Steven Reiken, Yuji Hisamatsu, Marta Gaburjakova, Jana Gaburjakova, Yi-Ming Yang, Nora Rosemblit e Andrew R. Marks. "Phosphorylation-Dependent Regulation of Ryanodine Receptors". Journal of Cell Biology 153, n. 4 (7 maggio 2001): 699–708. http://dx.doi.org/10.1083/jcb.153.4.699.
Testo completoAbstract (sommario):
Ryanodine receptors (RyRs), intracellular calcium release channels required for cardiac and skeletal muscle contraction, are macromolecular complexes that include kinases and phosphatases. Phosphorylation/dephosphorylation plays a key role in regulating the function of many ion channels, including RyRs. However, the mechanism by which kinases and phosphatases are targeted to ion channels is not well understood. We have identified a novel mechanism involved in the formation of ion channel macromolecular complexes: kinase and phosphatase targeting proteins binding to ion channels via leucine/isoleucine zipper (LZ) motifs. Activation of kinases and phosphatases bound to RyR2 via LZs regulates phosphorylation of the channel, and disruption of kinase binding via LZ motifs prevents phosphorylation of RyR2. Elucidation of this new role for LZs in ion channel macromolecular complexes now permits: (a) rapid mapping of kinase and phosphatase targeting protein binding sites on ion channels; (b) predicting which kinases and phosphatases are likely to regulate a given ion channel; (c) rapid identification of novel kinase and phosphatase targeting proteins; and (d) tools for dissecting the role of kinases and phosphatases as modulators of ion channel function.
16
Mazzochi, C., D. J. Benos e P. R. Smith. "Interaction of epithelial ion channels with the actin-based cytoskeleton". American Journal of Physiology-Renal Physiology 291, n. 6 (dicembre 2006): F1113—F1122. http://dx.doi.org/10.1152/ajprenal.00195.2006.
Testo completoAbstract (sommario):
The interaction of ion channels with the actin-based cytoskeleton in epithelial cells not only maintains the polarized expression of ion channels within specific membrane domains, it also functions in the intracellular trafficking and regulation of channel activity. Initial evidence supporting an interaction between epithelial ion channels and the actin-based cytoskeleton came from patch-clamp studies examining the effects of cytochalasins on channel activity. Cytochalasins were shown to either activate or inactivate epithelial ion channels. An interaction between the actin-based cytoskeleton and epithelial ion channels was further supported by the fact that the addition of monomeric or filamentous actin to excised patches had an effect on channel activity comparable to that of cytochalasins. Through the recent application of molecular and proteomic approaches, we now know that the interactions between epithelial ion channels and actin can either be direct or indirect, the latter being mediated through scaffolding or actin-binding proteins that serve as links between the channels and the actin-based cytoskeleton. This review discusses recent advances in our understanding of the interactions between epithelial ion channels and the actin-based cytoskeleton, and the roles these interactions play in regulating the cell surface expression, activity, and intracellular trafficking of epithelial ion channels.
17
Jacob, Nilan T. "Drug targets: ligand and voltage gated ion channels". International Journal of Basic & Clinical Pharmacology 6, n. 2 (28 gennaio 2017): 235. http://dx.doi.org/10.18203/2319-2003.ijbcp20170314.
Testo completoAbstract (sommario):
The elucidation of a drug target is one of the earliest and most important steps in the drug discovery process. Ion channels encompassing both the ligand gated and voltage gated types are the second most common drug targets after G-Protein Coupled Receptors (GPCR). Ion channels are basically pore forming membrane proteins specialized for conductance of ions as per the concentration gradient. They are further broadly classified based on the energy (ATP) dependence into active ion channels/pumps and passive ion channels. Gating is the regulatory mechanism of these ion channels by which binding of a specific molecule or alteration in membrane potential induces conformational change in the channel architecture to result in ion flow or its inhibition. Thus, the study of ligand and voltage gated ion channels becomes an important tool for drug discovery especially during the initial stage of target identification. This review aims to describe the ligand and voltage gated ion channels along with discussion on its subfamilies, channel architecture and key pharmacological modulators.
18
Schneider, Marius, Alexander D. Bird, Albert Gidon, Jochen Triesch, Peter Jedlicka e Hermann Cuntz. "Biological complexity facilitates tuning of the neuronal parameter space". PLOS Computational Biology 19, n. 7 (3 luglio 2023): e1011212. http://dx.doi.org/10.1371/journal.pcbi.1011212.
Testo completoAbstract (sommario):
The electrical and computational properties of neurons in our brains are determined by a rich repertoire of membrane-spanning ion channels and elaborate dendritic trees. However, the precise reason for this inherent complexity remains unknown, given that simpler models with fewer ion channels are also able to functionally reproduce the behaviour of some neurons. Here, we stochastically varied the ion channel densities of a biophysically detailed dentate gyrus granule cell model to produce a large population of putative granule cells, comparing those with all 15 original ion channels to their reduced but functional counterparts containing only 5 ion channels. Strikingly, valid parameter combinations in the full models were dramatically more frequent at -6% vs. -1% in the simpler model. The full models were also more stable in the face of perturbations to channel expression levels. Scaling up the numbers of ion channels artificially in the reduced models recovered these advantages confirming the key contribution of the actual number of ion channel types. We conclude that the diversity of ion channels gives a neuron greater flexibility and robustness to achieve a target excitability.
19
Selvaraj, Chandrabose, Gurudeeban Selvaraj, Satyavani Kaliamurthi, William C. Cho, Dong-Qing Wei e Sanjeev Kumar Singh. "Ion Channels as Therapeutic Targets for Type 1 Diabetes Mellitus". Current Drug Targets 21, n. 2 (22 gennaio 2020): 132–47. http://dx.doi.org/10.2174/1389450119666190920152249.
Testo completoAbstract (sommario):
Ion channels are integral proteins expressed in almost all living cells and are involved in muscle contraction and nutrient transport. They play a critical role in the normal functioning of the excitable tissues of the nervous system and regulate the action potential and contraction events. Dysfunction of genes encodes ion channel proteins, which disrupt the channel function and lead to a number of diseases, among which is type 1 diabetes mellitus (T1DM). Therefore, understanding the complex mechanism of ion channel receptors is necessary to facilitate the diagnosis and management of treatment. In this review, we summarize the mechanism of important ion channels and their potential role in the regulation of insulin secretion along with the limitations of ion channels as therapeutic targets. Furthermore, we discuss the recent investigations of the mechanism regulating the ion channels in pancreatic beta cells, which suggest that ion channels are active participants in the regulation of insulin secretion.
20
Linta, Leonhard, Marianne Stockmann, Qiong Lin, André Lechel, Christian Proepper, Tobias M. Boeckers, Alexander Kleger e Stefan Liebau. "Microarray-Based Comparisons of Ion Channel Expression Patterns: Human Keratinocytes to Reprogrammed hiPSCs to Differentiated Neuronal and Cardiac Progeny". Stem Cells International 2013 (2013): 1–25. http://dx.doi.org/10.1155/2013/784629.
Testo completoAbstract (sommario):
Ion channels are involved in a large variety of cellular processes including stem cell differentiation. Numerous families of ion channels are present in the organism which can be distinguished by means of, for example, ion selectivity, gating mechanism, composition, or cell biological function. To characterize the distinct expression of this group of ion channels we have compared the mRNA expression levels of ion channel genes between human keratinocyte-derived induced pluripotent stem cells (hiPSCs) and their somatic cell source, keratinocytes from plucked human hair. This comparison revealed that 26% of the analyzed probes showed an upregulation of ion channels in hiPSCs while just 6% were downregulated. Additionally, iPSCs express a much higher number of ion channels compared to keratinocytes. Further, to narrow down specificity of ion channel expression in iPS cells we compared their expression patterns with differentiated progeny, namely, neurons and cardiomyocytes derived from iPS cells. To conclude, hiPSCs exhibit a very considerable and diverse ion channel expression pattern. Their detailed analysis could give an insight into their contribution to many cellular processes and even disease mechanisms.
21
Kemp, Paul J., e Chris Peers. "Oxygen sensing by ion channels". Essays in Biochemistry 43 (10 agosto 2007): 77–90. http://dx.doi.org/10.1042/bse0430077.
Testo completoAbstract (sommario):
The ability to sense and react to changes in environmental oxygen levels is crucial to the survival of all aerobic life forms. In mammals, specialized tissues have evolved which can sense and rapidly respond to an acute reduction in oxygen and central to this ability in many is dynamic modulation of ion channels by hypoxia. The most widely studied oxygen-sensitive ion channels are potassium channels but oxygen sensing by members of both the calcium and sodium channel families has also been demonstrated. This chapter will focus on mechanisms of physiological oxygen sensing by ion channels, with particular emphasis on potassium channel function, and will highlight some of the consensuses and controversies within the field. Where data are available, this chapter will also make use of information gleaned from heterologous expression of recombinant proteins in an attempt to consolidate what we know currently about the molecular mechanisms of acute oxygen sensing by ion channels.
22
Sontheimer, H. "Astrocytes, as well as neurons, express a diversity of ion channels". Canadian Journal of Physiology and Pharmacology 70, S1 (15 maggio 1992): S223—S238. http://dx.doi.org/10.1139/y92-266.
Testo completoAbstract (sommario):
The electrophysiologist's view of brain astrocytes has changed markedly in recent years. In the past astrocytes were viewed as passive, K+ selective cells, but it is now evident that they are capable of expressing voltage- and ligand-activated channels previously thought to be restricted to neurons. The functional importance of most of these ion channels is not understood at present. However, from studies of astrocytes cultured from different species and brain regions, we learned that like their neuronal counterparts astrocytes are a heterogeneous group of brain cells showing similar heterogeneity in their ion-channel expression. Not only are subpopulations of astrocytes within areas of the brain equipped with specific sets of ion channels but, furthermore, regional heterogeneity is apparent. In addition, astrocyte ion channel expression is dynamic and changes during development. Some ion channels are only expressed postnatally, yet others appear to be expressed only during certain stages of development. Interestingly, the expression of some astrocyte channels, including Na+, Ca2+, and some K+ channels, appears to be controlled by neurons via mechanisms that are presently unknown. Some studies suggest roles for astrocyte channels in basic cell processes such as cell proliferation. Thus, although the role of some astrocyte channels remains unclear, our understanding of astrocyte physiology is starting to take shape and points towards roles of ion channels not involved in electrogenesis.Key words: astrocyte, ion channel, development, review, transmitter receptor.
23
Blandin, Camille E., Basile J. Gravez, Stéphane N. Hatem e Elise Balse. "Remodeling of Ion Channel Trafficking and Cardiac Arrhythmias". Cells 10, n. 9 (14 settembre 2021): 2417. http://dx.doi.org/10.3390/cells10092417.
Testo completoAbstract (sommario):
Both inherited and acquired cardiac arrhythmias are often associated with the abnormal functional expression of ion channels at the cellular level. The complex machinery that continuously traffics, anchors, organizes, and recycles ion channels at the plasma membrane of a cardiomyocyte appears to be a major source of channel dysfunction during cardiac arrhythmias. This has been well established with the discovery of mutations in the genes encoding several ion channels and ion channel partners during inherited cardiac arrhythmias. Fibrosis, altered myocyte contacts, and post-transcriptional protein changes are common factors that disorganize normal channel trafficking during acquired cardiac arrhythmias. Channel availability, described notably for hERG and KV1.5 channels, could be another potent arrhythmogenic mechanism. From this molecular knowledge on cardiac arrhythmias will emerge novel antiarrhythmic strategies.
24
Dworakowska, B., e K. Dołowy. "Ion channels-related diseases." Acta Biochimica Polonica 47, n. 3 (30 settembre 2000): 685–703. http://dx.doi.org/10.18388/abp.2000_3989.
Testo completoAbstract (sommario):
There are many diseases related to ion channels. Mutations in muscle voltage-gated sodium, potassium, calcium and chloride channels, and acetylcholine-gated channel may lead to such physiological disorders as hyper- and hypokalemic periodic paralysis, myotonias, long QT syndrome, Brugada syndrome, malignant hyperthermia and myasthenia. Neuronal disorders, e.g., epilepsy, episodic ataxia, familial hemiplegic migraine, Lambert-Eaton myasthenic syndrome, Alzheimer's disease, Parkinson's disease, schizophrenia, hyperekplexia may result from dysfunction of voltage-gated sodium, potassium and calcium channels, or acetylcholine- and glycine-gated channels. Some kidney disorders, e.g., Bartter's syndrome, policystic kidney disease and Dent's disease, secretion disorders, e.g., hyperinsulinemic hypoglycemia of infancy and cystic fibrosis, vision disorders, e.g., congenital stationary night blindness and total colour-blindness may also be linked to mutations in ion channels.
25
Scholz, A., G. Reid, W. Vogel e H. Bostock. "Ion channels in human axons". Journal of Neurophysiology 70, n. 3 (1 settembre 1993): 1274–79. http://dx.doi.org/10.1152/jn.1993.70.3.1274.
Testo completoAbstract (sommario):
1. Until now, no direct electrophysiological information has been available on the molecular basis of human nerve excitability. We here report patch-clamp recordings, both single- and multichannel, from acutely dissociated human axons. 2. Voltage-dependent sodium channels with a conductance gamma = 13 pS (measured in Ringer at room temperature) are found in the nodal area. 3. There are several types of voltage-dependent potassium channels: I channels (gamma = 34 pS), F channels (gamma = 50 pS), and channels with small conductance (gamma = 7-9 pS, all measured in high potassium solution). Most of them are closely similar to those already reported in Xenopus and rat axons; in addition a 200-pS, calcium-dependent potassium channel, similar to that in Xenopus, is present. 4. Differences between the electrical behavior of human axons and those of other species are probably not due to the presence of fundamentally different channel types, but may be due to differences in channel density or distribution. 5. As well as increasing our understanding of the basis of excitability in human nerve, this method may prove useful in the investigation of inherited and other human neuropathies.
26
Desai, Sanjay A. "Novel Ion Channel Genes in Malaria Parasites". Genes 15, n. 3 (26 febbraio 2024): 296. http://dx.doi.org/10.3390/genes15030296.
Testo completoAbstract (sommario):
Ion channels serve many cellular functions including ion homeostasis, volume regulation, signaling, nutrient acquisition, and developmental progression. Although the complex life cycles of malaria parasites necessitate ion and solute flux across membranes, the whole-genome sequencing of the human pathogen Plasmodium falciparum revealed remarkably few orthologs of known ion channel genes. Contrasting with this, biochemical studies have implicated the channel-mediated flux of ions and nutritive solutes across several membranes in infected erythrocytes. Here, I review advances in the cellular and molecular biology of ion channels in malaria parasites. These studies have implicated novel parasite genes in the formation of at least two ion channels, with additional ion channels likely present in various membranes and parasite stages. Computational approaches that rely on homology to known channel genes from higher organisms will not be very helpful in identifying the molecular determinants of these activities. Given their unusual properties, novel molecular and structural features, and essential roles in pathogen survival and development, parasite channels should be promising targets for therapy development.
27
Davis, Michael J., Xin Wu, Timothy R. Nurkiewicz, Junya Kawasaki, Peichun Gui, Michael A. Hill e Emily Wilson. "Regulation of ion channels by protein tyrosine phosphorylation". American Journal of Physiology-Heart and Circulatory Physiology 281, n. 5 (1 novembre 2001): H1835—H1862. http://dx.doi.org/10.1152/ajpheart.2001.281.5.h1835.
Testo completoAbstract (sommario):
Ion channels are regulated by protein phosphorylation and dephosphorylation of serine, threonine, and tyrosine residues. Evidence for the latter process, tyrosine phosphorylation, has increased substantially since this topic was last reviewed. In this review, we present a comprehensive summary and synthesis of the literature regarding the mechanism and function of ion channel regulation by protein tyrosine kinases and phosphatases. Coverage includes the majority of voltage-gated, ligand-gated, and second messenger-gated channels as well as several types of channels that have not yet been cloned, including store-operated Ca2+ channels, nonselective cation channels, and epithelial Na+ and Cl− channels. Additionally, we discuss the critical roles that channel-associated scaffolding proteins may play in localizing protein tyrosine kinases and phosphatases to the vicinity of ion channels.
28
Mizielinska, S. M. "Ion channels in epilepsy". Biochemical Society Transactions 35, n. 5 (25 ottobre 2007): 1077–79. http://dx.doi.org/10.1042/bst0351077.
Testo completoAbstract (sommario):
Neuronal excitability is determined by the flux of ions through ion channels. Many types of ion channels are expressed in the central nervous system, each responsible for its own aspect of neuronal excitability, from postsynaptic depolarization to action potential generation to neurotransmitter release. These mechanisms are tightly regulated to create a balance between excitation and inhibition. Disruption of this balance is thought to be key in many neurological disorders, including epilepsy syndromes. More and more ion channel mutations are being identified through genetic studies; however, their incidence is still small, suggesting the presence of undiscovered mutations or other causative mechanisms. Understanding wild-type channel function during epileptic activity may also provide vital insights into the remaining idiopathic epilepsies and provide targets for future antiepileptic drugs.
29
Elinder, Fredrik, e Peter Århem. "Metal ion effects on ion channel gating". Quarterly Reviews of Biophysics 36, n. 4 (novembre 2003): 373–427. http://dx.doi.org/10.1017/s0033583504003932.
Testo completoAbstract (sommario):
1. Introduction 3742. Metals in biology 3783. The targets: structure and function of ion channels 3804. General effects of metal ions on channels 3824.1 Three types of general effect 3824.2 The main regulators 3835. Effects on gating: mechanisms and models 3845.1 Screening surface charges (Mechanism A) 3875.1.1 The classical approach 3875.1.1.1 Applying the Grahame equation 3885.1.2 A one-site approach 3915.2 Binding and electrostatically modifying the voltage sensor (Mechanism B) 3915.2.1 The classical model 3915.2.1.1 The classical model as state diagram – introducing basic channel kinetics 3925.2.2 A one-site approach 3955.2.2.1 Explaining state-dependent binding – a simple electrostatic mechanism 3955.2.2.2 The relation between models assuming binding to smeared and to discrete charges 3965.2.2.3 The special case of Zn2+ – no binding in the open state 3965.2.2.4 Opposing effects of Cd2+ on hyperpolarization-activated channels 3985.3 Binding and interacting non-electrostatically with the voltage sensor (Mechanism C) 3985.3.1 Combining mechanical slowing of opening and closing with electrostatic modification of voltage sensor 4005.4 Binding to the pore – a special case of one-site binding models (Mechanism D) 4005.4.1 Voltage-dependent pore-block – adding extra gating 4015.4.2 Coupling pore block to gating 4025.4.2.1 The basic model again 4025.4.2.2 A special case – Ca2+ as necessary cofactor for closing 4035.4.2.3 Expanding the basic model – Ca2+ affecting a voltage-independent step 4045.5 Summing up 4056. Quantifying the action: comparing the metal ions 4076.1 Steady-state parameters are equally shifted 4076.2 Different metal ions cause different shifts 4086.3 Different metal ions slow gating differently 4106.4 Block of ion channels 4127. Locating the sites of action 4127.1 Fixed surface charges involved in screening 4137.2 Binding sites 4137.2.1 Group 2 ions 4147.2.2 Group 12 ions 4148. Conclusions and perspectives 4159. Appendix 41610. Acknowledgements 41811. References 418Metal ions affect ion channels either by blocking the current or by modifying the gating. In the present review we analyse the effects on the gating of voltage-gated channels. We show that the effects can be understood in terms of three main mechanisms. Mechanism A assumes screening of fixed surface charges. Mechanism B assumes binding to fixed charges and an associated electrostatic modification of the voltage sensor. Mechanism C assumes binding and an associated non-electrostatic modification of the gating. To quantify the non-electrostatic effect we introduced a slowing factor, A. A fourth mechanism (D) is binding to the pore with a consequent pore block, and could be a special case of Mechanisms B or C. A further classification considers whether the metal ion affects a single site or multiple sites. Analysing the properties of these mechanisms and the vast number of studies of metal ion effects on different voltage-gated ion channels we conclude that group 2 ions mainly affect channels by classical screening (a version of Mechanism A). The transition metals and the Zn group ions mainly bind to the channel and electrostatically modify the gating (Mechanism B), causing larger shifts of the steady-state parameters than the group 2 ions, but also different shifts of activation and deactivation curves. The lanthanides mainly bind to the channel and both electrostatically and non-electrostatically modify the gating (Mechanisms B and C). With the exception of the ether-à-go-go-like channels, most channel types show remarkably similar ion-specific sensitivities.
30
Chen, Gui-Lan, Jian Li, Jin Zhang e Bo Zeng. "To Be or Not to Be an Ion Channel: Cryo-EM Structures Have a Say". Cells 12, n. 14 (17 luglio 2023): 1870. http://dx.doi.org/10.3390/cells12141870.
Testo completoAbstract (sommario):
Ion channels are the second largest class of drug targets after G protein-coupled receptors. In addition to well-recognized ones like voltage-gated Na/K/Ca channels in the heart and neurons, novel ion channels are continuously discovered in both excitable and non-excitable cells and demonstrated to play important roles in many physiological processes and diseases such as developmental disorders, neurodegenerative diseases, and cancer. However, in the field of ion channel discovery, there are an unignorable number of published studies that are unsolid and misleading. Despite being the gold standard of a functional assay for ion channels, electrophysiological recordings are often accompanied by electrical noise, leak conductance, and background currents of the membrane system. These unwanted signals, if not treated properly, lead to the mischaracterization of proteins with seemingly unusual ion-conducting properties. In the recent ten years, the technical revolution of cryo-electron microscopy (cryo-EM) has greatly advanced our understanding of the structures and gating mechanisms of various ion channels and also raised concerns about the pore-forming ability of some previously identified channel proteins. In this review, we summarize cryo-EM findings on ion channels with molecular identities recognized or disputed in recent ten years and discuss current knowledge of proposed channel proteins awaiting cryo-EM analyses. We also present a classification of ion channels according to their architectures and evolutionary relationships and discuss the possibility and strategy of identifying more ion channels by analyzing structures of transmembrane proteins of unknown function. We propose that cross-validation by electrophysiological and structural analyses should be essentially required for determining molecular identities of novel ion channels.
31
Coates, Leighton. "Ion permeation in potassium ion channels". Acta Crystallographica Section D Structural Biology 76, n. 4 (1 aprile 2020): 326–31. http://dx.doi.org/10.1107/s2059798320003599.
Testo completoAbstract (sommario):
The study of ion channels dates back to the 1950s and the groundbreaking electrophysiology work of Hodgin and Huxley, who used giant squid axons to probe how action potentials in neurons were initiated and propagated. More recently, several experiments using different structural biology techniques and approaches have been conducted to try to understand how potassium ions permeate through the selectivity filter of potassium ion channels. Two mechanisms of permeation have been proposed, and each of the two mechanisms is supported by different experiments. The key structural biology experiments conducted so far to try to understand how ion permeation takes place in potassium ion channels are reviewed and discussed. Protein crystallography has made, and continues to make, key contributions in this field, often through the use of anomalous scattering. Other structural biology techniques used to study the contents of the selectivity filter include solid-state nuclear magnetic resonance and two-dimensional infrared spectroscopy, both of which make clever use of isotopic labeling techniques, while molecular-dynamics simulations of ion flow through the selectivity filter have been enabled by the growing number of potassium ion channel structures deposited in the Protein Data Bank.
32
Lin, Hao, e Wei Chen. "Briefing in Application of Machine Learning Methods in Ion Channel Prediction". Scientific World Journal 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/945927.
Testo completoAbstract (sommario):
In cells, ion channels are one of the most important classes of membrane proteins which allow inorganic ions to move across the membrane. A wide range of biological processes are involved and regulated by the opening and closing of ion channels. Ion channels can be classified into numerous classes and different types of ion channels exhibit different functions. Thus, the correct identification of ion channels and their types using computational methods will provide in-depth insights into their function in various biological processes. In this review, we will briefly introduce and discuss the recent progress in ion channel prediction using machine learning methods.
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Song, Tongtong, Wenting Hui, Min Huang, Yan Guo, Meiyi Yu, Xiaoyu Yang, Yanqing Liu e Xia Chen. "Dynamic Changes in Ion Channels during Myocardial Infarction and Therapeutic Challenges". International Journal of Molecular Sciences 25, n. 12 (12 giugno 2024): 6467. http://dx.doi.org/10.3390/ijms25126467.
Testo completoAbstract (sommario):
In different areas of the heart, action potential waveforms differ due to differences in the expressions of sodium, calcium, and potassium channels. One of the characteristics of myocardial infarction (MI) is an imbalance in oxygen supply and demand, leading to ion imbalance. After MI, the regulation and expression levels of K+, Ca2+, and Na+ ion channels in cardiomyocytes are altered, which affects the regularity of cardiac rhythm and leads to myocardial injury. Myocardial fibroblasts are the main effector cells in the process of MI repair. The ion channels of myocardial fibroblasts play an important role in the process of MI. At the same time, a large number of ion channels are expressed in immune cells, which play an important role by regulating the in- and outflow of ions to complete intracellular signal transduction. Ion channels are widely distributed in a variety of cells and are attractive targets for drug development. This article reviews the changes in different ion channels after MI and the therapeutic drugs for these channels. We analyze the complex molecular mechanisms behind myocardial ion channel regulation and the challenges in ion channel drug therapy.
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Charlton, Frank W., Hayley M. Pearson, Samantha Hover, Jon D. Lippiat, Juan Fontana, John N. Barr e Jamel Mankouri. "Ion Channels as Therapeutic Targets for Viral Infections: Further Discoveries and Future Perspectives". Viruses 12, n. 8 (3 agosto 2020): 844. http://dx.doi.org/10.3390/v12080844.
Testo completoAbstract (sommario):
Ion channels play key roles in almost all facets of cellular physiology and have emerged as key host cell factors for a multitude of viral infections. A catalogue of ion channel-blocking drugs have been shown to possess antiviral activity, some of which are in widespread human usage for ion channel-related diseases, highlighting new potential for drug repurposing. The emergence of ion channel–virus interactions has also revealed the intriguing possibility that channelopathies may explain some commonly observed virus induced pathologies. This field is rapidly evolving and an up-to-date summary of new discoveries can inform future perspectives. We herein discuss the role of ion channels during viral lifecycles, describe the recently identified ion channel drugs that can inhibit viral infections, and highlight the potential contribution of ion channels to virus-mediated disease.
35
MARSH, Derek. "Peptide models for membrane channels". Biochemical Journal 315, n. 2 (15 aprile 1996): 345–61. http://dx.doi.org/10.1042/bj3150345.
Testo completoAbstract (sommario):
Peptides may be synthesized with sequences corresponding to putative transmembrane domains and/or pore-lining regions that are deduced from the primary structures of ion channel proteins. These can then be incorporated into lipid bilayer membranes for structural and functional studies. In addition to the ability to invoke ion channel activity, critical issues are the secondary structures adopted and the mode of assembly of these short transmembrane peptides in the reconstituted systems. The present review concentrates on results obtained with peptides from ligand-gated and voltage-gated ion channels, as well as proton-conducting channels. These are considered within the context of current molecular models and the limited data available on the structure of native ion channels and natural channel-forming peptides.
36
Yan, Jiusheng, Qin Li e Richard W. Aldrich. "Closed state-coupled C-type inactivation in BK channels". Proceedings of the National Academy of Sciences 113, n. 25 (13 giugno 2016): 6991–96. http://dx.doi.org/10.1073/pnas.1607584113.
Testo completoAbstract (sommario):
Ion channels regulate ion flow by opening and closing their pore gates. K+ channels commonly possess two pore gates, one at the intracellular end for fast channel activation/deactivation and the other at the selectivity filter for slow C-type inactivation/recovery. The large-conductance calcium-activated potassium (BK) channel lacks a classic intracellular bundle-crossing activation gate and normally show no C-type inactivation. We hypothesized that the BK channel’s activation gate may spatially overlap or coexist with the C-type inactivation gate at or near the selectivity filter. We induced C-type inactivation in BK channels and studied the relationship between activation/deactivation and C-type inactivation/recovery. We observed prominent slow C-type inactivation/recovery in BK channels by an extreme low concentration of extracellular K+ together with a Y294E/K/Q/S or Y279F mutation whose equivalent in Shaker channels (T449E/K/D/Q/S or W434F) caused a greatly accelerated rate of C-type inactivation or constitutive C-inactivation. C-type inactivation in most K+ channels occurs upon sustained membrane depolarization or channel opening and then recovers during hyperpolarized membrane potentials or channel closure. However, we found that the BK channel C-type inactivation occurred during hyperpolarized membrane potentials or with decreased intracellular calcium ([Ca2+]i) and recovered with depolarized membrane potentials or elevated [Ca2+]i. Constitutively open mutation prevented BK channels from C-type inactivation. We concluded that BK channel C-type inactivation is closed state-dependent and that its extents and rates inversely correlate with channel-open probability. Because C-type inactivation can involve multiple conformational changes at the selectivity filter, we propose that the BK channel’s normal closing may represent an early conformational stage of C-type inactivation.
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Magra, Merzesh, Steven Hughes, Alicia J. El Haj e Nicola Maffulli. "VOCCs and TREK-1 ion channel expression in human tenocytes". American Journal of Physiology-Cell Physiology 292, n. 3 (marzo 2007): C1053—C1060. http://dx.doi.org/10.1152/ajpcell.00053.2006.
Testo completoAbstract (sommario):
Mechanosensitive and voltage-gated ion channels are known to perform important roles in mechanotransduction in a number of connective tissues, including bone and muscle. It is hypothesized that voltage-gated and mechanosensitive ion channels also may play a key role in some or all initial responses of human tenocytes to mechanical stimulation. However, to date there has been no direct investigation of ion channel expression by human tenocytes. Human tenocytes were cultured from patellar tendon samples harvested from five patients undergoing routine total knee replacement surgery (mean age: 66 yr; range: 63–73 yr). RT-PCR, Western blotting, and whole cell electrophysiological studies were performed to investigate the expression of different classes of ion channels within tenocytes. Human tenocytes expressed mRNA and protein encoding voltage-operated calcium channel (VOCC) subunits (Ca α1A, Ca α1C, Ca α1D, Ca α2δ1) and the mechanosensitive tandem pore domain potassium channel (2PK+) TREK-1. They exhibit whole cell currents consistent with the functional expression of these channels. In addition, other ionic currents were detected within tenocytes consistent with the expression of a diverse array of other ion channels. VOCCs and TREK channels have been implicated in mechanotransduction signaling pathways in numerous connective tissue cell types. These mechanisms may be present in human tenocytes. In addition, human tenocytes may express other channel currents. Ion channels may represent potential targets for the pharmacological management of chronic tendinopathies.
38
Gao, Jianzhao, Hong Wei, Alberto Cano e Lukasz Kurgan. "PSIONplusm Server for Accurate Multi-Label Prediction of Ion Channels and Their Types". Biomolecules 10, n. 6 (7 giugno 2020): 876. http://dx.doi.org/10.3390/biom10060876.
Testo completoAbstract (sommario):
Computational prediction of ion channels facilitates the identification of putative ion channels from protein sequences. Several predictors of ion channels and their types were developed in the last quindecennial. While they offer reasonably accurate predictions, they also suffer a few shortcomings including lack of availability, parallel prediction mode, single-label prediction (inability to predict multiple channel subtypes), and incomplete scope (inability to predict subtypes of the voltage-gated channels). We developed a first-of-its-kind PSIONplusm method that performs sequential multi-label prediction of ion channels and their subtypes for both voltage-gated and ligand-gated channels. PSIONplusm sequentially combines the outputs produced by three support vector machine-based models from the PSIONplus predictor and is available as a webserver. Empirical tests show that PSIONplusm outperforms current methods for the multi-label prediction of the ion channel subtypes. This includes the existing single-label methods that are available to the users, a naïve multi-label predictor that combines results produced by multiple single-label methods, and methods that make predictions based on sequence alignment and domain annotations. We also found that the current methods (including PSIONplusm) fail to accurately predict a few of the least frequently occurring ion channel subtypes. Thus, new predictors should be developed when a larger quantity of annotated ion channels will be available to train predictive models.
39
Alexander, S. P. H., A. Mathie e J. A. Peters. "Ion Channels". British Journal of Pharmacology 150, S1 (febbraio 2007): S96—S121. http://dx.doi.org/10.1038/sj.bjp.0707204.
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Alexander, S. P. H., A. Mathie e J. A. Peters. "Ion Channels". British Journal of Pharmacology 153, S2 (marzo 2008): S112—S145. http://dx.doi.org/10.1038/sj.bjp.0707755.
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41
Prince, Richard J. "Ion channels". Anaesthesia & Intensive Care Medicine 5, n. 10 (ottobre 2004): 348–49. http://dx.doi.org/10.1383/anes.5.10.348.52313.
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42
Laniado, M. E., P. D. Abel e E. N. Lalani. "Ion channels". BMJ 315, n. 7117 (8 novembre 1997): 1171–72. http://dx.doi.org/10.1136/bmj.315.7117.1171.
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Mangoldt, D. "Ion channels". Bioelectrochemistry and Bioenergetics 43, n. 1 (giugno 1997): 192. http://dx.doi.org/10.1016/s0302-4598(97)00031-7.
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Stephenson, F. Anne. "Ion channels". Current Opinion in Structural Biology 1, n. 4 (agosto 1991): 569–74. http://dx.doi.org/10.1016/s0959-440x(05)80079-x.
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Sansom, Mark S. P. "Ion channels:". Current Biology 9, n. 5 (marzo 1999): R173—R175. http://dx.doi.org/10.1016/s0960-9822(99)80106-7.
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46
Anson, Lesley. "Ion channels". Nature 440, n. 7083 (marzo 2006): 439. http://dx.doi.org/10.1038/440439a.
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47
Alexander, SPH, A. Mathie e JA Peters. "ION CHANNELS". British Journal of Pharmacology 164 (novembre 2011): S137—S174. http://dx.doi.org/10.1111/j.1476-5381.2011.01649_5.x.
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48
Hille, Bertil. "Ion channels". Scholarpedia 3, n. 10 (2008): 6051. http://dx.doi.org/10.4249/scholarpedia.6051.
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Bradding, Peter, e Heike Wulff. "Ion channels". Thorax 68, n. 10 (5 aprile 2013): 974–77. http://dx.doi.org/10.1136/thoraxjnl-2012-202786.
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Pandit, J. J., M. E. Laniado, P. D. Abel e E. N. Lalani. "Ion channels". BMJ 317, n. 7150 (4 luglio 1998): 77. http://dx.doi.org/10.1136/bmj.317.7150.77.
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