The 22nd Ion Channel Meeting,September 2011, France

The 22nd Ion Channel Meeting was organized by the French Ion Channel Society (Association Canaux Ioniques) from the 25th to the 28th of September 2011 on the French Riviera (Giens). This year again, more than one hundred researchers from France, Europe and extra-European countries gathered to present and discuss their recent advances and future challenges in the ion channels and transporters field. The scientific committee organized a plenary lecture and five thematic symposia by inviting international researchers to present their recent outstanding work on themes as diverse as muscular channelopathies, regulation of channels by extracellular matrix, receptor-channels interactions, localization and distribution of ion channels, their involvement in the cell life and death, and finally how they participate in the evolution and adaptability of cellular excitability. These presentations are summarized in this meeting report. Two sessions of oral communications selected from submitted abstracts and two poster sessions were also organized to present the ongoing work of young researchers worldwide.     

The 21(st) Ion Channel Meeting, September 2010, France

On September 12-15, 2010 the French Ion Channels Association organized its annual scientific meeting on the French coast of Mediterranean Sea. This meeting takes place in an attractive location and provides a great opportunity for principal investigators as well as young researchers to present and discuss their recent advances and future challenges in the field of ion channels and transporters. The French Ion Channels Association was created more than 20 years ago and its goal is to organize an annual meeting and more recently to promote interactions (through the website www.canaux-ioniques.fr) between active members of the international scientific community in the field of ion channels. In this report of the 21(st) edition of the meeting, we are summarizing the five main symposia that reflect original works and relevant developments in the domain of ions channels and transporters.     

The 21st Ion Channel Meeting,September 2010, France

On September 12-15, 2010 the French Ion Channels Association organized its annual scientific meeting on the French coast of Mediterranean Sea. This meeting takes place in an attractive location and provides a great opportunity for principal investigators as well as young researchers to present and discuss their recent advances and future challenges in the field of ion channels and transporters. The French Ion Channels Association was created more than 20 years ago and its goal is to organize an annual meeting and more recently to promote interactions (through the website www.canaux-ioniques.fr) between active members of the international scientific community in the field of ion channels. In this report of the 21^st edition of the meeting, we are summarizing the five main symposia that reflect original works and relevant developments in the domain of ions channels and transporters.     

The 19th Ion Channel Meeting,September 2008, France

The annual meeting of the French Ion Channels Society, held on the Mediterranean coast of France, is aimed at gathering the international scientific community working on various aspects of ion channels. In this report of the 19th edition of the meeting, held in September 2008, we summarize selected symposia on aspects of the ion channel field from fundamental to clinical research. The meeting is an opportunity for leading investigators as well as young researchers to present and discuss their recent advances and future challenges in the ion channel field.     

DICE：电压门控离子通道电生理实验数据库

针对现有相关文献中离子通道电生理数据繁多且分散的特点,开发了一套电压门控离子通道电生理实验数据库。数据库中目前主要包括钠离子通道序列数据、调制剂分子结构和序列数据,并收集整理了文献中调制剂和通道相互作用时的电生理学数据和药理学数据。系统实现了数据的收集、录入、存储和查询,为后期进行数据挖掘奠定了基础。用户可以通过网址http：／／biodb．sgst．cn／DICE对数据库进行访问。     

The 20th Ion Channel Meeting September 2009, France

The French Ion Channel society has existed since 1989 and its main goal is to annually organize a scientific meeting. This meeting, which gathers young and senior French scientists, provides a great opportunity for the exchange and interaction among the ion channel research community. Additionally, for many years, the French ion channel meeting has attracted a significant number of scientists from different European countries, elevating the discussion of new insights and advances, as well as aiding in the establishment of collaborations. In this report, we summarize the five symposia selected for their novelty and importance in human channelopathies, neuroplasticity, ion channel regulations, intracellular ion channels and plant physiology.     

离子通道与肿瘤相关性的研究进展

离子通道是一类对离子具有选择通透性跨膜的生物大分子。一些离子通道在肿瘤细胞中表达异常,并在细胞癌变、侵袭和转移等方面起着重要作用;另外,作用于离子通道的药物被发现可以逆转多药耐药,因而离子通道可作为潜在的抗肿瘤靶点。就离子通道与肿瘤相关性研究予以综述。     

Identification and experimental verification of a novel family of bacterial cyclic nucleotide-gated (bCNG) ion channels

Studies of bacterial ion channels have provided significant insights into the structure-function relationships of mechanosensitive and voltage-gated ion channels. However, to date, very few bacterial channels that respond to small molecules have been identified, cloned, and characterized. Here, we use bioinformatics to identify a novel family of bacterial cyclic nucleotide-gated (bCNG) ion channels containing a channel domain related by sequence homology to the mechanosensitive channel of small conductance (MscS). In this initial report, we clone selected members of this channel family, use electrophysiological measurements to verify their ability to directly gate in response to cyclic nucleotides, and use osmotic downshock to demonstrate their lack of mechanosensitivity. In addition to providing insight into bacterial physiology, these channels will provide researchers with a useful model system to investigate the role of ligand-gated ion channels (LGICs) in the signaling processes of higher organisms. The identification of these channels provides a foundation for structural and functional studies of LGICs that would be difficult to perform on mammalian channels. Moreover, the discovery of bCNG channels implies that bacteria have cyclic nucleotide-gated and cyclic nucleotide-modulated ion channels, which are analogous to the ion channels involved in eukaryotic secondary messenger signaling pathways.     

Using planar lipid-bilayers to study plant ion channels

Ion channels are found in most plant membranes. They catalyse the rapid passive uniport of particular ions with varying selectivity. Planar lipid-bilayer (PLB) techniques have been developed to study the electrical activities of single ion channels in well-defined lipid and aqueous environments. They greatly facilitate both the biophysical and biochemical characterisation of ion channels and complement both conventional impaling electrode and membrane-patch voltage-clamping (patch-clamping) electrophysiological techniques applied in vivo. Bilayers can be formed across the end of patch-clamp pipettes or across apertures in specifically designed chambers. Ion channels in native membranes and purified, genetically altered or synthetic ion channels, proteins and peptides can all be studied in PLBs. The main applications of PLBs are (1) to study ion channels in membranes inaccessible to patch-clamp electrodes, (2) to provide a functional assay system during channel-protein purification and (3) to investigate the relationship between the molecular structure of ion channels and their conductance properties. In the present article we describe the techniques available for reconstitution and analysis of ion channels in PLBs and discuss how the PLB technique has been, and may be, useful to the study of plant ion channels.     

The role of ion channels in plant nutrition and prospects for their genetic manipulation

Ion channels can function in three physiological modes through their ability to: 1) accommodate osmotically significant fluxes over short periods; 2) propagate signals along or across membranes; 3) control the membrane potential. With respect to mineral nutrition it is via the control of the membrane potential that ion channels are probably most significant. In this paper the physiology and prospects for molecular biology of plant ion channels are discussed. It is concluded that identifying and altering the primary structures that determine functional characteristics of plant ion channel genes could result in changes in the transport characteristics of higher plants.     

酸感受性离子通道生物学特性及其调控

酸感受离子通道(ASICs)为H -门控的阳离子通道,是一类新的配体门控性离子通道,属于钠通道超家族的新成员.作为近来研究的热点,ASICs具有许多重要的生物学功能,并很有可能成为抗癫痫、镇痛、提高学习记忆能力和保护神经元缺血损伤作用药理学新靶点.近来,ASICs各个亚基已被克隆,它们在生物体内分布、表达、功能和相关调节因素的研究正受到广泛重视.     

植物细胞质膜离子通道研究进展

多种有机和无机离子作为重要的营养物质、渗透物质、辅酶和信号分子, 参与植物生殖、生长发育和逆境反应等多种生物学过程。离子通道是离子跨质膜和内膜运动的重要渠道和动态调控因子, 直接影响和调控细胞内离子浓度及亚细胞分布的动态变化。目前, 植物尤其是模式植物拟南芥(Arabidopsis thaliana)的多个离子通道家族被先后鉴定出来, 其中部分离子通道蛋白定位在细胞质膜上, 其基本生物学功能, 诸如蛋白结构、离子选择性和通透性、门控特点、活性调控机理以及不同离子通道之间的协同关系等均取得重要进展。该文概要介绍近年来植物细胞质膜离子通道方面的研究进展。     

细胞内离子在气孔运动中的作用

气孔运动与植物水分代谢密切相关。保卫细胞中的无机离子作为第二信使（Ca2＋）或者渗透调节物质（K＋、Cl-）在响应外界理化因子的刺激、调节保卫细胞膨压过程中发挥重要作用。保卫细胞质膜和液泡膜上的离子通道作为各种刺激因素作用的靶位点,是保卫细胞离子转运的关键组分,在气孔运动调控过程中扮演关键角色。该文对近年来保卫细胞离子的作用和离子通道研究的进展进行了综述。     

Modulation of nociceptive ion channels and receptors via protein-protein interactions: implications for pain relief

In the last 2 decades biomedical research has provided great insights into the molecular signatures underlying painful conditions. However, chronic pain still imposes substantial challenges to researchers, clinicians and patients alike. Under pathological conditions, pain therapeutics often lack efficacy and exhibit only minimal safety profiles, which can be largely attributed to the targeting of molecules with key physiological functions throughout the body. In light of these difficulties, the identification of molecules and associated protein complexes specifically involved in chronic pain states is of paramount importance for designing selective interventions. Ion channels and receptors represent primary targets, as they critically shape nociceptive signaling from the periphery to the brain. Moreover, their function requires tight control, which is usually implemented by protein-protein interactions (PPIs). Indeed, manipulation of such PPIs entails the modulation of ion channel activity with widespread implications for influencing nociceptive signaling in a more specific way. In this review, we highlight recent advances in modulating ion channels and receptors via their PPI networks in the pursuit of relieving chronic pain. Moreover, we critically discuss the potential of targeting PPIs for developing novel pain therapies exhibiting higher efficacy and improved safety profiles.     

Simulations of ion current in realistic models of ion channels: the KcsA potassium channel

Realistic studies of ion current in biologic channels present a major challenge for computer simulation approaches. All-atom molecular dynamics simulations involve serious time limitations that prevent their use in direct evaluation of ion current in channels with significant barriers. The alternative use of Brownian dynamics (BD) simulations can provide the current for simplified macroscopic models. However, the time needed for accurate calculations of electrostatic energies can make BD simulations of ion current expensive. The present work develops an approach that overcomes some of the above challenges and allows one to simulate ion currents in models of biologic channels. Our method provides a fast and reliable estimate of the energetics of the system by combining semimacroscopic calculations of the self-energy of each ion and an implicit treatment of the interactions between the ions, as well as the interactions between the ions and the protein-ionizable groups. This treatment involves the use of the semimacroscopic version of the protein dipole Langevin dipole (PDLD/S) model in its linear response approximation (LRA) implementation, which reduces the uncertainties about the value of the protein "dielectric constant." The resulting free energy surface is used to generate the forces for on-the-fly BD simulations of the corresponding ion currents. Our model is examined in a preliminary simulation of the ion current in the KcsA potassium channel. The complete free energy profile for a single ion transport reflects reasonable energetics and captures the effect of the protein-ionized groups. This calculated profile indicates that we are dealing with the channel in its closed state. Reducing the barrier at the gate region allows us to simulate the ion current in a reasonable computational time. Several limiting cases are examined, including those that reproduce the observed current, and the nature of the productive trajectories is considered. The ability to simulate the current in realistic models of ion channels should provide a powerful tool for studies of the biologic function of such systems, including the analysis of the effect of mutations, pH, and electric potentials.     

Modulation of nociceptive ion channels and receptors via protein-protein interactions: implications for pain relief

In the last 2 decades biomedical research has provided great insights into the molecular signatures underlying painful conditions. However, chronic pain still imposes substantial challenges to researchers, clinicians and patients alike. Under pathological conditions, pain therapeutics often lack efficacy and exhibit only minimal safety profiles, which can be largely attributed to the targeting of molecules with key physiological functions throughout the body. In light of these difficulties, the identification of molecules and associated protein complexes specifically involved in chronic pain states is of paramount importance for designing selective interventions. Ion channels and receptors represent primary targets, as they critically shape nociceptive signaling from the periphery to the brain. Moreover, their function requires tight control, which is usually implemented by protein-protein interactions (PPIs). Indeed, manipulation of such PPIs entails the modulation of ion channel activity with widespread implications for influencing nociceptive signaling in a more specific way. In this review, we highlight recent advances in modulating ion channels and receptors via their PPI networks in the pursuit of relieving chronic pain. Moreover, we critically discuss the potential of targeting PPIs for developing novel pain therapies exhibiting higher efficacy and improved safety profiles.     

细胞内离子在气孔运动中的作用

气孔运动与植物水分代谢密切相关。保卫细胞中的无机离子作为第二信使(Ca²⁺)或者渗透调节物质(K⁺、Cl^–)在响应 外界理化因子的刺激、调节保卫细胞膨压过程中发挥重要作用。保卫细胞质膜和液泡膜上的离子通道作为各种刺激因素作 用的靶位点, 是保卫细胞离子转运的关键组分, 在气孔运动调控过程中扮演关键角色。该文对近年来保卫细胞离子的作用 和离子通道研究的进展进行了综述。     

Regulation of ion channels by integrins

Ion channels are regulated by protein phosphorylation and dephosphorylation of serine, threonine, and tyrosine residues. Evidence for regulation of channels by tyrosine phosphorylation comes primarily from investigations of the effects of growth factors, which act through receptor tyrosine kinases. The purpose of the present work is to summarize evidence for the regulation of ion channels by integrins, through their downstream, nonreceptor tyrosine kinases. We review both direct and indirect evidence for this regulation, with particular emphasis on Ca2+-activated K+ and voltage-gated Ca2+ channels. We then discuss the critical roles that cytoskeletal, focal-adhesion, and channel-associated scaffolding proteins may play in localizing nonreceptor tyrosine kinases to the vicinity of ion channels. We conclude by speculating on the physiological significance of these regulatory pathways.     

Launching Channels: A New Milestone in the Ion Channel Field

Ion channels underlie a plethora of physiological functions not only in the animal kingdom, but also in plants and microorganisms such as bacteria. Even though we have only known of the existence of channels for about four decades, a PubMed search for channels yields over 120,000 papers, with 40,000 of those appearing in the past five years alone. Even before ion channels had been formally discovered, their existence was hypothesized by Hodgkin and Huxley who were awarded the Nobel Prize in Physiology/Medicine for their work on electrical activity in axons. Subsequent Nobel awards for ion channel electrophysiology techniques (Bert Sakmann and Erwin Neher for Medicine in 1991) and ion channel structure and physiology (Rod MacKinnon and Peter Agre for Chemistry in 2003) underscored the contemporary importance of ion channel research. It is noteworthy that single channel recording is one of the most sensitive techniques in biology – allowing researchers to study the function of a single molecule in its native environment in real time.