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.     

A tale of two machines: a review of the BLAST meeting,Tucson, AZ, 20–24 January 2013

Since its inception, Bacterial Locomotion and Signal Transduction (BLAST) meetings have been the place to exchange and share the latest developments in the field of bacterial signal transduction and motility. At the 12th BLAST meeting, held last January in Tucson, AZ, researchers from all over the world met to report and discuss progress in diverse aspects of the field. The majority of these advances, however, came at the level of atomic level structures and their associated mechanisms. This was especially true of the biological machines that sense and respond to environmental changes.     

Transgenic Technology meeting 2008 in Toronto, Canada: a meeting report

In a history that goes back to 1999, the Transgenic Technology meetings started out in Sweden and over the years began to attract a growing community of technicians and researchers mainly from Europe. As the meetings started to attract an expanding worldwide audience, the community decided to found the International Society for Transgenic Technologies at the Barcelona meeting in 2005. The 2007 convention was held at Brisbane, Australia, and in 2008, the 8th Transgenic Technology meeting was held for the second time on behalf of ISTT and for the second time outside of Europe in Toronto, Canada. Due to its excellent program with over 400 participants the meeting was able to attract the highest number of delegates of all past TT meetings. With extended times for plenary discussions about technical and organizational aspects, as well as top level scientific presentations, both technicians and scientists enjoyed this as an extremely fruitful meeting from which they could take home solutions for daily routines as well as new insights and ideas for coming projects.     

Channel gate! Tension, leak and disclosure.

The crystal structure of a bacterial MscL shows how this homopentameric channel protein is held tightly shut to prevent leakage whilst at rest. By inference, the structure also shows how a stretch force in the lipid bilayer causes the channel to open. We now have a concrete picture as to how a stimulus 'gates' an ion channel.     

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 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.     

Castles and cuitlacoche: the first international Ustilago conference

The first international Ustilago conference was held in Marburg, Germany from August 22 to 25, 2002. The meeting focused on molecular genetic and cell biology research with Ustilago maydis, the causative agent of common smut of maize. This fungus has emerged as a useful experimental organism for studying the biology of basidiomycete fungi, with a particular emphasis on the interaction of the fungus with the host plant. Thus presentations at the meeting covered the range of current research topics including DNA recombination and repair, mating and sexual development, phytopathology, cell biology, the cell cycle, signaling, and genomics. The meeting also highlighted historical aspects of U. maydis research with presentations by pioneers in the field including Robin Holiday (recombination), Yigal Koltin (killer phenomenon) and Peter Day (plant pathology).     

Ion-channel properties of mastoparan, a 14-residue peptide from wasp venom, and of MP3, a 12-residue analogue.

Mastoparan, a 14-residue peptide, has been investigated with respect to its ability to form ion channels in planar lipid bilayers. In the presence of 0.3-3.0 microM mastoparan, two types of activity are seen. Type I activity is characterized by discrete channel openings, exhibiting multiple conductance levels in the range 15-700 pS. Type II activity is characterized by transient increases in bilayer conductance, up to a maximum of about 650 pS. Both type I and type II activities are voltage dependent. Channel activation occurs if the compartment containing mastoparan is held at a positive potential; channel inactivation if the same compartment is held at a negative potential. Channel formation is dependent on ionic strength; channel openings are only observed at KCl concentrations of 0.3 M or above. Furthermore, raising the concentration of KCl to 3.0 M stabilizes the open form of the channel. Mastoparan channels are weakly cation selective, PK/Cl approximately 2. A 12-residue analogue, des-Ile1,Asn2-mastoparan, preferentially forms type I channels. The ion channels formed by these short peptides may be modelled in terms of bundles of transmembrane alpha-helices.     

Stem cells down under-ISSCR 2007

Cairns, Queensland, Australia provided the venue for the 5th annual meeting of the International Society for Stem Cell Research (ISSCR), June 17-20, 2007. Consonant with the young society's mission to serve the international stem cell community, this meeting was the first held outside North America. The meeting drew attendees from 44 countries, with excellent representation from the Asia/Pacific region. The more than 120 presentations and 1000 posters covered virtually all aspects of the stem cell field and provided a snapshot of current areas of investigation. Here we review some of the newest findings in an effort to convey the energy and excitement of the meeting and the tempo of stem cell science.     

Flux, coupling, and selectivity in ionic channels of one conformation.

Ions crossing biological membranes are described as a concentration of charge flowing through a selective open channel of one conformation and analyzed by a combination of Poisson and Nernst-Planck equations and boundary conditions, called the PNP theory for short. The ion fluxes in this theory interact much as ion fluxes interact in biological channels and mediated transporters, provided the theoretical channel contains permanent charge and has selectivity created by (electro-chemical) resistance at its ends. Interaction occurs because the flux of different ionic species depends on the same electric field. That electric field is a variable, changing with experimental conditions because the screening (i.e., shielding) of the permanent charge within the channel changes with experimental conditions. For example, the screening of charge and the shape of the electric field depend on the concentration of all ionic species on both sides of the channel. As experimental interventions vary the screening, the electric field varies, and thus the flux of each ionic species varies conjointly, and is, in that sense, coupled. Interdependence and interaction are the rule, independence is the exception, in this channel.     

Molecular dynamics - potential of mean force calculations as a tool for understanding ion permeation and selectivity in narrow channels

Ion channels catalyze the permeation of charged molecules across cell membranes and are essential for many vital physiological functions, including nerve and muscle activity. To understand better the mechanisms underlying ion conduction and valence selectivity of narrow ion channels, we have employed free energy techniques to calculate the potential of mean force (PMF) for ion movement through the prototypical gramicidin A channel. Employing modern all-atom molecular dynamics (MD) force fields with umbrella sampling methods that incorporate one hundred 1-2 ns trajectories, we find that it is possible to achieve semi-quantitative agreement with experimental binding and conductance measurements. We also examine the sensitivity of the MD-PMF results to the choice of MD force field and compare PMFs for potassium, calcium and chloride ions to explore the basis for the valence selectivity of this narrow and uncharged ion channel. A large central barrier is observed for both anions and divalent ions, consistent with lack of experimental conductance. Neither anion or divalent cation is seen to be stabilized inside the channel relative to the bulk electrolyte and each leads to large disruptions to the protein and membrane structure when held deep inside the channel. Weak binding of calcium ions outside the channel corresponds to a free energy well that is too shallow to demonstrate channel blocking. Our findings emphasize the success of the MD-PMF approach and the sensitivity of ion energetics to the choice of biomolecular force field.     

Transporters of Neurotransmitters: Receptive, Transport, and Channel Functions

Based on possible unity of the evolutionary origin of some prokaryotic proteins with eukaryotic ion channels and receptors, this review analyzes interconnections between receptive, transport, and channel functions of integral proteins. This interconnection can be considered the best by the example of neurotransmitter transporters. Their role in chemical synapses and their possible participation in phenomena of synaptic plasticity are reviewed. There are discussed mechanisms of transporter functioning, such as the allosteric model and the model of activity by the principle of channel, as well as data about coupling by the transporters of reception of substrate and its transport with the substrate-activated channel of Cl^–-conductance and the ion leakage. The importance of the latter aspects of the neurotransmitter transporter functioning is usually underestimated in studying neuronal and glial electrogenesis.     

Breakdown of the potentiality principle and its impact on global stem cell research

Totipotency, defined as the ability of a single cell to generate an entire individual, has traditionally served as a cornerstone to frame the moral relevance of nascent human life. This "potentiality principle" has served as an ethical reference point for shaping legal regulations for stem cell research in most Western countries. Based on heterogeneous ethical, religious, and political views, different countries cope with recent advances in mammalian cloning and reprogramming in a remarkably diverse manner. This and related issues were key topics at a recent meeting held in Berlin, Germany, on ethical aspects of stem cell research in Europe. An emerging view from this event is that international heterogeneity in stem cell politics and legislation must be overcome in order to develop this field toward biomedical application.     

The spectacular landscape of chromatin and ncRNAs under the Tico sunlight

The biannual Abcam meeting on Chromatin: Structure & Function held last November covered many aspects of chromatin regulation in health and disease. Important discussion points were the dynamic aspects of chromatin and the ever‐increasing involvement of non‐coding RNAs in chromatin and epigenetic mechanisms.     

Single Cell Genomics meeting in Stockholm: from single cells to cell types

A report on the second Single Cell Genomics conference held in Stockholm, Sweden, September 9–11, 2014.The second Single Cell Genomics conference was held in Stockholm and hosted by the Karolinska Institute. The ‘Venice of the North’ was the setting for an exciting and intense meeting, with scientists from very different disciplines tackling the numerous challenges that single cell genomics presents.During three days, 35 talks and more than 60 posters addressed many aspects of single cell genomics, from new experimental techniques to computational strategies for data analysis. We report on some of the main themes that emerged and, in our opinion, best illustrate the progress made and the new directions being undertaken by the field.     

CCM8: The Eighth International Symposium on Inorganic Carbon Uptake by Aquatic Photosynthetic Organisms

The articles in this special issue of Photosynthesis Research arose from the presentations given at the Eighth International Symposium on Inorganic Carbon Uptake by Aquatic Photosynthetic Organisms held from May 27 to June 1, 2013 in New Orleans, Louisiana USA. The meeting covered all the aspects of CO₂ concentrating mechanisms (CCMs) present in photosynthetic bacteria, microalgae and macrophytes, and spanned disciplines from the molecular biology of CCMs to the importance of CCMs in aquatic ecosystems. The publications in this special issue represent our current understanding of CCMs and highlight recent advances in the field. The influences of CCMs on algal biofuel production as well as recent efforts to use the CCM to improve crop plants are also explored.     

Meeting report from the first meetings of the Computational Modeling in Biology Network (COMBINE)

The Computational Modeling in Biology Network (COMBINE), is an initiative to coordinate the development of the various community standards and formats in computational systems biology and related fields. This report summarizes the activities pursued at the first annual COMBINE meeting held in Edinburgh on October 6-9 2010 and the first HARMONY hackathon, held in New York on April 18-22 2011. The first of those meetings hosted 81 attendees. Discussions covered both official COMBINE standards-(BioPAX, SBGN and SBML), as well as emerging efforts and interoperability between different formats. The second meeting, oriented towards software developers, welcomed 59 participants and witnessed many technical discussions, development of improved standards support in community software systems and conversion between the standards. Both meetings were resounding successes and showed that the field is now mature enough to develop representation formats and related standards in a coordinated manner.     

Growing momentum in the molecular study of ion channels.

Long the sole domain of physiologists and electrical engineers, ion channel biophysics is going molecular, and with a vengeance. This summary of a recent meeting devoted to ion channel biophysics shows that the integration of techniques, reinforced by active communication among scientists of diverse backgrounds, is extremely potent.