Ion transport: Spot the difference

  title={Ion transport: Spot the difference},
  author={David C. Gadsby},
  • D. Gadsby
  • Published 26 February 2004
  • Physics
  • Nature
Common wisdom holds that ion channels and ion pumps, with their obvious functional differences, should have visibly dissimilar structures. It seems that's not necessarily so. 

Biochemical and functional characterisation of phospholipase C-η2

It is shown using a neuroblast model that PLCη2 is crucial for neuronal differentiation and neurite growth and it was revealed that it might be involved in regulating intracellular Ca 2+ dynamics, transcriptional activity and actin reorganisation in differentiating neurons.

Voltage-dependent charge movement associated with activation of the CLC-5 2Cl−/1H+ exchanger

  • Andrew J. SmithJ. Lippiat
  • Biology
    FASEB journal : official publication of the Federation of American Societies for Experimental Biology
  • 2010
The data suggest that voltage sensing is an intrinsic property of the CLC‐5 protein and that permeant anions, particularly Cl−, modulate a voltage‐dependent transition to an activated state from which Cl−/H+ exchange can occur.

Ion homeostasis, channels, and transporters: an update on cellular mechanisms.

  • G. Dubyak
  • Biology
    Advances in physiology education
  • 2004
This review will describe how postgenomics research in ion transport biology increasingly involves two powerful approaches: one involves elucidation of the molecular structures, at the atomic level in some cases, of model ion transport proteins, and the second uses the tools of cell biology to explore the cell-specific function or subcellular localization of Ion transport proteins.

Mathematical Model for Chemical Reactions in Electrolyte Applied to Cytochrome $c$ Oxidase: an Electro-osmotic Approach

A mathematical model for chemical reactions in electrolytes is developed using an Energy variational method consistent with classical thermodynamics. Electrostatics and chemical reactions are

Biomimetic Nanochannels: From Fabrication Principles to Theoretical Insights

Biological nanochannels which can regulate ionic transport across cell membranes intelligently play a significant role in physiological functions. Inspired by these nanochannels, numerous artificial

Fast transport of HCl across a hydrophobic layer over macroscopic distances by using a Pt(II) compound as the transporter: micro- and nanometric aggregates as effective transporters.

Thermodynamic parameters obtained from the study of acid-base behaviour of the system Pt(ii) species/HCl/CHCl3 also agree with the proposed mechanism of HCl transport.

Disease Detection with Molecular Biomarkers: From Chemistry of Body Fluids to Nature-Inspired Chemical Sensors.

This article aims to review nature-inspired chemical sensors for enabling fast, relatively inexpensive, and minimally invasive diagnostics and follow-up of the health conditions via monitoring of biomarkers and volatile biomarkers.

Automated Change Detection: Applications for Synthetic Aperture Sonar and Future Capabilities

The different processing steps of the automation: image coregistration, change-map generation, detection, and data reduction (false-alarm reduction) as it applies to automatic target recognition using sonar imagery are introduced.



Gating the Selectivity Filter in ClC Chloride Channels

A form of gating is revealed in which the glutamate carboxyl group closes the pore by mimicking a Cl– ion, which governs the electrical activity of muscle cells and certain neurons.

Open-state substructure of single chloride channels from Torpedo electroplax.

  • C. Miller
  • Biology
    Philosophical transactions of the Royal Society of London. Series B, Biological sciences
  • 1982
Chloride channels from Torpedo californica electroplax were inserted into planar phospholipid membranes, and single-channel currents were studied at high time-resolution, finding that the conducting of unit of Cl- channel is composed of two identical Cl- diffusion pathways, each with a voltage-dependent gate.

A biological role for prokaryotic ClC chloride channels

It is shown that Escherichia coli uses chloride channels of the widespread ClC family in the extreme acid resistance response and proposed that the channels function as an electrical shunt for an outwardly directed virtual proton pump that is linked to amino acid decarboxylation.

Secondary active transport mediated by a prokaryotic homologue of ClC Cl- channels

It is shown that this bacterial homologue of ClC-ec1 is not an ion channel, but rather a H+-Cl- exchange transporter, suggesting that the structural boundary separating channels and transporters is not as clear cut as generally thought.

Chemistry of ion coordination and hydration revealed by a K+ channel–Fab complex at 2.0 Å resolution

Here it is shown how the K+ channel displaces water molecules around an ion at its extracellular entryway, and how it holds a K+ ion in a square antiprism of water molecules in a cavity near its intracellular entry way.

X-ray structure of a ClC chloride channel at 3.0 Å reveals the molecular basis of anion selectivity

This work presents the X-ray structures of two prokaryotic ClC Cl- channels from Salmonella enterica serovar typhimurium and Escherichia coli at 3.0 and 3.5 Å, respectively, and establishes the physical and chemical basis of their anion selectivity.

The principle of gating charge movement in a voltage-dependent K+ channel

It is concluded that the voltage-sensor paddles operate somewhat like hydrophobic cations attached to levers, enabling the membrane electric field to open and close the pore.

Crystal structure and mechanism of a calcium-gated potassium channel

This work has cloned, expressed, analysed electrical properties, and determined the crystal structure of a K+ channel (MthK) from Methanobacterium thermoautotrophicum in the Ca2+-bound, opened state.