Voltage-dependent displacement of the scorpion toxin Ts3 from sodium channels and its implication on the control of inactivation

British Journal of Pharmacology
Fabiana V CamposPaulo Sérgio Lacerda Beirão

Abstract

The voltage-dependent displacement of the scorpion Tityus serrulatus alpha-toxin Ts3 was investigated in native sodium channels of GH3 cells by examining the removal of its effects in toxin-free solution. Toxin at saturating concentration was pulsed (approximately 1 s) directly onto the cell, thus causing an eight-fold increase of the slow component (taus = 6 ms) of fast inactivation, and a three-fold increase of the time constant of its fast component. At 0 mV, maximal conductance was achieved in cells before and after treatment with Ts3, and no displacement of the toxin could be detected. Toxin displacement occurred if stronger depolarising pulses (> 100 mV) were applied. The rate of displacement depended on the amplitude and duration of the pulses, and was not related with outward Na+ flux. We propose a model in which activation does not require complete movement of segment S4 of domain IV (IVS4) and that a more extensive movement of this segment is needed for normal fast inactivation. A kinetic model is presented that can account for the typical effects of site 3 toxins.

References

Nov 1, 1977·The Journal of General Physiology·C M Armstrong, F Bezanilla
Aug 1, 1976·Proceedings of the National Academy of Sciences of the United States of America·W A CatterallC S Morrow
Feb 1, 1987·The Journal of General Physiology·T Gonoi, B Hille
Jan 1, 1989·The Journal of General Physiology·G E KirschA M Brown
Dec 1, 1996·The Journal of General Physiology·L Q ChenR G Kallen
Feb 7, 1998·The Journal of Biological Chemistry·G R BenzingerD A Hanck
Sep 22, 1999·European Journal of Biochemistry·L D PossaniJ Tytgat
Mar 18, 2000·Pflügers Archiv : European journal of physiology·H ChenS H Heinemann
Aug 30, 2000·The Journal of General Physiology·R HornH J Gruber
Nov 22, 2000·Biochimie·S Cestèle, W A Catterall
Apr 30, 2002·Brain Research. Molecular Brain Research·David R Castañeda-CastellanosE Recio-Pinto
Oct 31, 2002·The Journal of General Physiology·Baron Chanda, Francisco Bezanilla
Oct 29, 2003·Biophysical Journal·Harold LecarMichael Grabe

❮ Previous
Next ❯

Citations

Jul 30, 2008·The Journal of General Physiology·Fabiana V CamposFrancisco Bezanilla
Aug 5, 2014·Journal of Molecular Biology·Jeet KaliaFrank Bosmans
Dec 30, 2015·The Journal of General Physiology·Christopher A AhernBaron Chanda
Mar 18, 2008·Toxicon : Official Journal of the International Society on Toxinology·André Junqueira ZaharenkoJosé Carlos de Freitas
Jun 18, 2015·PloS One·Thalita S CamargosElisabeth F Schwartz
Sep 27, 2005·Physiological Reviews·Werner Ulbricht
Jun 1, 2016·Angewandte Chemie·Bobo DangStephen B H Kent

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.