The evolution of voltage-gated sodium channels: were algal toxins involved?

Anderson, Peter; Roberts-Misterly, J. M.; Greenberg, Robert M.

doi:10.1016/j.hal.2003.12.007

Cited by 21 publications

(15 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This kind of increase in mean chain length was particularly notorious at sub-optimal temperatures. Vale G. catenatum produces potent neurotoxins (the PSTs), blockers of voltage-gated sodium channels in many animals (Anderson et al 2004), which might modify potassium channel gating (Wang et al 2003) and partially block calcium currents (Su et al 2004). The ecological role of these tetrahydropurine derivatives is not fully understood, nor the adaptation mechanisms for avoiding self-inhibition in the producing organisms.…”

Section: Discussionmentioning

confidence: 99%

Influence of solar and geomagnetic activity in Gymnodinium catenatum (Dinophyceae) cultures

Vale

2017

gpb

View full text Add to dashboard Cite

Laboratory cultures of the paralytic shellfish poisoning producing microalga Gymnodinium catenatum were subjected to a hypo-osmotic shock and changes in cell concentration were observed in two separate experiments of 8 and 24 hours duration, respectively. The increase in geomagnetic activity (GMA), radio and X-ray fluxes and solar X-ray flares were negatively correlated with cell numbers. Cell losses were observed in the short experiment, but not in the longest one. GMA action was related to the course of the experimental period, while electromagnetic radiation (EMR) was only significantly related when the previous hours before the experiments were considered. The differential action windows might be indicative of two differential disruptive mechanisms: EMR might act on DNA synthesis and mitosis phases of the cell cycle (taking place in the dark period) and GMA might be more disruptive at the end of mytosis or cytokinesis phases taking place in the light period. Formation of long chains (> 4 cells/chain) was reduced with salinity and with temperatures above 27ºC but increased with EMR and GMA, particularly when grown at the highest temperatures recorded during the study period (≥28ºC).

show abstract

Section: Discussionmentioning

confidence: 99%

Influence of solar and geomagnetic activity in Gymnodinium catenatum (Dinophyceae) cultures

Vale

2017

gpb

View full text Add to dashboard Cite

show abstract

“…It has been demonstrated recently that Na + channel diversification has been driven by predator-toxic prey interactions in vertebrates (Geffeney et al, 2005). Algal toxins may also have impacted on the early evolution of the Na v channels in animals (Anderson et al, 2005) and arguably influenced the evolution of ion channels in algae themselves. As algae possess homologues of voltage-gated and ionotropic channels, we may speculate that ion channel toxins from neighbouring algae could have resulted in selective pressure for the evolution of alternative or insensitive ion channels.…”

Section: Tansley Reviewmentioning

confidence: 99%

Calcium channels in photosynthetic eukaryotes: implications for evolution of calcium‐based signalling

et al. 2010

View full text Add to dashboard Cite

SummaryMuch of our current knowledge on the mechanisms by which Ca 2+ signals are generated in photosynthetic eukaryotes comes from studies of a relatively small number of model species, particularly green plants and algae, revealing some common features and notable differences between 'plant' and 'animal' systems. Physiological studies from a broad range of algal cell types have revealed the occurrence of animal-like signalling properties, including fast action potentials and fast propagating cytosolic Ca 2+ waves. Genomic studies are beginning to reveal the widespread occurrence of conserved channel types likely to be involved in Ca 2+ signalling. However, certain widespread 'ancient' channel types appear to have been lost by certain groups, such as the embryophytes. More recent channel gene loss is also evident from comparisons of more closely related algal species. The underlying processes that have given rise to the current distributions of Ca 2+

show abstract

“…The large 4-domain VGCs of eukaryotes form two major groups, the Ca 2+ and Na + VGCs, that were proposed to have arisen from gene duplication and undergone functional diversification (Strong, Chandy & Gutman, 1993;Cestèle & Catterall, 2000). Shared structural features between eukaryotic and prokaryotic VGCs lead to the hypothesis that VGCs ultimately originated from the ancestral one-domain prokaryote channel (Anderson, Roberts-Misterly & Greenberg, 2005), although, recent phylogenetic studies indicate independent origins (Verret et al, 2010;Liebeskind, Hillis & Zakon, 2013). However, in both bacterial and eukaryote VGCs the high field strength (HFS) residue in the pore loop between S5 and S6 determines ion selectivity and more recent structural and functional analyses PeerJ reviewing PDF | (2017:11:21903:1:1:NEW 2 Mar 2018)…”

Section: Discussionmentioning

confidence: 99%

Peer Review #2 of "Interaction of a dinoflagellate neurotoxin with voltage-activated ion channels in a marine diatom (v0.1)"

2018

View full text Add to dashboard Cite

Background. The potent neurotoxins produced by the harmful algal bloom species Karenia brevis are activators of sodium voltage-gated channels (VGC) in animals, resulting in altered channel kinetics and membrane hyperexcitability. Recent biophysical and genomic evidence supports widespread presence of homologous sodium (Na +) and calcium (Ca 2+) permeable VGCs in unicellular algae, including marine phytoplankton. We therefore hypothesized that VGCs of these phytoplankton may be an allelopathic target for waterborne neurotoxins produced by K. brevis blooms that could lead to ion channel dysfunction and disruption of signaling in a similar manner to animal Na + VGCs. Methods. We examined the interaction of brevetoxin-3 (PbTx-3), a K. brevis neurotoxin, with the Na + /Ca 2+ VGC of the non-toxic diatom Odontella sinensis using electrophysiology. Single electrode current-and voltage-clamp recordings from O. sinensis in the presence of PbTx-3 were used to examine the toxin's effect on voltage gated Na + /Ca 2+ currents. In silico analysis was used to identify the putative PbTx binding site in the diatoms. We identified Na + /Ca 2+ VCG homologs from the transcriptomes and genomes of 12 diatoms, including three transcripts from O. sinensis and aligned them with site-5 of Na + VGCs, previously identified as the PbTx binding site in animals. Results. Up to 1 μM PbTx had no effect on diatom resting membrane potential or membrane excitability. The kinetics of fast inward Na + /Ca 2+ currents that underlie diatom action potentials were also unaffected. However, the peak inward current was inhibited by 33%, delayed outward current was inhibited by 25%, and reversal potential of the currents shifted positive, indicating a change in permeability of the underlying channels. Sequence analysis showed a lack of conservation of the PbTx binding site in diatom VGC homologs, many of which share molecular features more similar to single-domain bacterial Na + /Ca 2+ VGCs than the 4-domain eukaryote channels. Discussion. Although membrane excitability and the kinetics of action potential currents were unaffected, the permeation of the channels underlying the diatom action potential was significantly altered in the presence of PbTx-3. However, at environmentally relevant concentrations the effects of PbTx-on diatom voltage activated currents and interference of cell signaling through this pathway may be limited. The relative insensitivity of phytoplankton VGCs may be due to divergence of site 5 (the putative PbTx binding site), and in some cases, such as O. sinensis, resistance to toxin effects may be because of evolutionary loss of the 4-domain eukaryote channel, while retaining a single domain bacterial-like VGC that may substitute in the generation of fast action potentials.

show abstract

The evolution of voltage-gated sodium channels: were algal toxins involved?

Cited by 21 publications

References 52 publications

Influence of solar and geomagnetic activity in Gymnodinium catenatum (Dinophyceae) cultures

Influence of solar and geomagnetic activity in Gymnodinium catenatum (Dinophyceae) cultures

Calcium channels in photosynthetic eukaryotes: implications for evolution of calcium‐based signalling

Peer Review #2 of "Interaction of a dinoflagellate neurotoxin with voltage-activated ion channels in a marine diatom (v0.1)"

Contact Info

Product

Resources

About