Brevetoxin (PbTx-2) influences the redox status and NPQ of Karenia brevis by way of thioredoxin reductase

Harmful Algae. 2018 Jan;71:29-39. doi: 10.1016/j.hal.2017.11.004.

Abstract

The Florida red tide dinoflagellate, Karenia brevis, is the major harmful algal bloom dinoflagellate of the Gulf of Mexico and plays a destructive role in the region. Blooms of K. brevis can produce brevetoxins: ladder-shaped polyether (LSP) compounds, which can lead to adverse human health effects, such as reduced respiratory function through inhalation exposure, or neurotoxic shellfish poisoning through consumption of contaminated shellfish. The endogenous role of the brevetoxins remains uncertain. Recent work has shown that some forms of NADPH dependent thioredoxin reductase (NTR) are inhibited by brevetoxin-2 (PbTx-2). The study presented herein reveals that high toxin and low toxin K. brevis, which have a ten-fold difference in toxin content, also show a significant difference in their ability, not only to produce brevetoxin, but also in their cellular redox status and distribution of xanthophyll cycle pigments. These differences are likely due to the inhibition of NTR by brevetoxin. The work could shed light on the physiological role that brevetoxin fills for K. brevis.

Keywords: Brevetoxin; Karenia brevis; NPQ; Thioredoxin; Thioredoxin reductase; Xanthophyll cycle.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Algal Proteins / metabolism
  • Dinoflagellida / drug effects*
  • Harmful Algal Bloom / drug effects*
  • Marine Toxins / administration & dosage*
  • Oxidation-Reduction
  • Oxocins / administration & dosage*
  • Photosynthesis / drug effects
  • Protozoan Proteins / metabolism*
  • Quorum Sensing / drug effects
  • Thioredoxin-Disulfide Reductase / metabolism*

Substances

  • Algal Proteins
  • Marine Toxins
  • Oxocins
  • Protozoan Proteins
  • Ptychodiscus brevis T2 toxin
  • Thioredoxin-Disulfide Reductase