Mutations to the cardiotonic steroid binding site of Na(+)/K(+)-ATPase are associated with high level of resistance to gamabufotalin in a natricine snake

Toxicon. 2016 May:114:13-5. doi: 10.1016/j.toxicon.2016.02.019. Epub 2016 Feb 21.

Abstract

Although toads are defended by bufadienolide toxins, some snakes have evolved resistance to bufadienolides and feed heavily on toads. We compared resistance in Nerodia rhombifer, which possesses mutations that confer target-site resistance, to Pituophis catenifer, which lacks those mutations. Even at the highest dosage tested, Nerodia showed no effects, whereas the lowest dose was lethal to Pituophis. Our results demonstrate a striking level of resistance to bufadienolides in a species possessing the mutations for resistance.

Keywords: Bufadienolide; Bufophagy; Gamabufotalin; Na(+)/K(+)-ATPase; Snake; Toad; Toxin resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites / genetics
  • Bufanolides / metabolism
  • Bufanolides / toxicity*
  • Bufonidae / metabolism
  • Cardiotonic Agents / toxicity*
  • Colubridae / genetics*
  • Colubridae / physiology
  • Feeding Behavior
  • Mutation
  • Sodium-Potassium-Exchanging ATPase / chemistry
  • Sodium-Potassium-Exchanging ATPase / genetics*
  • Species Specificity

Substances

  • Bufanolides
  • Cardiotonic Agents
  • gamabufotalin
  • Sodium-Potassium-Exchanging ATPase