Open Access受体的多样性驱动蛇毒的进化
Author(s) -
Xian-Hong Ji,
Shang-Fei Zhang,
Bin Gao,
Shunyi Zhu
Publication year - 2018
Publication title -
zoological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 19
ISSN - 2095-8137
DOI - 10.24272/j.issn.2095-8137.2018.063
Subject(s) - subfamily , venom , biology , adaptation (eye) , nicotinic acetylcholine receptor , receptor , acetylcholine receptor , evolutionary biology , computational biology , genetics , gene , biochemistry , neuroscience
Three-finger toxins (TFTs) are well-recognized non-enzymatic venom proteins found in snakes. However, although TFTs exhibit accelerated evolution, the drivers of this evolution remain poorly understood. The structural complexes between long-chain α-neurotoxins, a subfamily of TFTs, and their nicotinic acetylcholine receptor targets have been determined in previous research, providing an opportunity to address such questions. In the current study, we observed several previously identified positively selected sites (PSSs) and the highly variable C-terminal loop of these toxins at the toxin/receptor interface. Of interest, analysis of the molecular adaptation of the toxin-recognition regions in the corresponding receptors provided no statistical evidence for positive selection. However, these regions accumulated abundant amino acid variations in the receptors from the prey of snakes, suggesting that accelerated substitution of TFTs could be a consequence of adaptation to these variations. To the best of our knowledge, this atypical evolution, initially discovered in scorpions, is reported in snake toxins for the first time and may be applicable for the evolution of toxins from other venomous animals.