Evolutionary origin and status of two insect acetylcholinesterases and their structural conservation and differentiation. Issue 1 (January 2015)

• Record Type: Journal Article
• Authors: Cha, Deok Jea; Lee, Si Hyeock
• Is Part Of: Evolution & development. Volume 17:Issue 1(2015)
• Page Start: 109
• Page End: 119
• Publication Date: 2015-01
• Subjects: Evolution (Biology) -- Periodicals; Developmental biology -- Periodicals; 576.82
• DOI: 10.1111/ede.12111
• Languages: English
• ISSNs: 1520-541X

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>SUMMARY</title> <sec id="ede12111-sec-0001" sec-type="section"> <p>Acetylcholinesterase (AChE) plays a pivotal role in synaptic transmission in the cholinergic nervous system of most animals, including insects. Insects possess duplicated AChE gene loci (<italic>ace1</italic> vs. <italic>ace2</italic>) encoding two distinct AChEs (AChE1 and AChE2). A phylogenetic analysis suggested that the last common ancestor of two <italic>aces</italic> shared its origin with Platyhelminthes. In addition, the <italic>ace</italic> duplication event likely occurred after the divergence of Protostomian but before the split of Ecdysozoa. The <italic>ace1</italic> lineage exhibited a significantly lower evolutionary rate (<italic>d</italic> and <italic>dN/dS</italic> ratio) than the <italic>ace2</italic> lineage, suggesting that the <italic>ace1</italic> lineage has retained the essential function of synaptic transmission following its duplication. Therefore, the putative functional transition from <italic>ace1</italic> to <italic>ace2</italic> observed in some Hymenopteran insects appears to be a local and relatively recent event. The amino acid sequence comparison and three‐dimensional modeling of insect AChEs identified a few consistent differences in the amino acid residues in functionally crucial domains between two AChEs, which are likely responsible for the functional differentiation between two AChEs. A unique amino acid substitution causing a dramatic reduction in the catalytic activity of AChE1 in some Hymenopteran insects was suggested to be responsible for the aforementioned functional transition of <italic>ace</italic>.</p> </sec> </abstract>