Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
Department of Computational Biology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
Elife. 2020 Dec 4;9:e62507. doi: 10.7554/eLife.62507.
The insect chemosensory repertoires of Odorant Receptors (ORs) and Gustatory Receptors (GRs) together represent one of the largest families of ligand-gated ion channels. Previous analyses have identified homologous 'Gustatory Receptor-Like' (GRL) proteins across Animalia, but the evolutionary origin of this novel class of ion channels is unknown. We describe a survey of unicellular eukaryotic genomes for GRLs, identifying several candidates in fungi, protists and algae that contain many structural features characteristic of animal GRLs. The existence of these proteins in unicellular eukaryotes, together with protein structure predictions, provide evidence for homology between GRLs and a family of uncharacterized plant proteins containing the DUF3537 domain. Together, our analyses suggest an origin of this protein superfamily in the last common eukaryotic ancestor.
昆虫的化学感受受体（ORs）和味觉受体（GRs）的组合代表了最大的配体门控离子通道家族之一。以前的分析已经在动物界鉴定出同源的“味觉受体样”（GRL）蛋白，但这种新型离子通道的进化起源尚不清楚。我们对单细胞真核生物基因组进行了 GRL 调查，在真菌、原生动物和藻类中鉴定出了几个候选基因，它们包含许多动物 GRL 特有的结构特征。这些蛋白质在单细胞真核生物中的存在，以及蛋白质结构预测，为 GRL 与包含 DUF3537 结构域的一组未鉴定的植物蛋白之间的同源性提供了证据。综上所述，我们的分析表明，该蛋白超家族起源于最后一个共同的真核生物祖先。
