State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu Province 730046, China.
Jiangsu Co-Innovation Center for Prevention and Control of Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu Province 225009, China.
Biomed Res Int. 2021 Apr 29;2021:5546170. doi: 10.1155/2021/5546170. eCollection 2021.
NOD-like receptors (NLRs) are intracellular sensors of the innate immune system that recognize intracellular pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). Little information exists regarding the incidence of positive selection in the evolution of NLRs of birds or the structural differences between bird and mammal NLRs. Evidence of positive selection was identified in four avian NLRs (NOD1, NLRC3, NLRC5, and NLRP3) using the maximum likelihood approach. These NLRs are under different selection pressures which is indicative of different evolution patterns. Analysis of these NLRs showed a lower percentage of codons under positive selection in the LRR domain than seen in the studies of Toll-like receptors (TLRs), suggesting that the LRR domain evolves differently between NLRs and TLRs. Modeling of human, chicken, mammalian, and avian ancestral NLRs revealed the existence of variable evolution patterns in protein structure that may be adaptively driven.
核苷酸结合寡聚化结构域样受体（NLRs）是先天免疫系统的细胞内传感器，可识别细胞内病原体相关分子模式（PAMPs）和危险相关分子模式（DAMPs）。关于鸟类 NLRs 进化过程中的正选择以及鸟类和哺乳动物 NLRs 之间的结构差异，相关信息较少。利用最大似然法，在 4 种禽类 NLRs（NOD1、NLRC3、NLRC5 和 NLRP3）中发现了正选择的证据。这些 NLRs 受到不同的选择压力，这表明它们具有不同的进化模式。对这些 NLRs 的分析表明，LRR 结构域中受正选择影响的密码子比例低于 Toll 样受体（TLRs）的研究结果，这表明 NLRs 和 TLRs 之间的 LRR 结构域进化方式不同。对人、鸡、哺乳动物和禽类祖先 NLRs 的建模揭示了蛋白质结构中存在可变的进化模式，这些模式可能是适应性驱动的。
