Avian Interferon-Inducible Transmembrane Protein Family Effectively Restricts Avian Tembusu Virus Infection

Chen, Shilong; Wang, Long; Chen, Jieying; Zhang, Lanlan; Wang, Song; Goraya, Mohsan U.; Chi, Xiaojuan; Na, Yang; Shao, Wenhan; Yang, Zhou; Zeng, Xiancheng; Chen, Shaoying; Chen, Ji-Long

(http://www.ch.embnet.org/software/TMPRED_form.html). Chicken and duck IFITM1 and IFITM3 proteins could be divided into five domains reflecting their hydrophobicity and conservation as identified in other species (Figure 7A) , including a variable, hydrophobic N-terminal domain (NTD), a conserved hydrophobic intramembrane domain (IMD), a conserved intracellular loop (CIL), a variable, hydrophobic transmembrane domain (TMD), and a short, highly variable C-terminal domain (CTD). Although significant divergence is seen between avian and mammalian IFITM1 and IFITM3 sequences, several residues are conserved and important for antiviral function, including important amino acids (Y20, C74, C75, K86, K91, and K107) in IFITM3 (Smith et al., 2013; Blyth et al., 2015) . Phylogenetic analysis exhibited that avian IFITM1 and IFITM3 are distinct from those of mammalian species, but avian IFITM3 is more conserved than avian IFITM1 ( Figure 7B ).