Molecular characterization of feline type I interferon receptor 2.
The cDNA sequence of feline interferon receptor 2 (feIFNAR2) was generated using RT-PCR method in present study. This gene included 1,572 bp and encoded a 523 aminoacid (aa) protein with a 35 aa signal peptide. The deduced protein shared 61% amino acid identity to the human IFNAR2. There were two fibronectin type III (FBN-III) domains of about 110 residues in the extracellular domain. Homology modeling of feIFNAR2 presented a similar structure with other IFN receptors. The ELISA and FACS experiments demonstrated that the protein could bind to feIFN-alpha or feIFN-omega. However, antiviral activity assay found that feIFN-omega had broader species spectrum compared with feIFN-alpha. To define the functional differences, several point mutations of feIFNAR2 were constructed and the relative affinities of feIFN-alpha or feIFN-omega for feIFNAR2 and mutants were evaluated. The results suggested that feIFN-alpha and feIFN-omega had different binding sites on feIFNAR2. T75 and M77 on feIFNAR2 were hotspots for binding to feIFN-alpha, but not to feIFN-omega. These findings suggested that the cloned feline IFNAR2 interacted with both feIFN-alpha and feIFN-omega, however, not sharing the same binding sites.
Xue
Qinghua
Q
The Center for Molecular Virology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People's Republic of China.
Yang
Limin
L
Liu
Xiaoling
X
Liu
Wenjun
W
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002415:Cats; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D053633:Receptor, Interferon alpha-beta / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment
C508033:IFNAR2 protein, human; D053633:Receptor, Interferon alpha-beta