Molecular cloning and characterization of chicken interferon-gamma receptor alpha-chain.
In this study, a cDNA sequence of Huiyang chicken interferon-gamma (IFN-gamma) receptor alpha-chain (chIFNGR-1) gene wasgenerated using rapid amplification of cDNA ends (RACE) method for the first time. The predicted 422 amino acids showed approximately 25%-29% sequence identity and 53%-55% similarity to mammalian homologues. There are two fibronectin type-III (FN-III) domains of about 110 residues in the extracellular domain, and LPKS and YDKPH motifs in the intracellular domain, which are conserved in the mammalian IFNGR-1 as the binding sites of JAK1 and STAT1. Expression analysis by Northern blot revealed that the chIFNGR-1 was highly expressed in spleen, thymus, peripheral blood lymphocytes (PBLs), lung, cecum tonsil, and liver. The extracellular region of chIFNGR-1 (chIFNGR-1EC) was expressed in Escherichia coli and purified. The purified IFNGR-1EC was further characterized by mass spectroscopy and circular dichroism (CD) spectroscopy. The molecular weight of the recombinant chIFNGR-1EC (rchIFNGR-1EC) was measured as 24 364 Da, and its secondary structure contained 17.6% alpha-helix, 36.4% beta-sheet, 17.2% turn, and 28.8% random coil. Furthermore, three-dimensional modeling presented the most probable structure of chIFNGR-1EC. These * ndings show that the identified chicken cDNA sequence encodes an IFNGR1 homologue, and the chIFNGR-1EC resembles the similar structure with other IFN receptors.
Han
Xue
X
College of Veterinary Medicine, China Agricultural University, Beijing, China.
Chen
Tong
T
Wang
Ming
M
D000818:Animals; D002645:Chickens; D003001:Cloning, Molecular; D004926:Escherichia coli; D015870:Gene Expression; D020869:Gene Expression Profiling; D053613:Janus Kinase 1 / Q000276:immunology; D008968:Molecular Conformation; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D017471:Receptors, Interferon / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D050794:STAT1 Transcription Factor / Q000276:immunology; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D000096743:Interferon gamma Receptor
D053613:Janus Kinase 1; D017471:Receptors, Interferon; D050794:STAT1 Transcription Factor; D000096743:Interferon gamma Receptor