Expression and Signaling Specificity of the IFNAR Chain of the Type I Interferon Receptor Complex

• Published in: Proceedings of the National Academy of Sciences - PNAS 1995-11, Vol.92 (23), p.10487-10491
• Main Authors: Constantinescu, Stefan N., Croze, Edward, Murti, Aruna, Wang, Chiang, Basu, Leela, Hollander, Doris, Russell-Harde, Dean, Betts, Melissa, Garcia-Martinez, Victor, Mullersman, Jerald E., Pfeffer, Lawrence M.
• Format: Article
• Language: English
• Subjects: 3T3 cells; Animals; Binding sites; Cell lines; Cells; Cells, Cultured; Cellular biology; Down regulation; Glycosylation; HeLa cells; Humans; Interferon; Interferon Type I - metabolism; Janus Kinase 1; Membranes; Mice; Molecular chains; NIH 3T3 cells; Phosphorylation; Protein-Tyrosine Kinases - metabolism; Proteins - metabolism; Receptor, Interferon alpha-beta; Receptors; Receptors, Interferon - genetics; Receptors, Interferon - metabolism; Recombinant Proteins - metabolism; Signal Transduction; TYK2 Kinase; Tyrosine - metabolism; Vaccinia virus - genetics
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.92.23.10487

The IFNAR chain of the type I interferon (IFN) receptor (IFNIR) undergoes rapid ligand-dependent tyrosine phosphorylation and acts as a species-specific transducer for type I IFN action. Using the vaccinia/T7 expression system to amplify IFNAR expression, we found that human HeLa-S3 cells transiently express high levels of cell surface IFNAR chains (≈250,000 chains per cell). Metabolic labeling and immunoblot analysis of transfected HeLa cells show that the IFNAR chain is initially detected as 65-kDa and 98-kDa precursors, and then as the 130-kDa mature protein. Due to variation in N-glycosylation, the apparent molecular mass of the mature IFNAR chain varies from 105 to 135 kDa in different cells. IFNIRstructure was characterized in various human cell lines by analyzing125I-labeled IFN cross-linked complexes recognized by various antibodies against IFNIRsubunits and JAK protein-tyrosine kinases. Precipitation of cross-linked material from Daudi cells with anti-IFNAR antibodies showed that IFNAR was present in a 240-kDa complex. Precipitation of cross-linked material from U937 cells with anti-TYK2 sera revealed a 240-kDa complex, which apparently did not contain IFNAR and was not present in IFN-resistant HEC1B cells. The tyrosine phosphorylation and down-regulation of the IFNAR chain were induced by type I IFN in several human cell lines of diverse origins but not in HEC1B cells. However, of type I IFNs, IFN-β uniquely induced the tyrosine phosphorylation of a 105-kDa protein associated with the IFNAR chain in two lymphoblastoid cell lines (Daudi and U266), demonstrating the specificity of transmembrane signaling for IFN-β and IFN-α through the IFNAR chain.