The interferon receptors.

摘要: During the past decade, receptors for type I (alpha, beta, and omega) II (gamma) interferons (IFNs) have been identified. The IFN-gamma receptor consists of two transmembrane chains, IFN-gammaR1 IFN-gammaR2, both which are required activity. chain binds ligand, whereas IFN-gammaR2 is signal transduction. After ligand binding, Jak1 Jak2 kinases activated by phosphorylation then phosphorylate chain, serves as recruitment site Stat1alpha (signal transducers activators transcription). to phosphorylated released form a dimer that represents active transcription factor IFN-gamma-induced genes. An analogous paradigm exists IFN (IFN-alpha/beta) receptor. This appears consist IFN-alphaR1 IFN-alphaR2, can be present in different forms. Thus, full (IFN-alphaR1a) splice-variant (IFN-alphaR1s) lacking exons IV V; IFN-alphaR2 soluble, short, long forms (IFN-alphaR2a, IFN-alphaR2b, IFN-alphaR2c, respectively). Most likely, IFN-alphaR1a IFN-alphaR2c chains represent predominantly form. binding IFN-alpha, IFN-beta, or IFN-omega species, Tyk2 recruited complex activated. activation results subsequent Stat1 (Stat1alpha Stat1beta) Stat2, Stat1/Stat2 heterodimer after their phosphorylation. IFN-stimulated gene factor-3 formed association with p48 protein. promoter elements IFN-induced genes initiate transcription. Although overall motif clear, there much complexity these interactions various IFNs exhibit components. Apparently, each IFN-alpha species exhibits pattern reflects biologic activities will likely explain existence this large family all interact same basal