DIFFERENTIAL USE OF THE BETA(L) SUBUNIT OF THE TYPE-I INTERFERON (IFN) RECEPTOR DETERMINES SIGNALING SPECIFICITY FOR IFN-ALPHA-2 AND IFN-BETA

The signaling specificity for cytokines that have common receptor subu nits is achieved by the presence of additional cytokine-specific recep tor components. In the type I interferon (IFN) family, all 14 subtypes of IFN alpha, IFN beta, and IFN omega bind to the same alpha and beta (L), subunits of the type I IFN-R, yet differences in signaling and bi ological effects exist among them. Our data demonstrate that IFN alpha 2 and IFN beta utilize different regions of the beta(L), subunit for signaling, Thus, in contrast to other cytokine systems, signal diversi ty in the type I IFN system can be accomplished within the same recept or complex by utilizing different regions of the same receptor subunit s.