TI  - A region of the beta subunit of the  <prot><prot>interferon alpha</prot> receptor</prot>  different
      from box 1 interacts with  <prot>Jak1</prot>  and is sufficient to activate the <prot>Jak</prot>-Stat
      pathway and induce an antiviral state.
PG  - 26388-93
AB  - Coexpression of the alpha and betaL subunits of the human <prot><prot>interferon alpha</prot>
      (<prot>IFNalpha</prot>) receptor</prot> is required for the induction of an antiviral state by
      human <prot>IFNalpha</prot>. To explore the role of the different domains of the betaL
      subunit in <prot>IFNalpha</prot> signaling, we coexpressed wild-type alpha subunit and
      truncated forms of the betaL chain in L-929 cells. Our results
      demonstrated that the first 82 amino acids (AAs) (AAs 265-346) of the
      cytoplasmic domain of the betaL chain are sufficient to activate the
      <prot>Jak</prot>-Stat pathway and trigger an antiviral state after <prot>IFNalpha2</prot> binding to
      the receptor. This region of the betaL chain, required for <prot>Jak1</prot> binding
      and activation, contains the Box 1 motif that is important for the
      interaction of some cytokine receptors with <prot>Jak</prot> kinases. However, using
      glutathione S-transferase fusion proteins containing amino- and
      carboxyl-terminal deletions of the betaL cytoplasmic domain, we
      demonstrate that the main <prot>Jak1</prot>-binding region (corresponding to AAs
      300-346 on the beta subunit) is distinct from the Box 1 domain (AAs
      287-295).
AD  - Department of Pathology, University of Tennessee, Memphis, Tennessee
