JAK STAT SIGNALING BY CYTOKINE RECEPTORS

The JAK/STAT pathway is recognized as one of the major mechanisms by w hich cytokine receptors transduce intracellular signals. This system i s regulated at multiple levels, including JAK activation, nuclear traf ficking of STAT factors, and negative feedback loops. Gene deletion st udies have implicated selected STAT factors as predominant mediators f or a limited number of lymphokines. This signaling pathway influences normal cell survival and growth mechanisms and may contribute to oncog enic transformation.