| The TNF receptor , RELT , binds SPAK and uses it to mediate p 38 and JNK activation . ^^^ Using a yeast two hybrid system , we identified a Ste 20 related proline alanine rich kinase ( SPAK ) that binds RELT . ^^^ Disruption of the SPAK binding motif , 349RFRV , in RELT inhibited RELT activation of p 38 and JNK . ^^^ In addition , a kinase dead SPAK acted as an inhibitor of RELT signaling . ^^^ Thus , we conclude that RELT does not rely on the canonical TRAF pathways for its function , but instead uses a kinase , SPAK , to mediate p 38 and JNK activation . . ^^^ |