Molecular analysis of a novel JNK signaling regulatory protein

Abstract

The mitogen-activated protein kinase(mapk) cascades, in which the major compornents are MAPK, MAPKK, and MAPKKK, are conserved in eukarytic signaling pathways. The MAPKs in each pathway are ERK, JNK, and p38. Recently, JIPs (JNK Interacting Protein) are identified as JNK scaffold proteins, through interacting with MAPKKK, MAPKK, and MAPK. We isolated and identified a novel protein kinase (STK-X)that interacts with JIP proteins. The role and substrates of STK-X is unknown. We examined the role of STK-X in JNK signaling and apoptosis, using dominant negative STK-X or siRNA transfected cells.