PBP Antibody / PEBP1 / RKIP

Phosphatidylethanolamine-binding protein inhibits the phosphorylation and activation of MEK by RAF1. PBP coimmunoprecipitates with RAF1 and MEK from cell lysates and colocalizes with RAF1 when examined by confocal microscopy. Overexpression interferes with the activation of MEK and ERK, induction of AP1-dependent reporter genes, and transformation elicited by an oncogenically activated RAF1 kinase. PBP expression was rapidly upregulated during induction of chemotherapy-triggered apoptosis in human prostate and breast cancer cell lines, and maximal expression correlated perfectly with the onset of apoptosis by Chatterjee et al (2004) . Depletion of the protein decreased the mitotic index, the number of metaphase cells, traversal times from nuclear envelope breakdown to anaphase, and an override of mitotic checkpoints induced by spindle poisons.