Regulation of RKIP binding to the N‐region of the Raf‐1 kinase

Abstract

The Raf kinase inhibitory protein (RKIP) binds to Raf‐1 interfering with binding of the MEK substrate and potentially also Raf‐1 activation. In response to mitogen stimulation RKIP dissociates from Raf‐1 and later re‐associates. Here, using a combination of mutational approaches, biochemical studies, peptide arrays and plasmon surface resonance (BIAcore), we fine map and characterize a minimal 24 amino acid long RKIP binding domain in the Raf‐1 N‐region, which consists of constitutive elements at both flanks and a center element that is regulated by phosphorylation and enhances the re‐binding of RKIP to Raf‐1 in the later phase of mitogen stimulation.