B-Raf (N-terminus) Antibody

The Ras-Raf-MAP kinase signaling pathway is involved in control of cell proliferation and differentiation. The Raf kinase family includes A-Raf, B-Raf, and C-Raf. Each family member has three highly conserved regions (CR1-3) . The N-terminal CR1 contains the Ras-GTP-binding domain. The CR2 contains a negative regulatory serine residue (C-Raf (S259) /B-Raf (S365) ) that may bind 14-3-3 proteins. The CR3 is the catalytic domain that contains phosphorylation sites for Raf-regulating enzymes within two segments, the N-region and the activation segment. Activation of C-Raf involves phosphorylation at many sites including Ser-338, Tyr-341, and multiple catalytic domain sites. In B-Raf, multiple phosphorylation sites have been identified, but their specific roles are uncertain. Phosphorylation of Ser-446 may prime B-Raf for activation, and Ser-446 and/or Ser-447 phosphorylation may be critical for B-Raf biological activity during PC12 differentiation. Ser-579 is required for growth factor activation and kinase activity. Thus, multiple sites of phosphorylation within Rafs may be important for regulation of their activity.

The antibody detects 105 and 95 kDa* bands corresponding to the molecular mass of B-Raf. The doublet observed in Jurkat cells may represent multipe isoforms of the B-Raf, since all bands are blocked specifically with B-Raf (N-terminus) peptide. This sequence has high homology with similar regions in rat and mouse B-Raf, and has low homology to other Raf family members.