The Raf kinase family, A-Raf, B-Raf, and C-Raf, act as downstream effectors for Ras. These ser/thr kinases have homologous kinase domains referred to as conserved regions (CR1, CR2, and CR3). Rafs have a critical role in the response to many growth factors including: EGF, PDGF, insulin, IL-2, IL-3, CSF-1, and GM-CSF. Raf can directly interact with Ras-GTP and subsequently become activated. This leads to Raf activation of the MAP kinase pathway by phosphorylating and activating MEK, which then phosphorylates and activates MAP kinaes (ERK). A-Raf is a proto-onocogene that is highly expressed in urogenital and kidney tissues while B-Raf is expressed at high levels in cerebrum and testes. C-Raf appears to be uniformly and ubiquitously expressed. Cell transformation by A-Raf has been shown to be independent of p21ras, suggesting the possibility of an independent signal transduction pathway. B-Raf is expressed as multiple isoforms that range from 69-72 kDa and 79-99 kDa. In hematopoietic cells, B-Raf is activated by EPO, GM-CSF, and SCF. Thus, the Raf kinases are important Ras effectors involved in growth factor signaling in a wide variety of cells and tissues.
This antibody is routinely tested by western blot analysis. Other applications were tested at BD Biosciences Pharmingen during antibody development only or reported in the literature.