RAF1, RAF proto-oncogene serine/threonine-protein kinase
Enzyme Classification 18.104.22.168
Also Known as
RAF1_HUMAN, RAF1, RAF
Serine/threonine-protein kinase that acts as a regulatory link between the membrane-associated Ras GTPases and the MAPK/ERK cascade, and this critical regulatory link functions as a switch determining cell fate decisions including proliferation, differentiation, apoptosis, survival and oncogenic transformation. RAF1 activation initiates a mitogen-activated protein kinase (MAPK) cascade that comprises a sequential phosphorylation of the dual-specific MAPK kinases (MAP2K1/MEK1 and MAP2K2/MEK2) and the extracellular signal-regulated kinases (MAPK3/ERK1 and MAPK1/ERK2). The phosphorylated form of RAF1 (on residues Ser-338 and Ser-339, by PAK1) phosphorylates BAD/Bcl2-antagonist of cell death at 'Ser-75'. Phosphorylates adenylyl cyclases: ADCY2, ADCY5 and ADCY6, resulting in their activation. Phosphorylates PPP1R12A resulting in inhibition of the phosphatase activity. Phosphorylates TNNT2/cardiac muscle troponin T. Can promote NF-kB activation and inhibit signal transducers involved in motility (ROCK2), apoptosis (MAP3K5/ASK1 and STK3/MST2), proliferation and angiogenesis (RB1). Can protect cells from apoptosis also by translocating to the mitochondria where it binds BCL2 and displaces BAD/Bcl2-antagonist of cell death. Regulates Rho signaling and migration, and is required for normal wound healing. Plays a role in the oncogenic transformation of epithelial cells via repression of the TJ protein, occludin (OCLN) by inducing the up-regulation of a transcriptional repressor SNAI2/SLUG, which induces down-regulation of OCLN. Restricts caspase activation in response to selected stimuli, notably Fas stimulation, pathogen-mediated macrophage apoptosis, and erythroid differentiation. Monomer. Homodimer. Heterodimerizes with BRAF and this heterodimer possesses a highly increased kinase activity compared to the respective homodimers or monomers (PubMed:16508002). Heterodimerization is mitogen-regulated and enhanced by 14-3-3 proteins (PubMed:16508002). MAPK1/ERK2 activation can induce a negative feedback that promotes the dissociation of the heterodimer (PubMed:16508002). Forms a multiprotein complex with Ras (M-Ras/MRAS), SHOC2 and protein phosphatase 1 (PPP1CA, PPP1CB and PPP1CC) (PubMed:16630891). Interacts with LZTR1 (PubMed:30368668). Interacts with Ras proteins; the interaction is antagonized by RIN1 (PubMed:11784866). Weakly interacts with RIT1. Interacts (via N-terminus) with RGS14 (via RBD domains); the interaction mediates the formation of a ternary complex with BRAF, a ternary complex inhibited by GNAI1 (By similarity). Probably forms a complex composed of chaperones HSP90 and HSP70, co-chaperones CDC37, PPP5C, TSC1 and client protein TSC2, CDK4, AKT, RAF1 and NR3C1; this complex does not contain co-chaperones STIP1/HOP and PTGES3/p23 (PubMed:29127155). Interacts with STK3/MST2; the interaction inhibits its pro-apoptotic activity (PubMed:15618521). Interacts (when phosphorylated at Ser-259) with YWHAZ (unphosphorylated at 'Thr-232') (PubMed:9360956). Interacts with MAP2K1/MEK1 and MAP2K2/MEK2 (By similarity). Interacts with MAP3K5/ASF1 (via N-terminus) and this interaction inhibits the proapoptotic function of MAP3K5/ASK1 (PubMed:11427728). Interacts with PAK1 (via kinase domain) (PubMed:11733498). The phosphorylated form interacts with PIN1 (By similarity). The Ser-338 and Ser-339 phosphorylated form (by PAK1) interacts with BCL2 (PubMed:15849194). Interacts with PEBP1/RKIP and this interaction is enhanced if RAF1 is phosphorylated on residues Ser-338, Ser-339, Tyr-340 and Tyr-341 (PubMed:18294816). Interacts with ADCY2, ADCY5, ADCY6, DGKH, RCAN1/DSCR1, PPP1R12A, PKB/AKT1, PPP2CA, PPP2R1B, SPRY2, SPRY4, CNKSR1/CNK1, KSR2 and PHB/prohibitin (PubMed:10801873, PubMed:11719507, PubMed:12717443, PubMed:15385642, PubMed:15935327, PubMed:19710016, PubMed:10576742). Interacts with ROCK2 (By similarity). In its active form, interacts with PRMT5 (PubMed:21917714). Interacts with FAM83B; displaces 14-3-3 proteins from RAF1 and activates RAF1 (PubMed:22886302). Interacts with PDE8A; the interaction promotes RAF1 activity (PubMed:23509299). Interacts with MFHAS1 (PubMed:23327923).