DI2000028 14-3-3 zeta in complex with a diphosphorylated c-Raf peptide 4ihl X-ray 2.20 Homo sapiens Inferred from motif 2.00E-08 23808890 23808890 Molzan M, Kasper S, Röglin L, Skwarczynska M, Sassa T, Inoue T, Breitenbuecher F, Ohkanda J, Kato N, Schuler M, Ottmann C ACS Chem. Biol. 2013 One-third of all human cancers harbor somatic RAS mutations. This leads to aberrant activation of downstream signaling pathways involving the RAF kinases. Current ATP-competitive RAF inhibitors are active in cancers with somatic RAF mutations, such as BRAF(V600) mutant melanomas. However, they paradoxically promote the growth of RAS mutant tumors, partly due to the complex interplay between different homo- and heterodimers of A-RAF, B-RAF, and C-RAF. Based on pathway analysis and structure-guided compound identification, we describe the natural product cotylenin-A (CN-A) as stabilizer of the physical interaction of C-RAF with 14-3-3 proteins. CN-A binds to inhibitory 14-3-3 interaction sites of C-RAF, pSer233, and pSer259, but not to the activating interaction site, pSer621. While CN-A alone is inactive in RAS mutant cancer models, combined treatment with CN-A and an anti-EGFR antibody synergistically suppresses tumor growth in vitro and in vivo. This defines a novel pharmacologic strategy for treatment of RAS mutant cancers. GO:0042802 identical protein binding GO:0097159 organic cyclic compound binding GO:0019901 protein kinase binding GO:0007165 signal transduction GO:0030168 platelet activation GO:0043066 negative regulation of apoptotic process GO:0015833 peptide transport GO:0010468 regulation of gene expression GO:0051649 establishment of localization in cell GO:0006996 organelle organization GO:0022607 cellular component assembly GO:0009967 positive regulation of signal transduction GO:0051128 regulation of cellular component organization GO:0032879 regulation of localization GO:0005739 mitochondrion GO:0005829 cytosol GO:0005654 nucleoplasm No modifications of the original PDB file. 3 14-3-3 P RAF proto-oncogene serine/threonine-protein kinase Disordered Homo sapiens QHRYSTPHAFTFNTSSPSSEGSLSQRQRSTSTPNVH 233 233 S phosphoserine 259 259 S phosphoserine 36 P04049 229 264 5.6% UniRef90_P04049 229 264 A 14-3-3 protein zeta/delta Ordered component Homo sapiens MDKNELVQKAKLAEQAERYDDMAACMKSVTEQGAELSNEERNLLSVAYKNVVGARRSSWRVVSSIEQKTEGAEKKQQMAREYREKIETELRDICNDVLSLLEKFLIPNASQAESKVFYLKMKGDYYRYLAEVAAGDDKKGIVDQSQQAYQEAFEISKKEMQPTHPIRLGLALNFSVFYYEILNSPEKACSLAKTAFDEAIAELDTLSEESYKDSTLIMQLLRDNLTLWTS 230 P63104 1 230 93.9% UniRef90_P63104 1 230 secondary structure helix 2 15 secondary structure helix 19 31 secondary structure helix 38 67 secondary structure helix 73 108 secondary structure helix 112 130 secondary structure helix 137 159 secondary structure helix 165 181 secondary structure helix 185 201 secondary structure helix 203 205 secondary structure helix 211 229 pfam PF00244.17 14-3-3 9 229 B 14-3-3 protein zeta/delta Ordered component Homo sapiens MDKNELVQKAKLAEQAERYDDMAACMKSVTEQGAELSNEERNLLSVAYKNVVGARRSSWRVVSSIEQKTEGAEKKQQMAREYREKIETELRDICNDVLSLLEKFLIPNASQAESKVFYLKMKGDYYRYLAEVAAGDDKKGIVDQSQQAYQEAFEISKKEMQPTHPIRLGLALNFSVFYYEILNSPEKACSLAKTAFDEAIAELDTLSEESYKDSTLIMQLLRDNLTLWTS 230 P63104 1 230 93.9% UniRef90_P63104 1 230 secondary structure helix 2 15 secondary structure helix 19 31 secondary structure helix 42 57 secondary structure helix 60 65 secondary structure helix 71 104 secondary structure helix 108 127 secondary structure helix 133 154 secondary structure helix 160 175 secondary structure helix 180 195 secondary structure helix 198 200 secondary structure helix 206 224 pfam PF00244.17 14-3-3 9 229 P The protein region involved in the interaction contains two instances of a known functional linear motif (LIG_14-3-3_CanoR_1). A The 14-3-3 domain involved in the interaction is known to adopt a stable structure in isolation in dimeric form (see Pfam domain PF00244). A solved structure of the domain dimer without bound ligands is represented by PDB ID 1a4o. B The 14-3-3 domain involved in the interaction is known to adopt a stable structure in isolation in dimeric form (see Pfam domain PF00244). A solved structure of the domain dimer without bound ligands is represented by PDB ID 1a4o. 3cu8 3nkx 4fj3