title: Phosphorylation of RAF Kinase Dimers Drives Conformational Changes that Facilitate Transactivation.
abstract: RAF kinases are key players in the MAPK signaling pathway and are important targets for personalized cancer therapy. RAF dimerization is part of the physiological activation mechanism, together with phosphorylation, and is known to convey resistance to RAF inhibitors. Herein, molecular dynamics simulations are used to show that phosphorylation of a key N-terminal acidic (NtA) motif facilitates RAF dimerization by introducing several interprotomer salt bridges between the αC-helix and charged residues upstream of the NtA motif. Additionally, we show that the R-spine of RAF interacts with a conserved Trp residue in the vicinity of the NtA motif, connecting the active sites of two protomers and thereby modulating the cooperative interactions in the RAF dimer. Our findings provide a first structure-based mechanism for the auto-transactivation of RAF and could be generally applicable to other kinases, opening new pathways for overcoming dimerization-related drug resistance.
authors.affiliation: Department of Chemistry, King's College London, London, SE1 1DB, UK.
authors.forename: Pablo G
authors.initials: PG
authors.lastname: Jambrina
authors.affiliation: Systems Biology Ireland and Conway Institute, University College Dublin, Belfield, Dublin, 4, Ireland.
authors.forename: Nora
authors.identifier: http://orcid.org/0000-0001-6009-5177
authors.initials: N
authors.lastname: Rauch
authors.affiliation: Systems Biology Ireland and Conway Institute, University College Dublin, Belfield, Dublin, 4, Ireland.
authors.forename: Ruth
authors.initials: R
authors.lastname: Pilkington
authors.affiliation: Systems Biology Ireland and Conway Institute, University College Dublin, Belfield, Dublin, 4, Ireland.
authors.forename: Katja
authors.initials: K
authors.lastname: Rybakova
authors.affiliation: Systems Biology Ireland, University College Dublin, Belfield, Dublin, 4, Ireland.|Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, 3800, Australia.
authors.forename: Lan K
authors.initials: LK
authors.lastname: Nguyen
authors.affiliation: Systems Biology Ireland and Conway Institute, University College Dublin, Belfield, Dublin, 4, Ireland.
authors.forename: Boris N
authors.initials: BN
authors.lastname: Kholodenko
authors.affiliation: School of Physics and Complex and Adaptative Systems Laboratory, University College Dublin, Belfield, Dublin, 4, Ireland.
authors.forename: Nicolae-Viorel
authors.identifier: http://orcid.org/0000-0001-9861-1157
authors.initials: NV
authors.lastname: Buchete
authors.affiliation: Systems Biology Ireland and Conway Institute, University College Dublin, Belfield, Dublin, 4, Ireland. walter.kolch@ucd.ie.|School of Medicine & Medical Sciences, University College Dublin, Belfield, Dublin, 4, Ireland. walter.kolch@ucd.ie.
authors.forename: Walter
authors.initials: W
authors.lastname: Kolch
authors.affiliation: Department of Chemistry, King's College London, London, SE1 1DB, UK. edina.rosta@kcl.ac.uk.
authors.forename: Edina
authors.identifier: http://orcid.org/0000-0002-9823-4766
authors.initials: E
authors.lastname: Rosta
mesh_terms: D019281:Dimerization; D010766:Phosphorylation; D011487:Protein Conformation; D015533:Transcriptional Activation; D048490:raf Kinases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D048490:raf Kinases
keywords: RAF kinase; kinases; molecular dynamics; oncogenic signaling; phosphorylation