Impact of Feedback Phosphorylation and Raf Heterodimerization on Normal and Mutant B-Raf Signaling
Reads0
Chats0
TLDR
It is reported that normal and oncogenic B-Raf proteins are subject to a regulatory cycle of extracellular signal-regulated kinase (ERK)-dependent feedback phosphorylation, followed by PP2A- and Pin1-dependent dephosphorylation/recycling, and that B- raf and C-raf proteins containing mutations containing mutations identified in certain developmental disorders constitutively heterodimerize and that their signaling activity can also be modulated by feedbackAbstract:
The B-Raf kinase is a Ras pathway effector activated by mutation in numerous human cancers and certain developmental disorders. Here we report that normal and oncogenic B-Raf proteins are subject to a regulatory cycle of extracellular signal-regulated kinase (ERK)-dependent feedback phosphorylation, followed by PP2A- and Pin1-dependent dephosphorylation/recycling. We identify four S/TP sites of B-Raf phosphorylated by activated ERK and find that feedback phosphorylation of B-Raf inhibits binding to activated Ras and disrupts heterodimerization with C-Raf, which is dependent on the B-Raf pS729/14-3-3 binding site. Moreover, we find that events influencing Raf heterodimerization can alter the transforming potential of oncogenic B-Raf proteins possessing intermediate or impaired kinase activity but have no significant effect on proteins with high kinase activity, such as V600E B-Raf. Mutation of the feedback sites or overexpression of the Pin1 prolyl-isomerase, which facilitates B-Raf dephosphorylation/recycling, resulted in increased transformation, whereas mutation of the S729/14-3-3 binding site or expression of dominant negative Pin1 reduced transformation. Mutation of each feedback site caused increased transformation and correlated with enhanced heterodimerization and activation of C-Raf. Finally, we find that B-Raf and C-Raf proteins containing mutations identified in certain developmental disorders constitutively heterodimerize and that their signaling activity can also be modulated by feedback phosphorylation.read more
Citations
More filters
Journal ArticleDOI
Targeting RAS–ERK signalling in cancer: promises and challenges
TL;DR: Both intrinsic and acquired resistance to RAF and MEK inhibitors are frequently associated with the persistence of ERK signalling in the presence of the drug, implying the need for more innovative approaches to target the pathway.
Journal ArticleDOI
Dynamic Reprogramming of the Kinome in Response to Targeted MEK Inhibition in Triple-Negative Breast Cancer
James S. Duncan,Martin C. Whittle,Kazuhiro Nakamura,Amy N. Abell,Alicia A. Midland,Jon S. Zawistowski,Nancy Lassignal Johnson,Deborah A. Granger,Nicole Vincent Jordan,David B. Darr,Jerry Usary,Pei Fen Kuan,David M. Smalley,Ben Major,Xiaping He,Katherine A. Hoadley,Bing Zhou,Norman E. Sharpless,Charles M. Perou,William Y. Kim,Shawn M. Gomez,Xin Chen,Jian Jin,Stephen V. Frye,H. Shelton Earp,Lee M. Graves,Gary L. Johnson +26 more
TL;DR: The inhibitor-induced RTK profile suggested a kinase inhibitor combination therapy that produced GEMM tumor apoptosis and regression where single agents were ineffective, allowing rational design of combination therapies for cancer.
Journal ArticleDOI
Vemurafenib: the first drug approved for BRAF -mutant cancer
Gideon Bollag,James Tsai,Jiazhong Zhang,Chao Zhang,Prabha N. Ibrahim,K. B. Nolop,Peter Hirth +6 more
TL;DR: The underlying biology of BRAF, the technology used to identify vemurafenib and its clinical development milestones, along with future prospects based on lessons learned during its development are described.
Journal ArticleDOI
The role of BRAF V600 mutation in melanoma
Paolo A. Ascierto,John M. Kirkwood,Jean-Jacques Grob,Ester Simeone,Antonio M. Grimaldi,Michele Maio,Giuseppe Palmieri,Alessandro Testori,Francesco M. Marincola,Nicola Mozzillo +9 more
TL;DR: The first selective inhibitor of mutant BRAF, vemurafenib, after highly encouraging results of the phase I and II trial, was compared to dacarbazine in a phase III trial in treatment-naïve patients (BRIM-3) and showed a relative reduction in risk of death and risk of tumor progression.
Journal ArticleDOI
Regulation of RAF protein kinases in ERK signalling
Hugo Lavoie,Marc Therrien +1 more
TL;DR: The recent discovery that the catalytic activity of RAF depends on an allosteric mechanism driven by kinase domain dimerization is providing a vital new piece of information towards a comprehensive model of RAF function.
References
More filters
Journal ArticleDOI
Mechanism of Activation of the Raf-Erk Signaling Pathway by Oncogenic Mutations of B-Raf
Paul T C Wan,Mathew J. Garnett,S. Mark Roe,Sharlene Lee,Dan Niculescu-Duvaz,Valerie M. Good,Cancer Genome,C. Michael Jones,Christopher J. Marshall,Caroline J. Springer,David Barford,Richard Marais +11 more
TL;DR: The high activity mutants signal to ERK by directly phosphorylating MEK, whereas the impaired activity mutants stimulate MEK by activating endogenous C-RAF, possibly via an allosteric or transphosphorylation mechanism.
Journal ArticleDOI
Advanced mammalian gene transfer: high titre retroviral vectors with multiple drug selection markers and a complementary helper-free packaging cell line
Jay P. Morgenstern,Hartmut Land +1 more
TL;DR: Together, the pBabe vectors and omega E cell line should prove useful in experiments where highest frequencies of gene transfer, or concomitant expression of several different genes within a single cell are required with minimal risk of helper virus contamination.
Journal ArticleDOI
Hyperactive Ras in developmental disorders and cancer.
TL;DR: The implications of germline mutations in the Ras–Raf–MEK–ERK pathway for understanding normal developmental processes and cancer pathogenesis are discussed.
Journal ArticleDOI
Interaction of 14-3-3 with signaling proteins is mediated by the recognition of phosphoserine.
TL;DR: The results suggest that the interactions of 14-3-3 with signaling proteins are critical for the activation of signaling proteins and suggest novel roles for serine/threonine phosphorylation in the assembly of protein-protein complexes.
Journal ArticleDOI
The RAF proteins take centre stage
TL;DR: A report that implicates B-RAF in human cancer has highlighted the importance of all members of this protein kinase family and recent studies have uncovered intriguing new data relating to their complex regulation and biological functions.
Related Papers (5)
RAF inhibitors transactivate RAF dimers and ERK signalling in cells with wild-type BRAF
Mutations of the BRAF gene in human cancer
Helen Davies,Graham R. Bignell,Charles Cox,Philip J. Stephens,Sarah Edkins,S. M. Clegg,Jon W. Teague,Hayley Woffendin,Mathew J. Garnett,William Bottomley,Neil Davis,Ed Dicks,Rebecca Ewing,Yvonne Floyd,Kristian Gray,S. Hall,Rachel Hawes,Jaime Hughes,Vivian Kosmidou,Andrew Menzies,Catherine Mould,Adrian Parker,Claire Stevens,Stephen Watt,Steven Hooper,Rebecca Wilson,Hiran Jayatilake,Barry A. Gusterson,Colin Cooper,Janet Shipley,Darren Hargrave,Kathy Pritchard-Jones,Norman J. Maitland,Georgia Chenevix-Trench,Gregory J. Riggins,Darell D. Bigner,Giuseppe Palmieri,Antonio Cossu,Adrienne M. Flanagan,Andrew G. Nicholson,Judy W. C. Ho,Suet Yi Leung,Siu Tsan Yuen,Barbara L. Weber,Hilliard F. Seigler,Timothy L. Darrow,Hugh Paterson,Richard Marais,Christopher J. Marshall,Richard Wooster,Michael R. Stratton,P. Andrew Futreal +51 more
RAF inhibitors prime wild-type RAF to activate the MAPK pathway and enhance growth
Georgia Hatzivassiliou,Kyung Song,Ivana Yen,Barbara J. Brandhuber,Daniel Anderson,Ryan Alvarado,Mary J. C. Ludlam,David Stokoe,Susan L. Gloor,Guy Vigers,Tony Morales,Ignacio Aliagas,Bonnie Liu,Steve Sideris,Klaus P. Hoeflich,Bijay S. Jaiswal,Somasekar Seshagiri,Hartmut Koeppen,Marcia Belvin,Lori Friedman,Shiva Malek +20 more