Impaired binding of 14-3-3 to C-RAF in Noonan syndrome suggests new approaches in diseases with increased Ras signaling.
The Ras-RAF-mitogen-activated protein kinase (Ras-RAF-MAPK) pathway is overactive in many cancers and in some developmental disorders. In one of those disorders, namely, Noonan syndrome, nine activating C-RAF mutations cluster around Ser(259), a regulatory site for inhibition by 14-3-3 proteins. We show that these mutations impair binding of 14-3-3 proteins to C-RAF and alter its subcellular localization by promoting Ras-mediated plasma membrane recruitment of C-RAF. By presenting biophysical binding data, the 14-3-3/C-RAFpS(259) crystal structure, and cellular analyses, we indicate a mechanistic link between a well-described human developmental disorder and the impairment of a 14-3-3/target protein interaction. As a broader implication of these findings, modulating the C-RAFSer(259)/14-3-3 protein-protein interaction with a stabilizing small molecule may yield a novel potential approach for treatment of diseases resulting from an overactive Ras-RAF-MAPK pathway.
Molzan
Manuela
M
Chemical Genomics Centre of the Max Planck Society, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany.
Schumacher
Benjamin
B
Ottmann
Corinna
C
Baljuls
Angela
A
Polzien
Lisa
L
Weyand
Michael
M
Thiel
Philipp
P
Rose
Rolf
R
Rose
Micheline
M
Kuhenne
Philipp
P
Kaiser
Markus
M
Rapp
Ulf R
UR
Kuhlmann
Jürgen
J
Ottmann
Christian
C
D048948:14-3-3 Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D002522:Chlorocebus aethiops; D003460:Crystallization; D018360:Crystallography, X-Ray; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D018613:Microscopy, Confocal; D008958:Models, Molecular; D009154:Mutation; D009634:Noonan Syndrome / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D019908:Proto-Oncogene Proteins c-raf / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism*
D048948:14-3-3 Proteins; D049452:Green Fluorescent Proteins; D012694:Serine; D019908:Proto-Oncogene Proteins c-raf; D018631:ras Proteins