Anti-(Raf-1) RNA aptamers that inhibit Ras-induced Raf-1 activation.
RNA aptamers with affinity for the Ras-binding domain (RBD) of Raf-1 were isolated from a degenerate pool by in vitro selection. These aptamers efficiently inhibited the Ras interaction with the Raf-1 RBD, and also inhibited Ras-induced Raf-1 activation in a cell-free system. The RNA aptamer with the most potent inhibitory effect specifically inhibited the Ras-Raf-1 interaction and had no affinity for the RBD of the RGL protein, a homolog of the Ral GDP dissociation stimulator. Although the aptamer was capable of binding to the B-Raf RBD, the RNA did not inhibit the interaction between Ras and the B-Raf RBD. Enzymatic and chemical probing experiments indicated that the aptamer was folded into a pseudoknot structure, and some loop regions of the pseudoknot were located at the binding interface for the Raf-1 RBD.
Kimoto
Michiko
M
Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Shirouzu
Mikako
M
Mizutani
Shin
S
Koide
Hiroshi
H
Kaziro
Yoshito
Y
Hirao
Ichiro
I
Yokoyama
Shigeyuki
S
D001483:Base Sequence; D002460:Cell Line; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D019908:Proto-Oncogene Proteins c-raf / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012313:RNA / Q000737:chemistry / Q000494:pharmacology*; D018631:ras Proteins / Q000378:metabolism*
D012313:RNA; D019908:Proto-Oncogene Proteins c-raf; D018631:ras Proteins