A RasGAP SH3 peptide aptamer inhibits RasGAP-Aurora interaction and induces caspase-independent tumor cell death.
The Ras GTPase-activating protein RasGAP catalyzes the conversion of active GTP-bound Ras into inactive GDP-bound Ras. However, RasGAP also acts as a positive effector of Ras and exerts an anti-apoptotic activity that is independent of its GAP function and that involves its SH3 (Src homology) domain. We used a combinatorial peptide aptamer approach to select a collection of RasGAP SH3 specific ligands. We mapped the peptide aptamer binding sites by performing yeast two-hybrid mating assays against a panel of RasGAP SH3 mutants. We examined the biological activity of a peptide aptamer targeting a pocket delineated by residues D295/7, L313 and W317. This aptamer shows a caspase-independent cytotoxic activity on tumor cell lines. It disrupts the interaction between RasGAP and Aurora B kinase. This work identifies the above-mentioned pocket as an interesting therapeutic target to pursue and points its cognate peptide aptamer as a promising guide to discover RasGAP small-molecule drug candidates.
Pamonsinlapatham
Perayot
P
UFR Biomédicale, Laboratoire de Pharmacochimie Moléculaire et Cellulaire, INSERM U648, Université Paris Descartes, Paris, France.
Hadj-Slimane
Réda
R
Raynaud
Françoise
F
Bickle
Marc
M
Corneloup
Claudine
C
Barthelaix
Audrey
A
Lepelletier
Yves
Y
Mercier
Perrine
P
Schapira
Matthieu
M
Samson
Jérôme
J
Mathieu
Anne-Laure
AL
Hugo
Nicolas
N
Moncorgé
Olivier
O
Mikaelian
Ivan
I
Dufour
Sylvie
S
Garbay
Christiane
C
Colas
Pierre
P
D000595:Amino Acid Sequence; D064127:Aurora Kinases; D001665:Binding Sites; D020169:Caspases / Q000378:metabolism*; D017124:Conserved Sequence; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D020703:ras GTPase-Activating Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*
D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D020703:ras GTPase-Activating Proteins; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D020169:Caspases