Characterization of ATP-independent ERK inhibitors identified through in silico analysis of the active ERK2 structure.
The extracellular signal-regulated kinases (ERK1 and ERK2) are important mediators of cell proliferation. Constitutive activation of the ERK proteins plays a critical role in the proliferation of many human cancers. Taking advantage of recently identified substrate docking domains on ERK2, we have used computer-aided drug design (CADD) to identify novel low molecular weight compounds that interact with ERK2 in an ATP-independent manner and disrupt substrate-specific interactions. In the current study, a CADD screen of the 3D structure of active phosphorylated ERK2 protein was used to identify inhibitory compounds. We tested 13 compounds identified by the CADD screen in ERK-specific phosphorylation, cell proliferation, and binding assays. Of the 13 compounds tested, 4 compounds strongly inhibited ERK-mediated phosphorylation of ribosomal S6 kinase-1 (Rsk-1) and/or the transcription factor Elk-1 and inhibited the proliferation of HeLa cervical carcinoma cells with IC(50) values in the 2-10 microM range. These studies demonstrate that CADD can be used to identify lead compounds for development of novel non-ATP-dependent inhibitors selective for active ERK and its interactions with substrates involved in cancer cell proliferation.
Chen
Fengming
F
Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA.
Hancock
Chad N
CN
Macias
Alba T
AT
Joh
Joseph
J
Still
Kimberly
K
Zhong
Shijun
S
MacKerell
Alexander D
AD
Shapiro
Paul
P
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D001665:Binding Sites; D007700:Kinetics; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D008958:Models, Molecular; D011487:Protein Conformation; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*
D047428:Protein Kinase Inhibitors; D000255:Adenosine Triphosphate; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3