Rechfeld F, Gruber P, Kirchmair J, Boehler M, Hauser N, Hechenberger G, Garczarczyk D, Lapa GB, Preobrazhenskaya MN, Goekjian P, Langer T, Hofmann J. Thienoquinolines as novel disruptors of the PKCε/RACK2 protein-protein interaction.
J Med Chem 2014;
57:3235-46. [PMID:
24712764 PMCID:
PMC4001449 DOI:
10.1021/jm401605c]
[Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
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Ten
protein kinase C (PKC) isozymes play divergent roles in signal transduction.
Because of sequence similarities, it is particularly difficult to
generate isozyme-selective small molecule inhibitors. In order to
identify such a selective binder, we derived a pharmacophore model
from the peptide EAVSLKPT, a fragment of PKCε that inhibits
the interaction of PKCε and receptor for activated C-kinase
2 (RACK2). A database of 330 000 molecules was screened in
silico, leading to the discovery of a series of thienoquinolines that
disrupt the interaction of PKCε with RACK2 in vitro. The most
active molecule, N-(3-acetylphenyl)-9-amino-2,3-dihydro-1,4-dioxino[2,3-g]thieno[2,3-b]quinoline-8-carboxamide
(8), inhibited this interaction with a measured IC50 of 5.9 μM and the phosphorylation of downstream target
Elk-1 in HeLa cells with an IC50 of 11.2 μM. Compound 8 interfered with MARCKS phosphorylation and TPA-induced translocation
of PKCε (but not that of PKCδ) from the cytosol to the
membrane. The compound reduced the migration of HeLa cells into a
gap, reduced invasion through a reconstituted basement membrane matrix,
and inhibited angiogenesis in a chicken egg assay.
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