title: Identification of small-molecule inhibitors of the JIP-JNK interaction.
abstract: JNK1 (c-Jun N-terminal kinase 1) plays a crucial role in the regulation of obesity-induced insulin resistance and is implicated in the pathology of Type 2 diabetes. Its partner, JIP1 (JNK-interacting protein 1), serves a scaffolding function that facilitates JNK1 activation by MKK4 [MAPK (mitogen-activated protein kinase) kinase 4] and MKK7 (MAPK kinase 7). For example, reduced insulin resistance and JNK activation are observed in JIP1-deficient mice. On the basis of the in vivo efficacy of a cell-permeable JIP peptide, the JIP-JNK interaction appears to be a potential target for JNK inhibition. The goal of the present study was to identify small-molecule inhibitors that disrupt the JIP-JNK interaction to provide an alternative approach for JNK inhibition to ATP-competitive inhibitors. High-throughput screening was performed by utilizing a fluorescence polarization assay that measured the binding of JNK1 to the JIP peptide. Multiple chemical series were identified, revealing two categories of JIP/JNK inhibitors: 'dual inhibitors' that are ATP competitive and probably inhibit JIP-JNK binding allosterically, and 'JIP-site binders' that block binding through interaction with the JIP site. A series of polychloropyrimidines from the second category was characterized by biochemical methods and explored through medicinal-chemistry efforts. As predicted, these inhibitors also inhibited full-length JIP-JNK binding and were selective against a panel of 34 representative kinases, including ones in the MAPK family. Overall, this work demonstrates that small molecules can inhibit protein-protein interactions in vitro in the MAPK family effectively and provides strategies for similar approaches within other target families.
authors.affiliation: Department of Target Biology, Pfizer Research Technology Center, Cambridge, MA 02139, USA. tracy.chen@pfizer.com
authors.forename: Tracy
authors.initials: T
authors.lastname: Chen
authors.forename: Natasha
authors.initials: N
authors.lastname: Kablaoui
authors.forename: Jeremy
authors.initials: J
authors.lastname: Little
authors.forename: Sergei
authors.initials: S
authors.lastname: Timofeevski
authors.forename: William R
authors.initials: WR
authors.lastname: Tschantz
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
authors.forename: Junli
authors.initials: J
authors.lastname: Feng
authors.forename: Maura
authors.initials: M
authors.lastname: Charlton
authors.forename: Robert
authors.initials: R
authors.lastname: Stanton
authors.forename: Paul
authors.initials: P
authors.lastname: Bauer
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D015394:Molecular Structure; D009930:Organic Chemicals / Q000737:chemistry / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D009930:Organic Chemicals; D048031:JNK Mitogen-Activated Protein Kinases