title: Structural characterization of proline-rich tyrosine kinase 2 (PYK2) reveals a unique (DFG-out) conformation and enables inhibitor design.
abstract: Proline-rich tyrosine kinase 2 (PYK2) is a cytoplasmic, non-receptor tyrosine kinase implicated in multiple signaling pathways. It is a negative regulator of osteogenesis and considered a viable drug target for osteoporosis treatment. The high-resolution structures of the human PYK2 kinase domain with different inhibitor complexes establish the conventional bilobal kinase architecture and show the conformational variability of the DFG loop. The basis for the lack of selectivity for the classical kinase inhibitor, PF-431396, within the FAK family is explained by our structural analyses. Importantly, the novel DFG-out conformation with two diarylurea inhibitors (BIRB796, PF-4618433) reveals a distinct subclass of non-receptor tyrosine kinases identifiable by the gatekeeper Met-502 and the unique hinge loop conformation of Leu-504. This is the first example of a leucine residue in the hinge loop that blocks the ATP binding site in the DFG-out conformation. Our structural, biophysical, and pharmacological studies suggest that the unique features of the DFG motif, including Leu-504 hinge-loop variability, can be exploited for the development of selective protein kinase inhibitors.
authors.affiliation: Pfizer Global Research & Development, Groton, CT 06340, USA. seungil.han@pfizer.com
authors.forename: Seungil
authors.initials: S
authors.lastname: Han
authors.forename: Anil
authors.initials: A
authors.lastname: Mistry
authors.forename: Jeanne S
authors.initials: JS
authors.lastname: Chang
authors.forename: David
authors.initials: D
authors.lastname: Cunningham
authors.forename: Matt
authors.initials: M
authors.lastname: Griffor
authors.forename: Peter C
authors.initials: PC
authors.lastname: Bonnette
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Boris A
authors.initials: BA
authors.lastname: Chrunyk
authors.forename: Gary E
authors.initials: GE
authors.lastname: Aspnes
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Walker
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Brosius
authors.forename: Leonard
authors.initials: L
authors.lastname: Buckbinder
mesh_terms: D000595:Amino Acid Sequence; D002113:Calcification, Physiologic; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D051418:Focal Adhesion Kinase 2 / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000201:enzymology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009281:Naphthalenes / Q000494:pharmacology*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D011485:Protein Binding; D011487:Protein Conformation; D011720:Pyrazoles / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid; D010671:Phenylurea Compounds
chemical_list: D004791:Enzyme Inhibitors; D051418:Focal Adhesion Kinase 2; D009281:Naphthalenes; D011720:Pyrazoles; C103547:PTK2B protein, human; C452139:doramapimod; D010671:Phenylurea Compounds