Structural characterization of proline-rich tyrosine kinase 2 (PYK2) reveals a unique (DFG-out) conformation and enables inhibitor design.
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.
Han
Seungil
S
Pfizer Global Research & Development, Groton, CT 06340, USA. seungil.han@pfizer.com
Mistry
Anil
A
Chang
Jeanne S
JS
Cunningham
David
D
Griffor
Matt
M
Bonnette
Peter C
PC
Wang
Hong
H
Chrunyk
Boris A
BA
Aspnes
Gary E
GE
Walker
Daniel P
DP
Brosius
Arthur D
AD
Buckbinder
Leonard
L
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
D004791:Enzyme Inhibitors; D051418:Focal Adhesion Kinase 2; D009281:Naphthalenes; D011720:Pyrazoles; C103547:PTK2B protein, human; C452139:doramapimod; D010671:Phenylurea Compounds