Crystal Structures of PRK1 in Complex with the Clinical Compounds Lestaurtinib and Tofacitinib Reveal Ligand Induced Conformational Changes

Abstract

Protein kinase C related kinase 1 (PRK1) is a component of Rho-GTPase, androgen receptor, histone demethylase and histone deacetylase signaling pathways implicated in prostate and ovarian cancer. Herein we describe the crystal structure of PRK1 in apo form, and also in complex with a panel of literature inhibitors including the clinical candidates lestaurtinib and tofacitinib, as well as the staurosporine analog Ro-31-8220. PRK1 is a member of the AGC-kinase class, and as such exhibits the characteristic regulatory sequence at the C-terminus of the catalytic domain – the ‘C-tail’. The C-tail fully encircles the catalytic domain placing a phenylalanine in the ATP-binding site. Our inhibitor structures include examples of molecules which both interact with, and displace the C-tail from the active site. This information may assist in the design of inhibitors targeting both PRK and other members of the AGC kinase family.

Matrix stiffness regulates endosomal escape of uropathogenicE. coli

“…Dia1 and PRK1 are recruited to endosomes by RhoB where they assist in forming the endosome‐associated actin coat and regulate vesicle trafficking (Fernandez‐Borja, Janssen, Verwoerd, Hordijk, & Neefjes, ; Gampel et al, ; Mellor, Flynn, Nobes, Hall, & Parker, ). To determine which RhoB effector regulates bacterial growth, infected cells were treated with either the Dia1 inhibitor SMIFH2 (Rizvi et al, ) or the PRK1 inhibitor tofacitinib (Chamberlain et al, ). Only tofacitinib treatment led to increased UPEC proliferation suggesting that PRK1 is the specific RhoB effector responsible for inhibiting bacterial growth (Figure e).…”

“…Indeed, when RhoB expression was blocked using siRNA ( Figure S1c), UPEC growth increased significantly (Figure 2d). (Chamberlain et al, 2014).…”

Identification of Highly Potent Protein Kinase C‐Related Kinase 1 Inhibitors by Virtual Screening, Binding Free Energy Rescoring, and in vitro Testing

“…In their study Chamberlain et al . highlighted the major role of kinase plasticity, showing that PRK1 is able to adapt to different ligands and exhibit various conformational changes with the main motions observed in the region of the G‐loop and the C‐tail.…”

“…The calculated RMSD values show that the overall difference between all Ca atoms of the generated modelsa nd the crystal structures range from 1.43 (hm_STUw ith 4OTG)t o2 . 35 Comparing the binding pocketso fh omologym odelsa nd crystal structures showeda lso high similarity and low RMSD values (Figure 8a nd Figure S5 of the Supporting Information). Also, the different pockets in the crystal structures showed some deviations, demonstrating that binding site can adapt to different ligands.…”

“…In their study Chamberlain et al [35] highlighted the major role of kinase plasticity,s howing that PRK1 is able to adaptt o differentl igands and exhibit variousc onformational changes with the main motions observed in the region of the G-loop and the C-tail. It is worth noting that the observation that the C-terminuso ft he catalytic domain (C-tail) can adopt different conformations depending on the bound inhibitor and the conformationo fP he-910 (in the ATP-binding site or out), are in correspondence with our previous findings.…”