Emerging roles of the αC‐β4 loop in protein kinase structure, function, evolution, and disease

Proc. Natl. Acad. Sci. U.S.A.

Weng

Aoto

et al. 2021

To explore how pathogenic mutations of the multidomain leucine-rich repeat kinase 2 (LRRK2) hijack its finely tuned activation process and drive Parkinson’s disease (PD), we used a multitiered approach. Most mutations mimic Rab-mediated activation by “unleashing” kinase activity, and many, like the kinase inhibitor MLi-2, trap LRRK2 onto microtubules. Here we mimic activation by simply deleting the inhibitory N-terminal domains and then characterize conformational changes induced by MLi-2 and PD mutations. After confirming that LRRK2RCKW retains full kinase activity, we used hydrogen-deuterium exchange mass spectrometry to capture breathing dynamics in the presence and absence of MLi-2. Solvent-accessible regions throughout the entire protein are reduced by MLi-2 binding. With molecular dynamics simulations, we created a dynamic portrait of LRRK2RCKW and demonstrate the consequences of kinase domain mutations. Although all domains contribute to regulating kinase activity, the kinase domain, driven by the DYGψ motif, is the allosteric hub that drives LRRK2 regulation.

Section: Resultsmentioning

confidence: 74%

Conformation and dynamics of the kinase domain drive subcellular location and activation of LRRK2

Proc. Natl. Acad. Sci. U.S.A.

Weng

Aoto

et al. 2021

“…These authors identify the same hydrogen bond between Y2018 and the shell residue I1933. Our simulations provide strong independent evidence that Y2018 in wt LRRK2 is a key stabilizer of the inactive kinase conformation and may also act as a sensor of the αC-β4 loop conformation, a conserved hotspot for kinase allosteric modulation (61). Absence of the OH hydrogen bonds in the Y2018F mutation leads to greater Y2018F side chain dynamics and packing with L1924 that resembles an active kinase configuration (or a properly formed R-spine).…”

Section: Hdx-ms Shows That Changes In Conformation and Dynamics Of Thmentioning

confidence: 68%

Conformation and dynamics of the kinase domain drive subcellular location and activation of LRRK2

Weng²,

Aoto³

et al. 2020

Preprint

In a multi-tiered approach, we explored how Parkinson's Disease-related mutations hijack the finely tuned activation process of Leucine-Rich Repeat Kinase 2 (LRRK2) using a construct containing the ROC, Cor, Kinase and WD40 domains (LRRK2RCKW). We hypothesized that the N-terminal domains shield the catalytic domains in an inactive state. PD mutations, type-I LRRK2 inhibitors, or physiological Rab GTPases can unleash the catalytic domains while the active kinase conformation, but not kinase activity, is essential for docking onto microtubules. Mapping solvent accessible regions of LRRK2RCKW employing hydrogen-deuterium exchange mass spectrometry (HDX-MS) revealed how inhibitor binding is sensed by the entire protein. Molecular Dynamics simulations of the kinase domain elucidated differences in conformational dynamics between wt and mutants of the DYGψ motif. While all domains contribute to regulating kinase activity and spatial distribution, the kinase domain, driven by the DYGψ motif, coordinates domain crosstalk and serves as an intrinsic hub for LRRK2 regulation.

Section: Mapping the Conformational Changes Induced By Mli-2 Using Hymentioning

confidence: 69%

Conformation and Dynamics of the Kinase Domain Drive Subcellular Location and Activation of LRRK2.

Weng

Aoto

et al. 2020

Preprint

Background: Leucine-Rich Repeat Kinase 2 (LRRK2) is a complex multi-domain protein where LRRK2-mutations are associated with Parkinson´s Disease (PD). To explore how pathogenic PD-mutations hijack the finely tuned activation process of LRRK2, we here used a multi-tiered approach. Methods: First, the spatial and temporal distribution of full-length LRRK2 was investigated by a real-time cell-based assay in the presence and absence of LRRK2-kinase inhibitors. In a 2nd layer we explored the consequences of PD mutations as well as removal of the N-terminal domains employing a construct containing the ROC, Cor, Kinase and WD40 domains (LRRK2RCKW). We focused on the biochemical characterization of LRRK2RCKW variants based on kinase assays using Rab8a or LRRKtide as substrates. Next, we used hydrogen-deuterium exchange mass spectrometry (HDX-MS) to map the solvent accessible regions of LRRK2RCKW in the presence and absence of the LRRK2 inhibitor MLi-2. Finally, Molecular Dynamics simulations on the kinase domain were applied to elucidate differences in breathing dynamics between wild type and mutants of the DYGψ motif. Results: Our cellular approaches revealed that the kinase inhibitors MLi-2 and rebastinib both freeze the kinase domain in a stable conformation, however, only MLi-2 resembles an active conformation and induces filament formation. LRRK2RCKW showed, regardless of the mutation it was combined with, filament formation, indicating a shielding function of the N-terminal domains. This shielding function is impaired for pathogenic mutations in full length LRRK2. LRRK2RCKW retained kinase activity similar to full-length LRRK2. HDX-MS provided a comprehensive allosteric portrait of the kinase domain and revealed how MLi-2 binding is sensed by the entire protein. Molecular Dynamics simulations suggest that, while all domains contribute to regulating kinase activity and spatial distribution, it is the highly dynamic kinase domain, driven by the DYGψ motif, that coordinates the overall domain crosstalk and serves as a regulatory hub for the intrinsic regulation of LRRK2.Conclusion: These studies confirm our hypothesis that the N-terminal scaffolding domains shield the catalytic domains in an inactive state. PD mutations, MLi-2, or Rab GTPases can all unleash the catalytic domains while the active kinase conformation, but not kinase activity, is essential for docking onto microtubules.